Insulin resistance using HOMA model in obstructive sleep apnea: a cross sectional study

BACKGROUND AND OBJECTIVES: Obstructive sleep apnea (OSA) is a common disease affecting middle-aged patients and is associated with significant cardiovascular, cerebrovascular, and metabolic complications. Current evidences show inconclusive association between OSA and insulin resistance (IR). This study aims to examine the possible correlation between OSA parameters and IR. DESIGN AND SETTINGS: This was a cross-sectional study to examine the association between OSA parameters and IR using homeostasis model assessment (HOMA) on patients who underwent polysomnogram (PSG) in a tertiary center between March 2011 and March 2012 (1 year). PATIENTS AND METHODS: A total of 62 patients underwent PSG within the study period, of which 16 patients were excluded due to abnormal fasting blood sugar. Information on patients’ medical illnesses, medications, and Epworth sleepiness scale (ESS) was obtained. Patients’ body mass index (BMI), neck circumference, and waist circumference (WC) were measured. Blood samples were collected after 8 hours of fasting to measure HOMA–IR value. Overnight PSG was performed for all patients. Data was recorded and analyzed using SPSS, version 12.0 (SPSS Inc, Chicago, USA). RESULTS: The prevalence of IR in OSA patients was 64.3%. There was significant correlation between OSA parameters (apnea-hypopnea index, ESS, BMI, and WC) and HOMA–IR with correlation coefficient of 0.529, 0.224, 0.261, and 0.354, respectively. CONCLUSION: A linear correlation exists between OSA parameters and IR concluding a definite causal link between OSA and IR. IR screening is recommended in severe OSA patients.