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)

Community surveillance of coronary heart disease in the Atherosclerosis Risk in Communities (ARIC) Study: methods and initial two years' experience

The community surveillance component of the Atherosclerosis Risk in Communities (ARIC) Study is designed to estimate patterns and trends of coronary heart disease (CHD) incidence, case fatality, and mortality in four U.S. communities. Community surveillance involves ongoing review of death certificates and hospital discharge records to identify CHD events in community residents aged 35-74 years. Interviews with next of kin and questionnaires completed by physicians and medical examiners or coroners were used to collect information on deaths, and review and abstraction of hospital records were used to collect information on possible fatal and nonfatal myocardial infarctions (MIs). Events were classified using standardized criteria. The initial 2-years' experience with case ascertainment and availability of information needed for classification of events is described. Average annual age-adjusted attack rates of definite MI and CHD mortality rates for blacks in two communities and whites in the four communities are presented and compared with rates based on unvalidated hospital discharge data and vital statistics. Age-adjusted rates based on ARIC classification of definite MI were lower than those based on hospital discharge diagnosis code 410 (e.g., 5.60/1000 and 11.50/1000 among Forsyth County white men, respectively). Age-adjusted rates of definite fatal CHD based on ARIC classification were similarly lower than rates based on underlying cause of death code 410; for example, Jackson black men had rates of 2.82/1000 and 4.52/1000 for definite fatal CHD and UCOD 410-414 or 429.2, respectively.

Body mass index and the prevalence of hypertension and dyslipidemia

OBJECTIVE

To describe and evaluate relationships between body mass index (BMI) and blood pressure, cholesterol, high-density lipoprotein-cholesterol (HDL-C), and hypertension and dyslipidemia.

RESEARCH METHODS AND PROCEDURES

A national survey of adults in the United States that included measurement of height, weight, blood pressure, and lipids (National Health and Nutrition Examination Survey III 1988-1994). Crude age-adjusted, age-specific means and proportions, and multivariate odds ratios that quantify the association between hypertension or dyslipidemia and BMI, controlling for race/ethnicity, education, and smoking habits are presented.

RESULTS

More than one-half of the adult population is overweight (BMI of 25 to 29.9) or obese (BMI of > or =30). The prevalence of high blood pressure and mean levels of systolic and diastolic blood pressure increased as BMI increased at ages younger than 60 years. The prevalence of high blood cholesterol and mean levels of cholesterol were higher at BMI levels over 25 rather than below 25 but did not increase consistently with increasing BMI above 25. Rates of low HDL-C increased and mean levels of HDL-C decreased as levels of BMI increased. The associations of BMI with high blood pressure and abnormal lipids were statistically significant after controlling for age, race or ethnicity, education, and smoking; odds ratios were highest at ages 20 to 39 but most trends were apparent at older ages. Within BMI categories, hypertension was more prevalent and HDL-C levels were higher in black than white or Mexican American men and women.

DISCUSSION

These data quantify the strong associations of BMI with hypertension and abnormal lipids. They are consistent with the national emphasis on prevention and control of overweight and obesity and indicate that blood pressure and cholesterol measurement and control are especially important for overweight and obese people.

Report of the Conference on Low Blood Cholesterol: Mortality Associations

BACKGROUND

A 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 RESULTS

The 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.

CONCLUSIONS

Definitive 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.

The attributable mortality and costs of primary nosocomial bloodstream infections in the intensive care unit

Primary nosocomial bloodstream infection (BSI) is a common occurrence in the intensive care unit (ICU) and is associated with a crude mortality of 31.5 to 82.4%. However, an accurate estimate of the attributable mortality has been limited because of confounding by severity of illness. We undertook this study to assess the attributable mortality and costs associated with an episode of BSI. Infected patients were defined as those who had an episode of BSI during the study period. Uninfected control subjects were matched to the infected patients based upon a number of factors, including predicted mortality on the day prior to infection. The main outcome measures were crude ICU mortality, length of stay, and costs. We found no difference in the crude mortality for the infected and the uninfected patients (35.3 and 30.9%, respectively, p = 0.51). However, among survivors, the patients with nosocomial bloodstream infections did have excess length of stay (mean, 10 d; median, 5 d; p = 0.007) and increased direct costs (mean difference, $34,508; p = 0.008). After matching for severity of illness, we could not detect an association between primary nosocomial bloodstream infections and increased ICU mortality. We did find that primary nosocomial bloodstream infections increased ICU length of stay and costs.

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.

NHLBI Family Heart Study: objectives and design

The NHLBI Family Heart Study is a multicenter, population-based study of genetic and nongenetic determinants of coronary heart disease (CHD), atherosclerosis, and cardiovascular risk factors. In phase I, 2,000 randomly selected participants and 2,000 with family histories of CHD were identified among 14,592 middle-aged participants in epidemiologic studies. Medical histories from these individuals, their parents, and their siblings were used to calculate family risk scores that compared the number of reported and validated CHD events with the number expected based on the size, sex, and age of family members. A total of 657 families with the highest risk scores and early-onset CHD and 588 randomly sampled families had clinic examinations that included electrocardiograms, carotid artery ultrasound scans, spirometry, measurements of body size, blood pressure, lipids, lipoproteins, hemostatic factors, insulin, glucose, and routine chemistries. Additional biochemical and genetic studies are being performed on selected participants. Serum, plasma, lymphocytes, red cells, and DNA are stored for future studies, including genotyping of candidate genes and anonymous markers. Contributions of genes, shared and individual environments, and behaviors to variations in risk factors, preclinical atherosclerosis, and CHD will be estimated. Linkage studies, including the quantitative trait loci approach, are planned.

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 $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.

Spirometry reference values for women and men 65 to 85 years of age. Cardiovascular health study

Pulmonary function was assessed by spirometry in 5,201 ambulatory elderly participants of the Cardiovascular Health Study, sampled from four communities. A stringent quality assurance program exceeded American Thoracic Society (ATS) recommendations for spirometry. Less than 6% of the participants were unable to perform three acceptable spirometry maneuvers. A "healthy" subgroup of 777 women and men 65 to 85 yr of age was identified by excluding smokers and those with lung disease and other factors determined to independently, significantly, and negatively influence the FEV1. Results from black participants were examined separately. Reference equations and normal ranges for FEV1, FVC, and the FEV1/FVC ratio were determined from the healthy group. The results demonstrate differences in predicted values as great as 20% (0.5 to 1 L) for elderly patients when compared with the spirometry reference equations that are most commonly used in the United States.

Accuracy of proband reported family history: the NHLBI Family Heart Study (FHS)

Proband-reported family histories are widely used in research and counseling, yet little is known about the validity of family history reporting. The Family Heart Study (FHS), a population-based study of familial cardiovascular disease, gathered family history information from 3,020 middle-aged probands in four U.S. communities. Probands reported on the history of coronary heart disease (CHD), diabetes, hypertension, and asthma among a total of 10,316 living relatives (9,186 siblings, 1,130 parents) and 2,685 spouses. Questionnaires were returned by 6,672 siblings, 901 parents, and 2,347 spouses, yielding response rates of 73, 79, and 87%, respectively. Utilizing the relatives' self-report as the standard, sensitivity of the proband report on their spouse, parent, and sibling was 87, 85, and 81% for CHD, 83, 87, and 72% for diabetes, 77, 76, and 56% for hypertension, and 66, 53, and 39% for asthma, respectively. Most specificity values were above 90%. Analyses using generalized estimating equations (GEE) were performed to evaluate differences in proband accuracy based on the proband's age, gender, disease state, center, and ethnicity. In multivariate models, age, gender, and disease status were significantly associated with the accuracy of proband's report of sibling disease history, but had little effect on the accuracy of their report on spouses or parents. In general, older probands were significantly less accurate reporters of disease than younger probands. These results demonstrate that CHD family history can be captured effectively based on proband reports, but suggest that additional family contacts may be helpful when working with older probands or with chronic diseases that have few recognized medical events or procedures.

Obesity and hypertension: epidemiological and clinical issues

The relationship between obesity and hypertension has been investigated in a large number of cross-sectional population studies and a smaller number of prospective, observational studies. The results indicate that in most populations, blood pressure increases linearly with increasing body weight or body mass index. The relationship is present across all subgroups, although the magnitude of the association appears greater in whites than blacks and greater in younger than older persons. It is estimated that as much as one-third of all hypertension may be attributable to obesity in populations where hypertension and obesity are widely prevalent. Evidence from prospective studies and clinical trials suggests that hypertension in obese patients increases the risk of cardiovascular disease and that drug treatment of hypertension reduces the risk. However, it is uncertain whether the risks associated with hypertension and the benefits of treatment are as great in obese hypertensives as they are in lean hypertensives. The effects of weight reduction on blood pressure have been investigated in a small number of randomized, controlled trials involving a total of about 600 participants. Overall, the results of the trials indicate that weight reduction lowers blood pressure over intervals of up to one year. The magnitude of the blood pressure response appears to be directly proportional to the amount of weight loss achieved. However, the latter is inversely related to the length of follow-up. Adequate maintenance of weight loss remains a major problem for the much-needed, long-term trials of the effects of weight reduction on blood pressure and the cardiovascular complications of hypertension.

Reduction of cardiovascular disease-related mortality among postmenopausal women who use hormones: evidence from a national cohort

A national sample of 1944 white menopausal women greater than or equal to 55 years old from the epidemiologic follow-up of participants in the National Health and Nutrition Examination Survey was reviewed to investigate the role of hormone therapy in altering the risk of death from cardiovascular disease. Women in the study were observed for up to 16 years after the baseline survey in 1971 to 1975. By 1987 631 women had died; 347 of these deaths were due to cardiovascular disease. History of diabetes (relative risk, 2.38; 95% confidence interval 1.73 to 3.26), previous myocardial infarction (relative risk, 2.12; 95% confidence interval 1.56 to 2.86), smoking (relative risk, 2.18; 95% confidence interval, 1.69 to 2.81), and elevated blood pressure (relative risk, 1.49; 95% confidence interval, 1.14 to 1.94) were strong predictors of cardiovascular disease-related death in this cohort. After adjusting for known cardiovascular disease risk factors (smoking, cholesterol, body mass index, blood pressure, previous myocardial infarction, history of diabetes, age) and education, the use of postmenopausal hormones was associated with a reduced risk of death from cardiovascular disease (relative risk, 0.66; 95% confidence interval, 0.48 to 0.90). The same protective effect provided by postmenopausal hormone therapy was seen in women who experienced natural menopause (relative risk, 0.69; 95% confidence interval, 0.45 to 1.06).

Effectiveness of a psychosocial intervention, interpersonal counseling, for subdysthymic depression in medically ill elderly

BACKGROUND

Subdysthymic depression occurs in 20-50% of hospitalized elderly and is associated with physical and social disability, delayed recovery, and excess health service use. Despite this, little is known regarding the nature of such depressive symptomatology, or its responsivity to treatment. To address this, a randomized clinical trial assessing the feasibility and efficacy of Interpersonal Counseling (IPC), a short-term psychotherapy, was conducted.

METHODS

Patients 60+ with a Geriatric Depression Scale (GDS) score > 10 not meeting DSM-III-R criteria for major depression or dysthymia were recruited from the acute hospital. Thirty-five individuals were randomized to IPC and 41 to usual care (UC). IPC was delivered following hospital discharge by psychiatric clinical nurse specialists. Interviews were conducted at recruitment and 3, 6, and 12 months later. Primary outcomes were GDS scores, health ratings, and measures of physical and social functioning.

RESULTS

At 3 months, IPC group members showed greater improvement than UC members on all outcome variables; between-group differences did not reach statistical significance. At 6 months, a statistically significant difference in the rate of improvement in GDS, indicated by scores of 10 or less, was observed for IPC compared to UC members (60.6% vs 35.1%). Multivariate analyses confirmed a positive treatment effect on depressive symptoms. Similar multivariate analyses showed a statistically significant positive treatment effect on self-rated health but not on physical or social functioning.

CONCLUSIONS

IPC appears feasible, acceptable, and effective in short-term depressive symptom reduction and in improvement in self-rated health. Implementation of IPC interventions for subdysthymic hospitalized elderly is recommended.

Identification and characterization of MTR1, a novel gene with homology to melastatin (MLSN1) and the trp gene family located in the BWS-WT2 critical region on chromosome 11p15.5 and showing allele-specific expression

Alterations within human chromosomal region 11p15.5 are associated with the Beckwith-Wiedemann syndrome (BWS) and predisposition to a variety of neoplasias, including Wilms' tumors (WTs), rhabdoid tumors and rhabdomyosarcomas. To identify candidate genes for 11p15. 5-related diseases we compared human genomic sequence with expressed sequence tag and protein databases from different organisms to discover evolutionarily conserved sequences. Herein we describe the identification and characterization of a novel human transcript related to a putative Caenorhabditis elegans protein and the trp (transient receptor potential) gene. The highest homologies are observed with the human TRPC7 and with melastatin 1 ( MLSN1 ), whose transcript is downregulated in metastatic melanomas. Other genes related to and interacting with the trp family include the Grc gene, which codes for a growth factor-regulated channel protein, and PKD1/PKD2, involved in polycystic kidney disease. The novel gene presented here (named MTR1 for MLSN1 - and TRP -related gene 1) resides between TSSC4 and KvLQT1. MTR1 is expressed as a 4.5 kb transcript in a variety of fetal and adult tissues. The putative open reading frame is encoded in 24 exons, one of which is alternatively spliced leading to two possible proteins of 872 or 1165 amino acids with several predicted membrane-spanning domains in both versions. MTR1 transcripts are present in a large proportion of WTs and rhabdomyosarcomas. RT-PCR analysis of somatic cell hybrids harboring a single human chromosome 11 demonstrated exclusive expression of MTR1 in cell lines carrying a paternal chromosome 11, indicating allele-specific inactivation of the maternal copy by genomic imprinting.

Nongenomic effects of aldosterone on Ca2+ in M-1 cortical collecting duct cells

BACKGROUND

Aldosterone at physiological levels induces rapid (<5 min) increases in intracellular protein kinase C (PKC) activity and a rise in calcium and pH in mineralocorticoid hormone target epithelia, such as distal colon and sweat gland. The end targets of these rapid responses in epithelia are Na+/H+ exchange and K+ channels.

METHODS

The mouse cortical collecting duct (CCD) M-1 cell line was grown to confluency and loaded with Fura-2 for spectrofluorescence measurements of intracellular free calcium at 37 degrees C bathed in Krebs solution.

RESULTS

Aldosterone (1 nmol/L) produced a rapid, transient peak increase in [Ca2+]i in M-1 cells. This effect was abolished upon removal of extracellular Ca2+, but was unaffected by pretreatment with spironolactone (10 micromol/L) or actinomycin D (10 micromol/L). However, pretreatment with the specific PKC inhibitor chelerythrine chloride (1 micromol/L) prevented the aldosterone-induced rise in [Ca2+]i. Dexamethasone, at a concentration 10,000-fold higher than aldosterone (10 micromol/L), also produced a transient increase in [Ca2+]i, but this response was significantly smaller than that of aldosterone. In contrast, hydrocortisone had no effect on [Ca2+]i at either nmol/L or micromol/L concentrations. Both of the sex steroids, 17beta-estradiol (10 nmol/L) and progesterone (10 nmol/L), induced protein kinase C-dependent increases in [Ca2+]i.

CONCLUSIONS

Aldosterone and sex steroid hormones activate intracellular calcium signaling in CCD cells via a nongenomic PKC-dependent pathway, which may have important implications for renal transport.

Benefits and adverse effects of weight loss. Observations from the Framingham Study

OBJECTIVE

To identify the benefits and adverse effects of weight loss.

DESIGN

Longitudinal, epidemiologic study in a defined population.

PARTICIPANTS

Men and women (n = 2500) who were between 35 and 54 years old at baseline, followed for 20 years in Framingham, Massachusetts.

MEASUREMENTS

Height, weight, lipid levels, blood pressure, smoking status, diet, physical activity, prevalent and incident cardiovascular disease, diabetes, other diseases, and mortality rate were assessed.

RESULTS

Compared with those whose body mass index (BMI) or weight changed least, men and women who lost weight during a 10-year period were older, heavier, and had higher blood pressures and cholesterol levels initially but had the smallest gains in blood pressure and cholesterol levels. However, rates of cigarette smoking were higher, and rates of smoking cessation were lower. During 20 years of further follow-up, death rates were highest in those whose BMI decreased and in those with the highest BMI at study entry. Relative risks for death from cardiovascular disease, coronary heart disease, and all causes were significantly greater by 33% to 61% in men whose BMI decreased after adjusting for age and risk factors for cardiovascular disease. In women, weight loss and weight gain were associated with higher relative risks for cardiovascular disease and coronary heart disease, but only the 38% increase in total mortality rate among women who lost weight was statistically significant after adjusting for age.

CONCLUSIONS

Weight loss was associated with improvements in blood pressure and cholesterol levels but also with continued cigarette smoking, prevalent and incident cardiovascular disease, diabetes mellitus, other diseases, and higher death rates. Leanness and maintenance of stable weight were beneficial to risk factors, and to the prevention of morbidity, and death.

Evidence for major genes influencing pulmonary function in 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, age(2), age(3), Body Mass Index (BMI, kg/m(2)), 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.

Studies of blood pressure in Tecumseh, Michigan. I. Blood pressure in young people and its relationship to personal and familial characteristics and complications of pregnancy in mothers

Relationships between blood pressures (BPs) of young people and a number of personal, parental and familial characteristics have been assessed in the population of Tecumseh, Michigan. Systolic and fifth phase diastolic BPs were measured in 4500 persons under 20 years of age at the time of their first examination. Body size, fatness and heart rates of the subjects themselves were significantly related to their age- and sex-adjusted BP scores. The parents' BP scores were also correlated with those of the young subjects, and scores were significantly higher in those whose mothers had had high BP or toxemia in pregnancy of a stillbirth. A weak association between BP and socioeconomic circumstances was suggested by the slightly higher mean BP scores found in sons and daughters of men in blue collar jobs and of men and women with the least education. BP levels were not associated with birth order, sibship size or birth weight nor with the numbers of pregnancies, live births or abortions experienced by the mothers of young subjects. In a stepwise multiple regression, the most important determinants of BP were weight/height ratios of the subjects themselves and BP levels of their parents; a small additional effect of complications of pregnancy in the mother was detectable in the offspring 0--19 years laters.

Lower pulmonary function and cerebral subclinical abnormalities detected by MRI: the Atherosclerosis Risk in Communities study

STUDY OBJECTIVES

To investigate the association between pulmonary function and (1) cerebral infarction and (2) white matter lesions (WMLs), identified by MRI and believed to represent subclinical lesions of arteriosclerosis, generalized hypoperfusion, or ischemia of the brain.

DESIGN

Population-based, cross-sectional study.

SETTING

Two communities in the United States.

PARTICIPANTS

A sample of 1,917 African-American and white men and women 55 to 72 years old who were selected from the second follow-up examination of the Atherosclerosis Risk in Communities Study cohort.

INTERVENTIONS

Observational study.

MEASUREMENTS AND RESULTS

The lung function indexes, FEV1 and FVC, were assessed according to American Thoracic Society criteria. Subclinical cerebral infarction and WMLs were assessed by MRI. After adjusting for age, ethnicity, gender, height, and height squared, a 1-SD decrease of FEV1 in nonsmokers was associated with odds ratios (95% confidence interval [CI], 1.31 to 2.03) of 1.63 for infarction and 1.35 (95% CI, 1.08 to 1.69) for WMLs. Of those in the lowest quartile of FEV1, 15% had infarction and WMLs, in contrast to 6% of the individuals in the uppermost quartile of FEV1. Consistent associations were also observed by using FVC as an index of pulmonary function. Similar patterns of association were found among current smokers. The associations were not altered by additional adjustment of conventional risk factors of cardiovascular disease, comorbidity, or cognitive function.

CONCLUSION

The results from this population-based study suggest that lower pulmonary function is associated with subclinical cerebral abnormalities.