Mario R. García-Palmieri

Diet and its relation to coronary heart disease and death in three populations.

Baseline 24-hour dietary recalls from 16,349 men ages 45–64 years who had no evidence of coronary heart disease (CHD) were obtained in three prospective studies: the Framingham Study (859 men), the Honolulu Heart Study (7272 men) and the Puerto Rico Heart Health Program (8218 men). These men were followed for up to 6 years for the first appearance of CHD or death. Men who had a greater caloric intake or a greater caloric intake per kilogram of body weight were less likely to develop CHD manifest as myocardial infarction (MI) or CHD death, even though men of greater weight were more likely to develop CHD. This may reflect the benefit of greater physical activity. Men who consumed more alcohol were less likely to develop CHD, but more likely to die of causes other than CHD, particularly in the Honolulu study. In the Honolulu and Puerto Rico studies, but not in the Framingham study, men who consumed more starch were less likely to develop MI or CHD death. There was an inverse relation between starch intake and serum cholesterol, but it was too weak to explain fully the inverse starch-CHD association. There was also no evidence that the inverse relation between starch intake and incidence of CHD in the Honolulu and Puerto Rico studies was an indirect result of differences in fat intake. While the findings suggest additional areas for research, none of them would lead to an alteration of currently recommended preventive diets that emphasize lowering fat intake, because in isocaloric diets the logical way to balance a decreased fat intake is to increase the consumption of foods containing starch.

Differences in Coronary Heart Disease in Framingham, Honolulu and Puerto Rico

Abstract An effort to evaluate geographic differences in prevalence and incidence of coronary heart disease in men from Framingham, Japanese from Honolulu, and residents of Puerto Rico was made, using comparable methodology and criteria. The prevalence of CHD was twice as great in Framingham as in Honolulu and Puerto Rico. CHD incidence by ECG alone, by CHD death, or by both was from 2 to 4 times as high in Framingham as in Honolulu and Puerto Rico. There was a striking agreement among the studies with respect to the relationship of baseline characteristics to subsequent incidence of CHD. In particular, all three studies found a positive association of serum cholesterol and blood pressure to subsequent CHD incidence. A similar relationship was encountered with cigarette smoking in Framingham and Honolulu but not in Puerto Rico. All three found little or no relationship to the various measures of clinical and subclinical diabetes. A number of other variables showed relationships that were similar in all three studies. On the other hand, relative weight was a much weaker risk factor in Framingham than in Honolulu or Puerto Rico. Since serum cholesterol levels and the amount of cigarette smoking differ in the three populations it is logical to inquire whether this could account for the differences in CHD incidence. The answer is clear that the average Honolulu Japanese and Puerto Rican has a lower CHD incidence than his counterpart in Framingham. Even after allowing for differences in population characteristics, the difference is statistically significant and about 2-1 in magnitude. This suggests that new factors or explanations should be sought in order to clarify the additional protection against coronary heart disease found in some populations.

Distribution of triglyceride and total, LDL and HDL cholesterol in several populations: a cooperative lipoprotein phenotyping study.

Abstract Data on the distribution of triglyceride and total, LDL and HDL cholesterol are presented for age groups 40 yr and older. The populations represented came from Framingham, Albany, Honolulu, San Francisco, Evans County and Puerto Rico. They include white, Japanese and black persons and both sexes. Blood samples and lipid measurements were obtained after overnight fast by a common protocol as part of a cooperative study of lipoprotein phenotyping. Means, medians, standard deviations and 95th percentiles are given as well as intercorrelations among the various lipids. Average cholesterol levels ranged from 200 mg/dl (Puerto Rican men) to over 240 mg/dl (Framingham women). Average triglyceride levels ranged from less than 100 mg/dl (Evans County) to an average of 175 mg/dl (Japanese men). For men aged 50–69 triglyceride levels were higher in Puerto Rico than in Albany or Framingham, despite much lower levels of serum cholesterol. The 95th percentile for LDL cholesterol in age groups with at least 100 persons ranged from 196 to 209 mg/dl for men and between 221 and 228 mg/dl for women. The 95th percentile for triglyceride, however, varied greatly by age and population from as low as 249 mg/dl to as high as 451 mg/dl.

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.

Risk Factors and Prevalence of Coronary Heart Disease in Puerto Rico

In spite of an apparently increasing mortality rate from coronary heart disease in Puerto Rico, the age-specific mortality rate from this illness is considerably lower in the island than in the U. S. mainland. Examination of 9,814 Puerto Rican urban and rural men in the 45 to 64-year age group revealed sizable and statistically significant differences in monthly income, cigarette smoking, ingestion of fats, blood pressure, heart rate, relative weight, serum cholesterol, serum glycerides, prevalence of diabetes, and prevalence of hypertension (lower in rural dwellers), and also in vital capacity, consumption of calories per unit body weight, and physical activity (higher in rural area). No urban-rural difference in coronary heart disease prevalence was found, but the prevalence of definite myocardial infarction, established on basis of electrocardiographic criteria alone, was significantly higher in the 45 to 54-year urban group. Follow-up of this population to study incidence of disease and the influence of the various factors upon the development of disease is being conducted.

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.

Reversal of hyperkalemic cardiotoxicity with hypertonic saline.

Abstract Four cases of hyperkalemic cardiotoxicity are reported in which the dangerous effects of the increased levels of serum potassium were relieved by the administration of hypertonic (5 per cent) saline. A rapid intravenous administration of hypertonic saline might be a lifesaving procedure in selected cases of hyperkalemic cardiotoxicity. The possible mechanisms involved were discussed.

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.