Meta-analysis identifies 13 new loci associated with waist-hip ratio and reveals sexual dimorphism in the genetic basis of fat distribution

Waist-hip ratio (WHR) is a measure of body fat distribution and a predictor of metabolic consequences independent of overall adiposity. WHR is heritable, but few genetic variants influencing this trait have been identified. We conducted a meta-analysis of 32 genome-wide association studies for WHR adjusted for body mass index (comprising up to 77,167 participants), following up 16 loci in an additional 29 studies (comprising up to 113,636 subjects). We identified 13 new loci in or near RSPO3, VEGFA, TBX15-WARS2, NFE2L3, GRB14, DNM3-PIGC, ITPR2-SSPN, LY86, HOXC13, ADAMTS9, ZNRF3-KREMEN1, NISCH-STAB1 and CPEB4 (P = 1.9 × 10⁻⁹ to P = 1.8 × 10⁻⁴⁰) and the known signal at LYPLAL1. Seven of these loci exhibited marked sexual dimorphism, all with a stronger effect on WHR in women than men (P for sex difference = 1.9 × 10⁻³ to P = 1.2 × 10⁻¹³). These findings provide evidence for multiple loci that modulate body fat distribution independent of overall adiposity and reveal strong gene-by-sex interactions.

Presence of comorbid somatic disorders among patients referred to mental health care in the Netherlands

OBJECTIVE

Referral to mental health care was examined among persons with mental disorders with and without comorbid somatic conditions to determine whether certain conditions may make detection of mental disorders by primary care physicians more or less likely.

METHODS

Receipt of mental health care in the primary and specialty care settings by respondents to the Netherlands Mental Health Survey and Incidence Study who had mood disorders (N=573), anxiety disorders (N=912), and substance use disorders (N=533) was examined, first broadly by any of 31 somatic conditions and then by each of the five most common conditions.

RESULTS

Broadly, those with anxiety disorders and a somatic condition were more likely to use care in both settings (adjusted relative risk ratios [RRRs]=1.75 and 1.58 for primary and specialty care, respectively), and those with substance use disorders and a somatic condition were more likely to use specialty care (RRR=2.15). More narrowly, use of specialty care by persons with mood disorders was three times as likely for those with rheumatoid arthritis or a digestive tract disorder (RRRs=3.04 and 2.92). For anxiety disorders, specialty care was more likely for those with chronic backache (RRR=2.14) or a digestive tract disorder (RRR=3.56). For substance use disorders, those with chronic backache were six times as likely to use specialty care (RRR=6.05) and those with a digestive tract disorder were three times as likely (RRR=3.09).

CONCLUSIONS

Poor somatic health in general seemed to increase the likelihood of use of mental health care for persons with anxiety or substance use disorders, but not for those with mood disorders. Having certain somatic conditions appeared to enhance recognition and treatment of three common mental disorders.

Genome-wide association study of blood pressure extremes identifies variant near UMOD associated with hypertension

Hypertension is a heritable and major contributor to the global burden of disease. The sum of rare and common genetic variants robustly identified so far explain only 1%–2% of the population variation in BP and hypertension. This suggests the existence of more undiscovered common variants. We conducted a genome-wide association study in 1,621 hypertensive cases and 1,699 controls and follow-up validation analyses in 19,845 cases and 16,541 controls using an extreme case-control design. We identified a locus on chromosome 16 in the 5′ region of Uromodulin (UMOD; rs13333226, combined P value of 3.6×10⁻¹¹). The minor G allele is associated with a lower risk of hypertension (OR [95%CI]: 0.87 [0.84–0.91]), reduced urinary uromodulin excretion, better renal function; and each copy of the G allele is associated with a 7.7% reduction in risk of CVD events after adjusting for age, sex, BMI, and smoking status (H.R. = 0.923, 95% CI 0.860–0.991; p = 0.027). In a subset of 13,446 individuals with estimated glomerular filtration rate (eGFR) measurements, we show that rs13333226 is independently associated with hypertension (unadjusted for eGFR: 0.89 [0.83–0.96], p = 0.004; after eGFR adjustment: 0.89 [0.83–0.96], p = 0.003). In clinical functional studies, we also consistently show the minor G allele is associated with lower urinary uromodulin excretion. The exclusive expression of uromodulin in the thick portion of the ascending limb of Henle suggests a putative role of this variant in hypertension through an effect on sodium homeostasis. The newly discovered UMOD locus for hypertension has the potential to give new insights into the role of uromodulin in BP regulation and to identify novel drugable targets for reducing cardiovascular risk.

Hypertension is the leading contributor to global mortality with a global prevalence of 26.4% in 2000, projected to increase to 29.2% by 2025. While 50%–60% of population variation in blood pressure can be attributable to additive genetic factors, all the genetic variants robustly identified so far explain only 1%–2% of the population variance indicating the presence of additional undiscovered risk variants. Using an extreme case-control strategy, we have discovered a SNP in the promoter region of the uromodulin gene (UMOD) to be associated with hypertension (minor allele protective against hypertension). We then validated this association using large-scale population and case-control studies, where similar extreme criteria for selection of cases and controls have been used (21,466 cases and 18,240 controls). As the locus was related to uromodulin, a protein exclusively expressed in the kidneys, we show that the association is independent of renal dysfunction. We also show preliminary evidence that the SNP allele which is protective against hypertension is also protective against cardiovascular events in 26,654 Swedish subjects followed-up for 12 years. The newly discovered UMOD locus for hypertension has the potential to give unique insights into the role of uromodulin in BP regulation and to identify novel drugable targets.

Hundreds of variants clustered in genomic loci and biological pathways affect human height

Most common human traits and diseases have a polygenic pattern of inheritance: DNA sequence variants at many genetic loci influence the phenotype. Genome-wide association (GWA) studies have identified more than 600 variants associated with human traits, but these typically explain small fractions of phenotypic variation, raising questions about the use of further studies. Here, using 183,727 individuals, we show that hundreds of genetic variants, in at least 180 loci, influence adult height, a highly heritable and classic polygenic trait. The large number of loci reveals patterns with important implications for genetic studies of common human diseases and traits. First, the 180 loci are not random, but instead are enriched for genes that are connected in biological pathways (P = 0.016) and that underlie skeletal growth defects (P < 0.001). Second, the likely causal gene is often located near the most strongly associated variant: in 13 of 21 loci containing a known skeletal growth gene, that gene was closest to the associated variant. Third, at least 19 loci have multiple independently associated variants, suggesting that allelic heterogeneity is a frequent feature of polygenic traits, that comprehensive explorations of already-discovered loci should discover additional variants and that an appreciable fraction of associated loci may have been identified. Fourth, associated variants are enriched for likely functional effects on genes, being over-represented among variants that alter amino-acid structure of proteins and expression levels of nearby genes. Our data explain approximately 10% of the phenotypic variation in height, and we estimate that unidentified common variants of similar effect sizes would increase this figure to approximately 16% of phenotypic variation (approximately 20% of heritable variation). Although additional approaches are needed to dissect the genetic architecture of polygenic human traits fully, our findings indicate that GWA studies can identify large numbers of loci that implicate biologically relevant genes and pathways.

Genome-wide association analysis identifies multiple loci related to resting heart rate

Higher resting heart rate is associated with increased cardiovascular disease and mortality risk. Though heritable factors play a substantial role in population variation, little is known about specific genetic determinants. This knowledge can impact clinical care by identifying novel factors that influence pathologic heart rate states, modulate heart rate through cardiac structure and function or by improving our understanding of the physiology of heart rate regulation. To identify common genetic variants associated with heart rate, we performed a meta-analysis of 15 genome-wide association studies (GWAS), including 38,991 subjects of European ancestry, estimating the association between age-, sex- and body mass-adjusted RR interval (inverse heart rate) and approximately 2.5 million markers. Results with P < 5 × 10(-8) were considered genome-wide significant. We constructed regression models with multiple markers to assess whether results at less stringent thresholds were likely to be truly associated with RR interval. We identified six novel associations with resting heart rate at six loci: 6q22 near GJA1; 14q12 near MYH7; 12p12 near SOX5, c12orf67, BCAT1, LRMP and CASC1; 6q22 near SLC35F1, PLN and c6orf204; 7q22 near SLC12A9 and UfSp1; and 11q12 near FADS1. Associations at 6q22 400 kb away from GJA1, at 14q12 MYH6 and at 1q32 near CD34 identified in previously published GWAS were confirmed. In aggregate, these variants explain approximately 0.7% of RR interval variance. A multivariant regression model including 20 variants with P < 10(-5) increased the explained variance to 1.6%, suggesting that some loci falling short of genome-wide significance are likely truly associated. Future research is warranted to elucidate underlying mechanisms that may impact clinical care.

A genomewide association study of nicotine and alcohol dependence in Australian and Dutch populations

Persistent tobacco use and excessive alcohol consumption are major public health concerns worldwide. Both alcohol and nicotine dependence (AD, ND) are genetically influenced complex disorders that exhibit a high degree of comorbidity. To identify gene variants contributing to one or both of these addictions, we first conducted a pooling-based genomewide association study (GWAS) in an Australian population, using Illumina Infinium 1M arrays. Allele frequency differences were compared between pooled DNA from case and control groups for: (1) AD, 1224 cases and 1162 controls; (2) ND, 1273 cases and 1113 controls; and (3) comorbid AD and ND, 599 cases and 488 controls. Secondly, we carried out a GWAS in independent samples from the Netherlands for AD and for ND. Thirdly, we performed a meta-analysis of the 10,000 most significant AD- and ND-related SNPs from the Australian and Dutch samples. In the Australian GWAS, one SNP achieved genomewide significance (p < 5 x 10(-8)) for ND (rs964170 in ARHGAP10 on chromosome 4, p = 4.43 x 10(-8)) and three others for comorbid AD/ND (rs7530302 near MARK1 on chromosome 1 (p = 1.90 x 10(-9)), rs1784300 near DDX6 on chromosome 11 (p = 2.60 x 10(-9)) and rs12882384 in KIAA1409 on chromosome 14 (p = 4.86 x 10(-8))). None of the SNPs achieved genomewide significance in the Australian/Dutch meta-analysis, but a gene network diagram based on the top-results revealed overrepresentation of genes coding for ion-channels and cell adhesion molecules. Further studies will be required before the detailed causes of comorbidity between AD and ND are understood.

Race, psychosocial factors, and aortic pulse wave velocity: the Health, Aging, and Body Composition Study

BACKGROUND

Increasingly, researchers have begun to explore pathways through which psychosocial factors might influence cardiovascular disease, with some emphasis on early markers. The current study examined the cross-sectional association between psychosocial factors and aortic pulse wave velocity (an early marker of cardiovascular disease) in a biracial cohort of older adults. We were particularly interested in determining whether the association between psychosocial factors and aortic pulse wave velocity differed for older blacks compared with whites.

METHODS

Participants were 2,488 (40% black and 52% female) older adults from the Health, Aging, and Body Composition Study. Carotid-femoral aortic pulse wave velocity was assessed using standard methodologies. Depressive symptoms, anxiety symptoms, negative life events, and inadequate emotional support were assessed, and a summary psychosocial risk index was created.

RESULTS

In multivariable linear regression models, psychosocial risk was not associated with aortic pulse wave velocity (Estimate [Est] = .00, p = .83), but there was a significant Race × Psychosocial risk interaction (Est = .07, p = .01), after adjusting for age, race, sex, and education. Further analyses revealed that this association was driven by the inadequate emotional support component of psychosocial risk (Race × Inadequate emotional support, p = .005). In race-stratified analyses, inadequate emotional support was associated with higher levels of arterial stiffness in older blacks (Est = .05, p = .04) but not whites (Est = -.04, p = .13). This association persisted after adjusting for demographics, cardiovascular risk factors, and social network characteristics.

CONCLUSIONS

Findings suggest that older blacks may be particularly vulnerable to the effects of inadequate emotional support on vascular health. Interventions aimed at increasing social support among this population might be beneficial in reducing cardiovascular disease risk.

Sequence variants at CHRNB3-CHRNA6 and CYP2A6 affect smoking behavior

Smoking is a common risk factor for many diseases. We conducted genome-wide association meta-analyses for the number of cigarettes smoked per day (CPD) in smokers (n = 31,266) and smoking initiation (n = 46,481) using samples from the ENGAGE Consortium. In a second stage, we tested selected SNPs with in silico replication in the Tobacco and Genetics (TAG) and Glaxo Smith Kline (Ox-GSK) consortia cohorts (n = 45,691 smokers) and assessed some of those in a third sample of European ancestry (n = 9,040). Variants in three genomic regions associated with CPD (P < 5 x 10(-8)), including previously identified SNPs at 15q25 represented by rs1051730[A] (effect size = 0.80 CPD, P = 2.4 x 10(-69)), and SNPs at 19q13 and 8p11, represented by rs4105144[C] (effect size = 0.39 CPD, P = 2.2 x 10(-12)) and rs6474412-T (effect size = 0.29 CPD, P = 1.4 x 10(-8)), respectively. Among the genes at the two newly associated loci are genes encoding nicotine-metabolizing enzymes (CYP2A6 and CYP2B6) and nicotinic acetylcholine receptor subunits (CHRNB3 and CHRNA6), all of which have been highlighted in previous studies of smoking and nicotine dependence. Nominal associations with lung cancer were observed at both 8p11 (rs6474412[T], odds ratio (OR) = 1.09, P = 0.04) and 19q13 (rs4105144[C], OR = 1.12, P = 0.0006).

Screening for depression and anxiety: correlates of non-response and cohort attrition in the Netherlands study of depression and anxiety (NESDA)

A major problem in the analysis of attrition of cohorts in studies on mental health problems is that data on those who do not participate at the outset of a study are largely unavailable. It is not known how underlying psychopathology affects the first stages of screening where non-response and selectivity are usually highest. This article presents results of one of the centres of the Netherlands Study of Depression and Anxiety (NESDA), a longitudinal study aimed at describing the long-term course and consequences of depression and anxiety disorders. The aim is to describe the different ways of attrition during the first NESDA-wave in a cohort of patients aged 18-65 years of the Registration Network Groningen and to analyse whether attrition is related to gender, age and psychopathology as recorded in general practice. The attrition of the study cohort (n = 8475) was highest during the first stages, eventually leading to a population of 169 patients only who participated in the full NESDA-programme. Probabilities of transition from one stage of the screening process to the next were regressed on selected background variables using binary logistic regression. Correlates of participation were being female and being older (>40). Psychopathology was an important variable in the formation of the initial sample cohort, but only had a weak influence on patient response to the screening questionnaire. Study design factors had a stronger impact on the changing composition of the cohort at each screening stage compared to patient factors.

Sequence variants in three loci influence monocyte counts and erythrocyte volume

Blood cells participate in vital physiological processes, and their numbers are tightly regulated so that homeostasis is maintained. Disruption of key regulatory mechanisms underlies many blood-related Mendelian diseases but also contributes to more common disorders, including atherosclerosis. We searched for quantitative trait loci (QTL) for hematology traits through a whole-genome association study, because these could provide new insights into both hemopoeitic and disease mechanisms. We tested 1.8 million variants for association with 13 hematology traits measured in 6015 individuals from the Australian and Dutch populations. These traits included hemoglobin composition, platelet counts, and red blood cell and white blood cell indices. We identified three regions of strong association that, to our knowledge, have not been previously reported in the literature. The first was located in an intergenic region of chromosome 9q31 near LPAR1, explaining 1.5% of the variation in monocyte counts (best SNP rs7023923, p=8.9x10(-14)). The second locus was located on chromosome 6p21 and associated with mean cell erythrocyte volume (rs12661667, p=1.2x10(-9), 0.7% variance explained) in a region that spanned five genes, including CCND3, a member of the D-cyclin gene family that is involved in hematopoietic stem cell expansion. The third region was also associated with erythrocyte volume and was located in an intergenic region on chromosome 6q24 (rs592423, p=5.3x10(-9), 0.6% variance explained). All three loci replicated in an independent panel of 1543 individuals (p values=0.001, 9.9x10(-5), and 7x10(-5), respectively). The identification of these QTL provides new opportunities for furthering our understanding of the mechanisms regulating hemopoietic cell fate.

Common variants in TMPRSS6 are associated with iron status and erythrocyte volume

We report a genome-wide association study to iron status. We identify an association of SNPs in TPMRSS6 to serum iron (rs855791, combined P = 1.5×10⁻²⁰), transferrin saturation (combined P = 2.2×10⁻²³), and erythrocyte mean cell volume (MCV, combined P = 1.1×10⁻¹⁰). We also find suggestive evidence of association with blood haemoglobin levels (combined P = 5.3×10⁻⁷). These findings demonstrate the involvement of TMPRSS6 in control of iron homeostasis and in normal erythropoiesis.

Interleukin-1 receptor antagonist and incident depressive symptoms over 6 years in older persons: the InCHIANTI study

BACKGROUND

We test the hypothesis that in older persons higher plasma levels of inflammatory markers predict the development of depressive symptoms during a 6-year follow-up.

METHOD

This study is part of the InCHIANTI (Invecchiare in Chianti, aging in the Chianti area) study, a prospective population-based study of older persons. The sample consisted of 991 participants, ages 65 years and older. Serum levels of C-reactive protein, interleukin (IL)-1beta, IL-1 receptor antagonist (ra), tumor necrosis factor-alpha, IL-6, IL-6 receptor, and IL-18 were measured. Depressive symptoms were assessed at baseline and at the 3- and 6-year follow-ups with the Center for Epidemiological Studies-Depression Scale (CES-D). Depressed mood was defined as CES-D > 20. Potential confounders were baseline variables related to sociodemographic, somatic health, and functional status.

RESULTS

At baseline, IL-1ra levels were significantly higher (p = .004) in depressed compared with nondepressed participants. After adjustment for confounders, among subjects free of depression at baseline, those in the third and fourth IL-1ra quartiles compared with those in the lowest quartile had, respectively, a 2.32-fold (95% confidence interval: 1.21-4.42, p = .01) and 2.78-fold (95% confidence interval: 1.47-5.26, p = .002) higher risk of developing depressed mood during a 6-year follow-up.

CONCLUSIONS

In old age, persons with high plasma levels of IL1-ra had a higher risk of developing depressive symptoms over time. These findings suggest a potential causal role for inflammation in the development of depressive symptoms in older persons.

Added value of physical performance measures in predicting adverse health-related events: results from the Health, Aging And Body Composition Study

OBJECTIVES

To determine how three different physical performance measures (PPMs) combine for added utility in predicting adverse health events in elders.

DESIGN

Prospective cohort study.

SETTING

Health, Aging and Body Composition Study.

PARTICIPANTS

Three thousand twenty-four well-functioning older persons (mean age 73.6).

MEASUREMENTS

Timed gait, repeated chair stands, and balance (semi- and full-tandem, and single leg stands each held for 30 seconds) tests were administered at baseline. Usual gait speed was categorized to distinguish high- and low-risk participants using the previously established 1-m/s cutpoint. The same population-percentile (21.3%) was used to identify cutpoints for the repeated chair stands (17.1 seconds) and balance (53.0 seconds) tests. Cox proportional hazard analyses were performed to evaluate the added value of PPMs in predicting mortality, hospitalization, and (severe) mobility limitation events over 6.9 years of follow-up.

RESULTS

Risk estimates for developing adverse health-related events were similarly large for each of the three high-risk groups considered separately. Having more PPM scores at the high-risk level was associated with a greater risk of developing adverse health-related events. When all three PPMs were considered, having only one poor performance was sufficient to indicate a highly significantly higher risk of (severe) lower extremity and mortality events.

CONCLUSION

Although gait speed is considered to be the most important predictor of adverse health events, these findings demonstrate that poor performance on other tests of lower extremity function are equally prognostic. This suggests that chair stand and standing balance performance may be adequate substitutes when gait speed is unavailable.

Genome-wide association study of smoking initiation and current smoking

For the identification of genes associated with smoking initiation and current smoking, genome-wide association analyses were carried out in 3497 subjects. Significant genes that replicated in three independent samples (n = 405, 5810, and 1648) were visualized into a biologically meaningful network showing cellular location and direct interaction of their proteins. Several interesting groups of proteins stood out, including glutamate receptors (e.g., GRIN2B, GRIN2A, GRIK2, GRM8), proteins involved in tyrosine kinase receptor signaling (e.g., NTRK2, GRB14), transporters (e.g., SLC1A2, SLC9A9) and cell-adhesion molecules (e.g., CDH23). We conclude that a network-based genome-wide association approach can identify genes influencing smoking behavior.

Angiotensin-converting enzyme inhibition and novel cardiovascular risk biomarkers: results from the Trial of Angiotensin Converting Enzyme Inhibition and Novel Cardiovascular Risk Factors (TRAIN) study

BACKGROUND

Beneficial effects of angiotensin-converting enzyme (ACE) inhibitors seem to be mediated by mechanisms that are partly independent of blood pressure lowering. The present study evaluates effects of an ACE inhibitor (ie, fosinopril) intervention on novel cardiovascular risk factors.

METHODS

Data are from the Trial of Angiotensin Converting Enzyme Inhibition and Novel Cardiovascular Risk Factors (TRAIN) study, a double-blind, crossover, randomized, placebo-controlled trial enrolling subjects > or =55 years old with high cardiovascular disease risk profile. Biomarkers of hemostasis (ie, plasminogen activator inhibitor 1, D-dimer), inflammation (ie, C-reactive protein, interleukin-6), and endothelial function (ie, endothelin 1, vascular cell adhesion molecule 1) were measured at the baseline, at the midterm, and at end of follow-up (after 1 year) clinic visits. Paired t test analyses (after Sidak's adjustment, P < .009) were performed to compare biomarkers modifications after fosinopril/placebo interventions.

RESULTS

Mean age of the sample (n = 290, women 43.4%) was 66.0 years old. No significant differences were reported for C-reactive protein, interleukin 6, plasminogen activator inhibitor 1, vascular cell adhesion molecule 1, and endothelin 1 levels in the comparisons between fosinopril and placebo interventions. D-dimer was the only biomarker showing a significant difference between fosinopril intervention (median 0.32 microg/mL, interquartile range 0.22-0.52 microg/mL) and placebo (median 0.29 microg/mL, interquartile range 0.20-0.47 microg/mL, P = .007) when analyses were restricted to participants with higher compliance to treatment and receiving the maximum ACE inhibitor dosage.

CONCLUSIONS

Angiotensin-converting enzyme inhibition does not significantly modify major biomarkers of inflammation, hemostasis, and endothelial function. Further studies should confirm the possible effect of ACE inhibitors on the fibrinolysis pathway.

Vascular disease and future risk of depressive symptomatology in older adults: findings from the Health, Aging, and Body Composition study

BACKGROUND

The vascular depression hypothesis suggests that age-related vascular diseases and risk factors contribute to late-life depression. Although neuroimaging studies provide evidence for an association between depression and severity of vascular lesions in the brain, studies of depression and indicators of vascular risk have been less consistent.

METHODS

We examined 1796 elders ages 70-79 from the Health, Aging and Body Composition study without depression at baseline and examined the association between prevalent vascular disease and related conditions at baseline and 2-year incidence of elevated depressive symptoms, defined as a score > 8 on the 10-item Center for Epidemiologic Studies Depression (CES-D) scale.

RESULTS

After adjustment for demographic data and physical and cognitive functioning, several vascular conditions remained associated with increased risk of depressive symptomatology including metabolic syndrome and its components (low high-density lipoprotein cholesterol and high fasting glucose), coronary heart disease, a positive Rose questionnaire for angina, and high hemoglobin a1c. Cumulative vascular risk based upon a composite of 10 vascular diseases and risk factors was independently associated with incident elevated depression at 2-year follow-up after controlling for demographic data, physical and cognitive functioning, and selected comorbid medical conditions.

CONCLUSIONS

These results provide support for the vascular depression hypothesis in demonstrating an association between vascular conditions and risk factors and subsequent risk of depressive symptomatology. Older adults with vascular conditions and risk factors require close monitoring of depressive symptoms.

Low testosterone levels and decline in physical performance and muscle strength in older men: findings from two prospective cohort studies

OBJECTIVE

Progressive declines in serum levels of testosterone parallel the decline in physical performance and muscle strength in ageing men, although findings are not conclusive. We examined whether levels of testosterone were associated with 3-year decline in physical performance and muscle strength in older men.

DESIGN

Longitudinal data were available for 486 men (mean age 74.9 years, SD 6.4) from the Longitudinal Ageing Study Amsterdam (LASA) and 1071 well-functioning men (mean age 73.7 years, SD 2.8) from the Health, Ageing and Body Composition (Health ABC) study.

MEASUREMENTS

Three-year change in physical performance score and grip strength according to categories of total testosterone (TT) and free testosterone (FT) levels.

RESULTS

The mean 3-year change in physical performance was -1.1 (SD 2.7, -13.6%) in LASA and -0.3 (SD 1.5, -2.9%) in Health ABC. The mean 3-year change in grip strength was -9.7 kg (SD 12.2, -13.2%) in LASA and -4.4 kg (SD 11.4,-5.8%) in Health ABC. Low levels of TT were not associated with decline in physical performance or with decline in muscle strength [e.g. mean change in physical performance -1.09 (SD 0.26) in the lowest quartile (Q1) and -0.88 (0.24) in the highest quartile (Q4) of total testosterone in LASA, and -0.26 (0.07) vs.-0.36 (0.11) in Health ABC]. Similar results were found for FT.

CONCLUSIONS

Low levels of TT and FT were neither associated with 3-year decline in physical performance nor with 3-year decline in muscle strength in two independent samples of older men.

Contribution of metabolic syndrome components to cognition in older individuals

OBJECTIVE

Recent evidence suggests that the metabolic syndrome and inflammation affect cognitive decline in old age and that they reinforce each other. However, it is not known what the roles of the individual components of the metabolic syndrome on cognition are.

RESEARCH DESIGN AND METHODS

The sample consisted of 1,183 participants in the Longitudinal Aging Study Amsterdam who were aged 65-88 years. Metabolic syndrome (U.S. National Cholesterol Education Program definition) and its individual components and the inflammatory markers C-reactive protein (CRP) and alpha1-antichymotrypsin (ACT) were assessed. Cognitive assessments included general cognition (Mini-Mental State Examination), memory (verbal learning test), fluid intelligence (Raven's Matrices), and information processing speed (coding task).

RESULTS

Of the sample, 36.3% had metabolic syndrome. Metabolic syndrome was significantly associated with all cognitive measures (P < 0.05). Of the individual components, hyperglycemia was most strongly and significantly associated with cognitive function (multivariate adjusted models; B values, indicating differences in scores between both groups, ranging from -0.38 to -1.21). There was a significant interaction between metabolic syndrome and inflammation on cognition (P < 0.01-0.09). Metabolic syndrome was negatively associated with cognition in subjects with high inflammation (highest tertile for both CRP and ACT; B values ranging from -0.86 to -1.94, P < 0.05), whereas an association was absent in subjects with low inflammation (B values ranging from -0.10 to -0.70).

CONCLUSIONS

Subjects with metabolic syndrome showed poorer cognitive performance than subjects without metabolic syndrome, especially those with high levels of inflammation. Hyperglycemia was the main contributor of the association of metabolic syndrome with cognition.

Diabetes mellitus, glycemic control, and incident depressive symptoms among 70- to 79-year-old persons: the health, aging, and body composition study

BACKGROUND

Cross-sectional studies find an elevated prevalence of depression among subjects with diabetes mellitus (DM). The causal mechanisms and temporal sequence of this association have not been clearly delineated. This study investigated the prospective relationship between DM and depressive symptoms.

METHODS

The Health, Aging, and Body Composition Study was a cohort study conducted in the metropolitan areas of Memphis, Tenn, and Pittsburgh, Pa. The analysis included 2522 community-dwelling subjects, aged 70 to 79 years, without baseline depressive symptoms. Incident depressed mood was defined as use of antidepressants at follow-up visits or presence of depressive symptoms (score >or=10 on the 10-item Center for Epidemiological Studies Depression scale). Presence of incident depressed mood at 2 consecutive annual clinic visits defined the incidence of recurrent depressed mood. Diabetes mellitus status, glycosylated hemoglobin (HbA1c) level, and DM-related comorbidities were assessed at baseline. Diabetes mellitus status was further characterized as absent, controlled (HbA1c level <7%), or uncontrolled (HbA1c level >or=7%). Discrete time survival analysis was used to estimate depressive events risk.

RESULTS

During a mean follow-up of 5.9 years, participants with DM had a higher age-, sex-, race-, and site-adjusted incidence of depressed mood (23.5% vs 19.0%) (P = .02) and recurrent depressed mood (8.8% vs 4.3%) (P<.001) than those without DM. Diabetes mellitus was associated with a 30% increased risk of incident depressed mood (odds ratio [OR], 1.31; 95% confidence interval [CI], 1.07-1.61), which was attenuated after adjustment for DM-related comorbidities (OR, 1.20; CI, 0.97-1.48). A stronger relationship was observed between DM and recurrent depressed mood (OR, 1.91; CI, 1.32-2.76), particularly among participants with poor glycemic control.

CONCLUSION

Among well-functioning older adults, DM is associated with increased risk of depressive symptoms.

Anemia and cancer in older persons

Although the overall prevalence for many cancers is declining, cancer still remains a diagnosis more common in the elderly than in younger individuals. As the population ages, the proportion of patients with cancer who are elderly is expected to increase dramatically. Anemia occurs more often in older individuals for a variety of reasons, and its prevalence in elderly patients with cancer is significantly increasing. Although information on anemia in the elderly is limited, data on cancer patients of all ages have shown that the presence of anemia is associated with poorer prognosis and functional status. The impact of anemia on performance status in patients with cancer is matched by results from a large number of studies indicating negative effects of anemia on a wide variety of performance measures. Despite an apparent reluctance to undertake aggressive therapy in elderly patients with cancer, physicians are using a wider range of treatments with increasing frequency in this older population. Optimizing treatment outcomes in elderly patients with cancer depends on careful determination of performance status as well as the potential of therapies to treat anemia in these patients.

Hypercortisolemic depression is associated with the metabolic syndrome in late-life

INTRODUCTION

Depression has been hypothesized to be associated with metabolic abnormalities which increase the risk of cardiovascular disease (CVD) and diabetes. Such a link could be due to increased HPA-axis activity. This study investigates the cross-sectional relationship between depression, urinary cortisol and metabolic syndrome in an older population.

METHODS

Data are from 867 participants of the InChianti Study, aged 65 years. Depressive symptoms were assessed using the CES-D scale; cortisol levels were determined in 24-h urine samples. Metabolic syndrome was defined as three or more of the following: abdominal obesity, high triglycerides, low HDL cholesterol, high blood pressure, and high fasting glucose.

RESULTS

Clinically relevant depressed mood (CES-D20) was present in 20.6% of the sample, and 24.5% had the metabolic syndrome. After adjustment for sociodemographics and health indicators, depression score (per SD increase: OR=1.20, 95% CI=1.02-1.41) and urinary cortisol level (per SD increase: OR=1.23, 95% CI=1.01-1.51) were significantly associated with presence of metabolic syndrome. There was, however, a significant interaction (p=0.003) between depressed mood and urinary cortisol in the probability of having metabolic syndrome. The odds of metabolic syndrome in persons with both depressed mood and urinary cortisol excretion in the highest tertile was 1.84 (95% CI=1.02-3.34) compared to persons with neither condition.

DISCUSSION

This study suggests a synergistic relationship between depression, cortisol and metabolic syndrome. Hypercortisolemic depression may constitute a specific risk group for the metabolic syndrome.

Diabetes, inflammation, and functional decline in older adults: findings from the Health, Aging and Body Composition (ABC) study

OBJECTIVE

Age, diabetes, and elevated inflammatory markers independently increase the risk of functional decline. We examined the effect of C-reactive protein (CRP) and interleukin-6 (IL-6) on the incident mobility limitation in older adults with and without diabetes.

RESEARCH DESIGN AND METHODS

We analyzed data from a cohort of 2,895 well-functioning adults aged 70-79 years, followed for development of persistent functional limitation over 3.5 years. Participants were assessed for the presence of diabetes according to fasting glucose and/or hypoglycemic medication use and were divided into three equal groups (tertiles) according to level of CRP or IL-6. Persistent functional limitation was defined as difficulty climbing 10 steps or walking one-quarter mile on two consecutive semiannual assessments.

RESULTS

At baseline, 702 participants (24%) had diabetes. CRP values were (median +/- SD) 2.8 +/- 4.4 versus 3.7 +/- 5.4 for those with normal glucose and diabetes, respectively (P < 0.001). The unadjusted incidence of functional limitation associated with increased levels of CRP and IL-6 was greater among participants with diabetes. After adjusting for clinical and demographic covariates, persistent functional limitation for the highest tertile was greater compared with that for the lowest tertile of CRP or IL-6 for those with and without diabetes. CRP hazard ratios (HRs) were 1.7 (95% CI 1.2-2.3) versus 1.4 (1.1-1.6), respectively. IL-6 HRs were 1.8 (1.3-2.5) versus 1.6 (1.4-2.0), respectively.

CONCLUSIONS

In initially high-functioning older adults, those with diabetes and higher inflammatory burden had an increased risk of functional decline. Interventions at early stages to reduce inflammation may preserve function in these individuals.

Angiotensin-converting enzyme insertion/deletion genotype, exercise, and physical decline

CONTEXT

Physical performance in response to exercise appears to be influenced by the angiotensin-converting enzyme (ACE) insertion (I)/deletion (D) genotype in young adults, but whether this relationship could help explain variation in older individuals' response to exercise has not been well studied.

OBJECTIVE

To determine whether the ACE genotype interacts with significant physical activity to affect the incidence of mobility limitation in well-functioning older adults.

DESIGN, SETTING, AND PARTICIPANTS

The Health Aging and Body Composition (Health ABC) Cohort Study, conducted in the metropolitan areas of Memphis, Tenn, and Pittsburgh, Pa. A total of 3075 well-functioning community-dwelling adults aged 70 through 79 years were enrolled from 1997 to 1998 and had a mean of 4.1 years of follow-up.

MAIN OUTCOME MEASURE

Incident mobility limitation defined as the report of difficulty walking a quarter of a mile (0.4 km) or walking up 10 steps on 2 consecutive semiannual interviews (n = 1204).

RESULTS

Physically active participants (those reporting expending > or =1000 kcal/wk in exercise, walking, and stair climbing) were less likely to develop mobility limitation regardless of genotype. However, activity level interacted significantly with the ACE genotype (P = .002). In the inactive group, the ACE genotype was not associated with limitation (P = .46). In the active group, those with the II genotype were more likely to develop mobility limitation after adjusting for potential confounders compared with those with ID/DD genotypes (adjusted rate ratio, 1.45, 95% confidence interval, 1.08-1.94). The gene association was especially strong among participants reporting weightlifting. Exploration of possible physiological correlates revealed that among active participants, those with the II genotype had higher percentage of body fat (P = .02) and more intermuscular thigh fat (P = .02) but had similar quadriceps strength as those with ID/DD.

CONCLUSIONS

Among older individuals who exercised, those with the ACE DD or ID genotypes were less likely to develop mobility limitation than those with the II genotype. Regardless of genotype, individuals who exercised were less likely to develop mobility limitation than those who did not exercise.