Adults with prediabetes who reported sleeping 5 hours or less per night were nearly 70% more likely to progress to type 2 diabetes over 2 years compared with those who reported sleeping 7 hours each night, according to findings from a study conducted in South Korea.
“Previous studies have shown that sleep deprivation is associated with risk of development of diabetes,” Chan-Won Kim, MD, of the Center for Cohort Studies at Total Healthcare Center, Kangbuk Samsung Hospital, Seoul, South Korea, told Endocrine Today. “However, these studies defined diabetes based on self-report, which may influence this association, and no studies have investigated the association between sleep duration and progression of prediabetes to diabetes. We studied if insufficient sleep would be linked to an increased risk of progression to diabetes among persons with prediabetes, defined by HbA1c concentration. We found that short sleep duration was associated with progression of prediabetes to diabetes, independent of socioeconomic factors and lifestyle characteristics.”
Kim and colleagues analyzed data from 17,983 adults with prediabetes at baseline (defined as an HbA1c between 5.7% and 6.4%) and at least one follow-up visit (average, 2.4 visits) participating in the Kangbuk Samsung Health Study (mean age, 41 years; 33% women). Participants underwent comprehensive annual or biennial exams, including assessments of sleep duration and quality (using the Pittsburgh Sleep Quality Index) and measurements of high-sensitivity C-reactive protein, insulin, glucose and HbA1c, at hospital screening centers in Seoul and Suwon, South Korea. Diabetes was defined as an HbA1c of at least 6.5% or use of antidiabetes medications. Researchers used time-dependent proportional hazards models to evaluate the association between sleep duration and the risk for progression to diabetes.
Within the cohort, mean reported nightly sleep duration was 6.2 hours; 15.6% reported poor sleep quality.
During 31,582 person-years of follow-up (median follow-up period, 22 months), 664 incident cases of diabetes were identified; incidence rate was 21 per 1,000 person-years.
Compared with adults with prediabetes who reported sleeping 7 hours per night, those with prediabetes who slept 5 hours or less were 68% more likely to progress to type 2 diabetes (HR = 1.68; 95% CI, 1.3-2.16), those reporting sleeping 6 hours per night were 44% more likely to progress to type 2 diabetes (HR = 1.44; 95% CI, 1.17-1.76), whereas those who reported sleeping at least 8 hours per night were 23% more likely to develop diabetes (HR = 1.23; 95% CI, 0.85-1.78), according to researchers. Results persisted after adjustment for age, sex and study center, and after further adjustment for education, marital status, depressive symptoms, family history of diabetes, shiftwork and smoking status, among other variables.
“In addition, our results suggest that biomarkers of adiposity, fatty liver and insulin resistance partially mediate this association, expanding the understanding of the underlying metabolic dysfunction,” Kim said.
The researchers also found that poor, subjective sleep quality was not associated with the risk for incident diabetes.
“Our findings suggest that sufficient sleep should be part of a healthy lifestyle, especially among people with prediabetes,” Kim said. “For health care personnel, it may be helpful to assess sleep duration of their patients with prediabetes when they evaluate the risk of progression to diabetes. A population-level approach is also encouraged to reduce people’s exposure to sleep deprivation.” – by Regina Schaffer
For more information:
Chan Won Kim, MD, can be reached at the Center for Cohort Studies at Total Healthcare Center, Kangbuk Samsung Hospital, 29, Saemunan-ro, Jongno-gu, Seoul, South Korea; email: firstname.lastname@example.org.
Disclosures: The authors report no relevant financial disclosures.