To determine change in the prevalence of functional limitations and physical disability in community-dwelling elders across three decades.
We studied original participants of the Framingham Study, aged 79 to 88 years, at exam 15 (1977–1979, 177 women, 103 men), exam 20 (1988–1990, 159 women, 98 men) and exam 25 (1997 to 1999, 174 women, 119 men). Self-reported 1) functional limitation defined using the Nagi scale and 2) physical disability defined using the Rosow-Breslau and Katz scales.
Functional limitations declined across examinations from 74.6% to 60.5% to 37.9% (p< 0.001) in women and 54.2%, 37.8%, and 27.8% (p<0.001) in men. Physical disability declined from 74.5% to 48.5% to 34.6% (p< 0.001) in women and 42.3% to 33.3% to 22.8% (p=0.009) in men. Women had a greater decline in disability than men (p=0.03). In women, improvements in functional limitations (p=0.05) were greater from exam 20 to 25 whereas for physical disability (p=0.02) improvements were greater from exam 15 to 20. Improvements in function were constant across the three examinations in men.
Among community-dwelling elders the prevalence of functional limitations and physical disability declined significantly from the 1970s to the 1990s.
functional limitations; physical disability; trends; elders
We examined the relation between objectively measured physical activity with accelerometry and subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) in a community‐based sample.
Methods and Results
We evaluated 1249 participants of the Framingham Third Generation and Omni II cohorts (mean age 51.7 years, 47% women) who underwent assessment of moderate‐to‐vigorous physical activity (MVPA) with accelerometry over 5 to 7 days, and multi‐detector computed tomography for measurement of SAT and VAT volume; fat attenuation was estimated by SAT and VAT hounsfield units (HU). In women, higher levels of MVPA were associated with decreased SAT (P<0.0001) and VAT volume (P<0.0001). The average decrement in VAT per 30 minute/day increase in MVPA was −453 cm3 (95% CI −574, −331). The association was attenuated but persisted upon adjustment for BMI (−122 cm3, P=0.002). Higher levels of MVPA were associated with higher SAT HU (all P≤0.01), a marker of fat quality, even after adjustment for SAT volume. Similar findings were observed in men but the magnitude of the association was less. Sedentary time was not associated with SAT or VAT volume or quality in men or women.
MVPA was associated with less VAT and SAT and better fat quality.
accelerometry; physical activity; visceral adipose tissue
To examine the relation between measures of adiposity and depressive symptoms in a large well characterized community-based sample, we examined the relations of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) to depressive symptoms in 1581 women (mean age 52.2 years) and 1718 men (mean age 49.8 years) in the Framingham Heart Study. Depressive symptoms were measured using the Center for Epidemiologic Studies Depression (CES-D) scale. Regression models were created to examine the association between each fat depot (exposure) and depressive symptoms (outcome). Sex specific models were adjusted for age, body mass index, smoking, alcohol consumption, diabetes, hypertension, total and HDL cholesterol, lipid lowering treatment, CVD, menopause, C-reactive protein, and physical activity. Mean CES-D scores were 6.8 and 5.6 in women and men. High levels of depressive symptoms were present in 22.5% of women and 12.3% of men. In women, one standard deviation increase in VAT was associated with a 1.3 point higher CES-D score after adjusting for age and BMI (p<0.01) and remained significant in the fully adjusted model (p=0.03). The odds ratio of depressive symptoms per 1 standard deviation increase in VAT in women was 1.33 (p=0.015); results were attenuated in fully adjusted models (OR 1.29, p=0.055). In men, the association between VAT and CES-D score and depressive symptoms was not significant. SAT was not associated with CES-D score or depressive symptoms. This study supports an association between VAT and depressive symptoms in women. Further work is needed to uncover the complex biologic mechanisms mediating the association.
Genetic factors clearly contribute to exceptional longevity and healthy aging in humans, yet the identification of the underlying genes remains a challenge. Longevity is a complex phenotype with modest heritability. Age-related phenotypes with higher heritability may have greater success in gene discovery. Candidate gene and genome-wide association studies (GWAS) for longevity have had only limited success to date. The Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium conducted a meta-analysis of GWAS data for longevity, defined as survival to age 90 years or older, that identified several interesting associations but none achieved genome-wide significance. A recent GWAS of longevity conducted in the Leiden Longevity Study identified the ApoE E4 isoform as deleterious to longevity that was confirmed in an independent GWAS of long-lived individuals of German descent. Notably, no other genetic loci for longevity have been identified in these GWAS. To examine the conserved genetic mechanisms between the mouse and humans for life span, we mapped the top Cohorts for Heart and Aging Research in Genomic Epidemiology GWAS associations for longevity to the mouse chromosomal map and noted that eight of the ten top human associations were located within a previously reported mouse life-span quantitative trait loci. This work suggests that the mouse and human may share mechanisms leading to aging and that the mouse model may help speed the understanding of how genes identified in humans affect the biology of aging. We expect these ongoing collaborations and the translational work with basic scientists to accelerate the identification of genes that delay aging and promote a healthy life span.
Longevity; Genetics; Epidemiological studies
Little is known about the familial aggregation of intermittent claudication (IC). Our objective was to examine whether parental IC increased adult offspring risk of IC independent of established cardiovascular risk factors. We evaluated Offspring cohort participants of the Framingham Heart Study (FHS) who were 30 years or older, cardiovascular disease (CVD) free, and had both parents enrolled in the FHS (n= 2970 unique participants, 53% women). Pooled proportional hazards regression was used to examine whether the 12 year risk for incident IC in offspring participants was associated with parental IC adjusting for age, sex, diabetes, smoking, systolic blood pressure, total cholesterol, high density lipoprotein (HDL) cholesterol, anti-hypertensive and lipid treatment. Among 909 person-exams in the parental IC history group and 5397 person-exams in the no parental IC history group there were 101 incident IC events (29 with parental IC history, 72 without parental IC history) during follow-up. Age and sex adjusted 12-year cumulative incidence rates per 1000 person-years were 5.08 (95% CI: 2.74; 7.33) and 2.34 (95% CI: 1.46; 3.19) in participants with and without parental IC history. Parental history of IC significantly increased the risk of incident IC in offspring (multivariable adjusted hazard ratio of 1.81, 95% CI 1.14, 2.88). The hazard ratio was unchanged with adjustment for occurrence of CVD (1.83, 95% CI 1.15, 2.91). In conclusion, IC in parents increases risk for IC in adult offspring independent of established risk factors. These data suggest a genetic component of peripheral artery disease and support future research into genetic causes.
claudication; peripheral artery disease; risk factors; family history
More than 100 loci have been identified for age at menarche by genome-wide association studies; however, collectively these explain only ∼3% of the trait variance. Here we test two overlooked sources of variation in 192,974 European ancestry women: low-frequency protein-coding variants and X-chromosome variants. Five missense/nonsense variants (in ALMS1/LAMB2/TNRC6A/TACR3/PRKAG1) are associated with age at menarche (minor allele frequencies 0.08–4.6%; effect sizes 0.08–1.25 years per allele; P<5 × 10−8). In addition, we identify common X-chromosome loci at IGSF1 (rs762080, P=9.4 × 10−13) and FAAH2 (rs5914101, P=4.9 × 10−10). Highlighted genes implicate cellular energy homeostasis, post-transcriptional gene silencing and fatty-acid amide signalling. A frequently reported mutation in TACR3 for idiopathic hypogonatrophic hypogonadism (p.W275X) is associated with 1.25-year-later menarche (P=2.8 × 10−11), illustrating the utility of population studies to estimate the penetrance of reportedly pathogenic mutations. Collectively, these novel variants explain ∼0.5% variance, indicating that these overlooked sources of variation do not substantially explain the ‘missing heritability' of this complex trait.
Previous studies have linked over 100 genomic loci to age-at-menarche but that work was restricted to common autosomal variation. Here, Lunetta et al. identify associations with rare protein-coding and X-linked variants, implicating new mechanisms that regulate puberty timing.
Public health recommendations advocate breastfeeding in infancy as a means to reduce later-life obesity. Several prior studies relating breastfeeding to cardiovascular risk factors have been limited by lack of adjustment for maternal and participant confounding factors.
We ascertained breastfeeding history via questionnaire from mothers enrolled in the Framingham Offspring Study. In their young to middle-aged adult children enrolled in the Framingham Third Generation, we examined the relations between maternal breastfeeding history (yes, no) to cardiovascular risk factors, including: body mass index (BMI), HDL cholesterol, total cholesterol, triglycerides, fasting blood glucose, systolic and diastolic blood pressure. We applied Generalized estimating equations (GEE) to account for sibling correlations and adjusted for maternal and participant lifestyle, education and cardiovascular risk factors.
In Third Generation participants (n=962, mean age=41 years, 54% women), 26% of their mothers reported breastfeeding. Compared to non-breastfed individuals, breastfed adult participants had lower multivariable-adjusted BMI [26.1 kg/m2 vs. 26.9 kg/m2, p=0.04] and higher HDL cholesterol levels [HDL 56.6 mg/dL vs. 53.7 mg/dL, p=0.01]. Upon additional adjustment for BMI the association between breastfeeding and HDL cholesterol was attenuated (p=0.09). Breastfeeding was not associated with total cholesterol, triglycerides, fasting blood glucose, systolic blood pressure or diastolic blood pressure.
Breastfeeding in infancy is inversely associated with adult BMI and positively associated with HDL cholesterol. Associations between breastfeeding and BMI may mediate the association between breastfeeding and HDL cholesterol.
Breastfeeding; lactation; risk factors; early nutrition; infancy; body mass index; HDL cholesterol
Emerging evidence suggests that different inflammatory biomarkers operate through distinct biologic mechanisms. We hypothesized that the relation to peripheral arterial disease (PAD) varies for individual markers.
In a community-based sample we measured 12 biomarkers including plasma CD40 ligand, fibrinogen, lipoprotein-associated phospholipase-A2 mass and activity, osteoprotegerin, P-selectin, and tumor necrosis factor receptor 2 (TNFR2); and serum C-reactive protein, intracellular adhesion molecule-1, interleukin-6, monocyte chemoattractant protein-1, and myeloperoxidase in Framingham Offspring Study participants (n=2800, 53% women, mean age 61 years). We examined the cross-sectional relation of the biomarker panel to PAD using 1) a global test of significance to determine whether at least one of 12 biomarkers was related to PAD using the TEST statement in the LOGISTIC procedure in SAS and 2) stepwise multivariable logistic regression with forward selection of markers with separate models for 1) ankle-brachial index (ABI) category (<0.9, 0.9 to 1.0, >1.0) and 2) presence of clinical PAD (intermittent claudication or lower extremity revascularization).
The group of inflammatory biomarkers were significantly related to both ABI and clinical PAD (p= 0.01 and p= 0.02, respectively, multi-marker adjusted global significance test). Multivariable forward elimination regression retained interleukin-6 and TNFR2 as significantly associated with PAD. For one standard deviation change in interleukin-6 and TNFR2 concentrations, there was a 1.21 (p=0.005) and 1.19 (p=0.009) increased odds of a change in ABI level respectively. Similar results were observed for clinical PAD.
Interleukin-6 and TNFR2 were significantly associated with PAD independent of established risk factors and each other, suggesting that each marker represents a distinct biologic pathway.
peripheral arterial disease; ankle-brachial index; interleukin-6; tumor necrosis factor receptor 2
Age at menopause marks the end of a woman's reproductive life and its timing associates with risks for cancer, cardiovascular and bone disorders. GWAS and candidate gene studies conducted in women of European ancestry have identified 27 loci associated with age at menopause. The relevance of these loci to women of African ancestry has not been previously studied. We therefore sought to uncover additional menopause loci and investigate the relevance of European menopause loci by performing a GWAS meta-analysis in 6510 women with African ancestry derived from 11 studies across the USA. We did not identify any additional loci significantly associated with age at menopause in African Americans. We replicated the associations between six loci and age at menopause (P-value < 0.05): AMHR2, RHBLD2, PRIM1, HK3/UMC1, BRSK1/TMEM150B and MCM8. In addition, associations of 14 loci are directionally consistent with previous reports. We provide evidence that genetic variants influencing reproductive traits identified in European populations are also important in women of African ancestry residing in USA.
Background: offspring of long-lived individuals have lower risk for dementia. We examined the relation between parental longevity and cognition and subclinical markers of brain ageing in community-dwelling adult offspring.
Methods: offspring participants with both parents in the Framingham Heart Study, aged ≥55 years and dementia-free underwent baseline and repeat neuropsychological (NP) testing and brain magnetic resonance imaging (MRI). Parental longevity was defined as having at least one parent survive to age ≥85 years. To test the association between parental longevity and measures of cognition and brain volumes, we used multivariable linear and logistic regression adjusting for age, sex, education and time to NP testing or brain MRI.
Results: of 728 offspring (mean age 66 years, 54% women), 407 (56%) had ≥1 parent achieve longevity. In cross-sectional analysis, parental longevity was associated with better scores on attention (beta 0.21 ± 0.08, P = 0.006) and a lower odds of extensive white matter hyperintensity on brain MRI (odds ratio 0.59, 95% CI: 0.38, 0.92, P = 0.019). The association with white matter hyperintensity was no longer significant in models adjusted for cardiovascular risk factors and disease. In longitudinal analysis (6.7 ± 1.7 years later), offspring with parental longevity had slower decline in attention (0.18 ± 0.08, P = 0.038), executive function (beta 0.19 ± 0.09, P = 0.031) and visual memory (beta −0.18 ± 0.08, P = 0.023), and less increase in temporal horn volume (beta −0.25 ± 0.09, P = 0.005). The associations persisted in fully adjusted models.
Conclusion: parental longevity is associated with better brain ageing in middle-aged offspring.
brain ageing; brain imaging; cognition; longevity; neuropsychological testing; older people; parental longevity
Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality1. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation2,3, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (P<5×10−8) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1/WDR25, MKRN3/MAGEL2 and KCNK9) demonstrating parent-of-origin specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and gamma-aminobutyric acid-B2 receptor signaling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition.
To identify non-redundant atrial fibrillation (AF) genetic susceptibility signals and examine their cumulative relations with AF risk.
AF-associated loci span broad genomic regions that may contain multiple susceptibility signals. Whether multiple signals exist at AF loci has not been systematically explored.
We performed association testing conditioned on the most significant, independently associated genetic markers at nine established AF loci using two complementary techniques in 64,683 individuals of European ancestry (3,869 incident and 3,302 prevalent AF cases). Genetic risk scores were created and tested for association with AF in Europeans and an independent sample of 11,309 individuals of Japanese ancestry (7,916 prevalent AF cases).
We observed at least four distinct AF susceptibility signals on chromosome 4q25 upstream of PITX2, but not at the remaining eight AF loci. A multilocus score comprised of 12 genetic markers demonstrated an estimated 5-fold gradient in AF risk. We observed a similar spectrum of risk associated with these markers in Japanese. Regions containing AF signals on chromosome 4q25 displayed a greater degree of evolutionary conservation than the remainder of the locus, suggesting that they may tag regulatory elements.
The chromosome 4q25 AF locus is architecturally complex and harbors at least four AF susceptibility signals in individuals of European ancestry. Similar polygenic AF susceptibility exists between Europeans and Japanese. Future work is necessary to identify causal variants, determine mechanisms by which associated loci predispose to AF, and explore whether AF susceptibility signals classify individuals at risk for AF and related morbidity.
Atrial fibrillation; atrial flutter; genetic; risk; prognosis
Endogenous sex hormones have been related to cardiovascular outcomes and mortality. We hypothesized that sex hormones are related to atrial fibrillation (AF) in a community-based cohort of middle-aged to older men.
Methods and Results
We examined testosterone, estradiol, and dehydroepiandrosterone sulfate [DHEA-S]) in relation to incident AF in men participating in the Framingham Heart Study. We assessed the 10-year risk of AF in multivariable-adjusted hazard models. The cohort consisted of 1251 men (age 68.0±8.2), of whom 275 developed incident AF. We identified a significant interaction between age and testosterone, and therefore stratified men into age 55–69 (n=786), 70–79 (n=351), and ≥80 (n=114). In men 55–69 each 1-standard deviation (SD) decrease in testosterone was associated with hazard ratio (HR) 1.30 (95% confidence interval [CI], 1.07 to 1.59) for incident AF. The association between testosterone and 10-year incident AF in men 70–79 did not reach statistical significance. In men ≥80 years a 1-SD decrease in testosterone was associated with HR 3.53 (95% CI, 1.96 to 6.37) for AF risk. Estradiol was associated with incident AF (HR, 1.12; 95% CI, 1.01 to 1.26). DHEA-S had a borderline association with risk of AF that was not statistically significant (HR, 1.12; 95% CI, 0.99 to 1.28).
Testosterone and estradiol are associated with incident AF in a cohort of older men. Testosterone deficiency in men ≥80 is strongly associated with AF risk. The clinical and electrophysiologic mechanisms underlying the associations between sex hormones and AF in older men merit continued investigation.
atrial fibrillation; sex hormones; men; aging; epidemiology
Obesity is heritable and predisposes to many diseases. To understand the genetic basis of obesity better, here we conduct a genome-wide association study and Metabochip meta-analysis of body mass index (BMI), a measure commonly used to define obesity and assess adiposity, in up to 339,224 individuals. This analysis identifies 97 BMI-associated loci (P < 5 × 10−8), 56 of which are novel. Five loci demonstrate clear evidence of several independent association signals, and many loci have significant effects on other metabolic phenotypes. The 97 loci account for ~2.7% of BMI variation, and genome-wide estimates suggest that common variation accounts for >20% of BMI variation. Pathway analyses provide strong support for a role of the central nervous system in obesity susceptibility and implicate new genes and pathways, including those related to synaptic function, glutamate signalling, insulin secretion/action, energy metabolism, lipid biology and adipogenesis.
As creatinine-based estimates of renal function are inaccurate in older adults, an alternative is an estimated glomerular filtration rate (eGFRcys) based on cystatin C. We examined the prospective association between chronic kidney disease (CKDcys) as determined by eGFRcys with the primary outcome of incident mobility disability and the secondary outcome of change in gait speed.
Framingham Offspring Study participants older than 60 years and free of mobility disability at baseline (1998–2001) were eligible. Baseline CKDcys was defined as eGFRcys less than 60 mL/min/1.73 m2. At follow-up (2005–2008), the outcomes of mobility disability, defined as self-reported inability to walk 1/2 mile and/or climb a flight of stairs, and gait speed were measured. Logistic and linear regression models were adjusted for age, sex, body mass index, smoking, diabetes, C reactive protein, and physical activity.
Of 1,226 participants, 230 (19%) had CKDcys at baseline. After a mean follow-up of 6.6 years, 185 (15%) developed mobility disability. Of those with CKDcys, 60 (26%) developed mobility disability. Those with CKDcys had greater odds of mobility disability in the age- and sex-adjusted (odds ratio [OR] 1.91, 95% CI 1.32, 2.75) and fully adjusted (OR 1.55, 95% CI 1.05, 2.31) models compared with those without CKDcys. In fully adjusted models, participants with CKDcys had greater gait speed declines than those without CKDcys (β = 0.07 [SE 0.02], p = .0022).
CKDcys was associated with higher odds of incident mobility disability and greater decline in gait speed, highlighting the loss of physical independence in elders with CKD.
Chronic kidney disease; Cystatin C; Disability; Gait speed.
An increased inter-arm systolic blood pressure difference is an easily determined physical examination finding. The relationship between inter-arm systolic blood pressure difference and risk of future cardiovascular disease is uncertain. We described the prevalence and risk factor correlates of inter-arm systolic blood pressure difference in the Framingham Heart Study (FHS) original and offspring cohorts and examined the association between inter-arm systolic blood pressure difference and incident cardiovascular disease and all-cause mortality.
An increased inter-arm systolic blood pressure difference was defined as ≥10mmHg using the average of initial and repeat blood pressure measurements obtained in both arms. Participants were followed through 2010 for incident cardiovascular disease events. Multivariable Cox proportional hazards regression analyses were performed to investigate the effect of inter-arm systolic blood pressure difference on incident cardiovascular disease.
We examined 3,390 (56.3% female) participants aged 40 years and older, free of cardiovascular disease at baseline, mean age of 61.1 years, who attended a FHS examination between 1991 and 1994 (original cohort) and from 1995 to 1998 (offspring cohort). The mean absolute inter-arm systolic blood pressure difference was 4.6 mmHg (range 0 to 78). Increased inter-arm systolic blood pressure difference was present in 317 (9.4%) participants. The median follow-up time was 13.3 years, during which time 598 participants (17.6%) experienced a first cardiovascular event including 83 (26.2%) participants with inter-arm systolic blood pressure difference ≥10 mmHg. Compared to those with normal inter-arm systolic blood pressure difference, participants with an elevated inter-arm systolic blood pressure difference were older (63.0 years vs. 60.9 years), had a greater prevalence of diabetes mellitus (13.3% vs. 7.5%,), higher systolic blood pressure (136.3 mmHg vs. 129.3 mmHg), and a higher total cholesterol level (212.1 mg/dL vs. 206.5 mg/dL). Inter-arm systolic blood pressure difference was associated with a significantly increased hazard of incident cardiovascular events in the multivariable adjusted model (hazard ratio 1.38, 95% CI, 1.09 to 1.75). For each 1-standard deviation unit increase in absolute interarm systolic blood pressure difference, the hazard ratio for incident cardiovascular events was 1.07 (CI, 1.00 to 1.14) in the fully-adjusted model. There was no such association with mortality (hazard ratio 1.02, 95% CI 0.76 to 1.38).
In this community-based cohort, an inter-arm systolic blood pressure difference is common and associated with a significant increased risk for future cardiovascular events, even when the absolute difference in arm systolic blood pressure is modest. These findings support research to expand clinical use of this simple measurement.
inter-arm blood pressure difference; cardiovascular risk; cardiovascular disease
Physical activity is associated with several health benefits, including lower cardiovascular disease risk. The independent influence of physical activity on cardiac and vascular function in the community, however, has been sparsely investigated.
Measures and Results
We related objective measures of moderate‐ to vigorous‐intensity physical activity (MVPA, assessed by accelerometry) to cardiac and vascular indices in 2376 participants of the Framingham Heart Study third generation cohort (54% women, mean age 47 years). Using multivariable regression models, we related MVPA to the following echocardiographic and vascular measures: left ventricular mass, left atrial and aortic root sizes, carotid–femoral pulse wave velocity, augmentation index, and forward pressure wave. Men and women engaged in MVPA 29.9±21.4 and 25.5±19.4 min/day, respectively. Higher values of MVPA (per 10‐minute increment) were associated with lower carotid–femoral pulse wave velocity (estimate −0.53 ms/m; P=0.006) and lower forward pressure wave (estimate −0.23 mm Hg; P=0.03) but were not associated with augmentation index (estimate 0.13%; P=0.25). MVPA was associated positively with loge left ventricular mass (estimate 0.006 loge [g/m2]; P=0.0003), left ventricular wall thickness (estimate 0.07 mm; P=0.0001), and left atrial dimension (estimate 0.10 mm; P=0.01). MVPA also tended to be positively associated with aortic root dimension (estimate 0.05 mm; P=0.052). Associations of MVPA with cardiovascular measures were similar, in general, for bouts lasting <10 versus ≥10 minutes.
In our community‐based sample, greater physical activity was associated with lower vascular stiffness but with higher echocardiographic left ventricular mass and left atrial size. These findings suggest complex relations of usual levels of physical activity and cardiovascular remodeling.
echocardiography; epidemiology; physical activity; vascular measures
Coronary artery calcification (CAC) detected by computed tomography is a non-invasive measure of coronary atherosclerosis, that underlies most cases of myocardial infarction (MI). We aimed to identify common genetic variants associated with CAC and further investigate their associations with MI.
Methods and Results
Computed tomography was used to assess quantity of CAC. A meta-analysis of genome-wide association studies for CAC was carried out in 9,961 men and women from five independent community-based cohorts, with replication in three additional independent cohorts (n=6,032). We examined the top single nucleotide polymorphisms (SNPs) associated with CAC quantity for association with MI in multiple large genome-wide association studies of MI. Genome-wide significant associations with CAC for SNPs on chromosome 9p21 near CDKN2A and CDKN2B (top SNP: rs1333049, P=7.58×10−19) and 6p24 (top SNP: rs9349379, within the PHACTR1 gene, P=2.65×10−11) replicated for CAC and for MI. Additionally, there is evidence for concordance of SNP associations with both CAC and with MI at a number of other loci, including 3q22 (MRAS gene), 13q34 (COL4A1/COL4A2 genes), and 1p13 (SORT1 gene).
SNPs in the 9p21 and PHACTR1 gene loci were strongly associated with CAC and MI, and there are suggestive associations with both CAC and MI of SNPs in additional loci. Multiple genetic loci are associated with development of both underlying coronary atherosclerosis and clinical events.
cardiac computed tomography; coronary artery calcification; coronary atherosclerosis; genome-wide association studies; myocardial infarction
DNA methylation levels change with age. Recent studies have identified biomarkers of chronological age based on DNA methylation levels. It is not yet known whether DNA methylation age captures aspects of biological age.
Here we test whether differences between people’s chronological ages and estimated ages, DNA methylation age, predict all-cause mortality in later life. The difference between DNA methylation age and chronological age (Δage) was calculated in four longitudinal cohorts of older people. Meta-analysis of proportional hazards models from the four cohorts was used to determine the association between Δage and mortality. A 5-year higher Δage is associated with a 21% higher mortality risk, adjusting for age and sex. After further adjustments for childhood IQ, education, social class, hypertension, diabetes, cardiovascular disease, and APOE e4 status, there is a 16% increased mortality risk for those with a 5-year higher Δage. A pedigree-based heritability analysis of Δage was conducted in a separate cohort. The heritability of Δage was 0.43.
DNA methylation-derived measures of accelerated aging are heritable traits that predict mortality independently of health status, lifestyle factors, and known genetic factors.
Electronic supplementary material
The online version of this article (doi:10.1186/s13059-015-0584-6) contains supplementary material, which is available to authorized users.
It has been well-established, both by population genetics theory and direct observation in many organisms, that increased genetic diversity provides a survival advantage. However, given the limitations of both sample size and genome-wide metrics, this hypothesis has not been comprehensively tested in human populations. Moreover, the presence of numerous segregating small effect alleles that influence traits that directly impact health directly raises the question as to whether global measures of genomic variation are themselves associated with human health and disease.
We performed a meta-analysis of 17 cohorts followed prospectively, with a combined sample size of 46,716 individuals, including a total of 15,234 deaths. We find a significant association between increased heterozygosity and survival (P = 0.03). We estimate that within a single population, every standard deviation of heterozygosity an individual has over the mean decreases that person’s risk of death by 1.57%.
This effect was consistent between European and African ancestry cohorts, men and women, and major causes of death (cancer and cardiovascular disease), demonstrating the broad positive impact of genomic diversity on human survival.
Electronic supplementary material
The online version of this article (doi:10.1186/s12863-014-0159-7) contains supplementary material, which is available to authorized users.
Heterozygosity; Human; Survival; GWAS
Whereas greater physical activity (PA) is known to prevent cardiovascular disease (CVD), the relative importance of performing PA in sustained bouts of activity versus shorter bouts of activity on CVD risk is not known. The objective of this study was to investigate the relationship between moderate-to-vigorous physical activity (MVPA), measured in bouts ≥10 minutes and <10 minutes, and CVD risk factors in a well-characterized, community-based sample of white adults.
We conducted a cross-sectional analysis of 2109 Framingham Heart Study Third Generation participants (mean age 47 years, 55% women) who underwent objective assessment of PA by accelerometry over 5–7 days. Total MVPA, MVPA done in bouts ≥10 minutes (MVPA10+), and MVPA done in bouts <10 minutes (MVPA<10) were calculated. MVPA exposures were related to individual CVD risk factors, including measures of adiposity and blood lipid and glucose levels, using linear and logistic regression.
Total MVPA was significantly associated with higher high-density lipoprotein (HDL) levels, and with lower triglycerides, BMI, waist circumference and Framingham risk score (P <0.0001). MVPA<10 showed similar statistically significant associations with these CVD risk factors (P <0.001). Compliance with national guidelines (≥150 minutes of total MVPA) was significantly related to lower BMI, triglycerides, Framingham risk score, waist circumference, higher HDL, and a lower prevalence of obesity and impaired fasting glucose (P < 0.001 for all).
Our cross-sectional observations on a large middle-aged community-based sample confirm a positive association of MVPA with a healthier CVD risk factor profile, and indicate that accruing physical activity in bouts <10 minutes may favorably influence cardiometabolic risk. Additional investigations are warranted to confirm our findings.
accelerometer; heart disease; exercise; guidelines
Emerging data from longitudinal studies suggests that low sex steroid concentrations in men are associated with increased cardiovascular risk and mortality. The impact of longitudinal trajectory patterns from serial sex steroid and gonadotropin measurements on the observed associations is unknown to date.
We prospectively evaluated 254 elderly men (mean age: 75.5 years) of the Framingham Heart Study with up to four serial measurements of serum total testosterone (TT), dehydroepiandrosterone sulfate (DHEAS), follicle stimulating hormone (FSH), luteinizing hormone (LH), and total estradiol (EST); and constructed age- and multivariable-adjusted Cox proportional hazard regression models relating baseline hormone concentrations and their mean, slope, and variation over time (modelled as continuous and categorized into quartiles) to the incidence of clinical cardiovascular disease (CVD) and all-cause mortality at 5-years and 10-years of follow-up.
We observed no association between baseline concentrations of sex steroids, gonadotropins, and their trajectories with incident clinical CVD over 5-years and 10-years follow-up, respectively. Although higher baseline TT concentrations were associated with lower mortality risk at 5-years (hazard ratio per quartile increment, 0.74; 95% confidence interval, 0.56 – 0.98), correction for multiple statistical testing (p <0.005) rendered this association statistically non-significant. Repeat analyses at the 10-year follow-up time point also demonstrated no significant association between sex steroids, gonadotropins, or their trajectories and mortality.
Investigating longitudinal trajectory patterns of serial sex steroid and gonadotropin measurements, the present study found no consistent associations with incident clinical CVD and all-cause mortality risk in elderly men in the community.
sex steroids; gonadotropins; testosterone; men; cardiovascular disease; trajectories; longitudinal; Framingham Heart Study
To determine whether ectopic fat depots are prospectively associated with cardiovascular disease, cancer and all-cause mortality.
The morbidity associated with excess body weight varies among individuals of similar body mass index. Ectopic fat depots may underlie this risk differential. However, prospective studies of directly measured fat are limited.
Participants from the Framingham Heart Study (n=3086, 49% women, mean age 50.2 years) underwent assessment of fat depots (visceral adipose tissue, pericardial adipose tissue, and periaortic adipose tissue) using multidetector computed tomography, and were followed longitudinally for a median of 5.0 years. Cox proportional hazards regression models were used to examine the association of each fat depot (per 1 standard deviation increment) with the risk of incident cardiovascular disease, cancer, and all-cause mortality after adjustment for standard risk factors, including body mass index.
Overall, there were 90 cardiovascular events, 141 cancer events, and 71 deaths. After multivariable adjustment, visceral adipose tissue was associated with cardiovascular disease (HR 1.44, 95% CI 1.08–1.92, p=0.01) and cancer (HR 1.43, 95% CI 1.12–1.84, p=0.005). Addition of visceral adipose tissue to a multivariable model that included body mass index modestly improved cardiovascular risk prediction (net reclassification improvement of 16.3%). None of the fat depots were associated with all-cause mortality.
Visceral adiposity is associated with incident cardiovascular disease and cancer after adjustment for clinical risk factors and generalized adiposity. These findings support the growing appreciation of a pathogenic role of ectopic fat.
obesity; visceral fat; body fat distribution; cardiovascular disease; cancer
African-American (AA) women have earlier menarche on average than women of European ancestry (EA), and earlier menarche is a risk factor for obesity and type 2 diabetes among other chronic diseases. Identification of common genetic variants associated with age at menarche has a potential value in pointing to the genetic pathways underlying chronic disease risk, yet comprehensive genome-wide studies of age at menarche are lacking for AA women. In this study, we tested the genome-wide association of self-reported age at menarche with common single-nucleotide polymorphisms (SNPs) in a total of 18 089 AA women in 15 studies using an additive genetic linear regression model, adjusting for year of birth and population stratification, followed by inverse-variance weighted meta-analysis (Stage 1). Top meta-analysis results were then tested in an independent sample of 2850 women (Stage 2). First, while no SNP passed the pre-specified P < 5 × 10−8 threshold for significance in Stage 1, suggestive associations were found for variants near FLRT2 and PIK3R1, and conditional analysis identified two independent SNPs (rs339978 and rs980000) in or near RORA, strengthening the support for this suggestive locus identified in EA women. Secondly, an investigation of SNPs in 42 previously identified menarche loci in EA women demonstrated that 25 (60%) of them contained variants significantly associated with menarche in AA women. The findings provide the first evidence of cross-ethnic generalization of menarche loci identified to date, and suggest a number of novel biological links to menarche timing in AA women.
Obesity is of global health concern. There are well-described inverse relationships between female pubertal timing and obesity. Recent genome-wide association studies of age at menarche identified several obesity-related variants. Using data from the ReproGen Consortium, we employed meta-analytical techniques to estimate the associations of 95 a priori and recently identified obesity-related (body mass index (weight (kg)/height (m)2), waist circumference, and waist:hip ratio) single-nucleotide polymorphisms (SNPs) with age at menarche in 92,116 women of European descent from 38 studies (1970–2010), in order to estimate associations between genetic variants associated with central or overall adiposity and pubertal timing in girls. Investigators in each study performed a separate analysis of associations between the selected SNPs and age at menarche (ages 9–17 years) using linear regression models and adjusting for birth year, site (as appropriate), and population stratification. Heterogeneity of effect-measure estimates was investigated using meta-regression. Six novel associations of body mass index loci with age at menarche were identified, and 11 adiposity loci previously reported to be associated with age at menarche were confirmed, but none of the central adiposity variants individually showed significant associations. These findings suggest complex genetic relationships between menarche and overall obesity, and to a lesser extent central obesity, in normal processes of growth and development.
adiposity; body mass index; genetic association studies; menarche; obesity; waist circumference; waist:hip ratio; women's health