Cardiorespiratory fitness, all-cause mortality, and risk of cardiovascular disease in Trinidadian men - the St James survey

Background This study examined whether cardiorespiratory fitness is a risk factor for cardiovascular disease, myocardial infarction, and all-cause mortality in a low- to middle-income Trinidadian community of African, South Asian Indian, and European origin. Those of Indian descent have a distinctively high rate of myocardial infarction. Methods The St James Study is a prospective total community survey located in Port-of-Spain, Trinidad, West Indies. A random sample of 626 men aged 35-69 years, without angina of effort, previous myocardial infarction, partial or complete atrio-ventricular conduction defect, complete heart block, or exercise-induced asthma, was used for the assessment of cardiorespiratory fitness by cycle ergometry. Surveillance for morbidity and mortality was maintained for an average of 7.3 years. Results When the subjects were grouped into those with an age- and fat-free mass-adjusted peak oxygen uptake above and below the mean of 60.4 mmol/min (1.34 l/min), the hazard ratios (below/above) (95% confidence interval) for all-cause mortality, cardiovascular disease incidence, and incidence of myocardial infarction, after allowance for conventional cardiovascular risk factors, were 2.08 (1.23-3.52), 2.13 (1.22-3.69), and 2.36 (0.84-6.67), respectively. For those unable to achieve a level of work requiring an oxygen uptake of 67 mmol/min (1.5 l/min) during progressive exercise, the respective hazard ratios were 3.49 (1.57-7.76), 2.29 (1.21-4.33), and 5.45 (1.22-24.34). Indian ethnicity remained a predictor of myocardial infarction after allowance for cardiorespiratory performance. Conclusion Low cardiorespiratory fitness is a risk factor for cardiovascular disease morbidity and mortality in the low- to middle-income developing community of Trinidad.