Genes, environments, personality, and successful aging: toward a comprehensive developmental model in later life

Triangulated evidence provides no support for bidirectional causal pathways between diet/physical activity and depression/anxiety

BACKGROUND

Previous studies (various designs) present contradicting insights on the potential causal effects of diet/physical activity on depression/anxiety (and vice versa). To clarify this, we employed a triangulation framework including three methods with unique strengths/limitations/potential biases to examine possible bidirectional causal effects of diet/physical activity on depression/anxiety.

METHODS

Study 1: 3-wave longitudinal study (n = 9,276 Dutch University students). Using random intercept cross-lagged panel models to study temporal associations. Study 2: cross-sectional study (n = 341 monozygotic and n = 415 dizygotic Australian adult twin pairs). Using a co-twin control design to separate genetic/environmental confounding. Study 3: Mendelian randomization utilizing data (European ancestry) from genome-wide association studies (n varied between 17,310 and 447,401). Using genetic variants as instrumental variables to study causal inference.

RESULTS

Study 1 did not provide support for bidirectional causal effects between diet/physical activity and symptoms of depression/anxiety. Study 2 did provide support for causal effects between fruit/vegetable intake and symptoms of depression/anxiety, mixed support for causal effects between physical activity and symptoms of depression/anxiety, and no support for causal effects between sweet/savoury snack intake and symptoms of depression/anxiety. Study 3 provides support for a causal effect from increased fruit intake to the increased likelihood of anxiety. No support was found for other pathways. Adjusting the analyses including diet for physical activity (and vice versa) did not change the conclusions in any study.

CONCLUSIONS

Triangulating the evidence across the studies did not provide compelling support for causal effects of diet/physical activity on depression/anxiety or vice versa.

Latent subgroups with distinct patterns of factors associated with self-rated successful aging among 1,510 community-dwelling Americans: potential role of wisdom as an implicit promoter

OBJECTIVES

To investigate whether latent subgroups with distinct patterns of factors associated with self-rated successful aging can be identified in community-dwelling adults, and how such patterns obtained from analysis of quantitative data are associated with lay perspectives on successful aging obtained from qualitative responses.

METHODS

Cross-sectional data were collected from 1,510 community-dwelling Americans aged 21-99 years. Latent class regression was used to identify subgroups that explained the associations of self-rated successful aging with measures of physical, cognitive, and mental health as well as psychological measures related to resilience and wisdom. Natural language processing was used to extract important themes from qualitative responses to open-ended questions, including the participants' definitions of successful aging.

RESULTS

Two latent subgroups were identified, and their main difference was that the wisdom scale was positively associated with self-rated successful aging in only one subgroup. This subgroup had significantly lower self-rated successful aging and worse scores for all health and psychological measures. In the subgroup's qualitative responses, the theme of wisdom was only mentioned by 10.6%; this proportion was not statistically different from the other subgroup, for which the wisdom scale was not statistically associated with the self-rated successful aging.

CONCLUSION

Our results showed heterogeneous patterns in the factors underpinning successful aging even in community-dwelling adults. We found the existence of a latent subgroup with lower self-rated successful aging as well as worse health and psychological scores, and we suggest a potential role of wisdom in promoting successful aging for this subgroup, even though individuals may not explicitly recognize wisdom as important for successful aging.

Can healthy life style predict successful aging among Iranian older adults?

Background: Successful aging is a prominent and worldwide theme in gerontology. However, until recently, only few studies were conducted about successful aging in Iran. This study examined whether a healthy lifestyle could predict successful aging among older Iranians.

Methods: This cross sectional and descriptive study included 975 older Iranians who were selected through a multistage cluster-quota method from the health centers of Shiraz, Iran. A 5-part questionnaire, including demographic characteristics, the Seniors’ Healthy Lifestyle, Barthel Index, the Diner Life Satisfaction and Quality of Life, was used to collect the data. A logistic regression analysis was used in data analysis; data were analyzed using SPSS 21; and significance level was set at α = 0.05.

Results: The prevalence of successful aging among older Iranians was calculated at 24.0%. Results of multiple logistic regression analysis revealed that age (95% CI = 1.129- 1.702 and OR = 1.352), gender (95% CI = 0.412-0.764 and OR = 0.687), education level (95% CI = 1.443 – 1.699 and OR = 1.454), job (95% CI = 1.063-1.413 and OR = 1.185), monthly income (95% CI = 1.355-4.055 and OR = 2.272), insurance (95% CI = 0.344-0.842 and OR = 0.540), source of income (95% CI = 1.014-1.298 and OR = 1.145), and healthy lifestyle (95% CI = 0.772 - 0.858 and OR = 0.814) were predictors for successful aging.

Conclusion: Findings indicated that successful agers were mostly younger men, with higher education level and monthly income, who had insurance and a job and a healthy lifestyle. Thus, to age successfully, one must maintain and improve healthy lifestyle to prolong one’s health.

The Effect of Material and Social Deprivation on Well-Being of Elderly in Europe

In this work, attention is paid to 2 explanatory factors of successful aging. The first is material deprivation. There is growing evidence that poverty is associated with the onset of physical and mental disorders and, broadly, with aspects such as life satisfaction and happiness. The second factor is social deprivation. Social exclusion affects health due to lack of emotional and concrete support; moreover, participation in social activities among older people is associated with greater longevity and a lower risk of disability. The study describes the effect of material and social deprivation on depression (measured through the EURO-D scale) and quality of life (through CASP-12 scale), for individuals aged 50 and older in 14 European countries. Data is derived from Wave 5 of the SHARE project. To estimate the effect of material and social deprivation on outcomes and to determine whether it is moderated by the country in which people live, we apply 2 multi-group path models, respectively, for people aged 65 or younger and for those aged 66 years or older. Findings indicate that higher material and social deprivation is associated with greater levels of stress and worse quality of life. The effect of social deprivation would be stronger than that of material deprivation, and this result seems to be valid in all countries considered, although their intensity varies significantly between them.

The power of personality in successful ageing: a comprehensive review of larger quantitative studies

In this paper, we highlighted links between personality traits and successful ageing through a systematic review of recent empirical studies. Particularly, we addressed the question of whether personality traits are related to successful ageing and, if so, why and how? Answers to this question provided, for example, arguments that supported personality's role in planning an individual's future based on self-knowledge, thereby contributing to a sense of identity throughout their life. Then, considering longitudinal studies, we examined whether personality is stable over one's life course, or does it change and, if so, why and under what conditions? Answers to this question gave substance to the idea that a stable personality allows for continuous and consistent development. In addition, certain personality changes are likely to allow an individual to develop the resilience to better adapt to life's challenges. Therefore, the arguments brought by these two questions can help clarify the modulating role of personality for successful ageing via health and well-being outcomes. These insights may contribute to the development of new prevention approaches, more focused on inter- and intraindividual differences, to promote successful ageing.

Cognitive reserve and depression predict subjective reports of successful aging

BACKGROUND

With graying of western societies, successful aging is a hotly debated topic. Attaining successful aging brings benefits not only at the individual level, but also to society. To better understand successful aging, we conducted a study of older adults in the Republic of Slovenia.

METHODS

We recruited 213 community-dwelling adults, age 65 years and older, who responded to the Successful Aging Inventory (SAI), Purpose of Life Questionnaire (PIL), Satisfaction with Life Scale (SWLS), Beck Depression Inventory (BDI), Cognitive Reserve Index, Functional Activities Questionnaire (FAQ), and Multiple Abilities Self-Report Questionnaire (MASQ).

RESULTS

Responses to all scales were significantly correlated, which was taken into account when identifying covariates of latent successful aging in a structural equation model. Successful aging, as evaluated by the combination questionnaire responses, was most strongly associated with depression and marginally associated with cognitive reserve. Self-rated functional and cognitive capacities did not significantly explain individual differences in successful aging.

DISCUSSION

In our study of community-dwelling, older Slovenes, self-rated depression emerged as a strong correlate of successful aging and, to a lesser degree, cognitive reserve. Future studies of interventions that aim to promote successful aging should consider the role of depression and cognitive reserve in the older adult's experience of aging.

Feasibility and Effect of a Multidimensional Support Program to Improve Gerotranscendence Perception and Depression for Older Adults: A Pragmatic Cluster-Randomized Control Study

Improving perception of gerotranscendence can increase life satisfaction in older adults to achieve successful aging. The purpose of this study was to evaluate the feasibility and effect of a multidimensional support program (MSP) on gerotranscendence and depression in community-dwelling older adults. Using a cluster-randomized control trial design, four sites (98 participants) were randomly assigned to a MSP or control group. The Gerotranscendence Scale and Geriatric Depression Scale were administered pre- and postintervention. A total of 91 participants completed the study. The mean attendance rates in the MSP and control groups were 85.5% and 84.3%, respectively. The MSP was found to significantly enhance the perception of gerotranscendence in older adults but not their level of depression. This study demonstrated the MSP is a feasible and effective program to improve perception of gerotranscendence and may potentially lead to positive psychological well-being for older adults. [Res Gerontol Nurs. 2019; 12(3):148-158.].

Genetic variants associated with physical performance and anthropometry in old age: a genome-wide association study in the ilSIRENTE cohort

Unraveling the complexity of aging is crucial for understanding its mechanisms and its role as a risk factor for most chronic conditions. Advancements marked by genome-wide association studies (GWASs) have sparked interest in gene cataloguing in the context of aging and age-related conditions. Here, we used GWAS to explore whether single nucleotide polymorphisms (SNPs) were associated with functional and anthropometric parameters in a cohort of old community-dwellers enrolled in the ilSIRENTE study. Analyses were carried out in men and women aged 80+ years enrolled in the ilSIRENTE study (n = 286) and replicated in the inCHIANTI study (n = 1055). Genotyping was accomplished on Infinium Human610-QUAD version 1. In the ilSIRENTE population, genetic variants in ZNF295 and C2CD2 (rs928874 and rs1788355) on chromosome 21q22.3, were significantly associated with the 4-meter gait speed (rs928874, p = 5.61 × 10⁻⁸; rs1788355, p = 5.73 × 10⁻⁸). This association was not replicated in the inCHIANTI population. Our findings suggest that specific SNPs may be associated with a key measure of physical performance in older adults. GWASs using larger samples are needed to confirm these preliminary results to enhance our comprehension of complex age-associated phenomena.

Association between Age and the 7 Repeat Allele of the Dopamine D4 Receptor Gene

Longevity is in part (25%) inherited, and genetic studies aim to uncover allelic variants that play an important role in prolonging life span. Results to date confirm only a few gene variants associated with longevity, while others show inconsistent results. However, GWAS studies concentrate on single nucleotide polymorphisms, and there are only a handful of studies investigating variable number of tandem repeat variations related to longevity. Recently, Grady and colleagues (2013) reported a remarkable (66%) accumulation of those carrying the 7 repeat allele of the dopamine D4 receptor gene in a large population of 90-109 years old Californian centenarians, as compared to an ancestry-matched young population. In the present study we demonstrate the same association using continuous age groups in an 18-97 years old Caucasian sample (N = 1801, p = 0.007). We found a continuous pattern of increase from 18-75, however frequency of allele 7 carriers decreased in our oldest age groups. Possible role of gene-environment interaction effects driven by historical events are discussed. In accordance with previous findings, we observed association preferentially in females (p = 0.003). Our results underlie the importance of investigating non-disease related genetic variants as inherited components of longevity, and confirm, that the 7-repeat allele of the dopamine D4 receptor gene is a longevity enabling genetic factor, accumulating in the elderly female population.

Ballroom Dance: Linking Serious Leisure to Successful Aging

OBJECTIVE

This study explored ballroom dance as serious leisure and successful aging in a sample of community-dwelling older adults.

METHODS

Qualitative procedures were used to explore stories of ballroom dance and successful aging.

RESULTS

Participants described positive successful aging and active leisure engagement. Three themes emerged from thematic analyses: (a) Ballroom Dance as Serious Leisure: Its Dimensions; (b) Ballroom Dance: Its Link to Successful Aging; (c) The Affinity: We Love to Dance!.

CONCLUSION

The participants' ballroom dance revealed serious leisure characteristics in conjunction with their successful aging. They loved to dance, self-identified as ballroom dancers, and orchestrated their dance activities within its social world. Future research should examine the relation of successful aging to the social world of ballroom dance.

Apolipoprotein E and Clusterin can magnify effects of personality vulnerability on declarative memory performance in non-demented older adults

OBJECTIVES

Recent research has linked psychological (personality) factors and specific genetic risk polymorphisms to performance on neurocognitive phenotypes. We examined whether episodic or semantic memory performance is associated with (a) three personality traits (i.e. neuroticism, extraversion, and openness to experience), (b) two neurodegenerative-related polymorphisms (i.e. Apolipoprotein E (APOE; rs7412; rs429358), Clusterin (CLU; rs11136000)), and (c) cross-domain risk interactions (magnification effects).

METHODS

Linear growth models were examined to test independent associations between personality traits and declarative memory performance, and potential interaction effects with APOE and CLU genetic risk. Normal older adults (n = 282) with personality and genetic data from the Victoria Longitudinal Study were included at baseline and for up to 14 years of follow-up.

RESULTS

First, we observed that higher openness to experience levels were associated with better episodic and semantic memory. Second, three significant gene × personality interactions were associated with poorer memory performance at baseline. These synergistic effects are: (a) APOE allelic risk (ε4+) carriers with lower openness to experience levels, (b) CLU (no risk: T/T) homozygotes with higher extraversion levels, and (c) CLU (no risk: T/T) homozygotes with lower neuroticism levels.

CONCLUSIONS

Specific neurodegenerative-related genetic polymorphisms (i.e. APOE and CLU) moderate and magnify the risk contributed by selected personality trait levels (i.e. openness to experience, extraversion) on declarative memory performance in non-demented aging. Future research could target interactions of other personality traits and genetic polymorphisms in different clinical populations to predict other neurocognitive deficits or transitions to cognitive impairment and dementia.

Association between home and school food environments and dietary patterns among 9-11-year-old children in 12 countries

OBJECTIVES

We investigated the roles of home and school environments on dietary patterns among children from 12 countries differing widely in geographic region and levels of human and economic development.

METHODS

The sample included a total of 6685 (54% girls) 9-11-year-old children. Parents/guardians reported the availability of certain foods in the home, and trained researchers performed school audits recording the availability of foods for sale at schools. Foods were then divided into wholesome (nutrient-dense) and empty-calorie (nutrient-poor) foods and scored according to their availability. Children reported if their school provided school lunch and how many times during the last week they had eaten meals prepared away from home and school. Via principal components analysis, data-driven dietary pattern scores were calculated from food frequency questionnaires. Multilevel models were used to study the associations between home and school food environments (wholesome and empty-calorie foods) and dietary patterns (healthy and unhealthy diet pattern scores).

RESULTS

For low unhealthy diet pattern scores, low availability of empty-calorie foods at home was found to be more important than high availability of wholesome foods. More meals eaten outside home and school were associated with the higher unhealthy diet pattern scores. The availability of wholesome foods at home was positively associated with the healthy diet pattern scores. Food availability at school was not associated with the dietary patterns.

CONCLUSIONS

In this sample, the home food environment was more significant than the school food environment in predicting the dietary patterns. The availability of empty-calorie foods was associated with the unhealthy dietary pattern even when the availability of wholesome foods at home was high. Meals prepared away from home contributed to the unhealthy dietary pattern. Therefore, parents should be encouraged to limit the availability of empty-calorie foods and eating outside the home.

A Genetic Variant (COMT) Coding Dopaminergic Activity Predicts Personality Traits in Healthy Elderly

Association studies between the NEO five factor personality inventory and COMT rs4680 have focused on young adults and the results have been inconsistent. However, personality and cortical changes with age may put older adults in a more sensitive range for detecting a relationship. The present study examined associations of COMT rs4680 and personality in older adults. Genetic association analyses were carried out between the NEO and the targeted COMT rs4680 in a large, well-characterized sample of healthy, cognitively normal older adults (N = 616, mean age = 69.26 years). Three significant associations were found: participants with GG genotype showed lower mean scores on Neuroticism (p = 0.039) and higher scores on Agreeableness (p = 0.020) and Conscientiousness (p = 0.006) than participants with AA or AG genotypes. These results suggest that older adults with higher COMT enzymatic activity (GG), therefore lower dopamine level, have lower Neuroticism scores, and higher Agreeableness and Conscientiousness scores. This is consistent with a recent model of phasic and tonic dopamine release suggesting that even though GG genotype is associated with lower tonic dopamine release, the phasic release of dopamine might be optimal for a more adaptive personality profile.

Childhood Conscientiousness and Leukocyte Telomere Length 40 Years Later in Adult Women--Preliminary Findings of a Prospective Association

Leukocyte telomere length (LTL) shortens with age, and is a prospective marker of mortality related to cardiovascular disease. Many health behaviors and social environmental factors have been found to be associated with LTL. Several of these are also associated with conscientiousness, a dispositional personality trait. Conscientiousness is a propensity to be planful, adhere to social norms, and inhibit pre-potent responses. Like LTL, conscientiousness is prospectively related to mortality, possibly through cumulative effects on health over the life course via multiple pathways. As a result, we hypothesized that childhood levels of conscientiousness would predict LTL prospectively in adulthood. We selected a sample of 60 women in the Hawaii Personality and Health Cohort; 30 described by their teachers as high on conscientiousness in childhood and 30 described as low on the trait. Dried blood spot samples collected in adulthood 40 years later were used as sources of DNA for the LTL assay. Conscientiousness was associated with longer LTL (p = .02). Controlling for age did not account for this association. Controlling for education and physiological dysregulation partially attenuated the association, and the effect remained significant when accounting for differences in LTL across cultural groups. These results represent the first evidence that childhood personality prospectively predicts LTL 40 years later in adulthood. Our findings would be consistent with a mediation hypothesis whereby conscientiousness predicts life paths and trajectories of health that are reflected in rates of LTL erosion across the lifespan.

The Impact of Genetics on Physical Resilience and Successful Aging

Objective: To better understand the impact of genetics on resilience and successful aging, we tested a model of successful aging. Method: This was a descriptive study with a single interview and blood draw done with residents in a continuing care retirement community. Five genes associated with resilience were included in the model. The hypothesis was tested using structural equation modeling. Results: A total of 116 participants completed the survey. Two SNPs from SLC6A4 (rs25533 and rs1042173) and age were the only variables associated with physical resilience and explained 9% of the variance. Cognitive status, age, and depression were directly associated with successful aging; variance in rs25532 or rs1042173, resilience, and pain were indirectly associated with successful aging through depression. Discussion: Continued research to replicate these findings is needed so as to be able to recognize older adults at risk of low physical resilience and implement appropriate interventions.

Disorders without borders: current and future directions in the meta-structure of mental disorders

PURPOSE

Classification is the cornerstone of clinical diagnostic practice and research. However, the extant psychiatric classification systems are not well supported by research evidence. In particular, extensive comorbidity among putatively distinct disorders flags an urgent need for fundamental changes in how we conceptualize psychopathology. Over the past decade, research has coalesced on an empirically based model that suggests many common mental disorders are structured according to two correlated latent dimensions: internalizing and externalizing.

METHODS

We review and discuss the development of a dimensional-spectrum model which organizes mental disorders in an empirically based manner. We also touch upon changes in the DSM-5 and put forward recommendations for future research endeavors.

RESULTS

Our review highlights substantial empirical support for the empirically based internalizing-externalizing model of psychopathology, which provides a parsimonious means of addressing comorbidity.

CONCLUSIONS

As future research goals, we suggest that the field would benefit from: expanding the meta-structure of psychopathology to include additional disorders, development of empirically based thresholds, inclusion of a developmental perspective, and intertwining genomic and neuroscience dimensions with the empirical structure of psychopathology.

Transdiagnostic factors of psychopathology and substance use disorders: a review

PURPOSE

Research on the structure of mental disorders and comorbidity indicates that many forms of psychopathology and substance use disorders are manifestations of relatively few transdiagnostic latent factors. These factors have important consequences for mental disorder research and applied practice.

METHODS

We provide an overview of the transdiagnostic factor literature, with particular focus on recent advances.

RESULTS

Internalizing and externalizing transdiagnostic factors have been well characterized in terms of their structures, links with disorders, stability, and statistical properties (e.g., invariance and distributions). Research on additional transdiagnostic factors, such as thought disorder, is quickly advancing latent structural models, as are integrations of transdiagnostic constructs with personality traits. Genetically informed analyses continue to clarify the origins of transdiagnostic factor levels, and links between these factors and important environmental exposures provide promising new avenues of inquiry.

CONCLUSIONS

Transdiagnostic factors account for the development and continuity of disorders and comorbidity over time, function as the primary links between disorders and important outcomes such as suicide, mediate associations between environmental exposures and disorders, provide an empirically supported classification system, and serve as foci for efficient, broadband intervention approaches. Overall, transdiagnostic factor research indicates the paramount importance of understanding these constructs and, thereby, broadening our understanding of mental disorder in general.

What Drives Adult Personality Development? A Comparison of Theoretical Perspectives and Empirical Evidence

Increasing numbers of empirical studies provide compelling evidence that personality traits change across the entire lifespan. What initiates this continuing personality development and how does this development proceed? In this paper, we compare six theoretical perspectives that offer testable predictions about why personality develops the way it does and identify limitations and potentials of these perspectives by reviewing how they hold up against the empirical evidence. While all of these perspectives have received some empirical support, there is only little direct evidence for propositions put forward by the five–factor theory of personality and the theory of genotype → environment effects. In contrast, the neo–socioanalytic theory appears to offer a comprehensive framework that fits the empirical findings and allows the integration of other, more specialized, perspectives that focus on specific aspects of personality development like the role of time, systematic differences between categories of social roles or the active partake of the person himself or herself. We draw conclusions on the likely driving factors for adult personality development and identify avenues for future research. Copyright © 2014 European Association of Personality Psychology

Modulation of human longevity by SIRT3 single nucleotide polymorphisms in the prospective study "Treviso Longeva (TRELONG)"

Human sirtuins are seven proteins with deacetylase activity that are emerging as key modulators of basic physiological functions. Some evidence links SIRT3 to longevity in mammals. This study aimed to investigate whether variants within SIRT3 gene were associated to human longevity. We analyzed 549 genomic DNA collected during the prospective study "Treviso Longeva," including elderly over 70 years of age from the municipality of Treviso, a small city in the northeast of Italy. We genotyped SIRT3 rs3825075, rs4980329, and rs11555236 single nucleotide polymorphisms (SNPs) by real-time polymerase chain reaction allelic discrimination assay. A cross-sectional analysis performed by comparing people over and under 85 years of age did not evidence association among the SIRT3 SNPs and longevity. However, when we performed a longitudinal analysis considering mortality as a dependent variable, we observed an association of SIRT3 rs11555236 and rs4980329 with longevity in the whole population (p values corrected for potential confounders = 0.04 and 0.03, respectively). After stratification according to gender, the same SNPs were associated to female longevity only (p values corrected for potential confounders = 0.03 and 0.02, respectively). Finally, as rs11555236 was reported to be in linkage disequilibrium with a putative functional enhancer within the SIRT3 gene, we assessed whether rs11555236 genotypes correlated with a different level of SIRT3 protein in peripheral blood mononuclear cells. We found an increased level of SIRT3 in subjects homozygous for the (T) allele. We suggest that SIRT3 genetic variability might be relevant for the modulation of human longevity in the Italian population.

Impact of hip fracture on mortality: a cohort study in hip fracture discordant identical twins

Several studies have shown a long-lasting higher mortality after hip fracture, but the reasons for the excess risk are not well understood. We aimed to determine whether a higher mortality after hip fracture exists when controlling for genetic constitution, shared environment, comorbidity, and lifestyle by use of a nationwide cohort study in hip fracture discordant monozygotic twins. All 286 identical Swedish twin pairs discordant for hip fracture (1972 to 2010) were identified. Comorbidity and lifestyle information was retrieved by registers and questionnaire information. We used intrapair Cox regression to compute multivariable-adjusted hazard ratios (HRs) for death. During follow-up, 143 twins with a hip fracture died (50%) compared with 101 twins (35%) without a hip fracture. Through the first year after hip fracture, the rate of death increased fourfold in women (HR = 3.71; 95% confidence interval [CI] 1.32-10.40) and sevenfold in men (HR = 6.67; 95% CI 1.47-30.13). The increased rate in women only persisted during the first year after hip fracture (HR after 1 year = 0.99; 95% CI 0.66-1.50), whereas the corresponding HR in men was 2.58 (95% CI 1.02-6.62). The higher risk in men after the hip fracture event was successively attenuated during follow-up. After 5 years, the hazard ratio in men with a hip fracture was 1.19 (95% CI 0.29-4.90). On average, the hip fracture contributed to 0.9 years of life lost in women (95% CI 0.06-1.7) and 2.7 years in men (95% CI 1.7-3.7). The potential years of life lost associated with the hip fracture was especially pronounced in older men (>75 years), with an average loss of 47% (95% CI 31-61) of the expected remaining lifetime. We conclude that both women and men display a higher mortality after hip fracture independent of genes, comorbidity, and lifestyle.

DRD4 genotype predicts longevity in mouse and human

Longevity is influenced by genetic and environmental factors. The brain's dopamine system may be particularly relevant, since it modulates traits (e.g., sensitivity to reward, incentive motivation, sustained effort) that impact behavioral responses to the environment. In particular, the dopamine D4 receptor (DRD4) has been shown to moderate the impact of environments on behavior and health. We tested the hypothesis that the DRD4 gene influences longevity and that its impact is mediated through environmental effects. Surviving participants of a 30-year-old population-based health survey (N = 310; age range, 90-109 years; the 90+ Study) were genotyped/resequenced at the DRD4 gene and compared with a European ancestry-matched younger population (N = 2902; age range, 7-45 years). We found that the oldest-old population had a 66% increase in individuals carrying the DRD4 7R allele relative to the younger sample (p = 3.5 × 10(-9)), and that this genotype was strongly correlated with increased levels of physical activity. Consistent with these results, DRD4 knock-out mice, when compared with wild-type and heterozygous mice, displayed a 7-9.7% decrease in lifespan, reduced spontaneous locomotor activity, and no lifespan increase when reared in an enriched environment. These results support the hypothesis that DRD4 gene variants contribute to longevity in humans and in mice, and suggest that this effect is mediated by shaping behavioral responses to the environment.