OBJECTIVEPrevious studies on the association between hs-CRP and incident type 2 diabetes among African Americans have been inconclusive. We examined the association between hs-CRP and incident diabetes in a large African American cohort (Jackson Heart Study).RESEARCH DESIGN AND METHODShs-CRP was measured in 3,340 participants. Incident diabetes was defined by fasting glucose ≥126 mg/dL, physician diagnosis, use of diabetes drugs, or A1C ≥6.5% (48 mmol/mol) at follow-up. Cox regression was used to estimate hazard ratios (HRs) for incident diabetes, adjusting for age, sex, education, diabetes family history, alcohol, HDL, triglycerides, hypertension status, hypertension medications, physical activity, BMI, HOMA-insulin resistance (HOMAIR), and waist circumference.RESULTSParticipants (63% women) were aged 53.3 ± 12.5 years. During a median follow-up of 7.5 years, 17.4% developed diabetes (23.1/1,000 person-years, 95% CI 21.3–25.1). After adjustment, the HR (hs-CRP third vs. first tertile) was 1.64 (95% CI 1.26–2.13). In separate models, further adjustment for BMI and waist circumference attenuated this association (HR 1.28 [95% CI 0.97–1.69] and 1.35 [95% CI 1.03–1.78, P < 0.05 for trend], respectively). Upon adding HOMAIR in the models, the association was no longer significant. In adjusted HOMAIR-stratified analysis, the hs-CRP–diabetes association appeared stronger in participants with HOMAIR <3.0 compared with HOMAIR ≥3.0 (P < 0.0001 for interaction). The association was also stronger among nonobese participants, although not significant when adjusted for HOMAIR.CONCLUSIONSLow-grade inflammation, as measured by hs-CRP level, may have an important role in the development of diabetes among African Americans with a lesser degree of insulin resistance.

Activation of the renin-angiotensin-aldosterone system may play a significant role in the development of insulin resistance and diabetes in African Americans.

BackgroundThe concept of ideal cardiovascular health (CVH), defined by the American Heart Association primarily for coronary heart disease and stroke prevention, may apply to diabetes mellitus prevention among blacks.Methods and ResultsOur sample included 2668 adults in the Jackson Heart Study with complete baseline data on 6 of 7 American Heart Association CVH metrics (body mass index, healthy diet, smoking, total cholesterol, blood pressure, and physical activity). Incident diabetes mellitus was defined as fasting glucose ≥126 mg/dL, physician diagnosis, use of diabetes mellitus drugs, or glycosylated hemoglobin ≥6.5%. A summary CVH score from 0 to 6, based on presence/absence of ideal CVH metrics, was derived for each participant. Cox regression was used to estimate adjusted hazard ratios. Mean age was 55 years (65% women) with 492 incident diabetes mellitus events over 7.6 years (24.6 cases/1000 person‐years). Three quarters of participants had only 1 or 2 ideal CVH metrics; no participant had all 6. After adjustment for demographic factors (age, sex, education, and income) and high‐sensitivity C‐reactive protein, each additional ideal CVH metric was associated with a 17% diabetes mellitus risk reduction (hazard ratio, 0.83; 95% CI, 0.74–0.93). The association was attenuated with further adjustment for homeostasis model assessment for insulin resistance (hazard ratio, 0.89; 95% CI, 0.79–1.00). Compared with participants with 1 or no ideal CVH metric, diabetes mellitus risk was 15% and 37% lower in those with 2 and ≥3 ideal CVH metrics, respectively.ConclusionsThe AHA concept of ideal CVH is applicable to diabetes mellitus prevention among blacks. These associations were largely explained by insulin resistance.

Aims/hypothesis Ideal cardiovascular health (CVH) is associated with lower diabetes risk. However, it is unclear whether this association is similar across glycaemic levels (normal [<5.6 mmol/l] vs impaired fasting glucose [IFG] [5.6-6.9 mmol/l]). Methods A secondary data analysis was performed in the REasons for Geographic and Racial Differences in Stroke (REGARDS) study. Incident diabetes was assessed among 7758 participants without diabetes at baseline (2003-2007) followed over 9.5 years. Baseline cholesterol, blood pressure, diet, smoking, physical activity and BMI were used to categorise participants based on the number (0-1, 2-3 and ≥4) of ideal CVH components. Risk ratios (RRs) were calculated using modified Poisson regression, adjusting for cardiovascular risk factors. Results Among participants (mean age 63.0 [SD 8.4] years, 56% female, 73% white, 27% African-American), there were 891 incident diabetes cases. Participants with ≥4 vs 0-1 ideal CVH components with normal fasting glucose (n = 6004) had 80% lower risk (RR 0.20; 95% CI 0.10, 0.37), while participants with baseline IFG (n = 1754) had 13% lower risk (RR 0.87; 95% CI 0.58, 1.30) (p for interaction by baseline glucose status <0.0001). Additionally, the magnitude of the association of ideal CVH components with lower diabetes risk was stronger among white than African-American participants (p for interaction = 0.0338). Conclusions/interpretation A higher number of ideal CVH components was associated with a dose-dependent lower risk of diabetes for participants with normal fasting glucose but not IFG. Tailored efforts that take into account observed differences by race and glycaemic level are needed for the primordial prevention of diabetes.

Introduction The associations of modifiable lifestyle risk factors with incident diabetes are not well investigated in African Americans (AAs). This study investigated the association of modifiable lifestyle risk factors (exercise, diet, smoking, TV watching, and sleep disordered breathing burden) with incident diabetes among AAs. Methods Modifiable lifestyle risk factors were characterized among 3,252 AAs in the Jackson Heart Study free of diabetes at baseline (2000–2004) using baseline questionnaires and combined into risk factor categories: poor (0–3 points), average (4–7 points), and optimal (8–11 points). Incidence rate ratios (IRR) for diabetes (fasting glucose ≥126 mg/dL, physician diagnosis, use of diabetes drugs, or glycosylated hemoglobin A1c (HbA1c) ≥6.5%) were estimated using Poisson regression modeling adjusting for age, sex, education, occupation, systolic blood pressure, and BMI. Outcomes were collected 2005–2012 and data analyzed in 2016. Results Over 7.6 years there were 560 incident diabetes cases (mean age=53.3 years, 64% female). An average or optimal compared to a poor risk factor categorization was associated with a 21% (IRR=0.79, 95% CI=0.62, 0.99) and 31% (IRR=0.69, 95% CI=0.48, 1.01) lower risk of diabetes. Among BMI <30 kg/m2 participants, IRRs for average or optimal compared to poor categorization were 0.60 (95% CI=0.40, 0.91) and 0.53 (95% CI=0.29, 0.97), versus 0.90 (95% CI=0.67, 1.21) and 0.83 (95% CI=0.51, 1.34) among participants with BMI ≥30 kg/m2. Conclusions A combination of modifiable lifestyle factors are associated with a lower risk of diabetes among AAs, particularly among those without obesity.

BackgroundMechanistic studies suggest that aldosterone impairs glucose metabolism. We investigated the cross‐sectional associations of aldosterone and plasma renin activity with fasting plasma glucose, insulin resistance (IR), β‐cell function, and longitudinal association with incident diabetes mellitus among adults in MESA (the multiethnic study of atherosclerosis) prospective cohort study.Methods and ResultsHomeostatic model assessment of IR (HOMA2‐IR) and HOMA2‐β were used to estimate IR and β‐cell function, respectively. Incident diabetes mellitus was defined as fasting plasma glucose ≥126 mg/dL or anti‐diabetic medication use at follow‐up. Linear regression was used to examine cross‐sectional associations of aldosterone with fasting plasma glucose, HOMA2‐IR and HOMA2‐β; Cox regression was used to estimate hazard ratios (HR) for incident diabetes mellitus with multivariable adjustment. There were 116 cases of incident diabetes mellitus over 10.5 years among 1570 adults (44% non‐Hispanic white, 13% Chinese American, 19% Black, 24% Hispanic American, mean age 64±10 years, 51% female). A 100% increase in log‐aldosterone was associated with a 2.6 mg/dL higher fasting plasma glucose, 15% higher HOMA2‐IR and 6% higher HOMA2‐β (P<0.01). A 1‐SD increase in log‐aldosterone was associated with a 44% higher risk of incident diabetes mellitus (P<0.01) with the greatest increase of 142% (P<0.01) observed in Chinese Americans (P for interaction=0.09 versus other ethnicities). Similar cross‐sectional findings for log‐plasma renin activity existed, but log‐plasma renin activity was not associated with incident diabetes mellitus after full adjustment.ConclusionsAldosterone is associated with glucose homeostasis and diabetes mellitus risk with graded associations among Chinese Americans and blacks, suggesting that pleiotropic effects of aldosterone may represent a modifiable mechanism in diabetes mellitus pathogenesis with potential racial/ethnic variation.

BackgroundThe use of the electronic medical record (EMR) system in recruitment in clinical trials has the potential for providing a very reliable and cost-effective recruiting methodology which may improve participant recruitment in clinical trials. We examined a recruitment approach centered on the use of the EMR, as well as other traditional methods, in the Lifestyle Intervention for Treatment of Diabetes (LIFT Diabetes) trial.MethodsLIFT Diabetes is a randomized controlled trial designed to investigate the effects of two contrasting interventions on cardiovascular disease risk: a community-based intensive lifestyle program aimed at achieving weight loss and a clinic-based enhanced diabetes self-management program. Eligible participants were overweight/obese (body mass index, BMI ≥25 kg/m2) patients with type 2 diabetes who were aged 21 years or older. Recruitment strategies included the use of the EMR system (primary), direct referrals, media advertisements, and community screenings.ResultsA total of 1102 telephone screens were conducted, resulting in randomization of 260 participants (61.5 % from EMR, mean age 56.3 years, 66.2 % women, 48.1 % non-Hispanic blacks) over a 21-month period, with a yield of 23.6 %. Recruitment yields differed by recruitment method, with referrals having the highest yield (27.5 %). A history of cardiovascular disease was the main health reason for exclusion from the study (16.5 %). An additional 8.9 % were excluded for BMI <25 kg/m2 (<27 kg/m2 for insulin users), 5.4 % could not exercise, 5.2 % had an HbA1c >11 %, and 34.9 % were excluded for other non-medical reasons. Exclusion criteria did not appear to differentially affect enrollment in terms of race or ethnicity.ConclusionsFuture clinical studies should tailor their recruitment strategies based on the participant demographics of interest. Efficient methods such as using the EMR system and referrals should be prioritized over labor-intensive, low-yielding methods such as community screenings and mass mailings.Trial registrationClinicalTrials.gov: NCT01806727. Registered on 5 March 2013.Electronic supplementary materialThe online version of this article (doi:10.1186/s13063-016-1631-7) contains supplementary material, which is available to authorized users.

Background There is a paucity of data on the association of aldosterone and plasma renin activity (PRA) with incident cardiovascular disease (CVD) or all-cause mortality (mortality) among community-dwelling African Americans (AAs). Objective We examined the association of aldosterone and PRA with incident CVD (composite endpoint of coronary heart disease (CHD), stroke and heart failure) and mortality among AAs in the Jackson Heart Study. Methods A total of 4,985 AA adults, aged 21–94 years, were followed for 12 years. Aldosterone, PRA, and cardiovascular risk factors were collected at baseline (2000–2004). Incident events included CHD and stroke (assessed from 2000–2011) and heart failure (assessed from 2005–2011). Cox models were used to estimate hazard ratios (HR) for incident CVD and mortality adjusting for age, sex, education, occupation, current smoking, physical activity, dietary intake and body mass index. Results Among 4,160 participants without prevalent CVD over a median follow-up of 7 years, there were 322 incident CVD cases. In adjusted analyses, each 1-unit standard deviation (SD) increase in log-aldosterone and log-PRA were associated with HRs of 1.26 (95% CI: 1.14, 1.40) and 1.16 (95% CI: 1.02, 1.33) for incident CVD, respectively. Over a median of 8 years, 513 deaths occurred among 4,985 participants. In adjusted analyses, each 1-unit SD increase in log-aldosterone and log-PRA were associated with HRs of 1.13 (95% CI: 1.04, 1.23) and 1.12 (95% CI: 1.01, 1.24) for mortality, respectively. Conclusions Elevated aldosterone and PRA may play a significant role in the development of CVD and all-cause mortality among AAs.