New NUS study: Poor sleep health linked to increased Type 2 diabetes risk in high-risk women with history of gestational diabetes

Underscoring the critical role of sleep in diabetes prevention, investigators from the Global Centre for Asian Women’s Health (GloW) and the Department of Obstetrics and Gynaecology, based at the NUS Yong Loo Lin School of Medicine (NUS Medicine), in collaboration with Harvard T.H. Chan School of Public Health, Brigham and Women's Hospital and Harvard Medical School, has identified a significant link between sleep health and the risk of developing Type 2 diabetes (T2D) among women with a history of gestational diabetes (GDM).

GDM is one of the most common pregnancy complications, affecting up to 30% of pregnancies globally. Women with a history of GDM are nearly 10 times more likely to develop T2D later in life compared to those without GDM. More strikingly, in Singapore, more than 40 per cent of women may develop T2D within 5 years following pregnancies complicated by GDM.  While lifestyle factors such as diet and exercise are well-known preventive measures, this study sheds light on the often-overlooked role of sleep health in mitigating diabetes risk.

By prioritising better sleep, women with a history of GDM can take proactive steps toward reducing their long-term risk of developing T2D and improving overall metabolic health. Led by Professor Zhang Cuilin, Director of GloW, and Dr Yin Xin, Research Fellow at GloW, their team analysed data of nearly 3,000 women with a history of GDM over 17 years from the Nurses’ Health Study II and found that those who slept six hours or fewer per night had a 32 per cent higher risk of developing T2D compared to those who met the recommended seven to eight hours of sleep.

Additionally, regular snoring—defined as snoring most nights per week or every night—was associated with a 61% increased risk of T2D. Women who experienced both short sleep duration and regular snoring faced more than double the risk compared to those with healthy sleep patterns. Beyond increasing diabetes risk, regular snoring was also associated with unfavourable glucose metabolism biomarkers, including elevated levels of HbA1c, insulin, and C-peptide, all of which signal potential metabolic dysfunction.

“Our research highlights that improving sleep habits—such as increasing sleep duration and addressing snoring—can be a powerful, actionable step in preventing Type 2 diabetes among women with a high-risk of diabetes,” said Prof Zhang. She further emphasised, “Given the rising prevalence of GDM and diabetes, particularly in Asia, it is crucial to expand prevention strategies to include the improvement of sleep health, especially for women with a history of GDM. Dr Yin also pointed out that, “Women with GDM may have had sub-optimal glucose metabolism even before pregnancy.”

Having opened new avenues for diabetes prevention, the study's researchers are now looking to develop tailored interventions for Asian women that include improving sleep quality, diet, and other lifestyles, and to better understand underlying molecular mechanisms.

The study titled ‘Sleep Characteristics and Long-Term Risk of Type 2 Diabetes Among Women With Gestational Diabetes’ was published in JAMA Network Open on 5 March 2025.