Cardiovascular risk factors and subclinical atherosclerosis among Nunavik Inuit

OBJECTIVE: To evaluate subclinical atherosclerosis in Nunavik Inuit and its correlation to traditional cardiovascular disease risk factor. METHOD: The intima-media thickness (IMT) of 12 segments of the carotid arteries (IMT(12_seg)) free of plaque were assessed in randomly selected 40 years old and older Inuit from. Clinical assessment was performed which included fasting plasma glucose, fasting insulin, systemic blood pressure, body mass index, smoking, circulating blood lipids and oral glucose tolerance test. In addition, documented presence of ischemic heart disease (IHD), stroke, diabetes mellitus, hypertension and dyslipidemia were determined from medical files. RESULTS: The average age of the 287 participants was 51.2 ± 0.6 years (56.8% women). Mean IMT(12_seg) was 0.80 ± 0.17 mm (range: 0.55-1.47 mm). Compared with disease free Inuit, individuals with history of stroke showed greater carotid internal IMT (0.68 ± 0.01 mm vs. 0.96 ± 0.15 mm respectively; p<0.005) but no difference was observed for IHD. Hypertensive and dyslipidemic Inuit had higher IMT(12_seg) compared to risk factor free individuals but no difference was observed in diabetics. None of the clinical assessments were associated with IMT(12_seg). In a multivariate backward elimination model, only age, gender, and medically documented history of hypertension were found to be predictors of IMT(12_seg) (adjusted r-square of 0.54; p<0.0001). CONCLUSION: Compared with disease free Nunavik Inuit, subclinical signs of atherosclerosis determined by IMT was higher in individual diagnosed with stroke. Independent predictors of IMT(12_seg) in our group were age, gender and history of hypertension. No other traditional risk factors imparted IMT.