Interaction effect between long sleep duration in early pregnancy and prepregnancy overweight/obesity on gestational diabetes mellitus

Objective To explore the individual and interaction effects of sleep duration and prepregnancy body mass index (BMI) on gestational diabetes mellitus (GDM). Methods Pregnant women who attended antenatal visits in 2 hospitals were selected as the study population. Sleep duration and prepregnancy BMI were collected through a semiquantitative questionnaire, and GDM was diagnosed according to an oral glucose tolerance test (OGTT). Results In total, 196 women with GDM and 304 controls were included. Compared with the normal weight women, the prepregnancy overweight/obese group had an increased risk of GDM (OR: 7.04, p < 0.001); compared with women who slept 7–8.9 h/night, women who slept < 7, 9–9.9, or ≥ 10 h/night had an increased risk of GDM (all p < 0.001). The participants with a combination of long sleep duration (≥ 10 h/night) and prepregnancy overweight/obesity had the highest risk of GDM (OR = 39.57, p < 0.001), and this effect was greater than the product of the individual effects of a long sleep duration and overweight/obesity ( p value of the interaction 0.007). Conclusions A short or long sleep duration in early pregnancy and prepregnancy overweight/obesity is related to GDM, and there is a synergic effect between a long sleep duration and overweight/obesity on GDM.