Association between obstructive sleep apnea and serum uric acid levels in obese women

Abstract INTRODUCTION Controversial data exist on association of hyperuricemia both with increased cardiovascular risk, particularly in obese patients, and with the presence and severity of obstructive sleep apnea (OSA). AIM We correlated acid uric (AU) levels with metabolic and polygraphic parameters in obese patients with suspected OSA. METHODS We studied 86 patients (44M) aged 44.3+9.7 yr, BMI 43.9+6.7), all CPAP naïve. At the cardiorespiratory monitoring AHI was >5, >15 and >30 in 90,70,and 46% of them. RESULTS Mean UA was greater in men (7.30+1.7 vs 5.6+0.12, p 0,003) and in the upper versus lowest AHI quartiles (7+1.5vs 5.5+1.6, p 0.007). Men showed also greater values of AHI, ODI, creatinine, haemoglobin and lower HDL cholesterol levels than women, with similar age and BMI. UA was directly correlated with AHI and ODI (r 0.33-0.36, p 0.005), time spent with SpO2<90% (r 0.25, p 0.013), serum creatinine (r 0.29, p 0.014) and triglycerides (0.36, p=0.003), but not with age or BMI, and inversely with HDL cholesterol (r -0.36,p=0.001). Multiple linear regression demonstrated a significant association with AHI independent of age and BMI only in women and with glycated haemoglobin (HbA1c) in both sex subgroups. The correlations with nocturnal OSA parameters were even stronger among women (r 0.46-0.52, p<0.004) but not significant in men. CONCLUSION Our results support the hypothesis of a significant association between UA and OSAS in obese women, both for number of events and for induced hypoxemia, while in obese men the more complex interaction between OSA, UA and classical cardiovascular risk factors requires further clarification.