Sleep Quality is an Independent Predictor of Blood Glucose and Gestational Diabetes Mellitus: A Longitudinal Study of 4550 Chinese Women

PURPOSE: To investigate whether pregnant women’s subjective sleep quality during the first trimester independently predicted blood glucose and gestational diabetes mellitus (GDM). METHODS: A total of 4550 pregnant women in the first trimester were enrolled in Chongqing Health Center for Women and Children, China, from January to October 2020.The Pittsburgh Sleep Quality Index (PSQI) was used to measure subjective sleep quality. Depression symptoms and anxiety were measured with the Patient Health Questionnaire-9 (PHQ-9) and General Anxiety Disorder-7 (GAD-7). Oral glucose tolerance tests (OGTT) and blood glucose area under the curve (AUC) were used for estimation of blood glucose and diagnosis of GDM during the second trimester. Linear, mixed model, and logistic regression were used to analyze the association between PSQI and blood glucose as well as GDM. RESULTS: 946/4550 were diagnosed with GDM (20.8%). In the mixed model analysis, the blood glucose level of the highest-scoring group (PSQI score = 18) was 1.94 (95% CI: 0.45~3.43, P = 0.011) mmol/L higher than that of the lowest-scoring group (PSQI score = 0). After adjusting for potential confounders, a one-point PSQI score increase was associated with a 0.014 (95% CI: 0.001~0.027, P = 0.039) mmol/L increase in blood glucose level. Blood glucose AUC was also positively associated with PSQI scores (β = 0.034, 95% CI: 0.003~0.064, P = 0.030). The results for the logistic regression model showed that PSQI was marginal positively correlated with GDM (OR = 1.146, 95% CI: 0.995~1.321, P = 0.059) when age and BMI were not controlled for. When investigating the association between PSQI and the GDM-diagnosed time window, the 1-h diagnosed GDM had a borderline positive correlation with PSQI (OR = 1.182, 95% CI: 0.993~1.405, P = 0.060). CONCLUSION: Sleep quality during the first trimester may be a risk factor for elevated blood glucose and GDM later in gestation.