Associations between Fat Distribution and Obstructive Sleep Apnea Severity Among Individuals with Type 2 Diabetes: An MRI-based study

Study Objectives Obstructive Sleep Apnea (OSA) affects 1 billion people globally, with a male-to-female ratio of 2:1. While obesity is a major risk factor, sex differences in fat distribution may influence OSA risk. This study examined the relationship between visceral (VAT), subcutaneous (ASAT), and total abdominal fat (TAAT) and OSA severity in patients with type 2 diabetes (T2DM). Methods We enrolled 164 T2DM patients (97 males, 67 females) from the EPSONIP-Sleep study, of whom 151 with complete MRI and polygraphy data were analyzed. MRI-measured VAT, ASAT, and TAAT volumes and z-scores (normalized for sex and height) were assessed. OSA severity was evaluated via home respiratory polygraphy. Associations were analyzed using linear and logistic regression, descriptive statistics, and Kruskal-Wallis tests. Results In males, higher VAT, ASAT, and TAAT volumes correlated with OSA severity. Logistic regression identified ASAT (OR = 1.2/L, p = 0.048) and TAAT (OR = 1.1/L, p = 0.023) as predictors of moderate-to-severe OSA; VAT showed a non-significant trend. These associations were not significant after adjusting for BMI. Conclusion Sex differences influence the relationship between fat and OSA severity. In males, increased adiposity was linked to higher OSA severity, largely explained by BMI. No associations were found in females. If replicated, these findings could support adiposity-based risk stratification in men.