Raul Costas

Hematocrit and risk of coronary heart disease: the Puerto Rico Heart Health Program

Abstract Hematocrit was determined in 2555 rural and 6151 urban men age 45 to 64 years participating in the Puerto Rico Heart Health Program, a prospective epidemiologic study of coronary artery disease (CAD). These participants were reexamined three additional times and mortality by cause and coronary heart disease (CHD) morbidity were carefully documented for 8 years of follow-up. Since hematocrit (Hct) is an indirect measure of blood viscosity, its value as an independent risk factor of CHD was evaluated. Within the Puerto Rican cohort, Hct is slightly lower in older age groups, and appears slightly lower in the rural than in the urban area. In the rural area 4.6% had Hct values below 40%; in the urban area 3.0% were below 40%. A higher Hct level was associated with cigarette smoking, higher relative weight, higher blood pressure, and higher serum cholesterol. An elevated Hct level was also associated with an increased risk of myocardial infarction (MI), coronary insufficiency or CHD death in the urban area. Incidence of MI, coronary insufficiency, or CHD death was more than double in the high hematocrit group (Hct > 49%) compared to the low group (Hct

Increased physical activity: A protective factor against heart attacks in Puerto Rico

The incidence and potential risk factors of coronary heart disease were assessed in 2,585 rural and 6,208 urban men, aged 45 to 64 years, participating in the Puerto Rico Heart Health Program, a prospective epidemiologic study of coronary heart disease initiated in 1965. An index of daily physical activity and a metabolic equivalent of heaviest activity were estimated from each individual history. Rural men had higher mean levels of overall activity as well as higher levels of heavy activity than urban men. An 8 1/4 year follow-up study for coronary heart disease other than angina pectoris was analyzed for relationships with physical activity. Significant inverse associations were found for both urban and rural men. Metabolic equivalent of heaviest activity showed similar results. Although the physical activity index was inversely associated with most known coronary risk factors, multivariate analyses indicated that a significant independent inverse relationship existed with the incidence of coronary heart disease. In Puerto Rico, increased physical activity appears to be a separate protective factor against heart attacks.

Coronary heart disease risk factors in men with light and dark skin in Puerto Rico.

The association of skin color with coronary heart disease risk factors was studied in 4,000 urban Puerto Rican men. Skin color on the inner upper arm was classified according to the von Luschan color tiles. Using this grading, men were separated into two groups of light or dark skin color. The dark group had a lower socioeconomic status (SES) based on income, education, and occupation. Dark men had slightly higher mean systolic blood pressures (SBP) and lower mean serum cholesterol levels than the light, but the relative weights and cigarette smoking habits of both groups were similar. After controlling for the differences in SES, skin color showed a small but statistically significant association with SBP. Whether this association with skin color represents genetic or environmental influences on SBP could not be determined from this study.

Left ventricular hypertrophy among dark- and light-skinned Puerto Rican men: the Puerto Rico Heart Health Program.

Racial groups were assessed by determinations of skin color in 3366 urban men in the Puerto Rico Heart Health Program, an epidemiologic study of coronary heart disease in Puerto Rico. These men participated in a comprehensive cardiovascular examination that included assessment of blood pressure, relative weight, physical activity, cigarette smoking, left ventricular hypertrophy (LVH) as determined by ECG, and measurements of skinfold thickness. They were followed for mortality over the next 6 years. Dark-skinned Puerto Rican men had a higher prevalence of both definite and possible LVH-ECG after stratifying by levels of hypertension, relative weight, physical activity, number of cigarettes smoked, and subscapular skinfold thickness. After multivariate adjustment of these factors, the dark-skinned men had approximately twice the prevalence of both definite and possible LVH-ECG as the lighter skinned men. Definite LVH-ECG carries a high mortality risk over the next 6 years as compared to men without definite LVH (fivefold increased risk in lighter skinned and sevenfold increased risk in darker skinned Puerto Rican men).

Relation of lipids, weight and physical activity to incidence of coronary heart disease: The puerto rico heart study

The 2 1/2 year incidence of coronary heart disease was examined in relation to antecedent serum cholesterol and fasting triglyceride levels, physical activity status and relative weight in a cohort of 8,171 urban and rural men 45 to 64 years old participating in the Puerto Rico Heart Program. In this population with a low incidence rate of coronary heart disease, risk of coronary disease was related to serum cholesterol in both urban and rural groups, but this trend was statistically significant only in the urban population. Neither the urban nor the rural population showed a substantial or statistically significant association of serum triglyceride levels with incidence of coronary heart disease. Correlations among relative weight and serum triglyceride and serum cholesterol levels were noted. Despite small differences in incidence of coronary heart disease between urban and rural groups, values for serum cholesterol, triglycerides and relative weight were all significantly higher in the urban men. Only physical activity levels were higher in the rural men. Multivariate analysis, performed to sort out the net effects of these interrelated variables, revealed that serum cholesterol is related to the risk of coronary heart disease even when all variables are taken into account. Low levels of physical activity were significantly associated with a greater incidence of coronary heart disease only in urban men (P less than 0.05). Overweight, which was associated with higher lipid values and less physical activity, was not related to the development of coronary heart disease in either the urban or the rural cohort.

Abnormal Blood Glucose and Coronary Heart Disease: The Puerto Rico Heart Health Program

The presence of abnormal blood glucose (ABG) was determined for participants in the Puerto Rico Heart Health Program, a prospective epidemiological study of cardiovascular disease. Subjects were considered to have ABG at baseline if they were receiving treatment for diabetes (diet, oral hypoglycemics, or insulin), or if the blood glucose level was 140 mg/dl or more. Urban-rural comparisons of the prevalence of ABG were made in this cohort of 2585 rural and 6208 urban men aged 45–64 yr. The prevalence of ABG in the urban population was more than double that in the rural. This population has been followed up for coronary heart disease (CHD) over an 8¼-yr period. ABG at baseline is significantly associated with CHD death in urban men. When the relationship is controlled for smoking, systolic blood pressure, cholesterol, and relative weight, the relationship remains significant. The association with total CHD is similar. Either by adjusting for diabetes (i.e., when treated diabetes was excluded from analysis) or by entering both blood glucose and diabetes under treatment into the model, blood glucose was no longer statistically significant. This suggests that ABG, rather than blood glucose alone, is the important variable associated with CHD.

URBAN-RURAL DIFFERENCES IN 12 YEAR CORONARY HEART DISEASE MORTALITY: THE PUERTO RICO HEART HEALTH PROGRAM

Preliminary observations of the Puerto Rican population in 1965 indicated that the coronary heart disease mortality rate was lower than in the U.S., and that the rate in rural areas might be less than urban ones because of lower levels of cardiovascular risk factors. This prompted a prospective investigation of 8793 urban and rural men, aged 45-64 years. A 12-year mortality study has been completed with almost total follow-up. After excluding those with known coronary heart disease at baseline, age-adjusted rates for coronary heart disease, sudden, and stroke death are 19-37% higher in urban than rural men. Urban men had higher average blood pressure, cholesterol, glucose, and heart rate and were less physically active than rural men. When urban-rural differences for the known risk factors, including education and alcohol intake, are adjusted for by multivariate logistic regression analysis, no remaining significant urban-rural coronary heart disease mortality differential is present. Thus, it appears that variation in identified risk factors could explain the difference in mortality within Puerto Rico. The presence of unidentified protective factors cannot be excluded.

Factors Related to Diabetes Mellitus in Puerto Rican Men

Urban-rural comparisons of the prevalence of diabetes were made in a cohort of 2567 rural and 6190 urban participants aged 45 to 64, in the Puerto Rico Heart Health Program. The prevalence of diabetes in the urban population was more than double that in the rural. Consistent with this, blood glucose concentrations were significantly higher in urban than in rural populations. The prevalence of diabetes increased with age and relative weight. It was associated with elevations of serum cholesterol, blood pressure, and fasting serum triglycerides. A positive family history was found more commonly in diabetics than in nondiabetics. If there was a history in both a sibling and a parent, there was at least a threefold increased prevalence over those with no family history. The reason for the higher prevalence of diabetes in the urban than in the rural area is elusive. In obese men, the urban and rural prevalence rates are the same, but, among relatively lean men, the prevalence in the urban area is twice that of the rural men.

Coronary heart disease mortality—A death certificate study☆

Abstract A study of all deaths in the 20–64 age group in the San Juan Metropolitan Area was carried out for the period of 1 May 1963 to 31 October 1963. The methodology used is reported. Of all deaths 52.7 per cent had an autopsy. The revised figures for CHD deaths still reveal a lower age specific mortality rate in the San Juan Metropolitan Area as compared to the rates reported in the United States. The need of well controlled prospective epidemiological studies in different places of the world is emphasized.

Rheumatic fever in the tropics

Abstract Three hundred adult patients with rheumatic fever and/or rheumatic heart disease who were residents of a tropical zone without significant climatic alterations during the year were analyzed. This constituted 3.8 per cent of the total number of admissions to a charity hospital for a period of 8 years. Observations with regard to incidence, pathogenesis, clinical picture, and morbidity were presented. The manifestations of rheumatic fever and rheumatic heart disease in the indigent population of the tropical area of San Juan were not strikingly different from those reported in the temperate zones.