Longer Sleep Linked to Diabetic Nephropathy in Type 2 Diabetes

Study Links Longer Sleep Duration to Diabetic Nephropathy

Adults with type 2 diabetes who sleep longer durations show an increased risk for the incidence and progression of diabetic nephropathy. Researchers from Juntendo University Graduate School of Medicine in Tokyo tracked 678 Japanese outpatients between 25 and 70 years old. Over an average follow-up period of 6.0 plus or minus 2.7 years, 215 participants reached the composite kidney disease end point.

Investigators assessed participant lifestyle habits at baseline and again at year two or year five to calculate average values. Sleep duration was the only lifestyle factor in the analysis that showed a significant association with diabetic kidney disease progression.

Sleep Duration Hazard Ratios in the Study Cohort

Kidney disease risk climbed steadily as average sleep duration increased past six hours per night. Compared to individuals sleeping fewer than six hours nightly, the multivariable-adjusted hazard ratio, abbreviated as HR, was 1.08 for people averaging 6 to less than 7 hours of sleep.

The risk expanded further in groups with longer nightly rest. For participants sleeping 7 to less than 8 hours, the multivariable-adjusted HR was 1.56. For those averaging 8 or more hours per night, the multivariable-adjusted HR reached 1.92 after adjusting for key lifestyle and diabetes-related factors.

Stronger Associations in High-Risk Patient Groups

The statistical link between longer sleep and kidney decline was more pronounced in older participants and those with existing renal vulnerability. Specifically, individuals entering the study with microalbuminuria or reduced kidney function experienced a stronger association between extended sleep and disease progression.

Study co-author Tomoya Mita noted that tracking longer sleep patterns could help clinicians identify which patients require closer monitoring of kidney health.

Observational Limits and Industry Disclosures

These findings demonstrate an observational association rather than a confirmed cause of kidney damage. The study authors noted that people should not view these results as guidance to deliberately shorten their sleep duration.

Patients with concerns about sleep length or kidney laboratory values should discuss testing options with their physician. In the study publication, several authors disclosed financial relationships with medical technology and biopharmaceutical companies.