The metabolic syndrome among Danish seafarers

Representing a cluster of risk factors related to insulin resistance, the metabolic syndrome (MS) is defined by a constellation of increased waist circumference in combination with dyslipidaemia, hyperglycaemia, and/or increased blood pressure. MS is a strong risk factor for a number of chronic diseases, including diabetes and cardiovascular conditions. Approximately 1/5 of Danish adults have MS, which has an etiological relation to nutritional factors, sleep patterns, work-related stress, fatigue, and physical activity - all of which are critical issues at sea.

Out of 655 Danish seafarers attending medical fitness examination by seafarers'doctors in 4 clinics, 524 participants (mean age of 38.5 years) underwent waist circumference measurements and provided questionnaire information about their workplace on board and their consumption of tobacco and alcohol. Blood samples were taken if waist circumference was increased. MS was defined according to the International Diabetes Federation as central obesity in combination with 2 out of the following conditions: elevated triglycerides, blood pressure, fasting plasma glucose, and reduced HDL-cholesterol (or treated hyperlipaemia or hypertension, or previously diagnosed type 2 diabetes, respectively).

The crude baseline prevalence of MS was 25.9% among male and 10.7% among female Danish seafarers. 30.6% were current smokers. The alcohol consumption was comparable to that of Danes ashore, but exceeded recommendations of 18.6%.

MS was increased in this young group of seafarers. Seafarers with MS were advised to 10% weight-reduction, physical activity 1/2 hour/day, reduced intake of saturated fat and increased fibres indiet, smoking cessation, and control of alcohol consumption as an intervention measure. Follow-up will take place after 2 years.