Millicent Higgins

Prevalence of Hypertension in the US Adult Population: Results From the Third National Health and Nutrition Examination Survey, 1988-1991

The purpose of this study was to estimate the current prevalence and distribution of hypertension and to determine the status of hypertension awareness, treatment, and control in the US adult population. The study used a cross-sectional survey of the civilian, noninstitutionalized population of the United States, including an in-home interview and a clinic examination, each of which included measurement of blood pressure. Data for 9901 participants 18 years of age and older from phase 1 of the third National Health and Nutrition Examination Survey, collected from 1988 through 1991, were used. Twenty-four percent of the US adult population representing 43,186,000 persons had hypertension. The age-adjusted prevalence in the non-Hispanic black, non-Hispanic white, and Mexican American populations was 32.4%, 23.3%, and 22.6%, respectively. Overall, two thirds of the population with hypertension were aware of their diagnosis (69%), and a majority were taking prescribed medication (53%). Only one third of Mexican Americans with hypertension were being treated (35%), and only 14% achieved control in contrast to 25% and 24% of the non-Hispanic black and non-Hispanic white populations with hypertension, respectively. Almost 13 million adults classified as being normotensive reported being told on one or more occasions that they had hypertension; 51% of this group reported current adherence to lifestyle changes to control their hypertension. Hypertension continues to be a common finding in the general population. Awareness, treatment, and control of hypertension have improved substantially since the 1976-1980 National Health and Nutrition Examination Survey but continue to be suboptimal, especially in Mexican Americans.(ABSTRACT TRUNCATED AT 250 WORDS)

Trends in the Prevalence, Awareness, Treatment, and Control of Hypertension in the Adult US Population: Data From the Health Examination Surveys, 1960 to 1991

The objective of this study was to describe secular trends in the distribution of blood pressure and prevalence of hypertension in US adults and changes in rates of awareness, treatment, and control of hypertension. The study design comprised nationally representative cross-sectional surveys with both an in-person interview and a medical examination that included blood pressure measurement. Between 6530 and 13,645 adults, aged 18 through 74 years, were examined in each of four separate national surveys during 1960-1962, 1971-1974, 1976-1980, and 1988-1991. Protocols for blood pressure measurement varied significantly across the surveys and are presented in detail. Between the first (1971-1974) and second (1976-1980) National Health and Nutrition Examination Surveys (NHANES I and NHANES II, respectively), age-adjusted prevalence of hypertension at > or = 160/95 mm Hg remained stable at approximately 20%. In NHANES III (1988-1991), it was 14.2%. Age-adjusted prevalence at > or = 140/90 mm Hg peaked at 36.3% in NHANES I and declined to 20.4% in NHANES III. Age-specific prevalence rates have decreased for every age-sex-race subgroup except for black men aged 50 and older. Age-adjusted mean systolic pressures declined progressively from 131 mm Hg at the NHANES I examination to 119 mm Hg at the NHANES III examination. The mean systolic and diastolic pressures of every sex-race subgroup declined between NHANES II and III (3 to 6 mm Hg systolic, 6 to 9 mm Hg diastolic). During the interval between NHANES II and III, the threshold for defining hypertension was changed from 160/95 to 140/90 mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)

Report of the Conference on Low Blood Cholesterol: Mortality Associations.

BackgroundA National Heart, Lung, and Blood Institute (NHLBI) Conference was held October 9–10, 1990, to review and discuss existing data on U-shaped relations found between mortality rates and blood total cholesterol levels (TC) in some but not other studies. Presentations were given from 19 cohort studies from the United States, Europe, Israel, and Japan. A representative of each study presented its findings and also submitted tables of proportional hazards regression coefficients for entry TC levels in regard to death, and these were incorporated into a formal statistical overview adjusted for age, diastolic blood pressure, cigarette smoking, body mass index, and alcohol intake, as available. Methods and ResultsThe U-shape for total mortality in men and the flat relation in women resulted largely from a positive relation of TC with coronary heart disease death and an inverse relation with deaths caused by some cancers (e.g., lung but not colon), respiratory disease, digestive disease, trauma, and residual deaths. Risk for combined noncardiovascular, noncancer causes of death decreased steadily across the range of TC. The conference considered possible explanations for the statistical associations found between low TC levels or active TC lowering and certain causes of death. One is that TC is lowered by some disease conditions themselves, such as wasting in chronic pulmonary disease or reduced production and secretion of cholesterol-bearing lipoproteins with liver disease. In this sort of situation, the TC: mortality association found in observational studies may be due to preexisting disease. This was addressed by excluding early deaths from the analysis, which did not change the results. The conference considered as well the biological function of cholesterol, which, if seriously deranged, might hypothetically cause a wide variety of diseases and dysfunction. The conference also considered the biological functions that might provide plausible mechanisms for the associations found. ConclusionsDefinitive interpretation of the associations observed was not possible, although most participants considered it likely that many of the statistical associations of low or lowered TC level are explainable by confounding in one form or another. The conference focused on the apparent existence and nature of these associations and on the need to understand their source rather than on any pertinence of the findings for public health policy. Further research is recommended to explain the observed associations of low TC levels (and TC lowering) with certain noncardiovascular diseases. This includes studies of the time course of TC change in disease, the relation of TC to morbidity, further studies of possible epidemiological confounding, monitoring of population trends in TC and mortality, further studies of the relations in women, auditing of noncardiovascular events in trials, studies of cell membrane, genetic and molecular links to cholesterol metabolism, TC level and disease, studies of disease manifestations in specific lipid disorders, and further study of the proposed causal mechanisms linking low TC and hemorrhagic stroke.

Usefulness of cardiovascular family history data for population-based preventive medicine and medical research (The Health Family Tree Study and the NHLBI Family Heart Study) ☆

Detailed medical family history data have been proposed to be effective in identifying high-risk families for targeted intervention. With use of a validated and standardized quantitative family risk score (FRS), the degree of familial aggregation of coronary heart disease (CHD), stroke, hypertension, and diabetes was obtained from 122,155 Utah families and 6,578 Texas families in the large, population-based Health Family Tree Study, and 1,442 families in the NHLBI Family Heart Study in Massachusetts, Minnesota, North Carolina, and Utah. Utah families with a positive family history of CHD (FRS > or =0.5) represented only 14% of the general population but accounted for 72% of persons with early CHD (men before age 55 years, women before age 65 years) and 48% of CHD at all ages. For strokes, 11% of families with FRS > or =0.5 accounted for 86% of early strokes (<75 years) and 68% of all strokes. Analyses of >5,000 families sampled each year in Utah for 14 years demonstrated a gradual decrease in the frequency of a strong positive family history of CHD (-26%/decade) and stroke (-15%/decade) that paralleled a decrease in incidence rates (r = 0.86, p <0.001 for CHD; r = 0.66, p <0.01 for stroke). Because of the collaboration of schools, health departments, and medical schools, the Health Family Tree Study proved to be a highly cost-efficient method for identifying 17,064 CHD-prone families and 13,106 stroke-prone families (at a cost of about

Dietary n-3 polyunsaturated fatty acids and smoking-related chronic obstructive pulmonary disease

27 per high-risk family) in whom well-established preventive measures can be encouraged. We conclude that most early cardiovascular events in a population occur in families with a positive family history of cardiovascular disease. Family history collection is a validated and relatively inexpensive tool for family-based preventive medicine and medical research.

Epidemiology of asthma and allergic rhinitis in a total community, Tecumseh, Michigan: IV. Natural history☆

BACKGROUND Fish contain n-3 polyunsaturated fatty acids, principally eicosapentaenoic acid and docosahexaenoic acid, which are known to interfere with the bodys inflammatory response and may be of benefit in chronic inflammatory conditions. METHODS We studied the relation between the dietary intake of n-3 fatty acids and chronic obstructive pulmonary disease (COPD) in 8960 current or former smokers participating in a population-based study of atherosclerosis. Intake of fatty acids was estimated with a dietary questionnaire. The presence of COPD was assessed by a questionnaire on respiratory symptoms and by spirometry. Three case definitions of COPD were used: symptoms of chronic bronchitis (667 subjects), physician-diagnosed emphysema reported by the subject (185 subjects), and spirometrically detected COPD (197 subjects). RESULTS After control for pack-years of smoking, age, sex, race, height, weight, energy intake, and educational level, the combined intake of eicosapentaenoic acid and docosahexaenoic acid was inversely related to the risk of COPD in a quantity-dependent fashion. The adjusted odds ratio for the highest quartile of intake as compared with the lowest quartile was 0.66 for chronic bronchitis (95 percent confidence interval, 0.52 to 0.85; P < 0.001 for linear trend across the range of intake values), 0.31 for physician-diagnosed emphysema (95 percent confidence interval, 0.18 to 0.52; P for linear trend, 0.003), and 0.50 for spirometrically detected COPD (95 percent confidence interval, 0.32 to 0.79; P for linear trend, 0.007). CONCLUSIONS A high dietary intake of n-3 fatty acids may protect cigarette smokers against COPD.

Benefits and Adverse Effects of Weight Loss: Observations from the Framingham Study

Abstract The incidence and remission of allergic rhinitis and asthma were studied in 6,563 residents of Tecumseh, Michigan, who were examined on two occasions separated by an average interval of 4 years. The 4 year incidence of probable allergic rhinitis was 2 per cent for males and females, and the 4 year incidence of probable asthma was 1 per cent for both sexes. During this time interval the incidence of allergic rhinitis among males and females who previously had asthma was 3 per cent and 5 per cent, respectively. The incidence of asthma in persons who previously had allergic rhinitis was 1 per cent in males and 3 per cent in females. Remission occured in approximately 20 per cent of persons with asthma and 8 per cent with allergic rhinitis over a 2 year period. Either disease was as likely to remit if the other disease was present or not. Allergic rhinitis was more likely to remit when the duration was shorter than 5 years, while asthma remissions were not clearly influenced by duration. Persons with perennial allergic rhinitis were less likely to remit than those with seasonal symptoms.

Evidence for major genes influencing pulmonary function in the NHLBI family heart study.

Identifying the benefits and adverse effects of weight loss is difficult, especially because these assessments were not among the original goals of prospective evaluations of cardiovascular disease such as the Framingham Study. Attention previously focused on obesity, body fat distribution, and alternating cycles of weight gain and weight loss as risk factors for cardiovascular disease [112]. The Technology Assessment Conference [13] emphasized voluntary weight loss and control, whereas both voluntary and involuntary weight loss occur in free-living populations for various reasons, making it difficult to separate causes from consequences and benefits from adverse effects. Nevertheless, the availability of repeated measures of weight, body size, and fatness, together with follow-up for death, morbidity, and risk factors provides an opportunity to gain useful insights into the determinants and effects of weight changes. Methods The Framingham Study recruited 5209 men and women between ages 30 and 62 years beginning in 1948; observations made at 2-year intervals included measurements of weight and risk factors as well as ascertainment of cardiovascular events and morbidity and death from all causes [3, 1416]. Framingham Study Men and women between ages 35 and 54 years at the fourth examination of the Framingham cohort (1954-1958) were characterized with respect to change in body mass index (BMI, kg/m2) measured at 2-year intervals during a period of 10 years. Those who did not attend each examination were excluded (18% of those present at examination 4). Individual slopes, based on regressions of BMI for six examinations, were used to define three equal groups (tertiles) of individuals; characterizing approximately those who lost, those who remained relatively stable, and those who gained. Details of examination procedures, laboratory methods, diagnostic criteria, and follow-up methods have been published [3, 1416]. This report defined cardiovascular disease as coronary heart disease, stroke, intermittent claudication, and congestive heart failure. Coronary heart disease was defined as myocardial infarction, coronary insufficiency, and angina pectoris. Hypertension was defined by a blood pressure 160 mm Hg (systolic) or 95 mm Hg (diastolic) or by the use of antihypertensive medication. Pulmonary disease was diagnosed clinically or by self-report of chronic coughing or wheezing. Other clinically diagnosed diseases included mitral or aortic valve disease, arthritis, urinary disease, neurologic disease, and other vascular disease. The term any disease applied to any of these conditions. Statistical Analysis Individual slopes of weight, BMI, systolic blood pressure, diastolic blood pressure, and cholesterol were estimated for the 10-year period from examination 4 to examination 9. The coefficient of variation was defined as the standard deviation of BMI divided by the mean BMI for examinations 4 through 9. The variability around the BMI slope for examinations 4 through 9 was calculated as Equation 1 where y = predicted BMI, y = actual BMI, and df = degrees of freedom. Mean BMIs for examinations 4 through 9 were calculated for the population attending all of these examinations; means for examinations 1 through 3 and 10 through 18 were based on members of this population who attended the examination in question. Results from the first and third tertiles (loss and gain groups) were compared with those from the no change group using t-tests for continuous variables and chi-square analyses for dichotomous variables. Changes in lipid levels, blood pressure, and smoking status by change in weight were compared using analysis of variance and chi-square tests. Mortality rates were calculated for the cohort during 20 years of follow-up and excluded deaths occurring in the first 4 years. Age-adjusted and multivariate relative risks and 95% confidence intervals (CIs) were calculated from Cox regression coefficients with age, and age plus major risk factors at examination 9 in the models. In these regression analyses, the tertiles of BMI slope were entered as dummy variables and used the middle group as the referent. Results Figure 1 shows the age-adjusted mean levels of BMI for the three tertiles of BMI change for the 10-year classification period (examinations 4 through 9), together with mean levels of BMI for 6 years before and 18 years after this period. Each group has been subdivided into those who survived through examination 18 and those who died between examinations 9 and 18. Values of BMI were not available for those who did not return for any of examinations 10 through 18 because of death or for any other reason. In all three groups of BMI change, mean BMIs for those who survived through examination 18 were stable during follow-up. Figure 1. Mean body mass index at examinations 1 through 18. Among women whose BMIs decreased, the decline was greater and continued beyond examination 9 in the 31% who did not survive to examination 18. The absence of a similar pattern among men whose BMIs decreased may have been due to the higher proportion of these men (53%) who did not survive to examination 18. Twenty-eight percent of deaths were attributed to coronary heart disease in these men, and 15% were sudden, whereas 19% were attributed to coronary heart disease in women whose BMIs decreased, and 6% were sudden. Among men in the no-change group, mean BMIs were higher in those who died than in those who survived. Mean BMIs were similar, however, in these two groups of women. Among men who gained weight between examinations 4 and 9, those who died before examination 18 were heavier initially, but their BMIs decreased sharply toward the end of the follow-up period. A similar pattern was seen in women, but the discrepancy in BMI was greater. Those who did not survive were heavier until 8 years of follow up, when BMIs decreased sharply in those who did not survive to examination 18. Characteristics of the three BMI change groups during the classification period (examinations 4 through 9) are shown in Table 1. Weight loss ranged from losses of 24.4 and 24.0 kg (54 and 53 lb) to gains of 2.2 and 7.7 kg (5 and 17 lb) for men and women, respectively, in the BMI loss tertile. Men and women whose BMIs decreased were older; their mean BMIs were 27.1 and 25.7 at examination 4 and 25.3 and 24.2 at examination 9. They were the heaviest groups at the beginning and the lightest groups at the end of this period; BMIs averaged for the six examinations were identical for the three groups of men but were lowest for women whose BMI did not change. Change in BMI correlated weakly with BMI at examination 4 (r = 0.2 and 0.12),with mean BMI for examinations 4 through 9 (r = 0.05 and 0.11), with the coefficient of variation (r = 0.06 and 0.19), and with variability around the BMI slope (r = 0.04 and 0.12)for men and women, respectively. The coefficient of variation (variability around the mean) and variability around the slope of BMI were greater for those whose BMIs decreased or increased (Table 1). Table 1. Means of Selected Measures by Tertile of Change in Body Mass Index among Framingham Men and Women between Ages 35 and 54 Years Compared with those whose BMIs were unchanged, men and women whose BMIs decreased had higher systolic blood pressures and cholesterol levels initially but not at the end of the baseline period. Rates of cigarette smoking at examinations 4 and 9 were higher among those whose BMIs decreased, and the percentages of smokers who quit were lower among those whose BMIs decreased than among those whose BMIs changed only slightly. Rates of smoking cessation were twice as high in men and women who gained as in those who lost weight. Levels of physical activity were similar in the three groups of men but were slightly lower in the BMI loss group of women. At examination 7 or 8, 16% of men and women who lost weight were on weight control diets; 20% of women and 9% of men who gained and 11% of women and 7% of men whose weight remained unchanged reported being on similar diets. Average annual changes in weight and the major cardiovascular risk factors during the 10-year period are also shown in Table 1. Among men of average height (1.7 m [68 in]), the average annual weight change for the three tertiles of BMI change ranged from a loss of 0.51 kg (1.14 lb) to a gain of 0.60 kg (1.33 lb). Among women of average height (1.6 m [63 in]), average annual changes in weight varied from a loss of 0.39 kg (0.86 lb) to a gain of 0.71 kg (1.58 lb). Women with the most stable weights gained an average of 0.16 kg (0.36 lb) per year. Systolic and diastolic blood pressures increased least in those whose BMI decreased and increased most in those whose BMIs increased. Changes in cholesterol levels ranged from a decrease of 0.02 mmol/L (0.76 mg/dL) per year for men who lost weight to increases of 0.01 to 0.02 mmol/L (0.38 to 0.76 mg/dL) per year for those whose weight increased or remained unchanged. Changes in cholesterol were all positive in women, ranging from increases of 0.03 mmol/L (1.1 mg/dL) per year for those who lost weight to increases of 0.06 mmol/L (2.3 mg/dL) for other women. In contrast, rates of smoking cessation were more beneficial for health, that is, higher in those whose BMIs increased. Prevalence rates of cardiovascular disease and coronary heart disease were significantly higher at examination 9 among men whose BMIs decreased (see Table 1); diabetes, pulmonary disease, and the aggregate of all diseases were similarly more prevalent among men in this group than among those whose BMIs did not change. Diabetes was the only condition that was significantly more frequent in those whose BMIs increased than in those whose BMIs remained unchanged. Among women, prevalence rates of hypertension, pulmonary conditions, and any disease were significantly higher at examination 9 among those whose BMIs decreased than among those whose BMIs did not cha

Associations of candidate loci angiotensinogen and angiotensin-converting enzyme with severe hypertension: The NHLBI Family Heart Study.

Segregation analysis was performed on the pulmonary measures forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and the ratio of FEV1/FVC in 455 randomly ascertained families from the NHLBI Family Heart Study (FHS). Gender specific standardized residuals were used as the phenotypic variable in both familial correlation and segregation analyses. These residuals represented adjustments for the effects of age, age2, age3, Body Mass Index (BMI, kg/m2), height, the ratio of waist to hip measurements (WHR), the presence of coronary heart disease, smoking history, and pack years for current smokers. Sibling correlations were not different from parent‐offspring correlations for all three traits, and heritability estimates for FEV1, FVC, and the FEV1/FVC ratio were 0.515, 0.540, and 0.449, respectively. Segregation analysis of FEV1, a trait that measures airflow, indicated that a dominant major gene best fits the data, although a residual familial correlation supports the presence of an additional polygenic or common environmental component. For FVC, a trait that measures lung volume, alternative models could not be statistically differentiated, but the transmission probabilities do not support a Mendelian major gene. The best model for FEV1/FVC ratio is a non‐Mendelian codominant model, perhaps due to the mixing of the individual underlying distributions influencing airflow and lung volume. These results support the hypothesis that complex relationships exist for lung function traits and that multiple genes and environmental factors influence lung function. Genet. Epidemiol. 19:81–94, 2000. ©2000 Wiley‐Liss, Inc.

Physical activity in the prevention and treatment of obesity and its comorbidities: evidence report of independent panel to assess the role of physical activity in the treatment of obesity and its comorbidities.

PURPOSE In studies conducted in several different populations, the M235T substitution in the angiotensinogen (AGT) locus has been associated with hypertension. METHODS A case-control study was initiated in an attempt to replicate this finding. Persons with hypertension, age- and sex-matched normotensive controls, and randomly sampled individuals were probands from the Family Heart Study of the National Heart, Lung, and Blood Institute. Subjects were recruited from the Atherosclerosis Risk in Communities study (ARIC) in North Carolina and Minneapolis, MN, and from the Framingham Heart Study in Massachusetts. Genotypes were determined for the M235T substitution in the AGT locus and for the insertion/deletion polymorphism in the angiotensin-converting enzyme (ACE) locus. Simple association tests as well as logistic regression analyses were performed. RESULTS The association of AGT-T235 with hypertension was replicated in the Framingham sample (odds ratio, 1.60; 95% confidence interval, 1.11-2.30), but not in the ARIC white or black subjects. However, logistic regression analysis suggested a significant association of AGT with hypertension in both the ARIC white and Framingham samples when the effects of body mass index, triglycerides, and the presence of significant coronary heart disease were controlled. These analyses further suggested that, in the ARIC data, the relationship with the AGT locus is stronger in women than men and that there may be interaction (epistasis) between homozygotes for T235 and ACE-DD in the Framingham data. While the small sample size precluded logistic regression analysis, the frequency of the T235 allele in the black random sample was much higher than in the comparable white sample. CONCLUSIONS These results are compatible with the presence of a genetic risk factor for hypertension in or near the angiotensinogen locus.