Association of Adiposity With Incident Diabetes Among Black Adults in the Jackson Heart Study

Abstract

Background The prognostic value of anthropometric, adipokine, and computed tomography measures of adiposity to predict diabetes in Black, specifically by normoglycemia versus prediabetes, remains incompletely understood. Methods and Results Among Black participants without diabetes in the JHS (Jackson Heart Study), waist circumference [WC], body mass index, adiponectin, leptin, and leptin:adiponectin ratio were standardized in sample 1 (2422 participants at baseline [2000–2004]) and WC, body mass index, visceral adipose tissue (VAT), subcutaneous adipose tissue, and liver attenuation in 1537 participants at examination 2 (2005–2008) (sample 2). Hazard ratios (HRs) for diabetes were estimated using interval‐censored Cox modeling adjusting for traditional risk factors and validated with the C index. Over 5 years, 300 and 122 incident diabetes cases occurred in sample 1 and sample 2, respectively. In sample 1 and sample 2, a 1‐SD higher log‐leptin:adiponectin ratio and VAT had the strongest associations (HR, 1.95 [95% CI, 1.67–2.27] and 1.76 [95% CI, 1.52–2.04]) and discriminatory power (C index 0.68 [95% CI, 0.64–0.71] and C index 0.67 [95% CI, 0.61–0.74]) with diabetes. The normoglycemic compared with the prediabetes group had a 1.3 to 1.9 times greater magnitude of associations with diabetes for WC, liver attenuation, and VAT ( P interaction <0.10). In sample 2, C indices for WC (HR, 0.84; 95% CI, 0.73–0.95), VAT (HR, 0.91; 95% CI, 0.85–0.98), and liver attenuation (HR, 0.90; 95% CI, 0.77–1.00) were greater than HbA 1c (HR, 0.74; 95% CI, 0.57–0.90) in normoglycemia, whereas HbA 1c was best in prediabetes (HR, 0.72; 95% CI, 0.66–0.78). Conclusions Overall, among Black adults, multiple measures of adiposity were associated with incident diabetes with modest predictive ability. In Black patients with normoglycemia, WC, liver attenuation, and VAT may appropriately identify those at high risk for diabetes, whereas HbA 1c was the best predictor in individuals with prediabetes.