Associations between fat distribution and obstructive sleep apnea severity among individuals with type 2 diabetes: an MRI-based study.

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). We enrolled 164 T2DM patients (97 males, 67 females) from the EPSONIP-Sleep study; 151 had complete MRI and polygraphy data. OSA severity was evaluated by home respiratory polygraphy. Linear regression assessed AHI, logistic regression assessed moderate-to-severe OSA, and the Kruskal-Wallis test compared AHI across VAT-z/ASAT-z strata. In males, VAT, ASAT, and TAAT were associated with AHI in unadjusted analyses (β = 1.3, p = 0.009; β = 1.5, p = 0.010; β = 0.85, p = 0.009, respectively). ASAT (OR = 1.23/L, 95% CI 1.01-1.49, p = 0.049) and TAAT (OR = 1.10/L, 95% CI 1.00-1.22, p = 0.02), but not VAT, were associated with moderate-to-severe OSA. No statistically significant associations were detected in females. Associations were attenuated after BMI adjustment. AHI did not differ across VAT-z/ASAT-z strata (p = 0.430). Sex differences influenced the relationship between fat and OSA severity. In males, abdominal fat volumes were associated with higher OSA severity in unadjusted analyses, but not after BMI adjustment. No statistically significant associations were detected in females. These findings should be interpreted cautiously given the modest sample size.