Waist-to-hip ratio is the most relevant obesity index at each phase of insulin secretion among obese patients.

We aimed to explore the relationship between different obesity indices and insulin secretion at each phase among obese subjects and to find out the most relevant obesity index. Height, weight, waist circumstance, and hip circumstance were obtained among 419 obese subjects to calculate body mass index (BMI), waist-to-hip ratio (WHR), waist-to-height ratio, body adiposity index (BAI), conicity index, abdominal volume index and a body shape index (ABSI). Fasting plasma glucose and fasting insulin were detected to calculate HOMA-β. Early and late insulin secretion indices: ΔI30/ΔG30 and DI60-120 were calculated according to the result of a 75-g oral glucose tolerance test among the 235 subjects not meeting the standard of diabetes. Pearson correlation analysis and multiple linear regression analysis were used. BMI (β = 0.022, p = 0.000) and WHR (β = -1.557, p = 0.000) were independent correlation factors with HOMA-β. In 235 OGTT subjects, WHR was independently and negatively associated with ΔI30/ΔG30 and DI60-120 (β = -1.187, p = 0.026; β = -1.241, p = 0.001, respectively). ABSI was independently and negatively associated with ΔI30/ΔG30 (β = -17.249, p = 0.012). WHR was the best and consistently correlated factor with insulin secretion at each phase among obese subjects from Hunan Province in China.