Use of the National Heart, Lung, and Blood Institute Data Repository.

BACKGROUND: Research on data sharing from clinical trials has focused on elucidating perceptions, barriers, and attitudes among trialists and study participants with respect to sharing data. However, little information exists regarding utilization or associated publication of articles once clinical trial data have been widely shared. METHODS: We analyzed administrative records of investigator requests for data access, linked publications, and bibliometrics to describe the use of the National Heart, Lung, and Blood Institute data repository. RESULTS: From January 2000 through May 2016, a total of 370 investigators requested data from 1 or more clinical trials. Requests for trial data have been increasing, with 195 investigators (53%) initiating requests during the last 4.4 years of the study period. The predominant reason for requesting data was post hoc secondary analysis of new questions (72%), followed by analytic or statistical approaches to clinical trials (9%) and meta-analyses or pooled study research (7%). Of 172 requests with online project descriptions, only 2 requests were initiated for reanalysis of primary-outcome findings. Data from 88 of 100 available clinical trials were requested at least once, and the median time from repository availability to first request was 235 days. A total of 277 articles were published on the basis of data from 47 trials. Citation metrics from 224 articles indicated that half of the publications have cumulative citations that rank in the top 34% normalized for subject category and year of publication. CONCLUSIONS: Demand for trial data for secondary analysis has been increasing. Requesting data for the a priori purpose of reanalysis or verification of original findings was rare.

Individual education, area income, and mortality and recurrence of myocardial infarction in a Medicare cohort: the National Longitudinal Mortality Study.

BACKGROUND: The Medicare program provides universal access to hospital care for the elderly; however, mortality disparities may still persist in this population. The association of individual education and area income with survival and recurrence post Myocardial Infarction (MI) was assessed in a national sample. METHODS: Individual level education from the National Longitudinal Mortality Study was linked to Medicare and National Death Index records over the period of 1991-2001 to test the association of individual education and zip code tabulation area median income with survival and recurrence post-MI. Survival was partitioned into 3 periods: in-hospital, discharge to 1 year, and 1 year to 5 years and recurrence was partitioned into two periods: 28 day to 1 year, and 1 year to 5 years. RESULTS: First MIs were found in 8,043 women and 7,929 men. In women and men 66-79 years of age, less than a high school education compared with a college degree or more was associated with 1-5 year mortality in both women (HRR 1.61, 95% confidence interval 1.03-2.50) and men (HRR 1.37, 1.06-1.76). Education was also associated with 1-5 year recurrence in men (HRR 1.68, 1.18-2.41, < High School compared with college degree or more), but not women. Across the spectrum of survival and recurrence periods median zip code level income was inconsistently associated with outcomes. Associations were limited to discharge-1 year survival (RR lowest versus highest quintile 1.31, 95% confidence interval 1.03-1.67) and 28 day-1 year recurrence (RR lowest versus highest quintile 1.72, 95% confidence interval 1.14-2.57) in older men. CONCLUSIONS: Despite the Medicare entitlement program, disparities related to individual socioeconomic status remain. Additional research is needed to elucidate the barriers and mechanisms to eliminating health disparities among the elderly.

The Productivity of NHLBI-Funded Obesity Research, 1983-2013.

OBJECTIVE: To describe and elucidate the time trends of the academic productivity of NHLBI's obesity-related research funding via bibliometric analysis of 30 years of NHLBI-supported obesity-related publications. METHODS: In total, 3,545 NHLBI-funded obesity-related publications were identified in the Thomson Reuters InCites™ database. Shared references in a community detection algorithm were used to identify publication topics. Characteristics of publications and topical communities were analyzed based on citation count and percentile rank. A percentile rank >90 was considered "highly cited." RESULTS: Obesity-related publications increased more than 10-fold over 30 years, whereas NHLBI-funded publications only increased twofold NHLBI-funded obesity publications were cited a median of 23 times (IQR 8-55, range 0-2,047, mean 52). Thirty percent of these publications were highly cited compared to the expected ten percent. Six topical communities were present in 1983 compared to 16 in 2013. The most highly cited topical areas were sleep (n = 199 publications, 38% highly cited), cardiovascular morbidity and mortality (n = 277, 36%), obesity correlates and consequences (n = 588, 35%), and asthma and inflammation (n = 283, 35%). CONCLUSIONS: NHLBI-funded obesity publications have contributed substantially to the obesity literature, with many highly cited. Publications grew in number and topical diversity over 30 years and grew at a faster rate than total NHLBI publications.

Providing Contemporary Access to Historical Biospecimen Collections: Development of the NHLBI Biologic Specimen and Data Repository Information Coordinating Center (BioLINCC).

The National Heart, Lung, and Blood Institute (NHLBI), within the United States' National Institutes of Health (NIH), established a Biorepository in 1976 that initially archived biospecimens from population-based blood product safety surveys. It was later expanded to biospecimens from clinical and epidemiological studies in heart, lung, and blood disorders. The NHLBI also established a Data Repository in 2000 to store and distribute study data from NHLBI-sponsored research. The NHLBI Biologic Specimen and Data Repository Information Coordinating Center (BioLINCC) was established in 2008 to develop the infrastructure needed to link the contents of these two related NHLBI Repositories, facilitate access to repository resources, and streamline request processes. Three key program subcomponents were developed simultaneously: 1) the linkage of biospecimen electronic inventory records with their clinical or characterization data; 2) the development and implementation of a website with both public-facing information and private processing workspaces; and 3) the development of processes to maximize efficiency via a web-based system while maintaining workflow control, document tracking, and secure processes. The BioLINCC website was launched on October 1, 2009 with eight biospecimen collections and data from 72 research studies. By the end of the fourth online year, 38 biospecimen collections were linked and posted, and data from 108 research studies had been made available for request. The number of registered users by the end of the fourth online year approached 2600, and continues to show a trend towards an increasing rate of new users per year. BioLINCC has fulfilled 381 requests comprising 851 data collections, as well as 600 teaching dataset requests and 75 data renewal agreements. 154 biospecimen requests comprising 147,388 biospecimens were fulfilled or actively in process. We conclude that the BioLINCC program has been successful in its goal to increase the visibility and utilization of NHLBI biospecimen and data repository resources.

Duration and Degree of Weight Gain and Incident Diabetes in Younger Versus Middle-Aged Black and White Adults: ARIC, CARDIA, and the Framingham Heart Study.

OBJECTIVE: To determine whether duration and degree of weight gain are differentially associated with diabetes risk in younger versus middle-aged black and white adults. RESEARCH DESIGN AND METHODS: We combined data from three cohort studies: Atherosclerosis Risk in Communities (ARIC), Coronary Artery Risk Development in Young Adults (CARDIA), and the Framingham Heart Study. A total of 17,404 participants (56% women; 21% black) were stratified by baseline age (younger: ≥30 and <45 years; middle-aged: ≥45 and <60 years) and examined for incident diabetes (median follow-up 9 years). Duration and degree of gain in BMI were calculated as "BMI-years" above one's baseline BMI. RESULTS: Diabetes incidence per 1,000 person-years in the younger and middle-aged groups was 7.2 (95% CI 5.7, 8.7) and 24.4 (22.0, 26.8) in blacks, respectively, and 3.4 (2.8, 4.0) and 10.5 (9.9, 11.2) in whites, respectively. After adjusting for sex, baseline BMI and other cardiometabolic factors, and age and race interaction terms, gains in BMI-years were associated with higher risk of diabetes in the younger compared with middle-aged groups: hazard ratios for 1-unit increase in log BMI-years in younger versus middle-aged blacks were 1.18 (P = 0.02) and 1.02 (P = 0.39), respectively (P for interaction by age-group = 0.047), and in whites were 1.35 (P < 0.001) and 1.11 (P < 0.001), respectively (P for interaction by age-group = 0.008). CONCLUSIONS: Although middle-aged adults have higher rates of diabetes, younger adults are at greater relative risk of developing diabetes for a given level of duration and degree of weight gain.

Smoking and diabetes differ in their associations with subclinical atherosclerosis and coronary heart disease-the ARIC Study.

Atherosclerosis, nearly universally present in major arteries of Western adults, is characterized in all affected arteries by cholesterol-laden plaques and consistently associated with blood cholesterol levels. Other risk factors are reported to have relatively stronger or weaker associations with different atherosclerotic manifestations, but such differences have never previously been quantified. Measuring them may offer fresh clues to atherogenic processes and their prevention. The Atherosclerosis Risk in Communities Study (ARIC) ascertained incident coronary heart disease (CHD) and measured subclinical atherosclerosis as carotid artery intimal medial thickness using ultrasound and as lower extremity arterial disease (LEAD) using ankle-brachial blood pressure index. Blood cholesterol was associated with all endpoints. When standardized against LDL cholesterol associations, diabetes and smoking showed substantially different strengths of associations with different endpoints. Relative to associations with LDL cholesterol: (1) smoking, but not diabetes, increased in its strength of association with the severity of the underlying arterial disease; (2) the diabetes and smoking associations with CHD were much stronger in women than men, a phenomenon which, the standardization pattern suggests, is due to a gender difference in CHD pathogenesis, possibly attributable to arteriolar differences.

Sharing individual level data from observational studies and clinical trials: a perspective from NHLBI.

There are numerous benefits to the research community from data sharing, and yet the open sharing of participant level data is not without potential pitfalls. In addition to the scientific community, the interests of study participants who volunteered their data must be considered, along with the interests of study investigators who expend a substantial amount of effort into the design, conduct, and analytical plans for the study. The National Heart, Lung, and Blood Institute (NHLBI) has developed a data-sharing protocol focused on balancing the interests of study participants, study investigators, and the research community with independent oversight by the NHLBI IRB. The data repository presently includes individual level data on more than 560,000 participants from 100 Institute-supported clinical trials and observational studies.

Blood pressure and the risk of developing diabetes in african americans and whites: ARIC, CARDIA, and the framingham heart study.

OBJECTIVE: We examined the association between high blood pressure and incident type 2 diabetes in African Americans and whites aged 35-54 years at baseline. RESEARCH DESIGN AND METHODS: We combined data from the Atherosclerosis Risk in Communities (ARIC) study, the Coronary Artery Risk Development in Young Adults (CARDIA) study, and the Framingham Heart Study offspring cohort. Overall, 10,893 participants (57% women; 23% African American) were categorized by baseline blood pressure (normal, prehypertension, hypertension) and examined for incident diabetes (median follow-up 8.9 years). RESULTS: Overall, 14.6% of African Americans and 7.9% of whites developed diabetes. Age-adjusted incidence was increasingly higher across increasing blood pressure groups (P values for trend: <0.05 for African American men; <0.001 for other race-sex groups). After adjustment for age, sex, BMI, fasting glucose, HDL cholesterol, and triglycerides, prehypertension or hypertension (compared with normal blood pressure) was associated with greater risks of diabetes in whites (hazard ratio [HR] for prehypertension: 1.32 [95% CI 1.09-1.61]; for hypertension: 1.25 [1.03-1.53]), but not African Americans (HR for prehypertension: 0.86 [0.63-1.17]; for hypertension: 0.92 [0.70-1.21]). HRs for developing diabetes among normotensive, prehypertensive, and hypertensive African Americans versus normotensive whites were: 2.75, 2.28, and 2.36, respectively (P values <0.001). CONCLUSIONS: In African Americans, higher diabetes incidence among hypertensive individuals may be explained by BMI, fasting glucose, triglyceride, and HDL cholesterol. In whites, prehypertension and hypertension are associated with greater risk of diabetes, beyond that explained by other risk factors. African Americans, regardless of blood pressure, have greater risks of developing diabetes than whites.

Relationships of BMI to cardiovascular risk factors differ by ethnicity.

The burden of cardiovascular risk associated with obesity disproportionately affects African Americans and little is known about ethnic/racial differences in the relationship of obesity to cardiometabolic risk. This report assesses whether obesity is similarly associated with cardiometabolic risk factors in African Americans and whites of European ancestry. Cross-sectional observational data from the Jackson Heart Study (JHS) and the Framingham Heart Study (FHS) were compared. This analysis uses participants aged 35-74 years with BMI >18.5 kg/m(2), and free of prevalent cardiovascular disease (CVD), from the initial JHS clinical examination (2000-2004) and the FHS Offspring (1998-2001) and Third Generation (2002-2005) cohorts. Participants were evaluated for the presence of lipid abnormalities, hypertension, and diabetes. Overall, 4,030 JHS (mean age 54 years, 64% women) and 5,245 FHS (mean age 51 years, 54% women) participants were available for analysis. The prevalence of all risk factors except high triglycerides and low high-density lipoprotein (HDL) was substantially higher in JHS (all P < 0.001) and BMI was associated with increasing prevalence of most CVD risk factors within each race. For diabetes mellitus, hypertension, and low HDL, steeper relationships to BMI were observed in FHS than in JHS (P values <0.001-0.016). There were larger proportional increases in risk factor prevalence with increasing BMI in whites than in African Americans. The higher prevalence rates of cardiometabolic risk factors at nearly all levels of BMI in African Americans, however, suggest that additional factors contribute to the burden of CVD risk in African Americans.

Prevalence, awareness, treatment, and control of hypertension in the Jackson Heart Study.

African Americans have higher reported hypertension prevalence and lower control rates than other ethnic groups in the United States. Hypertension prevalence, awareness, treatment, and control (outcomes) and potentially associated demographic, lifestyle, comorbidity, and health care access factors were examined in 5249 adult participants (3362 women and 1887 men) aged 21 to 94 years enrolled in the Jackson Heart Study. Hypertension prevalence (62.9%), awareness (87.3%), treatment (83.2%), and control (66.4%) were high. Control declined with advancing age; estimates for all of the outcomes were higher for women compared with men. Lower socioeconomic status was associated with prevalence and control. Smoking was negatively associated with awareness and treatment, particularly among men. Comorbidities (diabetes, chronic kidney disease, and cardiovascular disease), likely driven by the high rates of obesity, correlated with hypertension prevalence, awareness, treatment, and control. Lack of health insurance was marginally associated with poorer control, whereas use of preventive care was positively associated with prevalence, awareness, and treatment, particularly among men. In comparisons with the 1994-2004 National Health and Nutrition Examination Survey data adjusted to Jackson Heart Study sex, age, and socioeconomic status distribution, control rates among Jackson Heart Study participants appeared to be higher than in their national counterparts and similar to that of whites. These results suggest that public health efforts to increase awareness and treatment among African Americans have been relatively effective. The Jackson Heart Study data indicate that better control rates can be achieved in this high-risk population.

Interactive effects between polymorphisms in the beta-adrenergic receptors and longitudinal changes in obesity.

We assessed interactions between polymorphisms in the beta-adrenergic receptor genes and longitudinal changes in obesity from childhood to adulthood using longitudinal data collected over a 24-year period from 1973 to 1996. Sex- and age-stratified analyses using random coefficients models were used to examine gene-gene interaction effects on obesity measures in 1179 African-American and white men and women (71% white, 57% women). Suggestive evidence for an interaction (p = 0.022) between the beta1- and beta2-adrenergic receptors was observed in men for longitudinal change in BMI. Men with Gly/Gly genotypes for both the beta1 and beta2 receptors showed significant increases (approximately 0.6%/yr) in BMI from childhood to adulthood. Women showed suggestive evidence for an interaction (p = 0.035) between the beta1- and beta3-adrenergic receptors for change over time in BMI. Women with Gly/Gly genotypes at the beta1-receptor and carrying at least one beta3-Arg allele showed notable increases in BMI. The regulation of lipolysis and development of obesity differ markedly between men and women and may be influenced by genetic polymorphisms, which contribute to the efficiency of the beta-adrenergic receptors, and hormonal effects on adrenergic receptor activity.

Vasectomy, inflammation, atherosclerosis and long-term followup for cardiovascular diseases: no associations in the atherosclerosis risk in communities study.

PURPOSE: Although human studies have failed to reveal an increased risk of clinical cardiovascular disease in men who undergo vasectomy, the possibility exists that an association may be detectable only after a long followup, or it may be more evident for subclinical than clinical disease. We assessed the association of vasectomy with inflammation and coagulation factors, carotid intimal-medial thickness, carotid plaque, prevalent peripheral arterial disease, and incident coronary heart disease and stroke in the Atherosclerosis Risk in Communities cohort. MATERIALS AND METHODS: Included in the study were 3,957 white men 45 to 64 years old who were free of coronary heart disease at the Atherosclerosis Risk in Communities (ARIC) baseline examination in 1987 to 1989. Data on vasectomy was collected at baseline by self-reporting. High resolution B-mode ultrasound was done to assess carotid intimal-medial thickness and carotid plaque. The cohort was followed an average of 9 years for incident cardiovascular events. RESULTS: Average time since vasectomy was 16 years. Approximately 20% of the population had undergone vasectomy 20 years or more ago at baseline. Multivariate analysis showed no association of vasectomy status with inflammation or coagulation factors, peripheral arterial disease, carotid plaque, carotid far wall thickness, incident coronary heart disease or stroke. Associations were unaffected by the time since vasectomy. CONCLUSIONS: There is no evidence in this population based sample of men indicating that vasectomy is related to atherosclerosis even after more than 20 years of followup.

Genetic variability of adult body mass index: a longitudinal assessment in framingham families.

OBJECTIVE: To explore the contribution of genetics to the mean, SD, maximum value, maximum less the mean, and change over time in body mass index (BMI) and the residual of body weight after adjustment for height. BMI is frequently used as a general indicator of obesity because of its ease and reliability in ascertainment. Cross-sectional twin and family studies have shown a moderate-to-substantial genetic component for BMI. However, the contribution of genetics to the long-term average, variability, or change over time in BMI is less clear. RESEARCH METHODS AND PROCEDURES: Longitudinal data from the Framingham heart study were used to create pedigrees of age-matched individuals. Heritability estimates were derived using variance-decomposition methods on a total of 1051 individuals from 380 extended pedigrees followed for a period of 20 years. All subjects were followed from approximately age 35 to 55 years. RESULTS: Moderate heritability estimates were found for the mean BMI (h(2) = 0.37), maximum BMI (h(2) = 0.40), and the mean residual of body weight (h(2) = 0.36). Low heritability estimates (h(2) congruent with 0.20) were found for the maximum less the mean in BMI and the SDs of BMI and residual of body weight. No additive genetic contribution was found for the average change over time in BMI or the residual of body weight. DISCUSSION: These findings suggest that there is a significant genetic component for the magnitude of BMI throughout an individual's middle-adult years; however, little evidence was found for a genetic contribution to the variability or rate of change in an individual's BMI.