The Associations of Aortic Valve Sclerosis, Aortic Annular Increased Reflectivity, and Mitral Annular Calcification with Subsequent Aortic Stenosis in Older Individuals: Findings from the Cardiovascular Health Study.

BACKGROUND: Although aortic valve sclerosis (AVS) is well described as preceding aortic stenosis (AS), the associations of AS with antecedent mitral annular calcification (MAC) and aortic annular increased reflectivity (AAIR) have not been characterized. In a population-based prospective study, the authors evaluated whether MAC, AAIR, and AVS are associated with the risk for incident AS. METHODS: Among participants of the Cardiovascular Health Study free of AS at the 1994-1995 visit, the presence of MAC, AAIR, AVS, and the combination of all three was evaluated in 3,041 participants. Cox proportional-hazards regression was used to assess the association between the presence of calcification and the incidence of moderate or severe AS in three nested models adjusting for factors associated with atherosclerosis and inflammation both relevant to the pathogenesis of AS. RESULTS: Over a median follow-up period of 11.5 years (interquartile range, 6.7-17.0 years), 110 cases of incident moderate or severe AS were ascertained. Strong positive associations with incident moderate or severe AS were found for all calcification sites after adjustment for the main model covariates: AAIR (hazard ratio [HR], 2.90; 95% CI, 1.95-4.32; P < .0005), AVS (HR, 2.20; 95% CI, 1.44-3.37; P < .0005), MAC (HR, 1.67; 95% CI, 1.14-2.45; P = .008), and the combination of all three (HR, 2.50; 95% CI, 1.65-3.78; P < .0005). In a secondary analysis, the risk for AS increased with the number of sites at which calcification was present. CONCLUSIONS: In a large cohort of community-dwelling elderly individuals, there were strong associations between each of AAIR, AVS, MAC, and the combination of the three and incident moderate or severe AS. The novel finding that AAIR had a particularly strong association with incident AS, even after adjusting for other calcification sites, suggests its value in identifying individuals at risk for AS and potential inclusion in routine assessment by transthoracic echocardiography.

Circulating differentiated and senescent lymphocyte subsets and incident diabetes risk in older adults: The Cardiovascular Health Study.

INTRODUCTION: Cellular senescence is a feature of aging implicated in the pathophysiology of diabetes mellitus (DM). Whether senescent lymphocytes are associated with the future occurrence of DM is uncertain. METHODS: We used cryopreserved peripheral blood mononuclear cells collected from 1860 Cardiovascular Health Study participants (average age 80.2 years) and flow cytometry immunophenotyping to evaluate the longitudinal relationships of naive (CD45RA+ ), memory (CD45RO+ ), senescent (CD28- ), and T effector memory RA+ (TEMRA) (CD28- CD57+ CD45RA+ ) CD4+ and CD8+ T cells, and memory B cells (CD19+ CD27+ ), with the risk of incident DM. In exploratory analyses we evaluated the relationships of 13 additional innate lymphocyte and CD4+ and CD8+ subsets with incident DM risk. RESULTS: Over a median follow-up time of 8.9 years, 155 cases of incident DM occurred. In Cox models adjusted for demographic variables (age, sex, race, study site and flow cytometry analytical batch) or diabetes risk factors (demographic variables plus education, body mass index, smoking status, alcohol use, systolic blood pressure, hypertension medication use and physical activity), no significant associations were observed for any CD4+ , CD8+ or CD19+ cell phenotypes with incident DM. CONCLUSIONS: These results suggest the frequencies of naive, memory and senescent T cells and memory B cells are not strongly associated with incident DM risk in older adults.

High-Density Lipoprotein and Long-Term Incidence and Progression of Aortic Valve Calcification: The Multi-Ethnic Study of Atherosclerosis.

BACKGROUND: Aortic valve calcification (AVC) shares pathological features with atherosclerosis. Lipoprotein components have been detected in aortic valve tissue, including HDL (high-density lipoprotein). HDL measures have inverse associations with cardiovascular disease, but relationships with long-term AVC progression are unclear. We investigated associations of HDL cholesterol, HDL-particle number and size, apoC3-defined HDL subtypes, and, secondarily, CETP (cholesteryl ester transfer protein) mass and activity, with long-term incidence and progression of AVC. METHODS: We used linear mixed-effects models to evaluate the associations of baseline HDL indices with AVC. AVC was quantified by Agatston scoring of up to 3 serial computed tomography scans over a median of 8.9 (maximum 11.2) years of follow-up in the Multi-Ethnic Study of Atherosclerosis (n=6784). RESULTS: After adjustment, higher concentrations of HDL-C (high-density lipoprotein cholesterol), HDL-P (HDL particles), large HDL-P, and apoC3-lacking HDL-C were significantly associated with lower incidence/progression of AVC. Neither small or medium HDL-P nor apoC3-containing HDL-C was significantly associated with AVC incidence/progression. When included together, a significant association was observed only for HDL-C, but not for HDL-P. Secondary analyses showed an inverse relationship between CETP mass, but not activity, and AVC incidence/progression. In exploratory assessments, inverse associations for HDL-C, HDL-P, large HDL-P, and apoC3-lacking HDL with AVC incidence/progression were more pronounced for older, male, and White participants. ApoC3-containing HDL-C only showed a positive association with AVC in these subgroups. CONCLUSIONS: In a multiethnic population, HDL-C, HDL-P, large HDL-P, and apoC3-lacking HDL-C were inversely associated with long-term incidence and progression of AVC. Further investigation of HDL composition and mechanisms could be useful in understanding pathways that slow AVC.

Relation of Cigarette Smoking and Heart Failure in Adults ≥65 Years of Age (From the Cardiovascular Health Study).

Cigarette smoking is associated with adverse cardiac outcomes, including incident heart failure (HF). However, key components of potential pathways from smoking to HF have not been evaluated in older adults. In a community-based study, we studied cross-sectional associations of smoking with blood and imaging biomarkers reflecting mechanisms of cardiac disease. Serial nested, multivariable Cox models were used to determine associations of smoking with HF, and to assess the influence of biochemical and functional (cardiac strain) phenotypes on these associations. Compared with never smokers, smokers had higher levels of inflammation (C-reactive protein and interleukin-6), cardiomyocyte injury (cardiac troponin T [hscTnT]), myocardial "stress"/fibrosis (soluble suppression of tumorigenicity 2 [sST2], galectin 3), and worse left ventricle systolic and diastolic function. In models adjusting for age, gender, and race (DEMO) and for clinical factors potentially in the causal pathway (CLIN), smoking exposures were associated with C-reactive protein and interleukin-6, sST2, hscTnT, and with N-terminal pro-brain natriuretic protein (in Whites). In DEMO adjusted models, the cumulative burden of smoking was associated with worse left ventricle systolic strain. Current smoking and former smoking were associated with HF in DEMO models (hazard ratio 1.41, 95% confidence interval 1.22 to 1.64 and hazard ratio 1.14, 95% confidence interval 1.03 to 1.25, respectively), and with current smoking after CLIN adjustment. Adjustment for time-varying myocardial infarction, inflammation, cardiac strain, hscTnT, sST2, and galectin 3 did not materially alter the associations. Smoking was associated with HF with preserved and decreased ejection fraction. In conclusion, in older adults, smoking is associated with multiple blood and imaging biomarker measures of pathophysiology previously linked to HF, and to incident HF even after adjustment for clinical intermediates.

Bone mineral density and long-term progression of aortic valve and mitral annular calcification: The Multi-Ethnic Study of Atherosclerosis.

BACKGROUND AND AIMS: Bone and mineral metabolism has been implicated in the pathophysiology of cardiac valve calcification. Whether bone demineralization, a common aging-related disorder, promotes calcific valve disease remains uncertain. We tested the hypothesis that low bone mineral density (BMD) is associated with greater incidence/progression of cardiac valve calcification in the Multi-Ethnic Study of Atherosclerosis. METHODS: Using linear mixed-effects models, we related baseline measurement of BMD of the thoracic vertebrae by computed tomography (CT) in 6768 participants to serial CT assessments of aortic valve calcification (AVC) and mitral annular calcification (MAC) obtained over a >10-year period. RESULTS: After multivariable adjustment, lower BMD (per SD decrement) was associated with accelerated increase in AVC over time in women (0.76 [95% CI 0.42,1.09] Agatston -units [AU]/year) and men (1.41 [95% CI 0.48,2.33] AU/year), as well as for MAC in women (3.22 [95% CI 1.16,5.28] AU/year) and men (3.59 [95% CI 2.09,5.09] AU/year). Significant effect modification was observed, with more pronounced BMD-related acceleration of AVC and MAC progression in older or white participants of one or both sexes, as well as by estimated glomerular filtration rate, though the latter differed by sex for AVC and MAC. CONCLUSIONS: In this multi-ethnic cohort, low thoracic BMD was significantly, but modestly, associated with increased AVC and MAC progression. This suggests that altered bone mineral metabolism does not have a major impact on calcific valve disease in the general population, but the possibility of a more meaningful influence in higher-risk individuals with osteoporosis will require further investigation.

Brief Report: Cystatin C-Based Estimation of Glomerular Filtration Rate and Association With Atherosclerosis Imaging Markers in People Living With HIV.

INTRODUCTION: Reduced estimated glomerular filtration rate (eGFR) is associated with increased risk of cardiovascular disease among people living with HIV (PLWH). It is unclear whether eGFR equations incorporating cystatin C (CysC) measurements are more predictive of preclinical cardiovascular disease than those using only creatinine (Cr). OBJECTIVES: The study aimed to determine which of the 3 Chronic Kidney Disease Epidemiology (CKD-EPI) eGFR equations is most associated with carotid intima media thickness (CIMT) and coronary artery calcium (CAC) score. METHODS: This cross-sectional analysis of pooled data from 3 large cohorts compared the associations between the 3 CKD-EPI eGFR equations (Cr, CysC, and Cr-CysC) with CIMT and CAC score using multivariable regression analysis. eGFR and CIMT were analyzed as continuous variables. CAC scores were analyzed as a binary variable (detectable calcification versus nondetectable) and as a log10 Agatston score in those with detectable CAC. RESULTS: Thousand four hundred eighty-seven participants were included, and of these 910 (562 HIV+ and 348 HIV-) had CIMT measurements and 366 (296 HIV+ and 70 HIV-) had CAC measurements available. In HIV- participants, GFR estimated by any CKD-EPI equation did not significantly correlate with CIMT or CAC scores. When PLWH were analyzed separately including HIV-specific factors, only GFR estimated using Cr-Cys C correlated with CIMT [ß= -0.90, 95% CI: (-1.67 to -0.13) µm; P = 0.023]. Similarly, eGFR correlated with Agatston scores only when using cystatin C-based eGFR [ß= -8.63, 95% CI: (-16.49 to -0.77) HU; P = 0.034]. Associations between other eGFR formulas and CAC did not reach statistical significance. CONCLUSIONS: In PLWH, preclinical atherosclerosis may be more closely correlated with eGFR using formulae that incorporate CysC measurements than Cr alone.

Valvular calcification and risk of peripheral artery disease: the Multi-Ethnic Study of Atherosclerosis (MESA).

AIMS: The detection of cardiac valvular calcification on routine imaging may provide an opportunity to identify individuals at increased risk for peripheral artery disease (PAD). We investigated the associations of aortic valvular calcification (AVC) and mitral annular calcification (MAC) with risk of developing clinical PAD or a low ankle-brachial index (ABI). METHODS AND RESULTS: AVC and MAC were measured on cardiac computed tomography in 6778 Multi-Ethnic Study of Atherosclerosis participants without baseline PAD between 2000 and 2002. Clinical PAD was ascertained through 2015. Incident low ABI, defined as ABI <0.9 and decline of ≥0.15, was assessed among 5762 individuals who had an ABI >0.9 at baseline and at least one follow-up ABI measurement 3-10 years later. Adjusted Cox proportional hazards and Poisson regression modelling were used to determine the association of valvular calcification with clinical PAD and low ABI, respectively. There were 117 clinical PAD and 198 low ABI events that occurred over a median follow-up of 14 years and 9.2 years, respectively. The presence of MAC was associated with an increased risk of clinical PAD [hazard ratio 1.79; 95% confidence interval (CI) 1.04-3.05] but not a low ABI (rate ratio 1.28; 95% CI 0.75-2.19). No significant associations were noted for the presence of AVC and risk of either clinical PAD. CONCLUSION: MAC is associated with an increased risk of developing clinical PAD. Future studies are needed to corroborate our findings and better understand whether MAC holds any predictive value as a risk marker for PAD.

Higher albumin:creatinine ratio and lower estimated glomerular filtration rate are potential risk factors for decline of physical performance in the elderly: the Cardiovascular Health Study.

INTRODUCTION: Mildly reduced renal function and elevated urine protein levels are each prospectively associated with hip fracture risk in older adults. Here we determine whether these markers are associated with reduced appendicular muscle performance. METHODS: We prospectively examined the associations of urine albumin:creatinine ratio (ACR) and reduced estimated glomerular filtration rate (eGFR) with longitudinal changes in grip strength and gait speed >2 years in 2317 older community-dwelling men and women (median age 77 years). The median ACR was 9.8 [interquartile range (IQR) 5.40-21.50] mg/g creatinine and the median eGFR was 71.6 (IQR 59.1-83.56) mL/min/1.73 m2. Models were adjusted for demographic factors, clinical history and biochemical measures in four candidate pathways: diabetes, oxidative stress, inflammation and fibrosis. RESULTS: In demographic- and covariate-adjusted models, a 2-fold higher baseline urine ACR was associated with longitudinal changes of -0.17 kg [95% confidence interval (CI) -0.29 to -0.06) in grip strength and -1.10 cm/s (95% CI -1.67 to -0.53) gait speed per year. Corresponding estimates for a 10 mL/min/1.73 m2 lower baseline eGFR were -0.13 kg (95% CI -0.23 to -0.04) and -0.89 cm/s (95% CI -1.37 to -0.40), respectively. The associations of a 2-fold higher baseline ACR and a 10 mL/min/1.73 m2 lower baseline eGFR using cystatin C with grip strength and gait speed were equivalent to ∼1.2-1.9 additional years of age. Adjustment for covariates in candidate pathways did not attenuate these estimates. CONCLUSIONS: In older adults, higher ACR and lower eGFR are potential risk factors for a decline of physical performance >2 years.

Association of bone mineral density with hemoglobin and change in hemoglobin among older men and women: The Cardiovascular Health Study.

PURPOSE: Osteoblasts and their precursors support hematopoiesis in the bone marrow. We hypothesized that declines in Hgb levels are associated with bone mineral density (BMD). METHODS: The Cardiovascular Health Study is a prospective longitudinal study that enrolled 5888 community-dwelling adults aged >65 years and measured hemoglobin twice, in 1989-90 and 1992-93, as well as BMD by dual-energy X-ray absorptiometry (DXA) in 1994-95. In a subset of 1513 men and women with a Hgb in 1992-93 and BMD, we used linear regression to estimate associations of Hgb (per standard deviation (SD)) with total hip (TH), lumbar spine (LS) and total body (TB) BMD, and used Poisson regression to estimate associations of anemia (in 1992-93; Hgb <13 g/dL in men; <12 g/dL in women) with "low BMD" defined as T-score less than -1 at the TH. In 1277 participants with Hgb measured on average 2.9 years apart and BMD, we used linear regression to estimate the associations of annualized change in Hgb with TH, LS and TB BMD. All models included age, sex, study-site, race, smoking, alcohol use, weight, height, steroid use, physical activity score, self-reported health, previous cardiovascular disease and prior anti-fracture medication use. RESULTS: No significant association was observed between Hgb, measured a mean 2.2 years prior to BMD, and BMD at the TH and LS in men (TH beta = -0.60 [x 10-2 g/cm2per 1.1 g/dL Hgb], 95% CI: -1.88 to 0.68; LS beta = -1.69, 95% CI: -3.83 to 0.45) or women (TH beta = -0.49 [x 10-2 g/cm2per 1.3 g/dL Hgb], 95% CI: -1.57 to 0.59; LS beta = -0.40, 95% CI: -2.57 to 1.76). Anemia was not observed to be significantly associated with low BMD in men (RR = 0.99, 95% CI: 0.72-1.40) nor women (RR = 0.98, 95% CI: 0.82-1.17). The mean change in Hgb was a loss of 0.06 g/dL/year (SD = 0.32). Change in Hgb was not observed to be significantly associated with BMD in men (TH beta = -0.55[x 10-2 g/cm2per 1 g/dL annualized Hgb change], 95% CI: -4.28 to 3.19; LS beta = 0.63, 95% CI: -5.38 to 6.65) or women (TH beta = 0.92, 95% CI: -1.96 to 3.79; LS beta = -1.77, 95% CI: -7.52 to 3.98). No significant association was observed between anemia and low bone density by T-score in men and women. CONCLUSIONS: These findings support neither the hypothesis that low Hgb prior to bone density or decreases in Hgb are associated with bone density in older community-dwelling adults nor the use of Hgb level as a case-finding tool to prompt BMD measurement.

Serum androgens and risk of atrial fibrillation in older men: The Cardiovascular Health Study.

BACKGROUND: Decline in serum androgens is common among older men and has been associated with cardiovascular disease, although its role in risk of atrial fibrillation (AF) has not been well defined. HYPOTHESIS: Low serum androgens are associated with an increased risk of AF. METHODS: We examined the prospective associations between testosterone, its more active metabolite dihydrotestosterone (DHT), and sex hormone-binding globulin (SHBG) with risk of AF among 1019 otherwise healthy men with average age 76.3 ±4.9 years in the Cardiovascular Health Study. RESULTS: After median follow-up of 9.5 years, 304 (30%) men developed AF. We detected a nonlinear association with risk of incident AF in both free and total DHT, in which subjects with the lowest levels had a higher risk of incident AF. After adjustment for demographics, clinical risk factors, left atrial diameter, and serum NT-proBNP levels, men with free DHT <0.16 ng/dL were at increased risk compared with men with higher levels (hazard ratio: 1.48, 95% confidence interval: 1.01-2.17, P <0.05). Sensitivity analyses confirmed that the increased risk was not cutpoint-specific, with a significant association noted up to cutpoints <~0.2 ng/dL. We also detected a complex nonlinear association between SHBG and incident AF, in which subjects in the middle quintile (52.9-65.3 nmol/L) had increased risk. CONCLUSIONS: Among older men, low free DHT is associated with an increased risk of incident AF. Further studies are needed to explore mechanisms for this association.

Higher plasma transforming growth factor (TGF)-ß is associated with kidney disease in older community dwelling adults.

BACKGROUND: TGF-ß is induced in the vasculature with aging suggesting that high plasma TGF-ß levels may be a risk factor for chronic kidney disease (CKD) in older adults. METHODS: We conducted a cross-sectional analysis of the association between plasma TGF-ß levels and CKD including data for 1722 older adults who had participated in the 1996/97 visit of the Cardiovascular Health Study (CHS). Prevalent CKD was defined as eGFR < 60 mL/min/1.73 m2 or urinary albumin/creatinine ratio (ACR) ≥30 mg/g. We also evaluated whether baseline TGF-ß levels predicted change in eGFR, cardiovascular (CV) events, or mortality in longitudinal analysis. RESULTS: Plasma TGF-ß levels were significantly and independently associated with lower eGFR in cross-sectional analysis. Doubling of TGF-ß was significantly associated with lower eGFR (ß estimate after adjusting for CV risk factors = -1.18, 95% CI -2.03, -0.32). We observed no association with albuminuria. There was no association between baseline TGF-ß and change in eGFR, but each doubling of TGF-ß at baseline was associated with increased risk of a composite outcome of CV events and mortality, adjusted HR 1.10 (95% C.I. 1.02- 1.20, p = 0.006). CONCLUSION: In this large cohort of community-dwelling older individuals, high plasma TGF-ß levels are modestly, but independently associated with lower eGFR but not with albuminuria in cross-sectional analysis. In addition, TGF-ß levels are associated with increased risk of CV events and mortality. Further research is needed to determine the direction of association between plasma TGF-ß and the risk of CKD and CKD-associated morbidities in older adults.

HIV Infection and Carotid Artery Intima-media Thickness: Pooled Analyses Across 5 Cohorts of the NHLBI HIV-CVD Collaborative.

BACKGROUND: Age and human immunodeficiency virus (HIV) treatment may affect the association of HIV infection with atherosclerosis. METHODS: We used identical carotid artery B-mode ultrasonographic methods in 5 cohorts participating in the National Heart, Lung, and Blood Institute HIV-CVD Collaborative to measure intima-media thickness of the right far wall of the common carotid artery (CCA-IMT) and carotid artery bifurcation (BIF-IMT) between 2010 and 2013. Participants aged 6-75 years were either HIV infected or uninfected. Linear regression assessed associations of CCA-IMT and BIF-IMT with HIV infection and cardiovascular disease risk factors, within age and HIV treatment groups. Adjustment variables included sex, race/ethnicity, smoking, height, weight, and use of antihypertensive and lipid-lowering drugs. RESULTS: We studied 867 HIV-infected and 338 HIV-uninfected male and 696 HIV-infected and 246 HIV-uninfected female participants. Among both middle-aged (30-49 years) and older adults (50-75 years), HIV-infected participants had CCA-IMT and BIF-IMT values that were similar to or lower than those in HIV-uninfected participants. In contrast, among those aged 6-29 years, HIV infection was associated with higher CCA-IMT and BIF-IMT values. Among HIV-infected participants, associations of higher systolic blood pressure and lower high-density lipoprotein cholesterol with Carotid artery intima-media thickness strengthened with age. CONCLUSIONS: The effects of HIV on carotid artery structure may differ across the lifespan, with traditional determinants of cardiovascular disease burden playing a larger role and HIV playing a lesser role in older adults than in young adults and children.

Agreement between circulating IGF-I, IGFBP-1 and IGFBP-3 levels measured by current assays versus unavailable assays previously used in epidemiological studies.

OBJECTIVE: Levels of insulin-like growth factor (IGF) proteins are associated with the risk of cancer and mortality. IGF assays produced by Diagnostic Systems Laboratories (DSL) were widely used in epidemiological studies, were not calibrated against recommended standards and are no longer commercially available. DESIGN: In a split sample study among 1471 adults participating in the Cardiovascular Health Study, we compared values obtained using DSL assays with alternative assays for serum IGF-I (Immunodiagnostic Systems, IDS), IGFBP-1 (American Laboratory Products Company, ALPCO) and IGFBP-3 (IDS). RESULTS: Results were compared using kernel density estimation plots, quartile analysis with weighted kappa statistics and linear regression models to assess the concordance of data from the different assays. Participants had a mean age of 77years. Results between alternative assays were strongly correlated (IGF-I, r=0.93 for DSL versus IDS; log-IGFBP-1, r=0.90 for DSL versus ALPCO; IGFBP-3, r=0.92 for DSL versus IDS). Cross tabulations showed that participants were usually in the same quartile categories regardless of the assay used (overall agreement, 74% for IGF-I, 64% for IGFBP-1, 71% for IGFBP-3). Weighted kappa also showed substantial agreement between assays (kw, 0.78 for IGF-I, 0.69 for IGFBP-1, 0.76 for IGFBP-3). Regressions of levels obtained with DSL assays (denoted X) to alternative assays were, IGF-I: 0.52X+15.2ng/ml, log-IGFBP-1: 1.01X-1.73ng/ml IGFBP-3: 0.87X+791.1ng/ml. Serum values of IGF-I, IGFBP-1 and IGFBP-3 measured using alternative assays are moderately correlated. CONCLUSIONS: Care is needed in the interpretation of data sets involving IGF analytes if assay methodologies are not uniform.

Changes in insulin-like growth factor-I and its binding proteins are associated with diabetes mellitus in older adults.

OBJECTIVES: To determine whether changes in insulin-like growth factor (IGF) protein levels are greater in participants with type 2 diabetes mellitus or worsening glycemia than in normoglycemic individuals over a 9-year follow-up period. DESIGN: Retrospective analysis of a cohort study. SETTING: Participants were recruited from North Carolina, California, Maryland, and Pennsylvania. PARTICIPANTS: Cardiovascular Health Study All Stars participants, a cohort study of community-dwelling adults aged 65 and older (N=897). MEASUREMENTS: Plasma IGF-I, IGF binding protein (IGFBP)-1, and IGFBP-3 levels were assessed and American Diabetes Association cut-points for impaired glucose tolerance (IGT), impaired fasting glucose (IFG), and diabetes mellitus were used to classify participants at baseline (1996-97) and follow-up (2005-06). RESULTS: At baseline, mean age was 76.3±3.6, and 18.5% had diabetes mellitus. Participants with IFG alone and IGT plus IFG had higher IGF-I levels and lower IGFBP-1 levels than those with normoglycemia or diabetes mellitus. The greatest percentage change in IGF levels occurred in those who had diabetes mellitus at baseline (9-year changes: -9.3% for IGF-I, 59.7% for IGFBP-1, -13.4% for IGFBP-3), the smallest in individuals who remained normoglycemic at follow-up (9-year changes: -3.7% for IGF-I, 25.6% for IGFBP-1, -6.4% for IGFBP-3), and intermediate in those who were normoglycemic but developed IFG at follow-up. CONCLUSION: Degrees of glycemic impairment are associated with varying degrees of change in IGF protein levels. The changes observed in the diabetes mellitus group have been previously shown to be associated with heart failure, cancer, and noncancer mortality.

Circulating levels of carboxy­methyl­lysine (CML) are associated with hip fracture risk: the Cardiovascular Health Study.

Advanced glycation end products (AGE) in bone tissue are associated with impaired biomechanical properties and increased fracture risk. Here we examine whether serum levels of the AGE carboxy­methyl­lysine (CML) are associated with risk of hip fracture.We followed 3373 participants from the Cardiovascular Health Study (age 78 years; range, 68­102 years; 39.8% male) for a median of 9.22 years (range, 0.01­12.07 years). Rates of incident hip fracture were calculated by quartiles of baseline CML levels, and hazard ratios were adjusted for covariates associated with hip fracture risk. A subcohort of 1315 participants had bone mineral density (BMD)measurement. There were 348 hip fractures during follow­up, with incidence rates of hip fracture by CML quartiles of 0.94, 1.34, 1.18, and 1.69 per 100 participant­years. The unadjusted hazard ratio of hip fracture increased with each 1 SD increase (189 ng/mL) of CML level (hazard ratio, 1.27; 95% confidence interval [CI], 1.16­1.40]; p<0.001). Sequential adjustment for age, gender, race/ethnicity,body mass index (BMI), smoking, alcohol consumption, prevalent coronary heart disease (CHD), energy expenditure, and estimated glomerular filtration rate (based on cystatin C), moderately attenuated the hazard ratio for fracture (1.17; 95% CI, 1.05­1.31; p=0.006).In the cohort with BMD testing, total hip BMD was not significantly associated with CML levels. We conclude that increasing levels of CML are associated with hip fracture risk in older adults, independent of hip BMD. These results implicate AGE in the pathogenesis of hip fractures.

No evidence of interaction between known lipid-associated genetic variants and smoking in the multi-ethnic PAGE population.

Genome-wide association studies (GWAS) have identified many variants that influence high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and/or triglycerides. However, environmental modifiers, such as smoking, of these known genotype-phenotype associations are just recently emerging in the literature. We have tested for interactions between smoking and 49 GWAS-identified variants in over 41,000 racially/ethnically diverse samples with lipid levels from the Population Architecture Using Genomics and Epidemiology (PAGE) study. Despite their biological plausibility, we were unable to detect significant SNP × smoking interactions.

Genetic risk factors for BMI and obesity in an ethnically diverse population: results from the population architecture using genomics and epidemiology (PAGE) study.

OBJECTIVE: Several genome-wide association studies (GWAS) have demonstrated that common genetic variants contribute to obesity. However, studies of this complex trait have focused on ancestrally European populations, despite the high prevalence of obesity in some minority groups. DESIGN AND METHODS: As part of the "Population Architecture using Genomics and Epidemiology (PAGE)" Consortium, we investigated the association between 13 GWAS-identified single-nucleotide polymorphisms (SNPs) and BMI and obesity in 69,775 subjects, including 6,149 American Indians, 15,415 African-Americans, 2,438 East Asians, 7,346 Hispanics, 604 Pacific Islanders, and 37,823 European Americans. For the BMI-increasing allele of each SNP, we calculated ß coefficients using linear regression (for BMI) and risk estimates using logistic regression (for obesity defined as BMI ≥ 30) followed by fixed-effects meta-analysis to combine results across PAGE sites. Analyses stratified by racial/ethnic group assumed an additive genetic model and were adjusted for age, sex, and current smoking. We defined "replicating SNPs" (in European Americans) and "generalizing SNPs" (in other racial/ethnic groups) as those associated with an allele frequency-specific increase in BMI. RESULTS: By this definition, we replicated 9/13 SNP associations (5 out of 8 loci) in European Americans. We also generalized 8/13 SNP associations (5/8 loci) in East Asians, 7/13 (5/8 loci) in African Americans, 6/13 (4/8 loci) in Hispanics, 5/8 in Pacific Islanders (5/8 loci), and 5/9 (4/8 loci) in American Indians. CONCLUSION: Linkage disequilibrium patterns suggest that tagSNPs selected for European Americans may not adequately tag causal variants in other ancestry groups. Accordingly, fine-mapping in large samples is needed to comprehensively explore these loci in diverse populations.

Phenome-wide association study (PheWAS) for detection of pleiotropy within the Population Architecture using Genomics and Epidemiology (PAGE) Network.

Using a phenome-wide association study (PheWAS) approach, we comprehensively tested genetic variants for association with phenotypes available for 70,061 study participants in the Population Architecture using Genomics and Epidemiology (PAGE) network. Our aim was to better characterize the genetic architecture of complex traits and identify novel pleiotropic relationships. This PheWAS drew on five population-based studies representing four major racial/ethnic groups (European Americans (EA), African Americans (AA), Hispanics/Mexican-Americans, and Asian/Pacific Islanders) in PAGE, each site with measurements for multiple traits, associated laboratory measures, and intermediate biomarkers. A total of 83 single nucleotide polymorphisms (SNPs) identified by genome-wide association studies (GWAS) were genotyped across two or more PAGE study sites. Comprehensive tests of association, stratified by race/ethnicity, were performed, encompassing 4,706 phenotypes mapped to 105 phenotype-classes, and association results were compared across study sites. A total of 111 PheWAS results had significant associations for two or more PAGE study sites with consistent direction of effect with a significance threshold of p<0.01 for the same racial/ethnic group, SNP, and phenotype-class. Among results identified for SNPs previously associated with phenotypes such as lipid traits, type 2 diabetes, and body mass index, 52 replicated previously published genotype-phenotype associations, 26 represented phenotypes closely related to previously known genotype-phenotype associations, and 33 represented potentially novel genotype-phenotype associations with pleiotropic effects. The majority of the potentially novel results were for single PheWAS phenotype-classes, for example, for CDKN2A/B rs1333049 (previously associated with type 2 diabetes in EA) a PheWAS association was identified for hemoglobin levels in AA. Of note, however, GALNT2 rs2144300 (previously associated with high-density lipoprotein cholesterol levels in EA) had multiple potentially novel PheWAS associations, with hypertension related phenotypes in AA and with serum calcium levels and coronary artery disease phenotypes in EA. PheWAS identifies associations for hypothesis generation and exploration of the genetic architecture of complex traits.

Effects of smoking on the genetic risk of obesity: the population architecture using genomics and epidemiology study.

BACKGROUND: Although smoking behavior is known to affect body mass index (BMI), the potential for smoking to influence genetic associations with BMI is largely unexplored. METHODS: As part of the 'Population Architecture using Genomics and Epidemiology (PAGE)' Consortium, we investigated interaction between genetic risk factors associated with BMI and smoking for 10 single nucleotide polymorphisms (SNPs) previously identified in genome-wide association studies. We included 6 studies with a total of 56,466 subjects (16,750 African Americans (AA) and 39,716 European Americans (EA)). We assessed effect modification by testing an interaction term for each SNP and smoking (current vs. former/never) in the linear regression and by stratified analyses. RESULTS: We did not observe strong evidence for interactions and only observed two interactions with p-values <0.1: for rs6548238/TMEM18, the risk allele (C) was associated with BMI only among AA females who were former/never smokers (ß = 0.018, p = 0.002), vs. current smokers (ß = 0.001, p = 0.95, p(interaction) = 0.10). For rs9939609/FTO, the A allele was more strongly associated with BMI among current smoker EA females (ß = 0.017, p = 3.5 x 10(-5)), vs. former/never smokers (ß = 0.006, p = 0.05, p(interaction) = 0.08). CONCLUSIONS: These analyses provide limited evidence that smoking status may modify genetic effects of previously identified genetic risk factors for BMI. Larger studies are needed to follow up our results. CLINICAL TRIAL REGISTRATION: NCT00000611.

Decline in circulating insulin-like growth factors and mortality in older adults: cardiovascular health study all-stars study.

BACKGROUND: The association between changes in IGF-I and IGF binding protein (IGFBP) levels and mortality in older adults is unknown. STUDY DESIGN: Participants were 997 persons 77 to 100 yr old enrolled in the Cardiovascular Health Study All Stars Study. Plasma levels of IGF-I, IGFBP-1, and IGFBP-3 were assessed at two study examinations (1996-1997 and 2005-2006). Mortality was assessed between 2006 and 2010. RESULTS: Cumulative mortality (CM) was similar among individuals who had at least 10% decreases over time in IGF-I levels (CM = 29.6%), individuals who had at least 10% increases over time in IGF-I levels (CM = 24.7%), and individuals who had IGF-I levels remaining within ±10% over time (CM = 23.5%). Adjusted for age, sex, race, diabetes, body mass index, creatinine, albumin, and C-reactive protein, decreasing IGF-I level had no significant association with overall cancer mortality or noncancer mortality. Levels of IGFBP-1 increased markedly over time by 38% (median). Individuals with the largest increases in IGFBP-1 level over time had significantly increased risk of mortality. The adjusted hazard ratio per sd of IGFBP-1 change was 1.40 for overall cancer mortality (95% confidence interval = 1.10, 1.77; P = 0.01) and 1.14 for noncancer mortality (95% confidence interval = 1.02, 1.27; P = 0.02). Changes in IGFBP-3 levels were not significantly associated with mortality. CONCLUSION: Among older adults, decreasing IGF-I level over time does not predict subsequent all-cause mortality, whereas increasing IGFBP-1 predicts increased risk of mortality.