Women with a history of gestational diabetes (GD) who sleep less than seven hours per day and snore frequently have a significantly increased risk of developing type 2 diabetes (T2D), according to a prospective cohort study published March 5 in JAMA Network Open.

The study included a subset of women from the Nurses' Health Study II (NHSII) who had a history of GD and answered questions on sleep characteristics in the NHSII questionnaire (administered June 2001 to June 2003), which served as a baseline for follow-up (mean duration, 17.3 years). Xin Yin, PhD, et al., aimed to assess sleep duration and quality (snoring, daytime sleepiness) among 2,891 women from the NHSII cohort diagnosed with a history of GD (mean age, 45.3 years) and determine their risk of developing T2D.

Results showed that 563 women (19.5%) with a history of GD developed T2D during 42,155 person-years of follow-up. Specifically, women who reported snoring occasionally or regularly had a significantly higher risk for T2D (adjusted hazard ratio [aHR], 1.61; 95% CI, 1.18-2.02) vs. women who rarely snored (aHR, 1.54; 95% CI, 1.21-2.13). Additionally, the risk for T2D was significantly higher for women with a short sleep duration (≤six hours) vs. compared with women who slept seven to eight hours (HR, 1.32). The highest risk for T2D was seen in women who slept six hours or less plus snored regularly (HR, 2.09).

The researchers also looked at biomarkers (glycated hemoglobin [HbA_1c], C-peptide and insulin) across sleep characteristic categories among the 527 women who provided fasting blood samples. Women who snored regularly vs. those who rarely snored had significantly higher HbA_1c (least-squares means [LSM], 5.89), C-peptide (LSM, 4.30) and insulin (LSM, 11.25) levels (p=0.01 for trend for all).

The investigators write that the findings demonstrate the importance of improving sleep health to prevent progression of T2D in women already at high risk due to a history of GD. Moreover, in an accompanying editorial comment, Christian Benedict, PhD, and Marie-Pierre St-Onge, PhD, write that the results "underscore the critical need to incorporate sleep health into a comprehensive strategy aimed at reducing long-term T2D risk" in this population.