Risk factors for the progression of carotid intima-media thickness over a 16-year follow-up period: The Malmö Diet and Cancer Study

OBJECTIVE: To evaluate the progression of carotid intima-media thickness (IMT) in the common carotid artery (CCA) and the bifurcation over a mean follow-up of 16 years in relation to cardiovascular risk factors. METHODS: The study population included 3426 middle-aged Swedish men and women participating in the 1991-1994 (baseline) and the 2007-2012 (re-examination) investigation of the cardiovascular cohort of the Malmö Diet and Cancer Study (MDCS). RESULTS: There were differences in risk factor patterns in arterial segments in that diabetes and male sex were associated with the progression of IMT in the bifurcation, but not in the CCA, and high-density lipoprotein cholesterol (HDL) was associated with the progression of IMT in the CCA, but not in the bifurcation. Favourable changes in systolic blood pressure (SBP), low-density lipoprotein cholesterol (LDL) and HDL during follow-up decreased the IMT progression rate in the CCA. There was a cumulative relationship between traditional cardiovascular risk factors (i.e., regular smoking, LDL/HDL-ratio ≥ 3, hypertension) and IMT progression rates. The odds ratio (OR) of high IMT CCA progression rate (>75th percentile) was 1.0 (reference), 1.4 (95% CI: 1.1, 1.7), 1.7 (95% CI: 1.3, 2.2) and 2.1 (95% CI: 1.4, 3.1), respectively, for individuals with none, one, two, and three risk factors. CONCLUSION: There were differences in the associations between risk factors and progression rate in different arterial segments. Favourable changes in SBP and lipids during the follow-up period were associated with reduced IMT progression rates in the CCA.