K Christensen

..This hypothesis predicts that longevity in one twin is associated with increased cancer risk in the cotwin...

..Performance of our method in detecting interaction effect is compared with that of the case-only model...

..The reason for this paradox is undoubtedly multifactorial with biological (hormonal, immunological, genetic), behavioural (smoking, risk behaviour, sickness behaviour), and social (the male role) factors...

..This study assesses whether patients with facial cleft have an increased risk of psychiatric diseases...

..For the individual, long life brings an increasing risk of loss of independence. For society, mortality reductions are not expected to result in exceptional levels of disability in cohorts of the very old...

..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 a population level...

..However, large-scale linkage studies of long-lived families, longitudinal candidate-gene association studies and the development of analytical methods provide the potential for future progress...

..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 singletons...

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

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..To evaluate whether genetic factors contribute to the association between low birth weight and increased blood pressure among adolescents...

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..This study estimates the relative importance of genetic and environmental factors to variation in functional abilities in elderly persons...

..This finding, together with technological and medical development and redistribution of work, will be important for our chances to meet the challenges of ageing populations...

..To determine whether perceived age correlates with survival and important age related phenotypes...

..CONCLUSION: The spectrum of register-based twin studies is very wide and have changed in accordance with methodological and data resource developments...

..However, there is no evidence that the risk of CL+/-P or CP is influenced by gene-environment interactions involving MSX1 or TGFB3 and either first trimester exposure to maternal cigarette smoke or alcohol consumption...

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..Nevertheless, the majority of the participants considered their health to be good and were satisfied with their lives...

..Application has shown that these methods can serve as useful tools in searching for important gene variations that contribute to human aging and longevity...

..As an example, we apply the methods to empirical data on Renin gene polymorphism and longevity. We show that our models can serve as useful tools in searching for important genetic variations implicated in human aging and longevity...

..Self-reported 1-month prevalence of back pain in older twins assessed at intake in a population-based longitudinal survey...

..To evaluate whether physical disability reaches a plateau in the oldest age groups...

..To investigate the cognitive functioning of migraineurs vs nonmigraineurs in a large population-based sample of middle-aged twins where headache diagnoses were established by neurologists...

..The genetic contribution to cardiovascular disease (CVD) decreases with increasing age, and it is therefore important to determine the heritability of hemostasis also in the elderly...

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..Classic twin study...

..Moreover, our results emphasize the need for socially and contextually informed analyses of nature and nurture that allow both factors to influence human reproductive behavior over time...

..We show that our logistic regression based haplotype model can be a helpful tool for researchers interested in the genetics of human aging and longevity...

..We conclude that BP is a common symptom in old age; however, the prevalence does not change with increasing age. BP may be part of a more general syndrome of poor health among the old...

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..To our knowledge, this is the first longitudinal study exploring the influence of GST gene polymorphisms on longevity and these data implies that GST gene copy numbers do affect mortality risk in the elderly...

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..The review also points toward the excellent opportunities for continued etiological CLP research in Denmark in the 21st century using already established resources and an on-going prospective cohort study of 100,000 pregnant women...

..We compared health status among same-sex male and female twin pairs who lived together during childhood and were discordant or concordant on adult marital status...

..91 for marker D12S1634 located at 148 cM, and thus indicates that the previously identified disease locus at 12q24 is also a general vulnerability locus affecting the normal range of mood...

..The aim of the present study was to estimate the relative importance of genetic and environmental factors to variations in these tests among the elderly...

..Results from both simulation and model application indicate that our survival analysis model is an efficient method for inferring haplotype effects on human survival in population-based association studies...

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..The purpose of this study was to quantify the average lifetime according to health status among the oldest olds in Denmark...

..CONCLUSIONS: The majority of the variation in baldness in elderly men can be explained by genetic factors, and hair quantity has little impact on perceived age in elderly men...

..To evaluate the extent to which relationships between apolipoprotein E, cognitive functioning, and survival in people aged 60 to 80 persist into advanced old age...

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..The Danish Twin Registry was established formally in 1954 and thus celebrates its 50th anniversary in 2004. Here we give an account of its founding and the early years, and a brief summary of more recent progress...

..The aim of this study was to explore and describe self-rated health in middle-aged and elderly Danes using both a cross-sectional and a longitudinal design. Global and (age) comparative self-rated health are examined and compared...

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..Cross-sectional and longitudinal analysis of data comprising 4486 Danish twins 70-102 years of age...

..65; 95% CI 0.47-0.91). This study supports that smoking is hazardous to the female fetus not only in the short term but also affects her future ability to conceive and makes it even more important to advise pregnant women to stop smoking...

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..To estimate the risk of occurrence of subarachnoid haemorrhage in first degree relatives (parents, siblings, children) of patients with subarachnoid haemorrhage...

..In conclusion, this study has confirmed the substantial impact, which genetic factors have in the etiology of epilepsy. The heritability of epilepsy is high and seems to increase with age...

..Furthermore, our study indicates that high social status, low depression score and being married are associated with a younger look, but the strength of the associations varies between genders...

..Such a process would heighten the rate of age-dependent LTL attrition, ultimately resulting in shortened LTL...

..By using updated information, we assessed the frequencies of dizygotic (DZ) and monozygotic (MZ) twin deliveries as a function of infertility (TTP > 12 months), as well as infertility treatment...

..In conclusion, higher plasma levels of CRP and lower plasma levels of fibrinogen were observed in women using HRT; however, genetic polymorphisms in ESR1, CRP and FGB were not associated with these effects of HRT...

..Two common polymorphisms in the genes coding for methylenetetrahydrofolate reductase (MTHFR 677C>T) and methionine synthase (MTR 2756A>G) have an impact on plasma homocysteine level...

..This sample is likely to provide an important resource for studying the genetics of epilepsy subtypes and febrile seizures...

..We found a modest, but significant, increase in the frequency of interleukin-6 -174GG homozygotes with age suggesting that this genotype is advantageous for longevity...

..Prospective cohort study...

..This information illustrates that the number of affected sib pairs for linkage studies is relatively limited, but the sample sizes are promising for association studies...

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..Using a longitudinal study of elderly twins we studied the association between ACE genotype and physical and cognitive functioning and survival in old age...

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..NP and BP in seniors are probably associated with difficulty but not inability to perform daily activities...

..Thus, the GEHA project represents a unique source in the search for genes related to healthy ageing and longevity...

..Here, we summarise the evidence currently available for a genetic influence on physical functioning and disposition to leisure time physical activity with a focus on recent Danish twin data...

..It is of value in the debate concerning screening for hereditary hemochromatosis to determine the significance of heterozygosity...

..In conclusion, our study strongly supports the idea that genetic factors play a major role in the etiology of GD and suggest that a further search for susceptibility genes is worthwhile...

..Familial clustering has been reported for urinary incontinence (stress and urge), but different etiologies for the two types of incontinence have been suggested...

..The present study found an association between oral clefts and smoking and, although not conclusive, supports an association of oral cleft with alcohol...

..This can provide clues for where to search for causes behind the changes in sex differential in mortality seen in many Western countries during the last decades...

..Power is drastically reduced when nonagenarians are considered cases, with a more than 5-fold difference in the size of the case sample required to achieve comparable power as that found with centenarians...

..14, 6.78), and primary lung cancer among males born with both cleft lip and cleft palate (SIR = 2.49, 95% CI: 1.00, 5.14). The results do not provide evidence for an increased overall cancer risk for individuals born with oral clefts...

..The objective was to examine cohort changes in cognitive function in 2 cohorts of centenarians born 10 years apart...

..In addition, we observe an interesting pattern of sibship correlation on gene expression that increases exponentially with the mean of gene expression reflecting the enhanced genetic control over the functionally active genes...

..The results raise the hypothesis that the catalase -262T allele serves as protection against neurodegenerative and physical decline, although replication in other studies is warranted for confirmation of these findings...

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..We used data from a prospective follow-up study to assess modification of smoking habits and to identify predictors of persistent smoking after first-ever stroke...

..This provides further evidence for a genetic component in cleft etiology and is useful information for genetic counseling of twin pairs discordant for clefting...

..In conclusion, the indirect design can be a good choice for studying longevity in comparison with other alternatives, when relatively large sample size is available...

..The present study revealed consistent sex differentials in survival and physical health, self-rated health and cognition at older ages, whereas the pattern of sex differences in depressive symptoms was country-specific...

..To describe the prevalence of urinary incontinence and to find characteristics useful in general practice for identifying middle-aged and elderly women with the problem...

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..Semen quality may therefore be a fundamental biomarker of overall male health...

..The results demonstrate that questionnaire based zygosity diagnosis can still be regarded as a valid and valuable classification method for most purposes...

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..A positive association between socio-economic position and breast cancer has been widely observed, but not hitherto within twin pairs, where shared familial factors were adjusted for...

..To select a simple method for assessing alcohol consumption and to compare how different reference periods and response categories influence the self-reported frequency of binge drinking...

..Furthermore, the 10 year period prevalence of diabetes in monozygotic twins is compared with that in dizygotic twins...

..Our findings suggest that susceptibility to CMV infection - even under continuous within-partnership exposure - appears to be more strongly influenced by early-life environment than by genetic factors and adult environment...

..Impaired fibrinolytic function is associated with an enhanced risk of cardiovascular disease and therefore the effect of HRT on fibrinolysis may be of importance...

..However, results from the paired sister study suggest the potential contribution of skewed XCI to orofacial clefting, particularly cleft lip and palate...

..We show, by applying the model to an empirical data set, that our method based on the well-known logistic regression model is a useful tool for haplotype association analysis of human disease traits...

..83, h(2)(elderly) = 0.71) in both the young and elderly twins. DISCUSSION: The h(2) estimates emphasize that body fat and distribution as determined by DXA scan are under extensive genetic control...

..We assessed these effects separately by gender, controlling for self-reported health. In addition, we examined whether interaction with the co-twin has a different impact on mortality for identical and fraternal twins...

..This study will provide a new level of understanding for a complex birth defect trait. ..