Correlation of Severity of Obstructive Sleep Apnea with Glycemic Status in Patients with Diabetes Mellitus: A Cross-sectional Study in a Tertiary Hospital Setup of South Tamil Nadu

Background: Obstructive sleep apnea (OSA) and diabetes mellitus (DM) are prevalent chronic conditions that often coexist.The bidirectional relationship between OSA and DM may influence glycemic control, particularly in obese individuals.Objective: To evaluate the correlation between the severity of OSA and glycemic control in diabetic patients and to assess the influence of body mass index (BMI) on HbA1c levels.Methodology: This cross-sectional observational study included 120 patients diagnosed with both OSA and DM.Data on age, gender, apneahypopnea index (AHI), BMI, and HbA1c levels were collected.Obstructive sleep apnea severity was classified based on AHI, and glycemic control based on the HbA1c levels (glycosylated hemoglobin).Statistical analysis included Chi-square tests to assess associations.Results: Among the 120 patients (65 males and 55 females), the majority were between 50 and 70 years.Severe OSA was present in 55 patients, moderate in 40, and mild in 25.Only three patients had normal HbA1c.A significant association was found between OSA severity and HbA1c ( 2 = 27.18,p = 0.0012).The Pearson correlation between AHI and HbA1c was r = 0.79 (p < 0.001), indicating a strong positive linear relationship.Similarly, BMI correlated significantly with HbA1c ( 2 = 45.26,p < 0.001, r = 0.88, p < 0.001) Conclusion: The study indicates a strong association between OSA severity and poor glycemic control in diabetic patients.Early screening for OSA in poorly controlled diabetics could help identify both metabolic and sleep-related outcomes.