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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.

Objective: To compare the incidence rates of hypertension and non-insulin dependent diabetes mellitus in relation to ethnicity and other characteristics in a rapidly developing community., Design: Prospective surveillance of a total community for five years., Subjects: Cohort of 2491 men and women aged 35 to 69 years (79% response), of African, Indian and "other' (mainly Afro-European) descent., Results: During surveillance, secular increases occurred in fasting blood glucose concentrations in both sexes and in body mass index (BMI) in men, with apparent secular reductions in systolic blood pressure in both sexes. Incidence rates of hypertension did not differ significantly with ethnicity, ranging between 33 and 41 per 1000 person-years in men and between 27 and 32 per 1000 person-years in women. In men, the incidence of diabetes (per 1000 person-years) in Indians (24) was significantly higher than in Africans (13) and others (11). In women, the diabetic incidence was similar to that for men in Indians (23) and Africans (14), but in others was twice that in men (21). In both sexes, weight gain was an important risk factor for hypertension, whereas risk of diabetes increased with BMI at baseline. The increased risk of diabetes in Indians among men was independent of baseline BMI and blood glucose., Conclusion: Apart from the increased risk of diabetes in Indians, ethnicity had no significant influence on incidence rates of hypertension and diabetes in Trinidad. Secular increases in blood glucose in both sexes and in BMI in men probably contributed to the concurrent increase in mortality from coronary heart disease in this community.

Vital statistics indicate that cardiovascular disorders are now major causes of morbidity and mortality in many Caribbean communities. In Trinidad and Tobago, for example, the death rate from myocardial infarction is now similar to that in the UK and USA. In a 10-year prospective survey of 1386 men aged 35 to 69 years at entry, who belonged to a defined community in Port-of Spain, Trinidad, serum high-density (HDL) and low-density (LDL) lipoprotein cholesterol concentrations were very similar to those found by the same methods in Bristol, England. The age-adjusted incidence of first coronary heart disease (CHD) events in men clinically free of the disease at recruitment (per 1000 person-years) was 16.4 in men of Indian descent, 6.8 in those of African origin, 6.2 in those of European origin, and 2.4 in men of mixed descent (the contemporaneous figure for Bristol was about 12/1000 person-years). Serum HDL and LDL cholesterol concentrations were strong and independent predictors of CHD in Trinidad, as they are in temperate climes. With effective control of tropical infectious diseases, and adoption of western patterns of consumerism, tropical developing communities will rapidly acquire the CHD risk factor status once more or less exclusive to developed populations in more temperate climes.

In a prospective cardiovascular study of 1341 Trinidadian men aged 35-69 years undertaken between 1977 and 1986, the baseline prevalence rates of cardiac and arterial disease and diabetes mellitus were increased in the 118 (8.8%) who had been but were no longer regular drinkers. This finding suggested that awareness of these disorders was a discouragement to drinking alcohol. When this group and all with coronary heart disease (CHD) or diabetes at entry were excluded, a significant inverse trend was found between alcohol consumption in the week before recruitment and risk of CHD across the subsequent average follow-up of 7.5 years. Men who had taken 5-14 drinks had about half the CHD risk of those who had had no alcohol, even after allowance for age, ethnicity, smoking, blood pressure and serum cholesterol concentration. The overall morbidity and mortality experience in this community indicated a protective effect of alcohol against CHD, but adverse health consequences from multiple causes in drinkers who were alcohol dependent.

Study Objective: The aim of the study was to determine whether the inverse association between high density lipoprotein cholesterol concentration and risk of coronary heart disease described in people of European stock was also present in other racial groups., Design: The study was a prospective population survey. Cardiovascular risk factors were examined, including fasting serum lipid estimation (obtained at recruitment)., Setting: This was a community based study within a defined survey area in Trinidad., Participants: All men aged between 35 and 69 years within the survey area were identified and followed between 1977 and 1986. Analysis was confined to those of African, Asian Indian, and mixed descent who were free of coronary heart disease at entry (n = 960, 69% of age eligible men in the survey population)., Measurements and Main Results: 64 men developed coronary heart disease during the study period. A strong inverse curvilinear relation was found between high density lipoprotein cholesterol and coronary heart disease incidence (p less than 0.005), independent of age or other relevant characteristics including low density lipoprotein cholesterol., Conclusions: A low serum concentration of high density lipoprotein cholesterol is a risk factor for coronary heart disease in non-whites as well as in whites.

A total population survey of serum lipoprotein concentrations was undertaken in an urban community in Port-of-Spain, Trinidad, and the results compared with rural survey on the same island and a study of healthy adults in Bristol, England. Lipoproteins were separated with identical techniques and lipid determinations made in a common laboratory. In Trinidad, response rates for men and women were 93 and 88% respectively in the urban survey, and 89% in the smaller rural study. Mean concentration of HDL cholesterol was significantly lower and LDL cholesterol significantly higher in urban men than rural men. No urban-rural differences were found in women. In urban men under 55 years, HDL and LDL cholesterol concentrations were similar in Port-of-Spain and Bristol while VLDL triglyceride was relatively high in Trinidad. Distinct ethnic differences in lipoprotein concentrations were found in Trinidad. Indian men and women tended to have a low HDL cholesterol relative to other ethnic groups, while African men and women were characterized by relatively low concentrations of LDL cholesterol and VLDL triglyceride. The reduction in HDL cholesterol of Indian men appeared to be due mainly to a relatively low HDL3 concentration. The results are consistent with reported regional, sex and ethnic differences in CHD incidence in Trinidad, and accord with statistics which show cardiovascular disease to have emerged as the major cause of death in this community.

A ten-year community survey was undertaken to investigate the high coronary heart disease (CHD) incidence among people of Indian (South Asian) descent in Trinidad, West Indies. Of 2491 individuals aged 35-69 years, 2215 (89%) were examined and 2069 (83%) found to be clinically free of CHD at baseline. After exclusion of 71 of minority ethnic groups, 786 African, 598 Indian, 147 European and 467 adults of Mixed descent were followed for CHD morbidity and mortality. In both sexes, adults of Indian origin had higher prevalence rates of diabetes mellitus, a low concentration of high-density lipoprotein (HDL) cholesterol, and recent abstinence from alcohol than other ethnic groups. Indian men also had larger skinfold thicknesses than other men. In participants free of CHD at entry, the age-adjusted relative risk of a cardiac event believed due to CHD was at least twice as high in Indian men and women as in other ethnic groups. In men, blood pressure, diabetes mellitus and low-density lipoprotein (LDL) cholesterol concentration were positively and independently related to risk of CHD, whereas alcohol consumption and HDL cholesterol concentration were inversely associated with risk after allowing for age and ethnic group. The ethnic contrasts in CHD persisted when these characteristics were taken into account. In the smaller sample of women, only ethnic group was predictive of CHD as defined. The failure of point estimates of risk to explain the high CHD incidence in Indians calls for focus on age of onset of risk and examination of other potential risk factors such as insulin concentration.

The presence of antibody to human T-cell leukaemia virus (HLTV-I) has been assessed in 2,143 men and women who represent 83% of all adults aged 35 to 69 years resident in a defined urban community in Trinidad. Individuals of African descent had a higher sero-positivity rate (7.0%) than those originating from India (1.4%), Europe (0%) or of mixed descent (2.7%). Women were infected more frequently than men, and the prevalence of infection increased with age in both sexes. Sero-positivity rates were significantly increased in adults who lived in housing of poor quality (p less than 0.001) or close to water courses (p less than 0.025). These data and others raise the possibility that one route of HLTV-I transmission may be via insect vectors under particular domestic circumstances.

In a prospective survey of 1342 Trinidadian men aged 35 to 69 years at recruitment, age-adjusted mean blood pressures were highest in those of African descent, intermediate in Indians and mean of Mixed origin, and lowest in Europeans. Age-adjusted fasting blood glucose concentrations were highest in Indians and lowest in men of European descent. Relative risks of all-cause, cardiovascular and cerebrovascular mortality increased progressively with increasing systolic pressure, whereas for fasting blood glucose concentration the associations were U-shaped. No ethnic differences were apparent in relative risks. For systolic pressure, mortality from all-causes and cardiovascular diseases respectively were about two and three times higher at 180 mmHg or more than at pressures below 130 mmHg. For blood glucose, all-cause and cardiovascular mortality were about four times higher at fasting concentrations greater than 7.7 mmol/l than in the lowest risk group (4.2-4.6 mmol/l). All-cause population attributable mortality rates for systolic pressures of 130 mmHg or more were 1.3 to 2.8 times higher in Indian men than in other groups. For blood glucose in excess of 4.6 mmol/l, population attributable mortality was between 2.9 and 6.9 times higher in Indians than in other groups. The findings emphasized the high mortality in men of Indian descent, partly due to an apparent underlying predisposition to cardiovascular disease, and partly to their high prevalence of diabetes mellitus.

Prevalence of coronary heart disease (CHD) and fasting serum lipoprotein concentrations in ethnic groups in Port of Spain, Trinidad, were compared. In a total community survey of 1416 men aged 35-69 years, angina pectoris, a history of possible myocardial infarction, and major Q waves on the electrocardiogram were significantly more common in men of Indian descent than in other ethnic groups (relative risk about 3/1). Indians had significantly lower high-density-lipoprotein-cholesterol (HDLCh) concentrations and significantly higher low-density-lipoprotein-cholesterol (LDLCh) concentrations than other groups. After allowance for age and ethnic group, men with major Q waves or a history of possible myocardial infarction had a significantly greater ratio of LDLCh/HDLCh that men without either. Comparison of surveys in the Caribbean suggests that in this region CHD is prevalent only in communities in which a sizeable proportion of men have an LDHCh/HDLCh ratio greater than 6 and an LDLCh concentration above 5 mmol/l.

Triceps skinfold, body mass index (BMI), blood pressure, blood glucose concentration and serum lipoprotein concentrations were measured in 590 (80 percent) of 738 women aged 35-69 years resident within a defined area of Port-of-Spain, Trinidad. A triceps skinfold of 32 mm or more (the 70th percentile of overall distribution) was found in 36 percent of women of African descent and 28 percent of women of other ethnic origin. Respective figures for a BMI of 30.0 kg/m2 or more were 32 percent and 27 percent at ages 40 to 64 years. Obesity was associated with an increase in blood pressure, increased fasting blood glucose, LDL cholesterol and VLDL triglyceride concentrations, and a reduction in HDL cholesterol concentration. Obese women had an increased tendency to a history of early menarche, multiparity and children of high birthweight. These findings suggested that, irrespective of ethnic origins, the effects of obesity on health in this female population resembled those in white N. American women.

Serum high-density lipoprotein (HDL) cholesterol, testosterone and sex-hormone-binding globulin (SHBG) were measured in 300 men, aged 35-64 years, of African and Indian descent who represented a 40% sample of participants in a community survey of coronary heart disease in Trinidad. Free testosterone was calculated from total testosterone and SHBG. In 113 men, HDL2 and HDL3 cholesterol were measured by a precipitation technique. Indian men had a significantly lower HDL-cholesterol concentration than African men (P = 0.003), which is known to be due to a reduction in the HDL3 fraction (demonstrable only in younger men in the subsample drawn for this study). Testosterone did not differ with ethnic group, but SHBG was reduced in Indians (P = 0.03). After allowance for age, ethnic group, alcohol consumption and smoking habit, HDL cholesterol was associated positively with SHBG (P = 0.025) but was not related significantly to either total testosterone or its free and bound components. Serum HDL2 cholesterol was associated positively and independently with SHBG (P = 0.001) and total and bound testosterone (P = 0.002), whereas HDL3 cholesterol showed no significant associations with these factors. Neither SHBG or testosterone afforded an explanation for the relatively low HDL and HDL3 cholesterol concentrations in Indian men.

Fasting serum lipoprotein lipid concentrations were measured in 64 subjects aged 11-18 and 72 aged 33-54 years, who comprised 86% of long-term residents of these ages in a rural community in Trinidad. Total HDL, HDL2, and HDL3 cholesterol concentrations were similar in males and females after allowance for alcohol consumption. The results differ from other societies in which HDL2 concentration is lower in men than women, and are thought to provide further evidence for interaction between hormonal status and factors such as adiposity and triglyceride concentration with respect to HDL concentration.

A prospective survey has been undertaken of a total community of 1343 men and 1149 women, aged 35-69 years at recruitment, living in Port-of-Spain, Trinidad. By comparison with adults of African descent, age-adjusted relative risks of death from all causes and from cardiovascular diseases were significantly increased in those of Indian origin (1.5 and 2.6, respectively) and reduced in those of mixed descent (0.5 and 0.3, respectively). Adults of European descent had an all-cause and cardiovascular mortality relative risk of 0.8 and 2.1, respectively. These ethnic differences in risk were not explained by systolic blood pressure, fasting blood glucose concentration, serum high-density lipoprotein or low-density lipoprotein concentration, or smoking habits. Differences in risk of cardiovascular death between Indian and European men seemed to be accounted for by the high prevalence of diabetes in Indians (19%) but other ethnic contrasts in mortality were unrelated to diabetes mellitus.