Comparison of prevalence of metabolic syndrome in submariners with shore-based naval personnel

Introduction: Metabolic syndrome refers to a clustering of metabolic risk factors including central obesity, glucose intolerance, low high-density lipoprotein (HDL) cholesterol, high triglycerides, and hypertension. In the naval setting, some occupational characteristics of submariners such as long work hours, lack of physical activity, disturbed circadian rhythm, and stress have a negative influence on the health status of individuals. It is worth speculating that the occupational factors might also influence the development of clinical conditions related to a greater cardiovascular risk such as metabolic syndrome. Materials and Methods: A cross-sectional study was conducted over a period of 2 years. Submariners posted onboard an operational submarine for the past 1 year in the age group 18–45 years and willing to participate in the study were included in the study. Shore-based personnel in the similar age group posted in shore billet for at least 1 year were taken as control. Universal sampling technique was used for selection of subjects. A total of 250 submariners and 250 age-matched shore-based naval personnel were enrolled in the study. The study group was assessed for prevalence and risk factors of metabolic syndrome using national cholesterol education program adult treatment panel III criteria. Results: The mean age of submariners and shore-based personnel was 29.7 ± 4.9 years and 29.3 ± 5.3 years, respectively (P = 0.77). 20.8% of the submariners had a body mass index (BMI) more than 25 kg/m2 compared to 16.8% in the shore-based group. BMI was higher for the submariners compared to shore-based personnel but the difference was not statistically significant (P = 0.097). The prevalence of systolic and diastolic hypertension in submariners was 16.8%–15.2% compared to 11.6% and 10.4% in shore-based group (P > 0.05). Fasting blood sugar levels >100 mg/dl was observed in 14% submariners compared to 8.4% shore-based personnel (P > 0.05). Triglyceride levels of >150 mg/dl was observed in 22.4% submariners compared to 16% shore-based personnel (P = 0.085). HDL level of <40 mg/dl was observed in 13.6% submariners compared to 8.8% in shore-based personnel (P = 0.12). The prevalence of risk factors such as alcohol consumption (34% vs. 26%) and smoking (3.6% vs. 1.1%) and low physical activity (30% vs. 21.2%) were higher in the submariners as compared to the shore-based personnel though the difference was not statistically significant. The prevalence of metabolic syndrome was 9.2% in submariners compared to 6.4% in shore-based personnel. The difference was not statistically significant (P = 0.31). The overall prevalence of metabolic syndrome among submariners was higher than shore-based personnel but it was less compared to studies conducted on the Indian general population in urban areas. Conclusion: There is a need for preventive and/or therapeutic programs focused on cardiovascular and metabolic health for submariners.