Regional obesity and risk of cardiovascular disease; the Framingham Study

Risk of cardiovascular events was determined over 24 years of surveillance in relation to general adiposity reflected by relative weight and by regional obesity estimated by skinfolds and waist girth per inch of height. Upper quintile values of relative weight, subscapular skinfolds and waist girth were each associated with increased risks of cardiovascular disease in both sexes. Risk of total cardiovascular events increased with the degree of regional, central or abdominal obesity. Mortality from cardiovascular disease was also increased. Increased relative weight and central obesity were both associated with increased risk factors including cholesterol, blood pressure, glucose and uric acid. Changes in weight were mirrored by changes in risk factors with linear trends over a 15 lb range of weight fluctuations. Subscapular skinfold and the ratio of subscapular-to-triceps skinfold, measures of central obesity, were in either sex also associated with an increased probability of coronary attacks in particular. The subscapular skinfold contributed to CHD risk independent of body mass index (BMI). Multivariate analyses taking all the risk factors into account indicate an independent effect of abdominal obesity on stroke, cardiac failure and cardiovascular and all-cause mortality in men. In women, only the subscapular-to-triceps skinfold ratio independently contributes to CHD, cardiovascular and all cause mortality. Regional obesity appears to be an independent contributor to cardiovascular disease at a given level of general adiposity, its effect only partially mediated through promotion of other known risk factors. These data suggest that cardiovascular disease is as closely linked to abdominal as to general adiposity.

Transition from pre-linguistic to linguistic communication in hearing-impaired infants

This paper examines the development of the ability to signal intentionality in hearing-impaired infants. Four infants were monitored from the time aids were accepted and worn consistently until an expressive vocabulary of ten words was recorded. The focus of the study was the child's developing ability to coordinate attention to both a person and an object. Longitudinal video-taping allowed analysis of the stages and rate at which these infants achieved this pattern of attention. These infants were found to follow a sequence of steps similar to that reported in studies of hearing children. This finding and its possible implications for early identification of hearing impairment are discussed.

Psychosocial correlates of alcohol intake among women aged 45 to 64 years: the Framingham Study

This study of 749 women, aged 45 to 64 years, investigates the psychological, behavioral, and social correlates of alcohol intake. These data from the Framingham Study are uniquely based on a community sample of women, which results in a normative study of drinking behavior in women. Two measures of alcohol intake were utilized in these analyses: (1) the frequency of alcohol intake over 1 week and (2) drinking vs abstaining from alcohol. Among this sample of women, increased socioeconomic status, worrying about aging, and being easily upset were positively associated with frequency of alcohol intake. The rigid attitude scale was the strongest discriminating variable for drinkers vs nondrinkers. Older women were more likely to be nondrinkers compared to younger women, however, among older women, being a homemaker was significantly associated with increased alcohol intake. Contrarily, younger women who were homemakers were more likely to be abstainers than women employed outside the home. As would be expected, cigarette smoking was associated with drinking alcohol.

Blood pressure as a risk factor for cardiovascular disease. The Framingham Study--30 years of follow-up

Data from 30 years of follow-up of the original Framingham Study cohort of 5,070 men and women aged 30-62 years who were first examined during the period 1948-1952 and who were free of cardiovascular disease reveal that blood pressure is a strong and consistent predictor of the development of coronary heart disease, stroke, transient ischemic attack, and congestive heart failure. Other factors related to blood pressure like obesity, left ventricular hypertrophy as demonstrated on electrocardiograms, and heart enlargement as shown by x-ray radiography made several selective additional independent contributions to risk; heart enlargement by x-ray radiography was the best predictor of congestive heart failure.

Cardiovascular risk factors and graded treadmill exercise endurance in healthy adults: The Framingham Offspring Study

To help describe the association between exercise endurance and cardiovascular risk factor profiles, 2,606 young and middle-aged healthy adults in the Framingham Offspring Study were given submaximal treadmill tests. For both men and women, exercise endurance was inversely related to resting heart rate (p less than 0.001), body mass index (p less than 0.001), systolic blood pressure (p less than 0.001) and blood glucose (p less than 0.01), and positively related to high density lipoprotein (HDL) cholesterol (p less than 0.05). In men, cigarette smoking (p less than 0.05), high levels of total cholesterol (p less than 0.01) and very low density lipoprotein (VLDL) cholesterol (p less than 0.001) were also associated with poor exercise endurance. After adjusting for age, resting heart rate and body mass index, significant independent associations persisted for HDL cholesterol (p less than 0.05) in both sexes and for systolic blood pressure, VLDL cholesterol, blood glucose and cigarette smoking in men (p less than 0.05). Risk factors associated with overt cardiovascular disease in older individuals are also associated with poor exercise endurance in those who are younger and asymptomatic.

Hypertension, antihypertensive treatment, and sudden coronary death. The Framingham Study

During 30 years of follow-up, there were 183 sudden deaths in men and 77 in women ages 35 to 94 years who participated in the Framingham Study. Risk of sudden death was increased threefold in hypertensive persons but only if there was no previously diagnosed coronary heart disease. Men receiving antihypertensive treatment had more than twice the risk of sudden death compared with those who were untreated, whether or not they had prior manifestations of coronary heart disease. More than twice as many men who died suddenly were receiving antihypertensive therapy compared with those in the population at risk of the same age. In those with overt coronary heart disease, 34% of those dying suddenly were on antihypertensive treatment compared with 18% of those of the same age in the general population. Multivariate analysis taking into account the level of blood pressure, electrocardiographic abnormalities, and previously diagnosed coronary heart disease and cardiac failure, all of which are predisposing factors for sudden death, indicated a persistent increased risk of sudden death in association with antihypertensive treatment. Tests of interaction indicate that the excess sudden death risk was not confined to those with electrocardiographic abnormalities. In women, it may be associated with diabetes. These data suggest that some feature of antihypertensive treatment as practiced in the general population may contribute to sudden death incidence in an ill-defined subgroup of hypertensive persons.

Metal-metal interactions among dietary toxic and essential trace metals in the rat

Exposure to toxic and essential metals is thought to be reflected by corresponding metal concentrations in tissues. However, toxic and essential metals may influence each other in regard to their retention in the body. Therefore a basic diet containing four toxic metals (As 7, Cd 9, Ni 13, and Pb 20 ppm) and adequate amounts of essential metals was fed to rats for 2 weeks. Test groups received the basic diet with increasing concentrations of one of the toxic metals (up to 90 ppm As, 180 ppm Cd, 365 ppm Ni, and 394 ppm Pb). As, Cd, Ni, Pb, Cu, Fe, Mn, and Zn were determined by atomic emission spectroscopy in liver, kidney, intestine, brain, muscle, bone, skin, hair, and blood. A linear relationship between diet and tissue concentration is observed for As and Ni in the kidney, for Cd in the liver, and for Pb in the bone. In other tissues saturation was observed. While Cd-Fe interactions were common to most of the tissues, other interactions were detected only in specific tissues, e.g., As-Cu in the kidney, Cd-Zn in the liver, and As-Mn, Cd-Mn, or Ni-Cu in the intestine. Increases of renal Pb and intestinal Cd by dietary Ni, and a decrease in bone As by dietary Pb were the most pronounced interactions between the toxic metals. The results demonstrate that potential target organs for the evaluation of metal exposure need to be carefully analyzed for interfering metal-metal interactions.

Appraisal of modifiable hospitalization risks

Nine prevention experts rated hospitalization risks of 64 hypothetical healthy adults between 20 and 65 years old. There was substantial agreement among seven out of the nine experts. Pairwise correlations between any two of the experts ranged between 0.66 and 0.86. Decision analytic tools were used to model the average of the experts' ratings. The panel of experts provided us with the factors used, the relationship between the factors, and the relative importance of each factor. An index based on this information was highly correlated with the judgments of seven experts. Thus, we concluded that the scoring procedure can simulate the experts' judgments. Next, the index was used in an interactive computer program to assess modifiable health risks of individuals. This program is provided along with the paper to facilitate further research on validity and impact of the program.

The relative importance of selected risk factors for various manifestations of cardiovascular disease among men and women from 35 to 64 years old: 30 years of follow-up in the Framingham Study

Substantial differences were noted in the risk profiles for various manifestations of cardiovascular disease (CVD) that occurred before the age of 65 during the first 30 years of follow-up of the 5070 subjects of the original Framingham cohort. Hypertension contributed most consistently to short-term risk of all manifestations of CVD. Differences were noted between the sexes and age groups in both the univariate and multivariate analyses. These patterns have biological, clinical, and statistical significance, particularly as they relate to the need for future studies to distinguish better between those factors that precipitate cardiovascular events and those that relate to the pathogenesis of the underlying atherosclerosis.

Incidence and precursors of hypertension in young adults: the Framingham Offspring Study

The occurrence of hypertension and its precursors is examined in the Framingham Offspring Study of 2,027 men and 2,267 women ages 20-49 years followed for 8 years. The age-specific prevalence of hypertension was similar at both the first (1971-1975) and the second (1979-1983) examination for both men and women. Prevalence rates were higher among men than among women, and there was a higher rate of hypertension treatment at the second exam, particularly among women, 75% of whom reported being treated for hypertension. The incidence of hypertension in participants free from hypertension at the first examination increased threefold from the second to the fifth age decades in men and eight-fold in women. Under age 40, men were twice as likely as women to develop hypertension, but after age 40, 8-year incidence rates were similar in men (14.2%) and women (12.9%). Adiposity, relative weight, heart rate, alcohol intake, hematocrit, blood sugar, serum protein, triglyceride, and phosphorous were all related to hypertension occurrence in one or both sexes, controlling for age. In multivariate analysis, adiposity (P less than 0.01), heart rate (P less than 0.01), and triglyceride (P less than 0.05) were all significant independent predictors of hypertension in men. In women, adiposity (P less than 0.001), heart rate (P less than 0.01), hematocrit (P less than 0.05), and alcohol consumption (P less than 0.05) were independent contributors. When controlling for blood pressure measured at the first examination, the best single predictor of hypertension incidence, the multivariate assessment changed very little. Adiposity stands out as a major controllable contributor to hypertension. Changes in body fat over 8 years were related to changes in both systolic and diastolic blood pressure. Markedly obese women in their fourth decade were seven times more likely to develop hypertension than were lean women of the same age. Weight control deserves a high priority in efforts to prevent hypertension in the general population.

Health assessment in the Framingham Offspring Study: a research proposal

This paper proposes that a broader health assessment be made in the Framingham Offspring/Spouse Study than is undertaken in the Framingham Study. The Offspring Study is composed of the children (and their spouses) of the members of the original Framingham Study cohort. The Offspring population has a broader age range and an average age that is approximately 30 years younger than the original parent cohort. Therefore, mortality and morbidity measures, which were used as indices of health status for the parent cohort and which focus on the negative "sickness" component of health, are less appropriate for use in this relatively healthy population. Thus, we propose a broader conceptual framework of health that emphasizes the positive "wellness" side of the health continuum. The essential components of the comprehensive health index we describe include global health perceptions, measures of physical, mental, and social functioning across valued social roles, the ability to withstand stress as mediated by the coping process and social resources, and the assessment of genetic, behavioral, and physiological risk factors. One purpose of the proposal is to stimulate discussion in the hope of achieving general agreement regarding a shared conceptual frame of reference that would guide the development and testing of a reliable and valid health status instrument.

Adjusting capitation using chronic disease risk factors: a preliminary study

Researchers have sought ways to modify Medicare's capitation formula, the adjusted average per capita cost (AAPCC), by including measures of individual health status. The present study assesses the value of risk factors for disease as predictors of hospitalization for Framingham Heart Study participants (1,210 males and 1,496 females) 60-65 years of age. Regression models including several common physiologic measures and prior hospitalizations yielded adjusted R2s of 9.69 percent for males and 3.61 percent for females. The contributions of the risk factors and prior hospitalization were about equal and independent. These results confirm the potential utility of disease risk factors for adjusting the AAPCC.

Predictors of good function: the Framingham Study

This paper asks the question: among 1474 Framingham Study participants aged 35-68 years who were healthy at their fourth examination (1954-1958), what are the physiologic, behavioral, and demographic characteristics that distinguish those who survive and report good function from those who do not after 21 years of biennial observations? Although a larger proportion of women than men survived, their functional status was not as good. Multiple logistic regression analysis revealed that age, alcohol intake, cigarette smoking, ventricular rate, and education were all significantly related to functional status for men, with all but the last of these factors inversely related to good function. For women, the only significant predictor other than age was education, which, as with men, was directly associated with good function. The effect of education is probably mediated by numerous factors such as availability and use of health care services, quality of health care, occupation, and lifestyle.

The spectrum of left ventricular hypertrophy in a general population sample: the Framingham Study

To assess the prevalence, characteristics, and correlates of echocardiographically determined left ventricular hypertrophy (echo LVH) in a free-living population, 510 men and 855 women from the original Framingham cohort (age 59 to 90 years) were studied by M-mode echocardiography. Offspring and offspring spouses (1718 men and 1892 women; age 17 to 75 years) were similarly studied. The severity of echo LVH, as reflected by left ventricular mass indexed to body surface area, ranged from 101 g/m2 (women) and 132 g/m2 (men) to more than 400 g/m2. The prevalence of electrocardiographically assessed LVH increased proportionately with increased echocardiographic left ventricular mass. Women with echocardiographic left ventricular mass indexes exceeding 200 g/m2 were three to four times more likely to have electrocardiographic LVH than men with similar elevations of echocardiographic left ventricular mass index. The prevalence of echo LVH ranged from 6.6% in the younger (offspring study) women to 33% in the older (original cohort) women (8.6% and 23.7%, respectively, for men) and included a spectrum of forms--eccentric-dilated, eccentric-nondilated, concentric, and disproportionate septal thickness--which varied in prevalence in the various age-sex groups. Each of these forms of echo LVH was associated with higher systolic blood pressures at the time of echocardiographic examination and over the previous 30 years when compared with blood pressures of Framingham subjects without echo LVH.

Gender differences in predicting loneliness from social network characteristics

In two studies we examined gender differences in predicting loneliness from measures of social network structure and a measure of perceived social support. The results showed that social network characteristics, especially density, were consistently better predictors of perceived loneliness for men than for women. Study 1 used the traditional measure of network density in which the number of relationships among network members was determined. Study 2 used a newly developed index of density that assessed the extent of closeness of relationships between pairs of network members. Uniformly, male subjects with more highly interconnected, cohesive sets of friends reported themselves to be less lonely, whereas density had little relation to loneliness in female subjects. These results are discussed as possibly indicating that men and women use different standards in evaluating whether they are lonely. It is suggested that men may use more group-oriented criteria in evaluating loneliness, whereas women focus more on the qualities of dyadic relationships.

Interrelationships of general internal medicine and preventive/community medicine

Clinical preventive medicine, efforts by clinicians to prevent disease in individual patients, is an important component of preventive medicine as a whole. Yet clinicians, including internists, apparently do not provide many preventive services of established effectiveness. This paper describes one approach to improving the practice of clinical preventive medicine: increased cooperation between general internists--one of the nation's largest groups of primary care physicians--and specialists in preventive/community medicine. The paper summarizes a larger report prepared by two societies representing these disciplines: the Society for Research and Education in Primary Care Internal Medicine and the Association of Teachers of Preventive Medicine. It was found that the two disciplines have many common goals, and much to offer each other, but do not often collaborate. The report concludes with 14 recommendations for improving the practice of clinical preventive medicine, which suggest that such improvement can be achieved in part through strengthening working relationships between general internists and preventive/community medicine specialists.

Detection of acquired immunodeficiency syndrome (AIDS) retrovirus antibody by lymphadenopathy-associated virus (LAV) enzyme immunoassay in low- and high-risk populations

Antibody to the acquired immunodeficiency syndrome (AIDS) retrovirus was evaluated by an lymphadenopathy-associated (LAV) enzyme immunosorbent assay (EIA) and compared with the standard human T-cell lymphotropic virus, Type III (HTLV-III) screening test in two groups of people. The first group consisted of those at low risk for AIDS, including 1352 random volunteer donors, 1140 of whom were prospective donors and 212 of whom were retrospective donors, repeatedly reactive by HTLV-III EIA. The second group was composed of those at high risk for AIDS, including 54 hemophiliacs, one of whom had AIDS, seven AIDS-related complex (ARC), and one immune thrombocytopenia (ITP). Of the 1140 prospective donors, one was repeatedly reactive by LAV EIA and four by HTLV-III EIA; none was positive by Western blot. Of the 212 retrospective donors, six were repeatedly reactive by LAV EIA and 212 by HTLV-III EIA; only six (the six LAV EIA positive) were positive by Western blot. Of the 54 hemophiliacs, 46 were repeatedly reactive by both LAV EIA and HTLV-III EIA, and all 46 were positive by Western blot. Both LAV EIA and HTLV-III EIA were positive in all hemophiliacs with AIDS, ARC, and ITP. The marked reduction in HTLV-III EIA repeatedly reactive, Western blot nonreactive samples by the LAV EIA system suggests that this assay may be as sensitive but more specific than the standard HTLV-III EIA in low-risk populations. The strong correlation between the LAV EIA and the Western blot assay further suggests that this assay may provide an efficient screening test for AIDS antibody in the donor population.

Gender differences in predicting loneliness from social network characteristics

In two studies we examined gender differences in predicting loneliness from measures of social network structure and a measure of perceived social support. The results showed that social network characteristics, especially density, were consistently better predictors of perceived loneliness for men than for women. Study 1 used the traditional measure of network density in which the number of relationships among network members was determined. Study 2 used a newly developed index of density that assessed the extent of closeness of relationships between pairs of network members. Uniformly, male subjects with more highly interconnected, cohesive sets of friends reported themselves to be less lonely, whereas density had little relation to loneliness in female subjects. These results are discussed as possibly indicating that men and women use different standards in evaluating whether they are lonely. It is suggested that men may use more group-oriented criteria in evaluating loneliness, whereas women focus more on the qualities of dyadic relationships.