Low plasma apelin in newly diagnosed type 2 diabetes in Chinese people.

I t has been unclear whether there is a pathway that regulates plasma glucose through the action of peripheral tissue of apelin with the secretory function of insulin, which exerts a control in adipo-cytes in addition to the direct regulation of plasma glucose. Our study was designed to identify the changes in plasma apelin levels in newly diagnosed type 2 diabetes in Chinese people. We also tried to investigate the possible association of apelin, the status of hyperglycemia, and insulin secretion. The study population consisted of 75 patients with newly diagnosed and untreated type 2 diabetes and 36 healthy control subjects matched for age, sex, and BMI. Fasting plasma glucose (FPG), fasting serum insulin, A1C, and C-reactive protein (CRP) were measured. A steady-state model (homeostasis model assessment [HOMA]) (1) was used to assess insulin resistance (HOMA-IR) and ␤-cell function. Plasma apelin-17 levels were determined by radioimmunoassay (RIA) (human apelin-17 125 I-tracer RIA kit; Bachem Americas) (sensitivity: [mini-mum detectable concentration] ϭ 0.1 ng/ml, IntraCV:5% and InterCV:10%). An unpaired Student t test and Mann-Whitney U test were used to compare mean values among the type 2 diabetic control subjects and the healthy control group. Spearman rank correlation test and multiple stepwise regression analysis were used to show the relationship among HOMA-insulin sensitivity (IS), apelin, FPG, and A1C. Plasma apelin levels were significantly lower in the diabetic group compared with the control subjects (0.11 vs.