Factors Associated With OSA in Non-Obese, Young Middle Eastern Adults: A Retrospective Case-Control Study

Background: Obstructive sleep apnea (OSA) affects nearly one billion adults globally, but data on its prevalence in the Middle East is very limited. While obesity and age are major risk factors, recent studies suggest that non-obese individuals may have a distinct OSA phenotype with varying prevalence and characteristics. This study investigates factors associated with OSA and its severity in young, non-obese Middle Eastern adults, emphasizing the importance of understanding it in this population. Methods: A retrospective case-control study was conducted on individuals aged 18-55 who underwent sleep studies between 2021 and 2022. The case group included individuals with OSA (apnea-hypopnea index [AHI] ≥ 5 events/h), while the control group had normal AHI (< 5 events/h). Data collected included age, gender, BMI, neck circumference, hypertension (HTN), COPD, alcohol usage, and lowest SpO2 levels. The t-test was used for comparison within groups, and multiple regression was used to assess the relationship between AHI and independent variables. A P-value of <0.05 was accepted to be significant. Results: Out of 2,517 records reviewed, 555 patients met the inclusion criteria. OSA was diagnosed in 67.2% of participants. The OSA group had a higher male/female ratio (80.4% vs 49.5%, P < .005) and were older (40.7 ± 8.9 vs. 35.3 ± 8.9 y, P < .005) (Table 1). OSA patients also had higher BMI (26.7 ± 2.8 vs. 25.3 ± 2.8 kg/m2, P < .005) and larger neck circumference (38.3 ± 4.0 vs. 35.7 ± 4.0 cm, P < .005). Hypertension and COPD were more prevalent in the OSA group (P = .003 and P = .03, respectively). Alcohol usage was significantly higher in the OSA group (13.3% vs. 8.7%, P = .005). Multiple linear regression identified age (β = 0.170, P = .005), neck circumference (β = 0.597, P < .001), hypertension (β = 6.495, P < .001), and lowest SpO2 (β = -0.907, P < .001) as significant predictors of OSA severity (Table 2). Conclusions: Males with larger neck circumference were at higher risk of OSA in this cohort. Despite being non-obese, OSA patients had higher BMI than controls. Hypertension and alcohol intake were also more common in OSA patients. Age, neck circumference, and hypertension were significant predictors of OSA severity.Baseline characteristics and resultsCharacteristicsTotal n (%)OSAnon-OSAp-valueTotal555&nbsp;&nbsp;&nbsp;Male390 (70)30090<0.005Female165 (30)7293&nbsp;Sleep study&nbsp;&nbsp;&nbsp;&nbsp;Type 1375 (67)265110&nbsp;Type 3180 (33)10872&nbsp;Comorbidities&nbsp;&nbsp;&nbsp;&nbsp;DM35 (6.3)23110.808HTN106 (19.1)84220.003CAD7 (1.3)610.207COPD5 (0.9)500.025PHTN7 (1.3)610.208Arrythmia1 (0.2)100.318Rhinosinusitis3 (0.5)300.083Polyps (NASAL)16 (2.9)1150.868Septal deviation141 (25.4)98430.566Sedative use169 (30.4)98710.162Anti-depressant54 (9.7)32220.397Alcohol74 (13.3)58160.005Mallampati score2.3 (1)2.42.20.314&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Mean (std dev)&nbsp;&nbsp;&nbsp;Age38.9 (8.9)40.735.3<0.005BMI26.2 (2.8)26.725.3<0.005Neck Circum (cm)37.3 (4)38.335.7<0.005ODI10.9 (16)13.85.2<0.005Lowest Spo2 %86.8 (6.7)84.990.5<0.005Mean SpO2 %86.8 (6.7)84.990.5<0.005Mean SpO2 %94.9 (1.9)94.495.4<0.005Results of the regression modelVariablesCoefficientsstd errort- statisticp-valueLower 95%Upper 95%Intercept38.91132.4831.1980.231-24.897102.718Age0.1700.0602.8450.0050.050.29Neck Circum (cm)0.5970.1583.7850.0000.290.91HTN6.4951.6204.0080.0009.683.31BMI-0.2050.185-1.1050.269-0.570.16Hypoxemia (mins)-0.0070.017-0.4310.666-0.040.03Lowest Spo2 %-0.9070.089-10.1500.000-1.08-0.73Mean SpO2 %0.3170.3400.9300.353-0.350.99