Lifestyle factors and incident metabolic syndrome. The Tromsø Study 1979-2001

To assess the relationship between lifestyle characteristics and incident metabolic syndrome.

A total of 17,014 men and women without the metabolic syndrome at baseline who participated in at least two of four surveys between 1979-1980 and 2001 were included in this population based longitudinal study in the municipality of Tromsø, Norway. At each survey the participants went through a physical examination, completed two questionnaires, and blood samples were taken. The metabolic syndrome was defined according to the Adult Treatment Panel III criteria with modifications.

The age-adjusted incidence rates of the metabolic syndrome per 1000 person-years for people age 20-56 years were 10.0 in men and 8.7 in women. The metabolic syndrome risk significantly increased with age in women, but not in men. Leisure-time physical activity was inversely related to the metabolic syndrome. Smoking more than 20 cigarettes per day was associated with an increased risk compared to non-smokers. The hazard ratios (95% confidence intervals) were 1.27 (1.04-1.54) and 1.40 (1.02-1.92) in men and women, respectively. Alcohol intake and education were inversely associated with metabolic syndrome in women but not in men.

Physical inactivity and heavy smoking increased the metabolic syndrome incidence in men and women. Low or no intake of alcohol was also associated with increased risk, but in women only.