Risk factors, atherosclerosis, and cardiovascular disease among Aboriginal people in Canada: the Study of Health Assessment and Risk Evaluation in Aboriginal Peoples (SHARE-AP)

Abstract

Little is known about the rates of cardiovascular disease (CVD), atherosclerosis, and their risk factors among Canada's Aboriginal people. To establish the relative prevalence of risk factors, atherosclerosis, and CVD, we undertook a population-based study among people of Aboriginal and European ancestry in Canada. We randomly recruited 301 Aboriginal people from the Six Nations Reservation, and 326 people of European origin from Hamilton, Toronto, and Edmonton, Canada. Clinical CVD was defined by history or electrocardiographic findings, atherosclerosis was measured by B-mode carotid ultrasonography, and conventional and new CVD risk factors were measured using standardised methods. Aboriginal people had significantly more carotid atherosclerosis (mean of the maximum intimal-medial thickness 0.82 (SD 0.20) mm vs 0.78 (0.20) mm, p=0.027), and had a higher frequency of CVD (18.5% vs 7.6%, p=0.00002) compared with Europeans. Aboriginal people had significantly higher rates of smoking, glucose intolerance, obesity, abdominal obesity, and substantially higher concentrations of fibrinogen, and plasminogen activator inhibitor-1. Aboriginal people had significantly higher rates of unemployment and a lower annual household income. For any given income level, Aboriginal people had higher rates of risk factors and CVD compared with the Europeans. A significant proportion of Aboriginal people live in poverty which is associated with high rates of CVD and CVD risk factors. Improvement of the socioeconomic status of Aboriginal people might be a key to reduce CVD in this group.