Snoring, Short Sleep Raise Type 2 Diabetes Risk After Gestational Diabetes

Shorter sleep duration and snoring frequency are associated with an increased risk for type 2 diabetes (T2D) among women with a history of gestational diabetes, according to the findings of a study published in JAMA Network Open.

Mounting evidence suggests there is an association between T2D risk and worse sleep characteristics among the general population.

To assess the link between sleep outcomes and T2D in gestational diabetes, researchers from the National University of Singapore sourced data for this study from the Nurses’ Health Study II (NHSII), which is an ongoing prospective cohort study of nurses. Women (N=2891; mean age, 45.3; White, 92.7%) with a history of gestational diabetes who responded to a questionnaire about sleep characteristics between 2001 and 2003 were evaluated for incident T2D through an average follow-up of 17.3 years.

Women who reported snoring regularly had less physical activity, a worse diet quality, and a higher body mass index (BMI). Women who slept 6 hours a night or less were more likely to be night shift workers, to be postmenopausal, to have depression, and to have a higher BMI. Those who reported more daytime sleepiness were more likely to be night shift workers, to have respiratory illness, to have depression, were less physically active, and had higher BMI.

A total of 19.5% of women were diagnosed with T2D during follow-up.

In the fully adjusted models, risk for T2D associated with regular (adjusted hazard ratio [aHR], 1.61; 95% CI, 1.21-2.13) and occasional (aHR, 1.54; 95% CI, 1.18-2.02) snoring relative to almost never snoring (P =.01) and with a sleep duration of 6 hours or less a night compared with 7 to 8 hours of sleep (aHR, 1.32; 95% CI, 1.06-1.64).

Risk for T2D was related with experiencing daytime sleepiness 4 or more days per week relative to rarely or never having daytime sleepiness in the minimally adjusted model (P =.002), however the significant relationship was attenuated with additional adjustment.

Snoring frequency was also related with T2D biomarkers, in which glycated hemoglobin (HbA_1c; least-squares mean [LSM], 5.89% vs 5.84% vs 5.78%; P =.01), C-peptide (LSM, 4.30 vs 3.99 vs 3.81 ng/mL; P =.01), and insulin (LSM, 11.25 vs 10.19 vs 9.16 mIU/mL; P =.01) levels were higher among individuals who regularly snored compared with occasionally or almost never snoring, respectively.

No significant relationship between T2D biomarkers and sleep duration were observed.

In a sensitivity analysis that included only the subset of women who reported sleep duration in 2001, 2009, and 2017 (n=802), no association between short sleep and T2D risk was observed (hazard ratio [HR], 1.49; 95% CI, 0.87-2.55).

The major limitation of this study was the reliance on self-reported sleep outcomes.

“[W]e observed that more frequent snoring was associated with an unfavorable metabolic biomarker profile among women with a history of GD [gestational diabetes] who did not have T2D at blood sample collection,” the researchers concluded.