ORIGINAL INVESTIGATION The metabolic syndrome and progression of carotid atherosclerosis over 13 years. The

Background: The metabolic syndrome (MetS) is associated with increased risk of cardiovascular disease. In this study, we examine if metabolic syndrome predicts progression of atherosclerosis over 13 years. Methods: Participants were 1442 men and 1532 women in the population-based Tromsø Study who underwent carotid ultrasound examinations at baseline in the 4th (1994–5) and at follow-up in the 6th survey (2007–8). Of these, 278 men and 273 women fulfilled the criteria for the MetS, defined according to a modified version of the National Cholesterol Education Program Adult Treatment Panel III (NCEP, ATPIII). Carotid atherosclerosis was assessed as total plaque area (TPA) and mean intima-media thickness (IMT) at follow-up and as change in IMT and TPA from baseline to follow-up. Associations between MetS and its components and carotid atherosclerosis were assessed in linear regression models adjusted for age, total cholesterol and daily smoking, stratified by sex. Results: IMT and TPA levels at follow-up (p < 0.0001) and progression of TPA (p = 0.02) were higher in the MetS group compared to the non-MetS group. In stepwise multivariable models, MetS was associated with TPA (β = 0.372 mm2, p = 0.009) and IMT (β = 0.051 mm, p < 0.0001) in men, and with IMT (β = 0.045 mm, p = 0.001) in women after 13 years of follow-up, but not with progression of IMT or TPA. In analyses stratified by age, MetS predicted progression of IMT (β = 0.043 mm, p = 0.046) and TPA (β = 1.02 mm2, p = 0.002) in men below 50 years of age. Hypertension was predictive of follow-up TPA and IMT in both genders and of progression of TPA in women