medwireNews: Shorter sleep duration and both regular and occasional snoring are associated with a significantly increased risk for type 2 diabetes among women with a history of gestational diabetes, researchers report in JAMA Network Open.
Cuilin Zhang (National University of Singapore) and colleagues say their findings “suggest that improving sleep health may be important to reduce [type 2 diabetes] incidence in this high-risk population.”
Using Nurses’ Health Study II data, they identified 2891 women (mean age 45 years) with a history of gestational diabetes who had provided details on sleep characteristics during the 2001 questionnaire.
Over a mean 17.3 years of follow-up, 563 (19.5%) of these women developed type 2 diabetes.
After adjusting for age, parity, family history of diabetes, diet, BMI, and other potential confounders, the researchers found that women who reported occasional snoring (1–2 nights/week) had a significant 1.54-fold higher risk for type 2 diabetes than those who reported almost never snoring (0 nights/week). For women who reported regular snoring (≥3 nights/week), the risk increase was a significant 1.61-fold relative to those who rarely snored.
Zhang et al also observed that women who slept for 6 or fewer hours/night were a significant 1.32 times more likely to develop type 2 diabetes than those who slept 7–8 hours/night, after adjustment for potential confounders.
The team then investigated whether snoring frequency and sleep duration had an additive effect on diabetes risk. They found that women who snored regularly and slept 6 or fewer hours/night had the highest risk for type 2 diabetes, at a hazard ratio (HR) of 2.06 versus women who almost never snored and slept 7–8 hours/night. The HR was 2.04 for women who occasionally snored and slept 6 or fewer hours/night.
The researchers also carried out a biomarker analysis for 527 women who provided fasting blood samples and sleep information. This showed that, compared with women who almost never snored, those who snored regularly had significantly higher least squares mean levels of glycated hemoglobin (5.89 vs 5.78%; 41 vs 40 mmol/mol), C-peptide (4.30 vs 3.81 ng/mL), and insulin (11.25 vs 9.16 µIU/mL).
By contrast, there was no significant association between sleep duration and metabolic biomarker levels.
Zhang and co-authors say: “Although the exact molecular mechanisms are unclear, the observed association of short sleep duration and [type 2 diabetes] is biologically plausible through the impacts of sympathetic nervous system activity and hormone changes on glucose metabolism.”
They also note that habitual snoring is often associated with obstructive sleep apnea (OSA), which is a common comorbidity in people with type 2 diabetes.
“Biologically, OSA may be linked to abnormal glucose metabolism and increased [type 2 diabetes] risk through intermittent hypoxemia and sleep fragmentation,” they write, adding: “Our biomarker results supported this biological mechanism linking habitual snoring with unfavorable glucose metabolism.”
In an accompanying comment, Christian Benedict (Uppsala University, Sweden) and Marie-Pierre St-Onge (Columbia University Irving Medical Center, New York, USA) say the study data “underscore the critical need to incorporate sleep health into a comprehensive strategy aimed at reducing long-term type 2 diabetes risk, especially for women with a history of gestational diabetes.”
They suggest: “Regular screening of long-term glycemic control should be accompanied by questions regarding sleep duration and quality to identify those at greatest risk of developing type 2 diabetes in the long term. Proactive management of sleep disturbances in this at-risk population could provide an important opportunity to mitigate the risk of type 2 diabetes onset.”
medwireNews is an independent medical news service provided by Springer Healthcare Ltd. © 2025 Springer Healthcare Ltd, part of the Springer Nature Group
JAMA Netw Open 2025; 8: e250142
JAMA Netw Open 2025; 8: e250149
