Difference in the prevalence of metabolic syndrome components between male pilots of the Republic of Korea Air Force and the general Korean male population: a cross-sectional comparative study

Introduction Military pilots are selectively healthy, yet face unique aeromedical stressors. Their metabolic risk has rarely been compared with a contemporaneous, age-matched national male cohort. Methods This cross-sectional study compared male Republic of Korea Air Force (ROKAF) pilots who underwent routine pilot health examinations (2021–2022) with men from the 2022 Korea National Health and Nutrition Examination Survey (KNHANES); metabolic syndrome (MetS) was defined by combined criteria for Asian men. Logistic regression was used to determine crude and adjusted ORs for overall MetS and for each of the five individual MetS criteria, adjusting for age, smoking, alcohol consumption and exercise. Results We analysed 2604 ROKAF pilots and 1093 men from KNHANES. MetS prevalence was 11.1% in pilots versus 37.1% in KNHANES (adjusted OR 0.30 (95% CI 0.24 to 0.36), p<0.001). Four of five components were less prevalent in pilots (adjusted ORs 0.18–0.79, all p≤0.009); the elevated-blood-pressure component was paradoxically more prevalent (47.7% vs 38.8%; adjusted OR 2.12 (95% CI 1.80 to 2.52), p<0.001). The lower MetS risk in pilots was robust across age strata and component-variable quartiles. After full adjustment for age, lifestyle, body mass index (BMI), and cardiometabolic medication use, four biomarkers retained significantly stronger associations with metabolic syndrome (MetS) in pilots: fasting glucose (Δβ 0.98, p<0.001), urate (Δβ 0.27, p=0.009), low-density lipoprotein cholesterol (LDL-C) (Δβ 0.24, p=0.022), and total cholesterol (Δβ 0.20, p=0.049). Conclusions ROKAF pilots have a substantially lower MetS prevalence than the general male Korean population in the same working-age range, consistent with a strong healthy-worker effect. Yet their MetS phenotype is asymmetrical; pilots fulfil MetS criteria predominantly through elevated BP and glycaemic pathways rather than adiposity or dyslipidaemia. Urate is informative in pilots but not in the general population, supporting targeted aeromedical screening of BP, fasting glucose and urate.