Bidirectional association between visceral adiposity and obstructive sleep apnoea: longitudinal findings from the Wisconsin Sleep Cohort

Background Obstructive sleep apnoea (OSA) is a prevalent sleep disorder strongly associated with metabolic syndrome. Visceral adiposity is the principal culprit of the metabolic syndrome leading to the development of OSA. The longitudinal relation between visceral adiposity and OSA remains unknown. Methods We included 311 subjects without OSA at baseline to examine the association between visceral adiposity and incident OSA and 559 subjects without visceral obesity at baseline to examine the association between OSA and incident visceral obesity in a general population sample. OSA was defined as an Apnoea-Hypopnoea Index (AHI) ≥5 events/hour or having been diagnosed or received treatment for OSA. Visceral obesity was defined as a lipid accumulation product (LAP) level higher than the 75th percentile of the overall sample. Results After a median follow-up duration of 9 years, higher LAP values at baseline predicted higher AHI at follow-up ( β =0.19, p=0.001) and visceral obesity at baseline was associated with higher odds of incident OSA (OR 7.10, 95% CI 3.05 to 16.51) after adjusting for confounders. Furthermore, higher AHI values at baseline predicted higher LAP values at follow-up ( β =0.09, p=0.002) and OSA at baseline was associated with incident visceral obesity (OR 2.87, 95% CI 1.28 to 6.43) after adjusting for confounders. This bidirectional association was only observed in adults younger than 55 years. Conclusions The association between visceral adiposity and OSA is bidirectional and significant in young and middle-aged but not in older adults. Our findings suggest that visceral adiposity might be the target of preventative and therapeutic strategies for OSA.