Emerging data suggests that type 2 diabetes (DM) incidence is rapidly rising in Africa. Beta-cell failure rather than insulin resistance (IR) may be the precipitator. As causative data allows for optimization of therapy, screening strategies to determine when beta-cell failure is the primary cause of DM are essential. OGTT were performed in 589 African-born Blacks (Male: 64% (374/589), Age: 39±11y (mean±SD), BMI: 27.1±4.5 kg/m2). Insulin resistance (IR) was defined by the threshold at the lowest quartile of the population distribution for Matsuda Insulin Sensitivity Index (MISI) (≤2.89) and upper quartile for HOMA-IR, Lipid Accumulation Product (LAP) and TG-Glucose Index (TyG) (Table). With the MISI as the standard, the ability to predict IR by each index was assessed by AUC-ROC. Beta-cell failure was defined by the presence of DM in the absence of IR. K-statistic was used for beta-cell failure detection by each index relative to the MISI. DM was identified in 7% (40/589). In Africans with DM, beta-cell failure occurred in 45% (18/40); IR in 55% (22/40). AUC-ROC for IR prediction was highest for HOMA-IR (Table). By k-statistic criteria, the ability of HOMA-IR to detect beta-cell failure was excellent, but only fair for LAP and TyG. Overall, nearly half of Africans with DM have beta-cell failure as the primary cause, denoting the critical need for determining DM pathophysiology, and HOMA-IR may be the most clinically relevant test to detect etiology.
M. Sayed: None. P. Thyparambil Aravindakshan: None. C. Worthy: None. E.A. Huefner: None. J. Hurston: None. C. DuBose: None. R. Jagannathan: None. A.E. Sumner: None.
