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Biomedical subjects

J B Croft

Publications and source records attributed to J B Croft.

At least 73 records · Page 4Linked to original sources
PubMed1993

Leisure-time physical activity and high-density lipoprotein cholesterol in a biracial community sample.

The purpose of this analysis was to describe the association of leisure-time physical activity and high-density lipoprotein cholesterol levels among a large community sample of African-American and white men and women. Physical assessment of high-density lipoprotein cholesterol, weight, height, waist, and hip measurements were obtained for 3121 randomly selected community participants (969 white men, 1409 white women, 205 African-American men, and 538 African-American women). Leisure-time physical activity was assessed from responses to a standard series of questions about participation in various leisure-time activities. We found an inverse relationship between leisure-time activities and high-density lipoprotein cholesterol levels in African Americans, in contrast to a positive association observed in whites; however, these associations failed to reach statistical significance after controlling for age and body composition. These results confirm a strong association of body composition with high-density lipoprotein cholesterol and support continued interventions designed to reduce overall body weight, particularly upper body weight. The results further suggest that the relationships between some life-style factors and HDL levels may be different among minorities.

Black or African American↗
PubMed1993

The independent effects of obesity and body fat distribution on blood pressure in black adults: the Pitt County study.

The relationship of obesity measures to blood pressure and hypertension prevalence was assessed in a community probability sample of 25-50-year-old black adults (1101 women and 655 men) who were examined in 1988 in Pitt County, North Carolina. Among black women, both body mass index and waist-to-hip ratio had independent relationships with systolic and diastolic blood pressures and hypertension prevalence after controlling for the effects of age, socio-economic status, physical activity, alcohol, and the other obesity measure (P < 0.05). Body mass index also had independent relationships with blood pressure levels and hypertension prevalence in black men (P < 0.05), while waist-to-hip ratio was associated with hypertension prevalence (P = 0.05) and diastolic blood pressure (P < 0.05), but not with systolic blood pressure. The relationships of waist-to-hip ratio with blood pressure and hypertension prevalence were considerably reduced in both sex groups after controlling for body mass index. This study presents new evidence that waist-to-hip ratio is related to hypertension and blood pressure level independent of body mass index, in young to middle-aged black adult women and men.

Abdomen↗
PubMed1992

Socioeconomic and behavioral correlates of body mass index in black adults: the Pitt County Study.

BACKGROUND: Obesity is more prevalent among Black women than Black men, but there is little information on the correlates of obesity in Blacks. This study describes the relations of sociodemographic factors and health behaviors to body mass index in a southern, Black population. METHODS: In 1988, a community probability sample of 1784 Black adults, aged 25 to 50, was examined in Pitt County, NC. RESULTS: More women than men were at least 20% overweight (57% vs 36%). The relation of socioeconomic status (a composite of education and occupation) to age-adjusted body mass index level was inverse in women but not in men. Body mass index did not differ with either current energy intake or energy expenditure. Smokers and drinkers had lower age-adjusted levels than non-smokers and abstainers. CONCLUSIONS: Since the excess body mass index levels associated with low socioeconomic status in women could not be explained after controlling for adverse health behaviors, further epidemiologic study of risk factors for obesity in Black women is recommended.

Adult↗
PubMed1990

Obesity, hypertension, and renal disease in relatives of Bardet-Biedl syndrome sibs.

The Bardet-Biedl syndrome is a rare autosomal recessive disorder characterized by pigmentary retinopathy, obesity, polydactyly, hypogonadism, and mental retardation. Renal abnormalities, hypertension, acquired heart disease, and hepatic fibrosis also occur in homozygotes. Two adult Bardet-Biedl sibs, a man with hypertension and cardiomegaly and a woman with biliary cirrhosis, and 75 relatives in 5 generations of the extended family were identified. Hospital records for major illnesses, death certificates, and autopsy reports were examined. The frequent observation of obesity, hypertension, diabetes mellitus, and renal disease in first-degree relatives, obligate gene carriers, and other blood relatives raise the possibility that Bardet-Biedl heterozygotes are also predisposed to these disorders.

Adult↗
PubMed1988

The interaction of alcohol and tobacco use in adolescents and young adults: Bogalusa Heart Study.

Alcohol and tobacco usage patterns were assessed in 1,811 children and young adults, 12-24 years of age. The prevalence of cigarette smoking and alcohol consumption increased with age in all race and sex groups. Smokeless tobacco use (chewing tobacco and snuff) was primarily seen in white males with the highest prevalence rates in 12-15 year olds. Among white males who reported smokeless tobacco usage, 44% of the 12-17 year olds and 80% of the 18-24 year olds reported concurrent alcohol use. There was a significant interaction between alcohol consumption and cigarette smoking in all four race-sex groups (p less than 0.001). Given the potential synergistic relationship between ethanol and tobacco products on oral and upper gastrointestinal tract cancer, as well as between smoking and cardiovascular disease, the long term effects from these behaviors could be troublesome. Since healthy lifestyles are established in youth, early intervention on alcohol and tobacco use is needed to prevent the future morbidity and mortality from cancer and cardiovascular disease.

Adolescent↗
PubMed1988

Cardiovascular risk in parents of children with extreme lipoprotein cholesterol levels: the Bogalusa Heart Study.

Fasting serum lipids, lipoprotein cholesterol, and other cardiovascular disease risk factors were examined in 321 natural parents of children with low and/or high levels of beta- and pre-beta-lipoprotein cholesterol. Parents of children from low pre-beta-lipoprotein groups had elevated alpha- and lower pre-beta-lipoprotein cholesterol levels. Parents whose children had high beta-lipoprotein cholesterol levels also had high serum total and beta-lipoprotein cholesterol levels. Parents of children with high levels of both beta- and pre-beta-lipoprotein cholesterol had a high prevalence of both abnormal risk factor levels, as well as clinical evidence of early coronary artery disease (before age 50 years). These observations show that parents of children with high beta- and/or pre-beta-lipoprotein cholesterol levels have greatly enhanced risk for cardiovascular disease, and children mirror their parents' lipoprotein cholesterol levels. These observations emphasize the need for cardiovascular risk evaluation early in life, especially in high-risk families.

Adolescent↗
PubMed1988

Trends in fatty acid intakes of 10-year-old children, 1973 to 1982.

Diets of four groups of 10-year-old children (no. = 871, 30% black, 70% white) were examined over 10 years with 24-hour dietary recalls to study temporal trends in cholesterol, fat, and fatty acid intakes in a community. Boys had higher intakes per day and per kilogram body weight than girls for all nutrients (p less than .0001), but there were no sex differences in nutrients per 1,000 kcal. The only racial difference detected was a higher myristic acid intake in whites (p less than .02). There was a 16% decline in dietary cholesterol intake between 1978 and 1982. Three shifts in fatty acid intake increased the P:S ratio from 0.29 in 1973 to 0.45 in 1978: (a) a 5% decline in oleic acid, coupled with a 5% rise in linoleic acid; (b) a quadrupling of linolenic acid; and (c) less stearic and more myristic acid, with palmitic acid unchanged. Total fat intake provided 38% of the calories in each survey, but the changes in proportions of fatty acids paralleled trends in food consumption patterns and nutrient sources. Despite the changes, few children met prudent diet recommendations, and serum total cholesterol and very-low-density-lipoprotein cholesterol levels did not change over time.

Body Constitution↗
PubMed1987

The association between cardiovascular response tasks and future blood pressure levels in children: Bogalusa Heart Study.

Children were selected from a total community survey and categorized into three blood pressure (BP) groups (low less than 10 percentile, midrange 10 to 90 percentile, high greater than 90 percentile) based on resting diastolic pressure (DBP). To examine the relationship of cardiovascular reactivity with BP levels 4 years later, three cardiovascular response tasks (orthostatic, handgrip, and cold pressor) were administered. Partial correlations, adjusted for initial resting BP, showed that peak BP responses to the three tasks were related to future resting systolic and diastolic BP. Further analyses showed that DBP reactivity was related to future BP tracking in children with high DBP levels. In the high DBP group, while resting DBP levels did not differ for trackers vs nontrackers, peak DBP responses to each of the three tasks did (orthostatic, p less than 0.001; handgrip, p less than 0.05; cold pressor, p less than 0.01). The combination of resting and peak BP levels may provide more powerful predictions of future BP levels in children.

Adolescent↗
PubMed1987

Racial difference in hemoglobin concentration of young adults.

Hemoglobin concentration was measured in 1,001 young adults (34% black, 66% white), ages 17 to 24 years, in a community survey. Hemoglobin levels were 0.9 g/dl lower in blacks than in whites (P less than 0.001) and 2.0 g/dl lower in females than in males (P less than 0.001). Black females had the highest prevalence of anemia (16%) and the lowest prevalence of polycythemia 3%), while white females had the lowest prevalence of anemia (1%) and highest prevalence of polycythemia (9%). Mean hemoglobin levels in females did not increase after approximately age 12 1/2 years, while those in males continued to increase until age 17 years. Regular cigarette smoking was a potent risk factor for polycythemia in white males. Number of cigarettes smoked per week and number of years as a regular smoker increased hemoglobin concentration. New criteria, based on population distribution of hemoglobin levels, may be needed for defining anemia and polycythemia in black populations and cigarette smokers.

Adolescent↗
PubMed1987

Adverse influences of alcohol, tobacco, and oral contraceptive use on cardiovascular risk factors during transition to adulthood.

Risk factors for cardiovascular disease were measured in 990 young adults, aged 17-24 years, in a 1982-1983 survey of the biracial (black-white) community of Bogalusa, Louisiana. Even after controlling for age and obesity, several lifestyle factors (cigarette smoking, alcohol consumption, and oral contraceptive use) were independently related (p less than 0.05) to levels of serum lipids, lipoprotein cholesterol fractions, and blood pressure. Oral contraceptive use was associated with increased levels of both serum triglycerides (20 mg/dl, blacks; 25 mg/dl, whites) and low density lipoprotein (LDL) cholesterol (19 mg/dl, whites), and decreased levels of high density lipoprotein (HDL) cholesterol (-6 mg/dl, whites). Linear regression analyses also showed that cigarette smoking was associated with elevated levels of serum triglycerides (ranging from 15 to 26 mg/dl) and decreased levels of HDL cholesterol (ranging from -9 to -11 mg/dl) in white males and females. Although persons who smoked cigarettes were also likely to consume alcohol, alcohol intake in nonsmokers was positively associated with levels of serum triglycerides, LDL cholesterol, and very low density lipoprotein cholesterol in white males, and with blood pressure levels in black males. A statistically significant association between alcohol intake and HDL cholesterol levels (r = 0.24) was observed only in white females who did not smoke. These adverse influences of lifestyle factors on cardiovascular disease risk may provide a rational basis for intervention during adolescence and early adulthood.

Adolescent↗
PubMed1986

Transitions of cardiovascular risk from adolescence to young adulthood--the Bogalusa Heart Study: I. Effects of alterations in lifestyle.

Adolescence and young adulthood represents a transition period for biologic and lifestyle characteristics. In a preliminary investigation of young adults (ages 18-20 years), the Bogalusa Heart Study documented patterns of alcohol, tobacco, and oral contraceptive use, as well as changes in education, occupational, marital and parenting status. Such behaviors accelerate the cardiovascular disease process and may differentially influence risk factor patterns of race and sex groups. Adverse levels of systolic blood pressure and alpha-lipoprotein cholesterol were more frequent in married vs single men; elevated triglyceride levels were more frequent in married vs single whites. However adverse levels of beta- and alpha-lipoprotein cholesterol were more frequent in nonparents than in parents. Cigarette smoking and oral contraceptive use were independently related to elevated beta-lipoprotein cholesterol and decreased alpha-lipoprotein cholesterol levels of young white women. Alcohol consumption was highest among white males, with 32% reporting daily consumption of the equivalent of two or more beers or one mixed drink. Alcohol consumption was negatively correlated with blood pressure in white males and positively correlated with alpha-lipoprotein cholesterol in black males. Since such lifestyle factors are related to physiologic risk factors that result in heart disease and adult cardiovascular morbidity and mortality in the older ages, early targeting during adolescence and young adulthood is important.

Adolescent↗
PubMed1986

Transitions of cardiovascular risk from adolescence to young adulthood--the Bogalusa Heart Study: II. Alterations in anthropometric blood pressure and serum lipoprotein variables.

Cardiovascular (CV) risk factors change over time with the emergence of clinically recognizable abnormalities (obesity, hypertension and hyperlipoproteinemia) in the second and third decades of life. A cohort of 286 subjects, aged 11-15 in 1973-74 were reexamined 6 years later to observe changes in height, weight, blood pressure, lipids and lipoproteins between adolescence and adulthood. During the 6 years of follow-up, 10-11 year-old males increased 30 cm in height and 32 kg in weight. Among 10-11 year-old girls, height increased 12-15 cm and weight increased 15 kg in whites and 20 kg in blacks. Mean systolic BP increased 16-23 mmHg in black males and 11-15 mmHg in white males. Mean serum total cholesterol levels increased with age such that levels in 20 year olds were 160-190 mg/dl, about 10 to 15 mg/dl higher than 18 year olds. In white males beta-lipoprotein cholesterol increased (13 mg/dl) with age; however, there was a simultaneous decrease in alpha-lipoprotein cholesterol (11 mg/dl), resulting in a dramatic rise in the beta-LPC/alpha-LPC ratio. These adverse changes in LPC may be related to the early development of atherosclerosis and risk for coronary heart disease of young white men. Early identification of hypertension and hyperlipoproteinemia should help to predict and prevent future CV disease.

Adolescent↗
PubMed1986

Cigarette smoking initiation and longitudinal changes in serum lipids and lipoproteins in early adulthood: the Bogalusa Heart Study.

To examine the influence of cigarette smoking initiation on serum lipid and lipoprotein changes in early life, 747 nonsmoking 9- to 17-year-olds from the biracial community of Bogalusa, Louisiana were reexamined five to six years following an initial screening. Upon reexamination in 1981-1983, 147 reported smoking cigarettes (mean duration, 3.5 years; median number of weekly cigarettes, 20). Compared with nonsmokers, persons who began smoking had more unfavorable changes in serum triglycerides and lipoprotein cholesterol levels during follow-up, independently of age, sexual maturation, obesity, alcohol consumption, and oral contraceptive use in females. Smoking initiation was not associated with increases in serum total cholesterol levels, but compared with nonsmokers, white males and white females smoking three or more packs weekly showed additional mean increases of 13.2 and 11.6 mg/dl in low density lipoprotein cholesterol, additional 5.9 and 2.4 mg/dl increases in very low density lipoprotein cholesterol (VLDL-C), and additional decreases of 15.6 and 9.2 mg/dl in high density lipoprotein cholesterol levels, respectively. Black smokers showed larger increases in serum triglycerides and VLDL-C levels than did black nonsmokers. These findings indicate that the start of even modest cigarette smoking may have potentially long-term atherogenic effects. Prevention of smoking in early life should therefore be an important aspect of cardiovascular disease intervention.

Adolescent↗
PubMed1986

Factors associated with adolescent participation in a cardiovascular risk factor assessment program.

A Student Attitude Survey was administered to high school seniors to determine attitudinal and behavioral factors associated with participation in a longitudinal cardiovascular risk factor screening program. Health beliefs, attitudes, and practices were assessed as were altruism, social skills, self-concept, conformity, and academic class standing. Male participants showed higher self-concept scores than non participants. Black participants were younger than black nonparticipants and black participants also showed greater perceived control over their health and more optimistic appraisals of the worth of medical research and practice. White male participants tended to be more likely to remain home from school or to see a doctor when ill. These observations suggest that attitudinal and behavioral factors related to participation in a health-related program can be assessed in childhood.

Adolescent↗
PubMed1986

Longitudinal patterns of cigarette smoking and smokeless tobacco use in youth: the Bogalusa Heart Study.

Tobacco use was studied during 1977-76 (n = 2880) and 1981-82 (n = 2158) in a total biracial community of children, aged 8-17 years, in Bogalusa, Louisiana. White males were the early adopters of tobacco products in both surveys. Cigarette smoking decreased in all race and gender groups while smokeless tobacco use increased in White males. Studies which find a decline in male adolescent smoking should investigate a possible concurrent increase in smokeless tobacco.

Adolescent↗
PubMed1986

Macronutrient intakes of 10-year-old children, 1973 to 1982.

Diets of four groups of 10-year-old children (no. = 871) from a biracial community were examined to document eating patterns and to note temporal trends in energy, protein, fat, and carbohydrate intakes. A 24-hour dietary recall method, incorporating numerous quality controls, was adapted for interviewing children. Protein provided 13%, fat 38%, and carbohydrate 49% of calories. Few racial differences in eating patterns were detected. Boys had higher energy intakes than girls, but after diets were adjusted per 1,000 kcal, no other sex differences in intake were found. Snacks yielded roughly one-third of daily energy intake, one-fifth of the day's protein, one-third of the fat, and two-fifths of the total carbohydrate intake. Density of macronutrients within the children's diets was consistent over time. Diets of children in the Bogalusa study typify the American eating pattern and are comparable with those found in major national surveys.

Anthropometry↗
PubMed1985

Cigarette smoking behavioral distinctions between experimental nonadopters and adopters in children and adolescents--a consideration of transitional smoking experience: the Bogalusa Heart Study.

A cigarette-smoking questionnaire to examine behavior, attitudes, and beliefs related to cigarette use was administered to children, ages 8-17, in a biracial community. Children who experimented with cigarettes but did not adopt the habit (experimental nonadopters) and children who continued to smoke (adopters) were identified and characterized. Follow-up behavior was examined 2 years later. Adopters were more likely to have smokers as friends and family members, more likely to have purchased their first cigarettes, more likely to believe smoking to be pleasurable for themselves and others, and less likely to consider smoking harmful. Adopters who maintained smoking behavior 2 years later had, during the initial survey, reported having more friends who also smoked and were more likely to believe smoking to be enjoyable. Experimental nonadopters were more likely to try the first cigarette alone, reported having fewer friends and family members who smoked, and believed greater health risks to be associated with cigarette use. Experimental nonadopters who maintained nonsmoking behavior 2 years later, especially in the older cohort, exhibited higher agreement with the negative consequences of cigarette smoking (health beliefs) and theories concerning smoking behavior of others.

Adolescent↗