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Biomedical subjects

J B Croft

Publications and source records attributed to J B Croft.

At least 55 records · Page 3Linked to original sources

Body fat distribution and race differences in apolipoprotein A1.

OBJECTIVE: This is the first study to assess the role of waist-to-hip ratio in explaining race differences in levels of serum apolipoprotein A1, a protective risk factor for atherosclerosis. METHODS: Linear regression analyses were used in a community-based survey of 3,043 adults (23.5% African-American) to assess associations of race, age, anthropometric measures, education, diabetes, blood pressure medication use, cigarette smoking, and leisure-time physical activity with apolipoprotein A1 levels. RESULTS: Higher apolipoprotein A1 levels were observed among African-American than among white adults (African-American men: +15.6 mg/dl than white men, African-American women: +3.1 mg/dl more than white women; p < 0.05). Waist-to-hip ratio and other variables did not account for race differences among men. African-American women had +8.6 mg/dl higher levels than white women after adjustment for differing distributions of waist-to-hip ratio, age, body mass index and education. Cigarette smoking, physical activity, and medical history accounted for no further differences among women. CONCLUSIONS: Higher levels of obesity indicators and lower educational attainment among African-American women reduced a potentially greater beneficial race difference in apolipoprotein A1. These findings also suggest that other environmental and biochemical factors may play roles in explaining the higher protective levels of apolipoprotein A1 observed among African-American children and adults.

Adipose Tissue↗

Leisure-time physical activity among older adults. United States, 1990.

OBJECTIVE: To investigate the prevalence and selected correlates of leisure-time physical activity in a nationally representative sample of persons aged 65 years or older. METHODS: Data from 2783 older male and 5018 older female respondents to the 1990 National Health Interview Survey were used. Regular physical activity was defined as participation in leisure-time physical activities 3 times or more per week for 30 minutes or more during the previous 2 weeks. Odds ratios (ORs) were estimated from multivariate logistic regression analysis. RESULTS: Prevalence of regular physical activity was 37% among older men and 24% among older women. Correlates of regular physical activity included the perception of excellent to good health (men: OR, 1.5; 95% confidence interval [CI], 1.1-1.9; women: OR, 1.6; 95% CI, 1.3-1.9), correct exercise knowledge (men: OR, 2.4; 95% CI, 1.9-3.1; women: OR, 2.7; 95% CI, 2.2-3.4), no activity limitations (men: OR, 1.3; 95% CI, 1.0-1.6; women: OR, 1.7; 95% CI, 1.4-2.0) and not perceiving "a lot" of stress during the previous 2 weeks (men: OR, 1.7; 95% CI, 1.2-2.4; women: OR, 1.3; 95% CI, 1.0-1.6). Among those who had been told at least twice that they had high blood pressure, physician's advice to exercise was associated with regular physical activity (men: OR, 1.6; 95% CI, 1.2-2.3; women: OR, 1.5; 95% CI, 1.2-1.9). The 2 major activities among active older adults were walking (men, 69%; women, 75%) and gardening (men, 45%; women, 35%). CONCLUSIONS: Prevalence of regular physical activity is low among older Americans. Identifying the correlates of physical activity will help to formulate strategies to increase physical activity in this age group.

Adult↗

Education, health behaviors, and the black-white difference in waist-to-hip ratio.

Few epidemiologic studies have investigated the impact of body mass index, low educational attainment, cigarette smoking, and physical activity on the considerable black-white difference in waist-to-hip ratio. These relationships were assessed with multivariable linear regression among 3,094 adults (24% black) who were examined in 1987 in South Carolina. The unadjusted mean waist-to-hip ratio was lower for black men than for white men (-0.03 units) and higher for black women than for white women (+0.03 units). After adjustment for age, body mass index, education, smoking, and physical activity, the black-white difference in mean waist-to-hip ratio was -0.02 units (p < 0.001) among men and +0.01 units (p < 0.01) among women. Although differing distributions of age, body mass index, and educational attainment accounted for a 59% reduction in the black-white difference among women, these factors did not explain the difference among men. Thus, these results suggest that other environmental or biologic factors may also play an important role in the marked variation in body fat distribution between the two ethnic groups. The results also support the importance of the prevention of cigarette smoking and overweight in potentially preventing abdominal obesity in both black adults and white adults.

Adult↗

Evaluation of smoking on the physical activity and depressive symptoms relationship.

Physical activity is inversely associated with depressive symptoms, and cigarette smoking is positively associated with depressive symptoms. Data from the first National Health and Nutrition Examination Survey (NHANES I) and the NHANES I Epidemiologic Follow-up study were analyzed to determine whether the relationship between physical activity and self-reported distress (depressive symptoms as measured by the Center for Epidemiologic Studies Depression Scale) was different for cigarette smokers and nonsmokers. Logistic regression was used to calculate odds ratios (adjusted for age, race, sex, education, alcohol use, and perceived health status) for depressive symptoms (> or = 16) associated with physical activity and smoking status among 2,054 respondents. At baseline, the odds ratio for depressive symptoms was about 2 times higher for moderately active smokers and nonsmokers, and 3 times higher for low active smokers and nonsmokers, compared with highly active nonsmokers. For 1,132 persons with a low number of depressive symptoms (< 16) at baseline, the incidence of depressive symptoms after 7-9 yr of follow-up was about 2 times higher for low/moderately active smokers and nonsmokers than for highly active nonsmokers. The association between physical activity and the prevalence and incidence of depressive symptoms is not significantly modified by smoking status.

Adult↗

Cognitive functioning and posttraumatic stress disorder.

OBJECTIVE: The authors examined the association of cognitive impairment with posttraumatic stress disorder (PTSD) and other psychiatric diagnoses known to affect cognitive functioning. METHOD: The results of standardized neuropsychological tests were compared in four groups of Vietnam veterans: veterans with both a lifetime history of PTSD and a current diagnosis of depression, anxiety, or substance abuse; veterans with only a PTSD diagnosis; veterans with only a current diagnosis of depression, anxiety, or substance abuse; and veterans with none of these diagnoses. RESULTS: Veterans with both PTSD and concurrent diagnoses. exhibited more impairment in cognitive functioning than did veterans without these diagnoses. CONCLUSIONS: Cognitive deficits seen among persons diagnosed with PTSD may be associated with their concomitant diagnoses.

Adult↗

Trends in mortality and health behaviors: status of white and African-American women.

A substantial proportion of mortality in the United States can be attributed to three major behaviors: using tobacco, maintaining an unhealthy diet, and being physically inactive. Using data from the South Carolina mortality files and Behavioral Risk Factor Surveillance System we were able to document state trends in mortality, cigarette smoking, physical inactivity, and unhealthy dietary practices. We found that, in spite of the declines in heart disease and stroke mortality noted nationally and in the state, the risk factor profiles for most women in South Carolina did not improve. This analysis further suggests that physical inactivity and dietary issues (excess caloric intake, low fruit and vegetable consumption) would be good choices for lifestyle interventions among women in South Carolina, not only because they ultimately affect mortality, but also because they exert interim effects on morbidity, including physical functioning and independence.

Black or African American↗

Changes in cardiovascular disease knowledge and behavior in a low-education population of African-American and white adults.

OBJECTIVE: Racial differences in secular changes in cardiovascular disease risk factor knowledge and behaviors were assessed among adults with low levels of education throughout a community-wide cardiovascular disease prevention program. METHODS: Four independent cross-sectional telephone surveys were conducted with the random-digit-dialing technique in 1987, 1988, 1989, and 1991 in a biracial South Carolina community. Community-wide cardiovascular disease intervention programs were initiated in 1988 and continued through 1990. Changes in the prevalence of cardiovascular risk factor knowledge, dietary fat intake, leisure-time physical activity, smoking, and cholesterol screening behavior were compared between African-American and white respondents in a population subset with less than 12 years of education using analysis of covariance regression techniques. RESULTS: Mean intake of high fat foods was lower in 1991 than in 1987 among both white and African-American respondents; the trend for lower mean intake began in 1989 among African-American adults. Prevalence of the correct exercise knowledge was higher in 1988 than in 1987 for both groups, but this trend was maintained only among white respondents. However, prevalence of leisure-time physical activity did not change significantly between 1987 and 1991. Prevalence of cholesterol level knowledge and screening behavior increased over time among both groups; however, greater increasing trends between 1987 and 1991 were observed among white adults. CONCLUSIONS: Favorable secular changes in fat intake, exercise knowledge, cholesterol level knowledge, and cholesterol screening behavior were observed among both race groups during a time period that coincided with community-wide intervention efforts and messages. Greater changes in most of these behaviors and knowledge were observed among white adults suggesting that health behavior messages may not have reached all segments of this community.

Adolescent↗

Predictors of adopting leisure-time physical activity among a biracial community cohort.

Literature on the correlates and predictors of leisure-time physical activity among African-American population is sparse. This cohort study assessed correlates of leisure-time physical activity (specific large muscle activities during the past month at least three times a week) in a biracial population in 1987 and predictors for the adoption of this behavior 4 years later among those initially inactive. Random digit dialing methods were used to identify residents of two South Carolina communities in 1987. In 1991, 3,223 of these residents were resurveyed (62% response rate). In general, the correlates of leisure-time physical activity (education, > or = 12 years; nonsmoking; weight loss behaviors; and physician advice) were similar for each sex and race group. In 1987, the definition of leisure-time physical activity was not met by 831 (54% of 1,542) white women, 374 (76% of 489) African-American women, 586 (59% of 991) white men, and 126 (63% of 201) African-American men. Among those who were inactive in 1987, 22-24% of white adults and African-American men and 14% of African-American women adopted physical activity 4 years later. Twelve years or more of education was a predictor among white women (risk ratio = 1.7, 95% confidence interval 1.2-2.6) and African-American women (risk ratio = 3.1, 95% confidence interval 1.4-6.9), but not among men. Having a physician discuss physical activity was a predictor among white women (risk ratio = 1.9, 95% confidence interval 1.3-2.7), African-American women (risk ratio = 1.7, 95% confidence interval 0.9-3.2), white men (risk ratio = 2.0, 95% confidence interval 1.3-3.1), and African-American men (risk ratio = 2.7, 95% confidence interval 1.0-7.6). These results highlight the strong effect of educational attainment on adoption of healthy behaviors and support the involvement of physicians to promote physical activity among all race and sex groups.

Adult↗

Relation of body fat distribution to ischemic heart disease. The National Health and Nutrition Examination Survey I (NHANES I) Epidemiologic Follow-up Study.

Although an excess of adipose tissue in the abdominal and truncal regions is associated with various metabolic alterations, relatively few cohort studies have examined its importance in the development of ischemic heart disease, and little information is available from black populations. The authors examined the relation of central obesity, as characterized by a thick subscapular skinfold relative to the triceps skinfold, to the incidence of ischemic heart disease among 9,822 persons in the Epidemiologic Follow-up Study of the National Health and Nutrition Examination Survey I; baseline data were collected in 1971-1975 and follow-up was through 1987. We found that, independently of relative weight, cigarette smoking, and other covariates, the hazard rate ratios for ischemic heart disease incidence contrasting the upper and lower quintiles of central obesity were 1.75 (95% confidence interval 1.3-2.3) among women and 1.65 (95% confidence interval 1.3-2.2) among men. Although central obesity was related similarly to disease among white and black men, the association among women differed between whites (rate ratio = 1.94) and blacks (rate ratio = 0.73); p = 0.002 for race x the central obesity product term. Additional research is needed to clarify the relation of various anthropometric measurements to ischemic heart disease, particularly among blacks, but the assessment of fat distribution may help identify high-risk persons for whom weight loss might be most beneficial.

Adipose Tissue↗

Obesity in heterozygous carriers of the gene for the Bardet-Biedl syndrome.

Obesity and renal failure are common manifestations in the autosomal recessive Bardet-Biedl (BB) syndrome. Because obesity and hypertension have been reported frequently in non-homozygous relatives of BB patients, we hypothesized that BB heterozygotes are predisposed to these conditions. Clinical information was collected from 34 patients of BB homozygotes, who are obligate heterozygotes. The proportion of severely overweight fathers (26.7%) was significantly higher than that in comparably aged United States white males (8.9%). We conclude that the BB gene may predispose male heterozygous carriers to obesity. If BB heterozygotes are 1% of the general population, we estimate that approximately 2.9% of all severely overweight white males carry a single BB gene. The BB parents of both sexes were also significantly taller than U.S. white men and women of comparable age.

Adult↗

Waist-to-hip ratio in a biracial population: measurement, implications, and cautions for using guidelines to define high risk for cardiovascular disease.

Cutoff points for high waist-to-hip ratio (WHR) that may define high risk for cardiovascular disease have been suggested for men (0.95) and women (0.80). The WHRs of groups defined by age, race, and sex among 3,118 South Carolina adults were compared with these cutoff points. Measurement methodology, mean WHRs, and prevalence of elevated WHR in this biracial study population were compared with data from other populations. A review of anthropometric measurement methods used in recent epidemiologic studies indicates that a standard method for measuring waist and hip girth is required before comparisons of mean levels can be valid. The paucity of evidence that a high WHR is associated with cardiovascular disease mortality in black populations, and the high number of women who have an elevated WHR in this and other epidemiologic studies, support the following conclusion: Current WHR cutoff points, which are based on evidence from primarily white populations, may not be appropriate for women, older age groups, and some racial or ethnic groups in the United States.

Adult↗

Serum folate and risk for ischemic stroke. First National Health and Nutrition Examination Survey epidemiologic follow-up study.

BACKGROUND AND PURPOSE: A serum folate concentration < or = 9.2 nmol/L has been associated with elevated levels of plasma homocyst(e)ine. Elevated homocyst(e)ine levels have been associated with ischemic stroke in case-control studies; however, the results from prospective studies have been equivocal. We investigated whether a folate concentration < or = 9.2 nmol/L was associated with ischemic stroke in a national cohort. METHODS: We used data from the First National Health and Nutrition Examination Survey Epidemiologic Follow-up Study (n = 2006). Cox proportional hazards analyses were used to adjust for differences in follow-up time and covariates. During the 13-year follow-up, 98 ischemic strokes occurred. RESULTS: After adjusting for age, race, sex, education, diabetes, history of heart disease, systolic blood pressure, body mass index, hemoglobin level, cigarette smoking, and alcohol intake, participants with a folate concentration < or = 9.2 nmol/L were at slightly increased risk for ischemic stroke (relative risk [RR], 1.37; 95% confidence interval [CI], 0.82 to 2.29). There was a folate-race interaction (P = .11 for interaction term). Whites with a folate concentration < or = 9.2 nmol/L had a relative risk of 1.18 (95% CI, 0.67 to 2.08), whereas blacks had a relative risk of 3.60 (95% CI, 1.02 to 12.71). CONCLUSIONS: These findings suggest that a folate concentration < or = 9.2 nmol/L may be a risk factor for ischemic stroke, especially in blacks. However, given the small number of stroke events, additional studies are needed to assess the role of folate in the epidemiology of ischemic stroke.

Adult↗

The association between alcohol use and health behaviors related to the risk of cardiovascular disease: the South Carolina Cardiovascular Disease Prevention Project.

OBJECTIVE: This study examines the relationship between alcohol use and health behaviors related to the risk of cardiovascular disease (CVD). In particular, we examined the relationship between alcohol use and leisure time physical activity, participation in community physical activity programs and behaviors used for weight loss. Numerous studies have found a "protective" effect of moderate alcohol consumption on the risk of CVD. However, most of these studies have not adequately controlled for potential confounding by health behaviors associated with alcohol use. METHOD: We used descriptive and logistic regression analyses to examine cross-sectional survey data from 2,072 participants in the South Carolina Cardiovascular Disease Prevention Project. RESULTS: After controlling for age, race, education and preexisting CVD, moderate and heavy drinkers who do not smoke were more likely than nondrinkers to report engaging in regular leisure time physical activity. The relationship between other health behaviors and alcohol consumption was less clear. Among men, moderate and heavy drinkers were no more likely than nondrinkers to participate in community physical activity programs; among women, moderate and heavy drinkers were more likely than nondrinkers to report this activity. Moderate drinkers were more likely than nondrinkers to report that they were attempting to lose weight, however this difference was not statistically significant. CONCLUSIONS: These data suggest that at least some of the apparent protective effect of moderate alcohol consumption found in other studies may be due to differences between nondrinkers and drinkers with respect to physical activity and other health practices.

Adolescent↗

Trends in oral contraceptive use and cigarette smoking. Behavioral Risk Factor Surveillance System, 1982 and 1988.

OBJECTIVE: To investigate trends in oral contraceptive (OC) use and smoking among women of reproductive age and to determine factors related to smoking among OC users. DESIGN, SETTING, AND PARTICIPANTS: Telephone interviews of women aged 18 through 45 years in 16 states and the District of Columbia who participated in the Behavioral Risk Factor Surveillance System in 1982 (N = 3553) and in 1988 (N = 7384). RESULTS: Between 1982 and 1988, the prevalence of smoking decreased from 31% to 24% among OC users and from 32% to 28% among non-OC users. In both 1982 and 1988, more than half of the OC users who smoked were heavy smokers (smoked 15 or more cigarettes per day). Nearly one fourth of 35- to 45-year-old women who used OCs were smokers. After we standardized for age, race, and education, the decline in the prevalence of smoking among OC users did not differ substantially from the decline in smoking among non-OC users. CONCLUSIONS: Despite the possible synergistic effects of smoking and OC use on the risk of cardiovascular disease, we found no accelerated decline in the prevalence of smoking among OC users. As of 1988, nearly one fourth of all OC users were smokers. These data emphasize the need to reduce the prevalence of smoking among women who use OCs before they reach the age at which their risk for cardiovascular disease increases substantially.

Adolescent↗

Community intervention and trends in dietary fat consumption among black and white adults.

OBJECTIVE: This study assessed whether a state public health department could effectively implement an affordable nutrition intervention program at the community level. DESIGN: Cross-sectional data were collected via telephone surveys of 9,839 adults, aged 18 years or older, in 1987, 1989, and 1991 in two South Carolina communities. Nutrition education programs began in 1988 in one community. The other community served as a comparison site. We assessed and compared changes in community levels of dietary fat and weekly meat consumption, salt use, and nutrition promotion awareness with analysis of covariance regression techniques that included race, sex, and age as covariates. RESULTS: We observed favorable changes in most eating behaviors and levels of awareness in both communities. The intervention community experienced greater absolute changes that the comparison community in use of animal fats (-8.9% vs -4.0%; P = .02) and liquid or soft vegetable fats (+8.4% vs +3.6%; P = .04), and in awareness of restaurant nutrition information (+33.0% vs +19.4%; P = .0001). Although the primary type of dietary fat used differed between black and white respondents, we observed significant change among both groups. CONCLUSIONS: These results suggest that community-wide nutrition education programs may have augmented regional or national changes in dietary behavior among white and black adults in the intervention community.

Adult↗

The relation of documented coronary artery disease to levels of total cholesterol and high-density lipoprotein cholesterol.

Recommendations for identifying persons at high risk for coronary heart disease are based primarily on levels of total and low-density lipoprotein cholesterol. We examined whether, given knowledge of these levels, information on the high-density lipoprotein cholesterol level would improve the prediction of arteriographically documented coronary artery disease among 591 men. We found that even at levels of total and low-density lipoprotein cholesterol considered desirable, high-density lipoprotein cholesterol was inversely related to disease severity. For example, among the 112 men with a total cholesterol level <180 mg per dl, the mean occlusion score (representing the overall severity of disease) was 107 among men with a high-density lipoprotein cholesterol level < or = 30 mg per dl vs a mean score of 52 among men with levels > or = 45 mg per dl. Furthermore, men with low levels of both low-density lipoprotein cholesterol (< 110 mg per dl) and high-density lipoprotein cholesterol (< or = 30 mg per dl) had as much occlusive disease as did men with high levels of both lipoprotein fractions. Given information on the ratio of high-density lipoprotein cholesterol to total cholesterol, the actual levels of the lipoprotein fractions did not improve disease prediction. Our results emphasize the importance of considering high-density lipoprotein cholesterol when assessing coronary heart disease risk.

Adult↗

Trends in survival after stroke among Medicare beneficiaries.

BACKGROUND AND PURPOSE: Most strokes occur among people aged 65 years and older. The increasing proportion of persons who are in this age group underlines the importance for health-care providers to be aware of trends in poststroke survival. We investigated poststroke survival trends from 1985 to 1989 among Medicare beneficiaries. METHODS: Medicare hospital claim records and enrollment data were obtained on 1 901 439 Medicare patients with a principal diagnosis of stroke occurring during the years 1985 through 1989. Cox proportional hazard techniques were used to compare the 2-year poststroke survival for strokes occurring in 1986, 1987, 1988, and 1989 relative to strokes occurring in 1985. Poststroke survival trends were examined among groups defined by age, race, region, type of stroke, and, for a 20% subset, history of stroke. RESULTS: We observed a modest improvement in poststroke survival from 1985 to 1989 (1989:1985 hazard ratio, 0.96; P < .05). Trends for persons with hemorrhagic stroke showed more improvement (hazard ratio, 0.88; P < .05) than those for persons with ischemic stroke (hazard ratio, 0.98; P < .05). Improvement was also greater among persons without known prior hospitalization for stroke (hazard ratio, 0.94; P < .05) and during periods of follow-up shorter than 2 years. CONCLUSIONS: The variations in poststroke survival among subgroups of the population have important implications for the quality of life of stroke survivors and for the future medical and nursing needs of these populations.

Age Factors↗

Correlates of high-density lipoprotein cholesterol in black and white women.

The relationships of high-density lipoprotein (HDL) cholesterol with body composition, leisure-time physical activity, cigarette smoking, and education were examined in a community-based sample of 480 Black and 1337 White women. Univariate and multivariate analyses indicated inverse associations of HDL with body mass index and waist-to-hip ratio in both groups, and with cigarette smoking and low educational attainment among White women only. Since correlates of HDL cholesterol differ for Black and White women, further investigation of the differences in these correlates is warranted.

Adult↗