Kaare Christensen

Publication List Details

Period

1997 - 2009

Number

133

Co-Authors

A Combinatory Approach for Selecting Prognostic Genes in Microarray Studies of Tumour Survivals (2009)

Qihua Tan, Mads Thomassen, Kirsten M. Jochumsen, Ole Mogensen, Kaare Christensen, Torben A. Kruse

Different from significant gene expression analysis which looks for genes that are differentially regulated, feature selection in the microarray-based prognostic gene expression analysis aims at...

Good Semen Quality and Life Expectancy: A Cohort Study of 43,277 Men (2009)

Jensen, Tina Kold, Jacobsen, Rune, Christensen, Kaare, Nielsen, Niels Christian, Bostofte, Erik

Fertility status may predict later mortality, but no studies have examined the effect of semen quality on subsequent mortality. Men referred to the Copenhagen Sperm Analysis Laboratory by general...

Lifetime according to health status among the oldest olds in Denmark (2009)

Brønnum-Hansen, Henrik, Petersen, Inge, Jeune, Bernard, Christensen, Kaare

Background: policy makers face increasing demands for care of the aged and therefore need more information about the health status of very old people. The purpose of this study was to quantify the...

A Combinatory Approach for Selecting Prognostic Genes in Microarray Studies of Tumour Survivals (2009)

Qihua Tan, Mads Thomassen, Kirsten M. Jochumsen, Ole Mogensen, Kaare Christensen, Torben A. Kruse

Different from significant gene expression analysis which looks for genes that are differentially regulated, feature selection in the microarray-based prognostic gene expression analysis aims at...

Health-Related Phenotypes and Longevity in Danish Twins (2009)

Kulminski, Alexander M., Arbeev, Konstantin G., Culminskaya, Irina V., Ukraintseva, Svetlana V., Christensen, Kaare, Yashin, Anatoli I.

Aging studies can be facilitated by refocusing from longevity phenotypes to their proxies (intermediate phenotypes). Robust selection of the intermediate phenotypes requires data on such phenotypes...

Geographical structure and differential natural selection among North European populations (2009)

McEvoy, Brian P., Montgomery, Grant W., McRae, Allan F., Ripatti, Samuli, Perola, Markus, Spector, Tim D., ...

Population structure can provide novel insight into the human past, and recognizing and correcting for such stratification is a practical concern in gene mapping by many association methodologies. We...

Discordant MZ Twins With Cleft Lip and Palate: A Model for Identifying Genes in Complex Traits (2008)

Maria Adela Mansilla, Jane Kimani, Laura E. Mitchell, Kaare Christensen, Dorret I. Boomsma, Y Daack-hirsch, ...

Monozygotic (MZ) twins may be discordant for complex traits due to differential environmental exposure in utero, epigenetic variability in imprinting, X chromosome inactivation, or stochastic...

Offspring's Leukocyte Telomere Length, Paternal Age, and Telomere Elongation in Sperm (2008)

Masayuki Kimura, Lynn F. Cherkas, Bernet S. Kato, Serkalem Demissie, Jacob B. Hjelmborg, Michael Brimacombe, ...

Leukocyte telomere length (LTL) is a complex genetic trait. It shortens with age and is associated with a host of aging-related disorders. Recent studies have observed that offspring of older fathers...

Offspring's Leukocyte Telomere Length, Paternal Age, and Telomere Elongation in Sperm (2008)

Masayuki Kimura, Lynn Cherkas, Bernet Kato, Serkalem Demissie, Jacob Hjelmborg, Michael Brimcombe, ...

Leukocyte telomere length (LTL) is a complex genetic trait. It shortens with age and is associated with a host of aging-related disorders. Recent studies have observed that offspring of older fathers...

Human Biodemography: Some challenges and possibilities (2008)

Kaare Christensen

This opinion report - in a series on the future of biodemography - focuses on promising areas that I think will be valuable to develop in the future in order to get a better understanding of the...

Feature ranking and feature redundancy reduction for prognostic microarray study of tumor clinical outcomes (2008)

Tan, Qihua, Thomassen, Mads, Christensen, Kaare, Kruse, Torben A.

Different from significant gene expression analysis which looks for all genes that are differentially regulated, feature selection in prognostic gene expression analysis aims at finding a subset of...

Telomere Length and Mortality: A Study of Leukocytes in Elderly Danish Twins (2008)

Kimura, Masayuki, Hjelmborg, Jacob V. B., Gardner, Jeffrey P., Bathum, Lise, Brimacombe, Michael, Lu, Xiaobin, ...

Leukocyte telomere length, representing the mean length of all telomeres in leukocytes, is ostensibly a bioindicator of human aging. The authors hypothesized that shorter telomeres might forecast...

Familial Aggregation of Hypospadias: A Cohort Study (2008)

Schnack, Tine H., Zdravkovic, Slobodan, Myrup, Charlotte, Westergaard, Tine, Christensen, Kaare, Wohlfahrt, Jan, ...

Hypospadias is one of the most common birth defects. However, its etiology remains largely unknown. The authors investigated the contribution of genetic and environmental factors to familial...

The Intergenerational Transmission of Parental Schooling and Child Development: New Evidence using Danish Twins and their Children (2008)

Bingley, Paul, Christensen, Kaare, Jensen, Vibeke Myrup

Understanding the causal relationship between parental schooling and child development is important to create polices raising schooling level. We use unique Danish administrative data with...

The Intergeneratonal Transmission of Parental Schooling and Child Development: New Evidence using Danish Twins and their Children (2008)

Bingley, Paul, Christensen, Kaare, Jensen, Vibeke Myrup

 Understanding the causal relation between mothers and fathers schooling and child development is important to create polices raising schooling level. We use unique Danish administrative data with...

Feature ranking and feature redundancy reduction for prognostic microarray study of tumor clinical outcomes (2008)

Tan, Qihua, Thomassen, Mads, Christensen, Kaare, Kruse, Torben A.

Different from significant gene expression analysis which looks for all genes that are differentially regulated, feature selection in prognostic gene expression analysis aims at finding a subset of...

Retrospective analysis of main and interaction effects in genetic association studies of human complex traits (2007)

Tan, Qihua, Christiansen, Lene, Brasch-Andersen, Charlotte, Zhao, Jing, Li, Shuxia, Kruse, Torben A, ...

Abstract Background The etiology of multifactorial human diseases involves complex interactions between numerous environmental factors and alleles of many genes. Efficient statistical tools are...

Combined Genome Scans for Body Stature in 6,602 European Twins: Evidence for Common Caucasian Loci (2007)

Markus Perola, Sampo Sammalisto, Tero Hiekkalinna, Nick G. Martin, Peter M. Visscher, Grant W. Montgomery, ...

Twin cohorts provide a unique advantage for investigations of the role of genetics and environment in the etiology of variation in common complex traits by reducing the variance due to environment,...

Socioeconomic position and twins' health: a life-course analysis of 1266 pairs of middle-aged Danish twins (2007)

Osler, Merete, McGue, Matt, Christensen, Kaare

Background The association between socioeconomic circumstances and health in adulthood could come about through processes that may be divided into factors experienced early in life and those...

Combined genome scans for body stature in 6602 European twins: evidence for common Caucasian loci (2007)

Markus Perola, Sampo Sammalisto, Tero Hiekkalinna, Nick Martin, Peter M. Visscher, Grant W. Montgomery, ...

Twin cohorts provide a unique advantage for investigations of the role of genetics and environment in the etiology of variation in common complex traits by reducing the variance due to environmental,...

Infertility, infertility treatment and twinning: the Danish National Birth Cohort (2007)

Zhu, Jin Liang, Basso, Olga, Obel, Carsten, Christensen, Kaare, Olsen, Jørn

BACKGROUND We have previously observed that an increasing time to pregnancy (TTP) is associated with a reduced frequency of twin deliveries in couples not receiving infertility treatment. By using...

Genetics of healthy aging in europe (2007)

Franceschi, Claudio, Bezrukov, Vladyslav, Blanché, Hélène, Bolund, Lars, Christensen, Kaare, De Benedictis, Giovanna, ...

The aim of the 5-year European Union (EU)-Integrated Project GEnetics of Healthy Aging (GEHA), constituted by 25 partners (24 from Europe plus the Beijing Genomics Institute from China), is to...

Infertility, infertility treatment and twinning: the Danish National Birth Cohort (2007)

Zhu, Jin Liang, Basso, Olga, Obel, Carsten, Christensen, Kaare, Olsen, Jørn

BACKGROUND We have previously observed that an increasing time to pregnancy (TTP) is associated with a reduced frequency of twin deliveries in couples not receiving infertility treatment. By using...

Infertility, infertility treatment and twinning: the Danish National Birth Cohort (2007)

Zhu, Jin Liang, Basso, Olga, Obel, Carsten, Christensen, Kaare, Olsen, Jørn

BACKGROUND We have previously observed that an increasing time to pregnancy (TTP) is associated with a reduced frequency of twin deliveries in couples not receiving infertility treatment. By using...

Association between Height and Coronary Heart Disease Mortality: A Prospective Study of 35,000 Twin Pairs (2006)

Silventoinen, Karri, Zdravkovic, Slobodan, Skytthe, Axel, McCarron, Peter, Herskind, Anne Maria, Koskenvuo, Markku, ...

An inverse association between height and risk of coronary heart disease (CHD) is well demonstrated, but it is not known whether this association is because of genetic factors, socioeconomic...

Influence of environmental factors on facial ageing (2006)

Rexbye, Helle, Petersen, Inge, Johansens, Mette, Klitkou, Louise, Jeune, Bernard, Christensen, Kaare

Background: a recent twin study has shown that ‘looking old for one’s age’ is associated with increased mortality. Approximately 40% of the variation in perceived age is due to non-genetic...

Influence of environmental factors on facial ageing (2006)

Rexbye, Helle, Petersen, Inge, Johansen, Mette, Klitkou, Louise, Jeune, Bernard, Christensen, Kaare

Background: a recent twin study has shown that ‘looking old for one’s age’ is associated with increased mortality. Approximately 40% of the variation in perceived age is due to non-genetic...

The heritability of CHD mortality in Danish twins after controlling for smoking and BMI (2005)

Wienke, Andreas, Herskind, Anne M., Christensen, Kaare, Skytthe, Axel, Yashin, Anatoli I.

Cause-specific mortality data on Danish monozygotic and dizygotic twins are used to analyze heritability estimates of susceptibility to coronary heart disease (CHD) after controlling for smoking and...

Estimating haplotype relative risks on human survival in population-based association studies (2005)

Tan, Qihua, Christiansen, Lene, Bathum, Lise, Zhao, Jing H., Yashin, Anatoli I., Vaupel, James W., ...

Association-based linkage disequilibrium (LD) mapping is an increasingly important tool for localizing genes that show potential influence on human aging and longevity. As haplotypes contain more LD...

Haplotype effects on human survival: logistic regression models applied to unphased genotype data (2005)

Tan, Qihua, Christiansen, Lene, Bathum, Lise, Zhao, Jing H., Vach, Werner, Vaupel, James W., ...

Haplotype based linkage disequilibrium (LD) mapping exhibits higher power than the single locus approach because it makes use of the LD information contained in the flanking markers. New statistical...

The heritability of Telomere length among the elderly and oldest-old (2005)

Bischoff, Claus, Graakjaer, Jesper, Petersen, Hans C., Hjelmborg, Jacob V.B., Vaupel, James W., Bohr, V. A., ...

A tight link exists between telomere length and both population doublings of a cell culture and age of a given organism. The more population doublings of the cell culture or the higher the age of the...

No evidence for an association between extreme longevity and Microsomal Transfer Protein polymorphisms in a longitudinal study of 1651 nonagenarians (2005)

Bathum, Lise, Christiansen, Lene, Tan, Qihua, Vaupel, James W., Jeune, Bernard, Christensen, Kaare

Previous studies have reported two SNPs and a haplotype marker within the Microsomal Transfer Protein gene associated with extreme longevity. Here, we test this finding in a longitudinal study of...

Cancer Risk in Persons with Oral Cleft--A Population-based Study of 8,093 Cases (2005)

Bille, Camilla, Winther, Jeanette Falck, Bautz, Andrea, Murray, Jeffrey C., Olsen, Jørn, Christensen, Kaare

The authors conducted a nationwide study of the occurrence of cancer among 8,093 Danish oral cleft cases born in 1936 through 1998 and followed in the Danish Cancer Registry from 1968 through 1998, a...

Time trends in waiting time to pregnancy among Danish twins (2005)

Jensen, Tina Kold, Joffe, Mike, Scheike, Thomas, Skytthe, Axel, Gaist, David, Christensen, Kaare

BACKGROUND: Little is known about time trends in fecundity because few population-based data are available. In a survey among female twins born from 1953 to 1976, their time to pregnancy did not...

Twins with implanted pacemakers: Is there an increased mortality risk for the co-twin? A follow-up study based on the Danish Twin Registry and the Danish Pacemaker Register (2005)

Tveskov, Claus, Skytthe, Axel, Arnsbo, Per, Vaupel, James W., Møller, Mogens, Christensen, Kaare

Background The main indications for implanting a cardiac pacemaker are either acquired atrio-ventricular block (AVB) or sick sinus syndrome (SSS). In general, the exact aetiology of these conditions...

Time trends in waiting time to pregnancy among Danish twins (2005)

Jensen, Tina Kold, Joffe, Mike, Scheike, Thomas, Skytthe, Axel, Gaist, David, Christensen, Kaare

BACKGROUND: Little is known about time trends in fecundity because few population-based data are available. In a survey among female twins born from 1953 to 1976, their time to pregnancy did not...

Power of non-parametric linkage analysis in mapping genes contributing to human longevity in long-lived sib-pairs (2004)

Tan, Qihua, Zhao, Jing H., Iachine, Ivan A., Hjelmborg, Jacob, Vach, Werner, Vaupel, James W., ...

This report investigates the power issue in applying the non-parametric linkage analysis of affected sib-pairs (ASP) [Kruglyak and Lander, 1995: Am J Hum Genet 57:439-454] to localize genes that...

Multidisciplinary approaches in genetic studies of human aging and longevity (2004)

Tan, Qihua, Yashin, Anatoli I., Christensen, Kaare, Jeune, Bernard, De Benedictis, Giovanna, Kruse, Torben A., ...

The amount of research on human aging and longevity has been growing rapidly in recent years. Multidisciplinary approaches, which integrate classic population genetics methods with the principles of...

Assessing genetic association with human survival at multi-allelic loci (2004)

Tan, Qihua, De Benedictis, Giovanna, Yashin, Anatoli I., Bathum, Lise, Christiansen, Lene, Dahlgaard, Jesper, ...

Genetic variation plays an important role in natural selection and population evolution. However, it also presents geneticists interested in aging research with problems in data analysis because of...

Fecundity and twinning. A study within the Danish National Birth Cohort (2004)

Basso, Olga, Christensen, Kaare, Olsen, Jørn

BACKGROUND. Decreased fecundity has been hypothesized as one of the causes of the widespread decline in twin rates in the 1960s and 1970s. The association between high fecundity and twinning is not,...

The heritability of cause-specific mortality: a correlated gamma-frailty model applied to mortality due to respiratory diseases in Danish twins born 1870 -1930 (2003)

Wienke, Andreas, Holm, Niels V., Christensen, Kaare, Skytthe, Axel, Vaupel, James W., Yashin, Anatoli I.

The genetic influence on susceptibility to diseases of the respiratory system and all-cause mortality was studied using data for identical (MZ)and fraternal (DZ) twins. Data from the Danish Twin...

Major genetic susceptibility for venous thromboembolism in men: a study of Danish twins (2003)

Larsen, Torben Bjerregaard, Sørensen, Henrik Toft, Skytthe, Axel, Johnsen, Søren Paaske, Vaupel, James W., Christensen, Kaare

Background. Although several genetic determinants (mutations or polymorphisms) have been associated with increased risk of venous thromboembolism, the overall influence of genetic factors on this...

Cognitive impairment and survival at older ages (2003)

Maier, Heiner, McGue, Matthew, Vaupel, James W., Christensen, Kaare

Several studies suggest that cognitive impairment is a risk factor for mortality among older adults. However, the mechanisms that generate the association between cognitive function and survival are...

Predictors of mortality in 2,249 nonagenarians - the Danish 1905-cohort survey (2003)

Nybo, Hanne, Petersen, Hans C., Gaist, David, Jeune, Bernard, Andersen, Kjeld, McGue, Matthew, ...

OBJECTIVES: To elucidate whether well-known predictions of mortality are reduced or even reversed, or whether mortality is a stochastic process in the oldest old. DESIGN: A multidimensional survey of...

Age trajectories of genetic variance in physical functioning: a longitudinal study of Danish twins aged 70 years and older (2003)

Christensen, Kaare, Frederiksen, Henrik, Vaupel, James W., McGue, Matthew

Genetic-evolutionary theories of aging predict that the genetic variance for fitness traits increases with age, while epidemiological-gerontological theories predict an increase in the environmental...

The correlation of fecundability among twins: evidence of a genetic effect on fertility? (2003)

Christensen, Kaare, Kohler, Hans-Peter, Basso, Olga, Olsen, Jørn, Vaupel, James W., Rodgers, Joseph L.

Background. Numerous rare genetic conditions are known to influence fecundability in both males and females. It is less clear to what extent more subtle genetic differences influence fecundability on...

Angiotensin I-Converting Enzyme (ACE) gene polymorphism in relation to physical performance, cognition and survival: a follow-up study of elderly Danish twins (2003)

Frederiksen, Henrik, Gaist, David, Bathum, Lise, Andersen, Kjeld, McGue, Matthew, Vaupel, James W., ...

PURPOSE: Studies of younger individuals have suggested an association between ACE genotype and physical and cognitive performance. Using a longitudinal study of elderly twins we studied the...

Logistic regression models for polymorphic and antagonistic pleiotropic gene action on human aging and longevity (2003)

Tan, Qihua, Bathum, Lise, Christiansen, Lene, De Benedictis, Giovanna, Dahlgaard, Jesper, Frizner, N, ...

In this paper, we apply logistic regression models to measure genetic association with human survival for highly polymorphic and pleiotropic genes. By modelling genotype frequency as a function of...

Retinoic Acid Receptor Alpha Gene Variants, Multivitamin Use, and Liver Intake as Risk Factors for Oral Clefts: A Population-based Case-Control Study in Denmark, 1991-1994 (2003)

Mitchell, Laura E., Murray, Jeffrey C., O’Brien, Sarah, Christensen, Kaare

Previous studies suggest that the risks of nonsyndromic cleft lip with or without cleft palate (CL±P) and isolated cleft palate are influenced by variation at several loci and that these loci...

The Danish twin registry: 127 cohorts of twins (2002)

Skytthe,Axel, Christensen,Kaare, Vaupel,James W., Holm,Niels V., Kyvik,Kirsten

The Danish Twin Registry is the oldest national twin register in the world, initiated in 1954 by ascertainment of twins born from 1870 to 1910. During a number of studies birth cohorts have been...

Frequency and heritability of depression symptomatology in the second half of life: evidence from Danish twins over 45 (2002)

McGue,Matthew, Johnson,Wendy, Christensen,Kaare, Vaupel,James W., Gaist,David

BACKGROUND: Self-reported depressive symptoms among the elderly have generated considerable interest because they are readily available measures of overall well-being in a population often thought to...

Frequency and heritability of depression symptomatology in the second half of life: evidence from Danish twins over 45 (2002)

Johnson,Wendy, Christensen,Kaare, Vaupel,James W., Gaist,David, McGue,Matthew

Background. Self-reported depressive symptoms among the elderly have generated considerable interest because they are readily available measures of overall well-being in a population often thought to...

Har børn af længelevende forældre en bedre alderdom? (2002)

Frederiksen,Henrik, McGue,Matthew, Jeune,Bernard, Gaist,David, Nybo,Hanne, Skytthe,Axel, ...

BACKGROUND: Long-lived individuals are rare and may be selected in part for the genetic factors that promote successful aging. The children of long-lived parents may therefore age more successfully...

Reproduction life history and hip fractures (2002)

Petersen,Hans C., Jeune,Bernard, Vaupel,James W., Christensen,Kaare

PURPOSE: The present study assesses the association between reproduction and hip fractures. METHODS: We used two surveys on elderly Danish twins of both sexes and the Danish National Register of...

Do children of long-lived parents age more successfully? (2002)

Frederiksen,Henrik, McGue,Matthew, Jeune,Bernard, Gaist,David, Nybo,Hanne, Skytthe,Axel, ...

BACKGROUND: Long-lived individuals are rare and may be selected in part for the genetic factors that promote successful aging. The children of long-lived parents may therefore age more successfully...

Cognitive impairment and mortality among nonagenarians: the Danish 1905 cohort survey (2002)

Andersen,Kjeld, Christensen,Kaare, Vaupel,James W., Jeune,Bernard, McGue,Matthew, Petersen,Hans C., ...

Cognitive impairment has been associated with increased mortality. Most studies, however, have only included small numbers, if at all, of the very old. In a large nationwide survey of all Danes born...

Genetic analysis of cause of death in a bivariate lifetime model with dependent competing risks (2002)

Wienke,Andreas, Christensen,Kaare, Skytthe,Axel, Yashin,Anatoli I.

A mixture model in multivariate survival analysis is presented, whereby heterogeneity among subjects creates divergent paths for the individual's risk of experiencing an event (i.e., disease), as...

The influence of smoking and BMI on heritability in susceptibility to coronary heart disease (2002)

Wienke,Andreas, Herskind,A. M., Christensen,Kaare, Skytthe,Axel, Yashin,Anatoli I.

Cause-specific mortality data on Danish monozygotic (MZ) and dizygotic (DZ) twins are used to analyze the influence of smoking and body mass index (BMI) on heritability estimates of susceptibility to...

The fertility pattern of twins and the general population compared: evidence from Danish cohorts 1945-64 (2002)

Kohler,Hans-Peter, Knudsen,Lisbeth B., Skytthe,Axel, Christensen,Kaare

Twin studies provide an important possibility for demographers to analyze patterns of heritability and to estimate structural models with controls for endowments. These possibilities are increasingly...

A case-only approach for assessing gene by sex interaction in human longevity (2002)

Tan,Qihua, Yashin,Anatoli I., Bladbjerg,Else M., De Maat,Moniek, Andersen-Ranberg,Karen, Jeune,Bernard, ...

As one aspect of the complex feature of longevity, gene by sex interaction plays an important role in influencing human life span. With advances in molecular genetics, more studies aimed at assessing...

Genetic analysis of cause of death in a mixture model of bivariate lifetime data (2002)

Wienke,Andreas, Christensen,Kaare, Skytthe,Axel, Yashin,Anatoli I.

A mixture model in multivariate survival analysis is presented, whereby heterogeneity among subjects creates divergent paths for the individual's risk of experiencing an event (i.e., disease), as...

The fertility pattern of twins and the general population compared: evidence from Danish cohorts 1945-64 (2002)

Kohler,Hans-Peter, Christensen,Kaare, Skytthe,Axel, Knudsen,Lisbeth B.

Twin studies provide an important possibility for demographers to analyze patterns of heritability and to estimate structural models with controls for endowments. These possibilities are increasingly...

Genetic contribution to rate of change in functional abilities among Danish twins aged 75 years or more (2002)

Christensen,Kaare, Gaist,David, Vaupel,James W., McGue,Matthew

In a previous cross-sectional study of twins, the authors found evidence of a substantial genetic influence on functional abilities among elderly women. It has been suggested that rate of change in...

Hand grip strength: a phenotype suitable for identifying genetic variants affecting mid- and late-life physical functioning (2002)

Frederiksen,Henrik, Christensen,Kaare, Vaupel,James W., McGue,Matthew, Hjelmborg,Jacob, Petersen,Hans C., ...

Physical functioning late in life has been shown to be affected by genetic factors. Only a few genetic variants have been suggested to be associated with physical functioning, and this only in...

A case-only approach for assessing gene by sex interaction in human longevity (2002)

Tan, Qihua, Yashin, Anatoli I., Bladbjerg, Else M., De Maat, Moniek, Andersen-Ranberg, Karen, Jeune, Bernard, ...

As one aspect of the complex feature of longevity, gene by sex interaction plays an important role in influencing human life span. With advances in molecular genetics, more studies aimed at assessing...

The Danish twin registry: 127 cohorts of twins (2002)

Skytthe, Axel, Christensen, Kaare, Vaupel, James W., Holm, Niels V., Kyvik, Kirsten

The Danish Twin Registry is the oldest national twin register in the world, initiated in 1954 by ascertainment of twins born from 1870 to 1910. During a number of studies birth cohorts have been...

Frequency and heritability of depression symptomatology in the second half of life: evidence from Danish twins over 45 (2002)

McGue, Matthew, Johnson, Wendy, Christensen, Kaare, Vaupel, James W., Gaist, David

BACKGROUND: Self-reported depressive symptoms among the elderly have generated considerable interest because they are readily available measures of overall well-being in a population often thought to...

Genetic analysis of cause of death in a mixture model of bivariate lifetime data (2002)

Wienke, Andreas, Christensen, Kaare, Skytthe, Axel, Yashin, Anatoli I.

A mixture model in multivariate survival analysis is presented, whereby heterogeneity among subjects creates divergent paths for the individual's risk of experiencing an event (i.e., disease), as...

Reproduction life history and hip fractures (2002)

Petersen, Hans C., Jeune, Bernard, Vaupel, James W., Christensen, Kaare

PURPOSE: The present study assesses the association between reproduction and hip fractures. METHODS: We used two surveys on elderly Danish twins of both sexes and the Danish National Register of...

The fertility pattern of twins and the general population compared: evidence from Danish cohorts 1945-64 (2002)

Kohler, Hans-Peter, Christensen, Kaare, Skytthe, Axel, Knudsen, Lisbeth B.

Twin studies provide an important possibility for demographers to analyze patterns of heritability and to estimate structural models with controls for endowments. These possibilities are increasingly...

Frequency and heritability of depression symptomatology in the second half of life: evidence from Danish twins over 45 (2002)

Johnson, Wendy, Christensen, Kaare, Vaupel, James W., Gaist, David, McGue, Matthew

Background. Self-reported depressive symptoms among the elderly have generated considerable interest because they are readily available measures of overall well-being in a population often thought to...

Genetic contribution to rate of change in functional abilities among Danish twins aged 75 years or more (2002)

Christensen, Kaare, Gaist, David, Vaupel, James W., McGue, Matthew

In a previous cross-sectional study of twins, the authors found evidence of a substantial genetic influence on functional abilities among elderly women. It has been suggested that rate of change in...

Har børn af længelevende forældre en bedre alderdom? (2002)

Frederiksen, Henrik, McGue, Matthew, Jeune, Bernard, Gaist, David, Nybo, Hanne, Skytthe, Axel, ...

BACKGROUND: Long-lived individuals are rare and may be selected in part for the genetic factors that promote successful aging. The children of long-lived parents may therefore age more successfully...

Do children of long-lived parents age more successfully? (2002)

Frederiksen, Henrik, McGue, Matthew, Jeune, Bernard, Gaist, David, Nybo, Hanne, Skytthe, Axel, ...

BACKGROUND: Long-lived individuals are rare and may be selected in part for the genetic factors that promote successful aging. The children of long-lived parents may therefore age more successfully...

Hand grip strength: a phenotype suitable for identifying genetic variants affecting mid- and late-life physical functioning (2002)

Frederiksen, Henrik, Christensen, Kaare, Vaupel, James W., McGue, Matthew, Hjelmborg, Jacob, Petersen, Hans C., ...

Physical functioning late in life has been shown to be affected by genetic factors. Only a few genetic variants have been suggested to be associated with physical functioning, and this only in...

Cognitive impairment and mortality among nonagenarians: the Danish 1905 cohort survey (2002)

Andersen, Kjeld, Christensen, Kaare, Vaupel, James W., Jeune, Bernard, McGue, Matthew, Petersen, Hans C., ...

Cognitive impairment has been associated with increased mortality. Most studies, however, have only included small numbers, if at all, of the very old. In a large nationwide survey of all Danes born...

The influence of smoking and BMI on heritability in susceptibility to coronary heart disease (2002)

Wienke, Andreas, Herskind, A. M., Christensen, Kaare, Skytthe, Axel, Yashin, Anatoli I.

Cause-specific mortality data on Danish monozygotic (MZ) and dizygotic (DZ) twins are used to analyze the influence of smoking and body mass index (BMI) on heritability estimates of susceptibility to...

The fertility pattern of twins and the general population compared: evidence from Danish cohorts 1945-64 (2002)

Kohler, Hans-Peter, Knudsen, Lisbeth B., Skytthe, Axel, Christensen, Kaare

Twin studies provide an important possibility for demographers to analyze patterns of heritability and to estimate structural models with controls for endowments. These possibilities are increasingly...

Genetic analysis of cause of death in a bivariate lifetime model with dependent competing risks (2002)

Wienke, Andreas, Christensen, Kaare, Skytthe, Axel, Yashin, Anatoli I.

A mixture model in multivariate survival analysis is presented, whereby heterogeneity among subjects creates divergent paths for the individual's risk of experiencing an event (i.e., disease), as...

Correlation of scrotal temperature in twins: Brief Communication (2002)

Hjollund, Niels Henrik I., Storgaard, Lone, Ernst, Erik, Bonde, Jens Peter E., Christensen, Kaare, Olsen, Jørn

BACKGROUND: Scrotal temperature and semen quality have been found to be inversely correlated in several studies, and variation in scrotal temperature may contribute to the well known variation in...

Genetic Contribution to Rate of Change in Functional Abilities among Danish Twins Aged 75 Years or More (2002)

Christensen, Kaare, Gaist, David, Vaupel, James W., McGue, Matt

In a previous cross-sectional study of twins, the authors found evidence of a substantial genetic influence on functional abilities among elderly women. It has been suggested that rate of change in...

Poor semen quality may contribute to recent decline in fertility rates (2002)

Jensen, Tina Kold, Carlsen, Elisabeth, Jørgensen, Niels, Berthelsen, Jørgen G., Keiding, Niels, Christensen, Kaare, ...

During past decades, we have witnessed a remarkable decline in fertility rates (number of births per 1000 women of reproductive age) in the industrialized world. It seems beyond doubt that the...

Evaluation of Two Putative Susceptibility Loci for Oral Clefts in the Danish Population (2001)

Mitchell, Laura E., Murray, Jeffrey C., O'Brien, Sarah, Christensen, Kaare

Previous studies suggest that the risk of nonsyndromic cleft lip with or without cleft palate (CL±P) and isolated cleft palate (CP) is influenced by genetic variation at several loci and that the...

Recurrence Risk of Congenital Anomalies-the Impact of Paternal, Social, and Environmental Factors: A Population-based Study in Denmark (1999)

Basso, Olga, Olsen, Jørn, Christensen, Kaare

The authors investigated the recurrence risk of congenital anomalies as a function of changes in genetic and environmental factors in single births following the birth of a child with an anomaly. The...

Oral Clefts, Transforming Growth Factor Alpha Gene Variants, and Maternal Smoking: A Population-based Case-Control Study in Denmark, 1991-1994 (1999)

Christensen, Kaare, Olsen, Jøm, Nørgaard-Pedersen, Bent, Basso, Olga, Støvring, Henrik, Milhollin-Johnson, Lisa, ...

Studies in the United States have indicated that maternal first trimester smoking and infant transforming growth factor alpha (TGFA) locus mutations are associated with non-syndromic cleft lip...

Biodemographic trajectories of longevity (1998)

James W. Vaupel, James R. Carey, Kaare Christensen, Thomas E. Johnson, Anatoli I. Yashin, Niels V. Holm, ...

Old-age survival has increased substantially since 1950. Death rates decelerate with age for insects, worms, and yeast, as well as humans. This evidence of extended postreproductive survival is...

Risk of preterm delivery, low birthweight and growth retardation following spontaneous abortion: a registry-based study in Denmark (1998)

Basso, Olga, Olsen, Jørn, Christensen, Kaare

Background Some studies have found an association between spontaneous abortion and adverse birth outcome in the subsequent pregnancy, but results are conflicting, maybe due to lack of confounder...

No Increased Mortality in Later Life for Cohorts Bom during Famine (1997)

Kannisto, Väinö, Christensen, Kaare, Vaupel, James W.

Nutrition early in life may influence adult mortality. The fetal-origins hypothesis suggests that nourishment before birth and during the individual's infancy programs the development of risk factors...

The Fertility Pattern of Twins and the General Population Compared: Evidence from Danish Cohorts 1945-64

Hans-Peter Kohler, Lisbeth B. Knudsen, Axel Skytthe, Kaare Christensen

Twin studies provide an important possibility for demographers to analyze patterns of heritability and to estimate structural models with controls for endowments. These possibilities are increasingly...

Long term follow up study of survival associated with cleft lip and palate at birth

Christensen, Kaare, Juel, Knud, Herskind, Anne Maria, Murray, Jeffrey C

Objective To assess the overall and cause specific mortality of people from birth to 55 years with cleft lip and palate.

Genetic Association Analysis of Human Longevity in Cohort Studies of Elderly Subjects: An Example of the PON1 Gene in the Danish 1905 Birth Cohort

Tan, Qihua, Christiansen, Lene, Bathum, Lise, Li, Shuxia, Kruse, Torben A., Christensen, Kaare

Although the case-control or the cross-sectional design has been popular in genetic association studies of human longevity, such a design is prone to false positive results due to sampling bias and a...

Long term follow up study of survival associated with cleft lip and palate at birth

Christensen, Kaare, Juel, Knud, Herskind, Anne Maria, Murray, Jeffrey C

Objective To assess the overall and cause specific mortality of people from birth to 55 years with cleft lip and palate.

Genetic Association Analysis of Human Longevity in Cohort Studies of Elderly Subjects: An Example of the PON1 Gene in the Danish 1905 Birth Cohort

Tan, Qihua, Christiansen, Lene, Bathum, Lise, Li, Shuxia, Kruse, Torben A., Christensen, Kaare

Although the case-control or the cross-sectional design has been popular in genetic association studies of human longevity, such a design is prone to false positive results due to sampling bias and a...

Comparison of academic performance of twins and singletons in adolescence: follow-up study

Christensen, Kaare, Petersen, Inge, Skytthe, Axel, Herskind, Anne Maria, McGue, Matt, Bingley, Paul

Objectives To determine whether twins in recent cohorts show similar academic performance in adolescence to singletons and to test the effect of birth weight on academic performance in twins and...

Combined Genome Scans for Body Stature in 6,602 European Twins: Evidence for Common Caucasian Loci

Perola, Markus, Sammalisto, Sampo, Hiekkalinna, Tero, Martin, Nick G, Visscher, Peter M, Montgomery, Grant W, ...

Twin cohorts provide a unique advantage for investigations of the role of genetics and environment in the etiology of variation in common complex traits by reducing the variance due to environment,...

Orofacial Cleft Risk Is Increased with Maternal Smoking and Specific Detoxification-Gene Variants

Shi, Min, Christensen, Kaare, Weinberg, Clarice R., Romitti, Paul, Bathum, Lise, Lozada, Anthony, ...

Maternal smoking is a recognized risk factor for orofacial clefts. Maternal or fetal pharmacogenetic variants are plausible modulators of this risk. In this work, we studied 5,427 DNA samples,...

Telomere Fluorescence Measurements in Granulocytes and T Lymphocyte Subsets Point to a High Turnover of Hematopoietic Stem Cells and Memory T Cells in Early Childhood

Rufer, Nathalie, Brümmendorf, Tim H., Kolvraa, Steen, Bischoff, Claus, Christensen, Kaare, Wadsworth, Louis, ...

To study telomere length dynamics in hematopoietic cells with age, we analyzed the average length of telomere repeat sequences in diverse populations of nucleated blood cells. More than 500...

Offspring's Leukocyte Telomere Length, Paternal Age, and Telomere Elongation in Sperm

Kimura, Masayuki, Cherkas, Lynn F, Kato, Bernet S, Demissie, Serkalem, Hjelmborg, Jacob B, Brimacombe, Michael, ...

Leukocyte telomere length (LTL) is a complex genetic trait. It shortens with age and is associated with a host of aging-related disorders. Recent studies have observed that offspring of older fathers...

Genetic analysis of cause of death in a bivariate lifetime model with dependent competing risks

Andreas Wienke, Kaare Christensen, Axel Skytthe, Anatoli I. Yashin

A mixture model in multivariate survival analysis is presented, whereby heterogeneity among subjects creates divergent paths for the individual's risk of experiencing an event (i.e., disease), as...

The age at first birth and completed fertility reconsidered: findings from a sample of identical twins

Hans-Peter Kohler, Axel Skytthe, Kaare Christensen

In this paper we use new methods and data to reassess the relationship between the age at first birth and completed fertility. In particular we attempt to properly estimate the postponement effect,...

A case-only approach for assessing gene-sex interaction in human longevity

Qihua Tan, Anatoli I. Yashin, Else M. Bladbjerg, Moniek De Maat, Karen Andersen-Ranberg, Bernard Jeune, ...

As one aspect of the complex feature of longevity, gene-sex interaction plays an important role in influencing human life span. With advances in molecular genetics, more studies aimed at assessing...

The influence of smoking and BMI on heritability in susceptibility to coronary heart disease

Andreas Wienke, Anne M. Herskind, Kaare Christensen, Axel Skytthe, Anatoli I. Yashin

Cause-specific mortality data on Danish monozygotic (MZ) and dizygotic (DZ) twins are used to analyze the influence of smoking and body mass index (BMI) on heritability estimates of susceptibility to...

The fertility pattern of twins and the general population compared: evidence from Danish cohorts 1945-64

Hans-Peter Kohler, Lisbeth B. Knudsen, Axel Skytthe, Kaare Christensen

Twin studies provide an important possibility for demographers to analyze patterns of heritability and to estimate structural models with controls for endowments. These possibilities are increasingly...

The Returns to Observable and Unobservable Skills over time: Evidence from a Panel of the Population of Danish Twins

Paul Bingley, Kaare Christensen, Ian Walker

This paper provides estimates of the private financial return to education based on large samples of monozygotic (MZ) and dizygotic (DZ) twins which we obtain from Danish population registers. Our...

Being born under adverse economic conditions leads to a higher cardiovascular mortality rate later in life – evidence based on individuals born at different stages of the business cycle

Van Den Berg, Gerard J., Doblhammer-Reiter, Gabriele, Christensen, Kaare

We connect the recent medical and economic literatures on the long-run effects of early-life conditions, by analyzing the effects of economic conditions on the individual cardiovascular (CV)...

Being Born Under Adverse Economic Conditions Leads to a Higher Cardiovascular Mortality Rate Later in Life: Evidence Based on Individuals Born at Different Stages of the Business Cycle

Van Den Berg, Gerard J., Doblhammer-Reiter, Gabriele, Christensen, Kaare

We connect the recent medical and economic literatures on the long-run effects of early-life conditions, by analyzing the effects of economic conditions on the individual cardiovascular (CV)...

Is Fertility Behavior in Our Genes? Findings from a Danish Twin Study

Hans-Peter Kohler, Joseph L. Rodgers, Kaare Christensen

This article investigates the fertility of Danish twins born during the periods 1870-1910 and 1953-64 in order to pursue two central questions for understanding human reproduction: Do genetic...

Human Biodemography: Some challenges and possibilities

Kaare Christensen

This opinion report - in a series on the future of biodemography - focuses on promising areas that I think will be valuable to develop in the future in order to get a better understanding of the...

Exogenous determinants of early-life conditions, and mortality later in life

Gabriele Doblhammer-Reiter, Kaare Christensen

We analyze causal effects of conditions early in life on the individual mortality rate later in life. Conditions early in life are captured by transitory features of the macro environment around...

Exceptional longevity does not result in excessive levels of disability

Christensen, Kaare, McGue, Matt, Petersen, Inge, Jeune, Bernard, Vaupel, James W.

Late-life loss of independence in daily living is a central concern for the aging individual and for society. The implications of increased survival to advanced age may be different at the population...

Sex differential in mortality trends of old-aged Danes: a nation wide study of age, period and cohort effects

Jacobsen, Rune, Oksuzyan, Anna, Engberg, Henriette, Jeune, Bernard, Vaupel, James W., Christensen, Kaare

Objective Over the last half century the mortality rates in Denmark for females above age 80 have declined dramatically whereas the decline for males have been modest, resulting in a change in...

Power for Genetic Association Study of Human Longevity Using the Case-Control Design

Tan, Qihua, Zhao, Jing Hua, Zhang, Dongfeng, Kruse, Torben A., Christensen, Kaare

The efficiency of the popular case-control design in gene-longevity association studies needs to be verified because, different from a binary trait, longevity represents only the extreme end of the...

Geographical structure and differential natural selection among North European populations

McEvoy, Brian P., Montgomery, Grant W., McRae, Allan F., Ripatti, Samuli, Perola, Markus, Spector, Tim D., ...

Population structure can provide novel insight into the human past, and recognizing and correcting for such stratification is a practical concern in gene mapping by many association methodologies. We...