Researchers conducted this study to identify leanness and impaired insulin secretion with Japanese gestational diabetes mellitus (GDM). 

A cross-sectional study was conducted comprising 219 at-risk pregnant women who underwent a 75g glucose tolerance test at a single institute in Tokyo, Japan. We identified GDM and standard glucose tolerance (NGT). Researchers determined the cut-off value of the HOMA-IR for detecting GDM. We compared the prepregnancy BMI and homeostasis model assessment of β-cell function (HOMA-β) between the group comprising low insulin resistance (LIR) and HIR. 

Researchers identified seventy GDM cases and 149 NGT cases. By using receiver operating characteristic curve analysis, the HOMA-IR cut-off value was determined to be 1.41. Twenty-five GDM cases (36%) were classified as LIR, and forty-five GDM cases (64%) were classified as HIR. The background, including indications for having 75gOGTT and the gestational age of having 75gOGTT, did not differ between groups. The LIR group’s BMI was significantly lower than that of the HIR group, and the HOMA-β of the LIR group was considerably lower than that of the HIR group.

Leanness with impaired insulin secretion is deeply involved in Japanese gestational diabetes mellitus.