Biomedical subjects

B B Duncan

Publications and source records attributed to B B Duncan.

At least 37 records · Page 2Linked to original sources

PubMed1999

Factor VIII and other hemostasis variables are related to incident diabetes in adults. The Atherosclerosis Risk in Communities (ARIC) Study.

OBJECTIVE: Our objective was to evaluate whether selected hemostasis variables, some of which may reflect inflammation or endothelial dysfunction, are independently associated with the development of diabetes. RESEARCH DESIGN AND METHODS: We studied a biethnic cohort of 12,330 men and women, 45-64 years of age, of the Atherosclerosis Risk in Communities Study. New cases of diabetes were diagnosed by a reported physician diagnosis, hypoglycemic medication use, or a casual or fasting serum glucose level of > or = 11.1 or > or = 7 mmol/l, respectively. RESULTS: Over an average follow-up of 7 years, 1,335 new cases of diabetes were detected. The odds ratios (4th versus 1st quartile) of developing diabetes, adjusted by logistic regression for age, sex, race, study center, family history of diabetes, fasting glucose, physical activity, and smoking, were 1.2 (95% CI 1.0-1.5) for fibrinogen and 1.4 (1.1-1.6) for factor VII. Associations for factor VIII, von Willebrand factor, and activated partial thromboplastin time were found to be 1.8 (1.3-2.3), 1.4 (1.1-1.8), and 0.63 (0.49-0.82), respectively, in women. Although further adjustment for BMI and waist-to-hip ratio diminished the relationships, a highly statistically significant association (P = 0.001) remained for factor VIII (1.6 [1.2-2.1]) in women. CONCLUSIONS: Factor VIII and other hemostasis variables are associated with the development of diabetes in middle-aged adults. These findings support a role for inflammation and, particularly in women, endothelial dysfunction in the pathogenesis of type 2 diabetes.

Arteriosclerosis↗

PubMed1998

African American-white differences in lipids, lipoproteins, and apolipoproteins, by educational attainment, among middle-aged adults: the Atherosclerosis Risk in Communities Study.

Measures of socioeconomic status have been shown to be related positively to levels of high density lipoprotein (HDL) cholesterol in white men and women and negatively in African American men. However, there is little information regarding the association between educational attainment and HDL fractions or apolipoproteins. The authors examined these associations in 9,407 white and 2,664 African American men and women aged 45-64 years who participated in the Atherosclerosis Risk in Communities Study baseline survey, and they found racial differences. A positive association for HDL cholesterol, its fractions HDL2 and HDL3 cholesterol, and its associated apolipoprotein A-I was found in white men and white women, but a negative association was found in African American men, and there was no association in African American women. In whites, there was also an inverse association of low density lipoprotein (LDL) cholesterol and apolipoprotein B with educational attainment. With the exception of African American men, advanced education was associated with a more favorable cardiovascular lipid profile, which was strongest in white women. Racial differences in total cholesterol (women only), plasma triglycerides, LDL cholesterol, apolipoprotein B (women only), HDL cholesterol, HDL2 and HDL3 cholesterol, and apolipoprotein A-I were reduced at higher levels of educational attainment. Apart from triglycerides in men and HDL3 cholesterol in women, these African American-white lipid differences associated with educational attainment remained statistically significant after multivariable adjustment for lifestyle factors. Lipoprotein(a) showed no association with educational attainment. These findings confirm African American-white differences in lipids, lipoproteins, and apolipoproteins across levels of educational attainment that were not explained by conventional nondietary lifestyle variables. Understanding these differences associated with educational attainment will assist in identifying measures aimed at prevention of cardiovascular disease.

Black or African American↗

PubMed1998

Prevalence and clinical correlates of unsuccessful use of drugs to induce menstruation.

Despite its prohibition, illegal abortion is widely practiced in Brazil, with important adverse health consequences. This report aims to document the prevalence and correlates of the unsuccessful use of drugs to "induce menstrual flow" in a cohort of pregnant Brazilian women. In a cross-sectional study, 6,102 pregnant women between gestation weeks 21 and 28 were interviewed in prenatal clinics of the Brazilian National Health Care System from April 1991 to November 1995. When asked "In order to know if you were pregnant, did you take any medication to induce menstrual flow", 874 (14.4%) responded "yes." The most frequently used drugs were herbal teas (41%), estrogens and/or progestogens (30%), and misoprostol (16%). As demonstrated through logistic regression analysis, independent correlates of such use were unplanned pregnancy (odds ratio [OR] 4.3), low educational attainment (OR 3.3), absence of a husband or partner (OR 1.8), number of children (one or more) (OR 1.5), a history of a previous induced abortion (OR 1.4), and use of oral contraceptives at the time (OR 1.4). Misoprostol use occurred in 2.2% of pregnancies, and showed a very strong association with an unplanned pregnancy (OR 16.0), absence of a husband or partner (OR 3.5), and a history of a previous induced abortion (OR 2.2). It was not associated with a history of menstrual irregularity. In contradistinction, the use of medroxyprogesterone was strongly associated with previous menstrual irregularity (OR = 5.0). The use of drugs and teas, many of which are unknown in terms of fetal risk, in early pregnancy to induce menstrual flow is quite common in women in the Brazilian National Health System. Although the objective of such drug use appears to be varied, analysis of the clinical correlates of use suggest attempted abortion to be the principal aim.

Abortifacient Agents, Nonsteroidal↗

PubMed1998

Alcohol intake and blood pressure: the importance of time elapsed since last drink.

BACKGROUND: A positive association of chronic exposure to alcoholic beverages with blood pressure and the prevalence of hypertension has been described in epidemiological surveys, but the influence of time elapsed since last ingestion in this setting was not demonstrated. DESIGN: A cross-sectional, population-based survey. METHODS: In total 1089 adults from Porto Alegre, randomly selected from a population-based, multi-stage probability sample, were interviewed at home. The average daily alcohol intake of each subject was calculated taking into account the concentration of ethanol in the beverages (distilled or fermented beverages), and the time elapsed between the last ingestion of ethanol and the moment of blood pressure determination. Standardized sitting blood pressure and anthropometric parameters were collected. The magnitude and shape of the associations were analyzed considering blood pressure as a continuous variable and the prevalence of arbitrarily defined hypertension. Simple and multiple linear regression models, including models to identify nonlinear associations, with quadratic and cubic terms of the amount of alcohol consumed, were employed. Blood pressure means were compared by analysis of variance and analysis of covariance. The association between hypertension and exposure to ethanol was analyzed through logistic regression models, controlling for various potential confounders. RESULTS: Positive nonlinear associations of the amount of alcohol consumed with blood pressure and the prevalence of hypertension (> or = 160/95 mmHg) were found, independent of age, years of education, smoking, and use of oral contraceptive and antihypertensive drugs. The consumption of 30 g/day ethanol was associated with increases of 1.5 and 2.3 mmHg in diastolic and systolic blood pressures, respectively, for men, and 2.1 and 3.2 mmHg, respectively, for women. The prevalence of hypertension was higher among those ingesting more than 30 g/day (odds ratio = 2.9, P < 0.01). The time elapsed between the last ingestion and blood pressure measurement was independently associated with the prevalence of hypertension. Men with last consumption of alcohol 13-23 h prior to measurement had odds of being hypertensive 2.6 (confidence interval 1.3-5.0) greater than did subjects who had consumed alcoholic beverages 24 h and more before the blood pressure determination. For men, systolic and diastolic blood pressures were lower during the first 3 h after ingestion and increased afterward. Frequency of consumption and type of beverage consumed were not independently associated with level of blood pressure. CONCLUSION: A time-dependent association between alcohol consumption and effects on blood pressure, demonstrated in experimental studies, was found for free-living individuals selected at random.

Adolescent↗

PubMed1997

Development of the multiple metabolic syndrome in the ARIC cohort: joint contribution of insulin, BMI, and WHR. Atherosclerosis risk in communities.

PURPOSE: The natural history of the multiple metabolic syndrome (MMS) and its predictors has rarely been addressed in population samples. This study evaluated the predictive role of fasting serum insulin, body mass index (BMI), and waist-to-hip ratio (WHR) on the development of incident MMS components (diabetes, hypertension, and dyslipidemias) over the course of three years. METHODS: The study population comprised the cohort of middle-aged African American and European American men and women of the Atherosclerosis Risk in Communities Study (1987-1992). RESULTS: Among 6113 individuals free of MMS components at baseline, high insulin (> 14 microU/ ml) was independently predictive of the development of one or more MMS components (OR:1.5, 95% CI:1.2-1.8), as was a BMI > or = 30 (OR:1.7, 95% CI:1.4-2.0), and a high WHR (> 0.98) (OR:1.5, 95% CI:1.3-1.8) adjusting statistically for age, gender, and ethnicity/center. These associations were markedly stronger for combinations of MMS components (two or more) than for isolated components. CONCLUSIONS: The findings confirm earlier reports on the predictive role of insulin, BMI, and WHR, and suggest that these antecedent factors may be integral to the development of combinations of disorders, i.e., the particular clustering identified as the MMS.

Analysis of Variance↗

PubMed1997

Risk factors differ for carotid artery plaque with and without acoustic shadowing. Atherosclerosis Risk in Communities Study Investigators.

To investigate the association of gender, ethnicity, and several cardiovascular risk factors with carotid artery plaque and plaque with acoustic shadowing in a population-based sample, high-resolution B-mode ultrasonography was used to characterize lesions in the common and internal carotid arteries, and at the carotid bifurcation in 12,796 US men and women, aged 45 to 64 years, participating in the Atherosclerosis Risk in Communities Study (ARIC) baseline survey. In multiple logistic regression analyses, male gender (odds ratio and 95% confidence interval: 1.52 [1.39-1.67]) and increased total (1.47 [1.32-1.63]) and low-density-lipoprotein cholesterol (1.49 [1.34-1.65]) levels were statistically significantly associated only with the presence of plaque. In contradistinction, smoking (2.22 [1.79-2.75]) and hypertension (1.54 [1.30-1.82]) were additionally associated with acoustic shadowing. Hyperfibrinogenemia (1.33 [1.12-1.59]) was associated only with lesions accompanied by acoustic shadowing. While ethnicity associations with plaque alone varied across the artery segments, among those with plaque, being white was uniformly associated with acoustic shadowing. After multivariable adjustment, high-density-lipoprotein cholesterol was not associated with either manifestation of atherosclerosis. In conclusion, differences were seen in the associations of established cardiovascular risk factors with discretely characterized carotid artery plaque lesions, according to the presence or absence of acoustic shadowing suggestive of mineralization of plaque.

Carotid Artery, Common↗

PubMed1997

Waist circumference and waist-to-hip ratio are related to gestational glucose tolerance.

OBJECTIVE: To evaluate the relationship of central fat distribution with gestational glucose tolerance during the usual time for screening gestational diabetes. RESEARCH DESIGN AND METHODS: This cross-sectional study investigated 1,113 consecutive women, > or = 20 years old, pregnant for approximately 21 to 28 weeks, without history of previous diabetes outside pregnancy, who attended two general prenatal care units in Porto Alegre, Brazil, from 1991 to 1993. Weight, height, waist and hip circumferences, and skinfolds were measured, and a 2-h, 75-g glucose tolerance test was performed. Data were analyzed using multiple linear regression models. RESULTS: Waist-to-hip ratio (WHR) and waist circumference were independently associated with higher 2-h glycemia. Glycemic level was 0.11 and 0.13 mmol/l greater for each standard deviation increase in WHR (0.06) and waist circumference (8.0 cm), respectively (P < 0.02). Restricting analyses to the subset of women with uterine height < or = 26 cm improved the association (0.13 and 0.19 mmol/l, respectively, P < 0.02); differences of 0.22 and 0.19 mmol/l were observed for 1 SD changes in the sum of skinfold thicknesses (24.7 mm) and in age (5.5 years), respectively. CONCLUSIONS: Central fat distribution measured in pregnancy is an independent predictor of gestational glucose intolerance. This finding supports the concept that NIDDM and gestational diabetes are parts of the same disease, differing basically in their moment of detection. The usefulness of these anthropometric measurements in identifying pregnant women at high risk of having gestational glucose intolerance merits further investigation.

Adipose Tissue↗

PubMed1996

Clustering of dyslipidemia, hyperuricemia, diabetes, and hypertension and its association with fasting insulin and central and overall obesity in a general population. Atherosclerosis Risk in Communities Study Investigators.

Clustering of elevated triglycerides, decreased high-density lipoprotein cholesterol (HDL-C), hyperuricemia, diabetes, and hypertension has been related to insulin resistance/high insulin levels and central and/or overall obesity. The extent to which these abnormalities cluster and whether hyperinsulinemia, central adiposity, and overall obesity each independently associate with this clustering were evaluated in 14,481 US whites and African-Americans 45 to 64 years of age. With the exception of hypertension, abnormalities rarely existed in isolated form. Clustering greatly exceeded chance association (P < .001). Although this clustering was greater in relative terms (ratio of observed to expected cluster frequency) in the lean and less centrally obese, it was greater in absolute terms (observed minus expected cluster frequency as a percent of total population) in the more centrally and more generally obese. The greatest excesses were found for clusters that included both hypertriglyceridemia and low HDL-C. Multiple logistic regression models showed strong and independent graded relationships of clusters with quintiles of fasting insulin (fifth quintile odds ratio, 10 to 54, P < .001) and to a lesser degree with quintiles of the waist to hip ratio (2.2 to 5.4, P < .001 for most) and of body mass index (1.6 to 4.5, P < .05 for most). In conclusion, all abnormalities cluster in excess of that predicted by chance, with clusters showing remarkable and graded independent associations with fasting hyperinsulinemia and to a lesser extent with central and overall obesity. Thus, a metabolic syndrome occurs in both lean and obese middle-aged US adults.

Cluster Analysis↗

PubMed1996

A metabolic syndrome in whites and African-Americans. The Atherosclerosis Risk in Communities baseline study.

OBJECTIVE: To describe clustering of hypertriglyceridemia, low HDL cholesterol, hypertension, diabetes, and hyperuricemia and its association with fasting insulin, waist-to-hip ratio (WHR), and BMI for African-American and white men and women. RESEARCH DESIGN AND METHODS: Observed frequencies of clusters were compared with those expected in 14,481 participants, 45-64 years of age, of the Atherosclerosis Risk in Communities (ARIC) baseline survey, 1987-1989. Associations of clusters with insulin, central adiposity, and overall obesity, as well as with abnormalities, were analyzed through multiple logistic regression. RESULTS: Clustering beyond chance was observed in all four sex/ethnic groups (P < 0.001), with 7% of the sample presenting 30% of the abnormalities in large clusters (> or = 3 abnormalities per individual). The odds ratio (OR) for the association of each abnormality with clustering of the remaining four ranged from 1.6 to 8.8 (P < 0.01). These odds of clustering were notably large in white women. Of the abnormalities, hypertriglyceridemia demonstrated the highest OR (5.0-8.8) and diabetes had the lower OR in African-American subjects than in white subjects (P < 0.001). Insulin, WHR, and BMI were statistically associated with clustering in all groups (P < 0.001, except for BMI in African-Americans.

Arteriosclerosis↗

PubMed1995

Association of the waist-to-hip ratio is different with wine than with beer or hard liquor consumption. Atherosclerosis Risk in Communities Study Investigators.

Specific alcoholic beverage associations with the waist-to-hip ratio were characterized in 12,145 African-American and white men and women ages 45-64 years. Estimated waist-to-hip ratios of those consuming more than six nonwine alcohol drinks/week and more than six wine drinks/week (vs. nondrinkers) were 0.007 larger (p < 0.001) and 0.009 smaller (p < 0.05), respectively. In similar comparisons, the odds ratios for a large waist-to-hip ratio were 1.4 (95% confidence interval 1.1-1.7) for nonwine and 0.45 (95% confidence interval 0.21-0.95) for wine intake. The opposite direction in adjusted associations for wine and nonwine (mainly beer) drinking supports the popular concept of the "beer belly."

Adipose Tissue↗

PubMed1995

Correlates of body fat distribution. Variation across categories of race, sex, and body mass in the atherosclerosis risk in communities study. The Atherosclerosis Risk in communities (ARIC) Study Investigators.

Though central adiposity is a strong, independent risk factor for cardiovascular and all-cause mortality, relatively little is known about its determinants. To characterize the association of central adiposity with several of its possible determinants, while describing variability in these associations across sex, race, and level of body mass index, we conducted a cross-sectional survey of 15,800 white and African-American men and women ages 45 to 64 years participating in the Atherosclerosis Risk in Communities baseline survey, 1987 to 1989. After adjustment for other possible determinants, African Americans had markedly larger subscapular skinfold thickness and subscapular/triceps ratios than did whites, while whites had larger waist/hip ratios. Large, statistically significant variations in waist/hip ratio associations with age, percent of weight gained after age 25, smoking, and physical activity in the workplace existed across categories of sex, race, and body mass index. Based on our findings, we concluded that major variation exists in the waist/hip ratio and in its associations with its possible determinants across categories of race, sex and obesity.

Adipose Tissue↗

PubMed1995

Social inequality in mortality in São Paulo State, Brazil.

BACKGROUND: Epidemiological studies have consistently demonstrated social inequality to be an important factor in the distribution of illness and death in society. However, little work has been published on social differentials in mortality in the world's developing countries, where socioeconomic contrasts are often considerably greater. METHODS: In order to evaluate the extent of social differentials in mortality in a setting of major social inequality -- the State of São Paulo, Brazil, deaths in men aged 15-64 years residing in São Paulo from 1980 to 1982 were linked in broad, occupationally-determined categories to estimates of population size based on the 1980 Brazilian national census. The occupational categorizations utilized a Brazilian classification scheme and additionally that of the British Registrar General. RESULTS: Mortality was 3.8 and 2.9 times greater comparing least to most socially favoured occupational category in each of the two classification systems, respectively. Independent of system, mortality decreased approximately 1.1% for each 1% increase along the occupationally-defined social gradient. This decrease was 48% greater than the equivalent calculated decrease for men of England and Wales. CONCLUSIONS: These data support the contention that mortality for Brazilian adults, even more so than for adults of the world's more economically developed nations, is inextricably bound to the issue of social equity.

Adolescent↗

PubMed1994

Variation in glucose tolerance with ambient temperature.

Ambient temperature may affect venous glucose concentration after glucose tolerance tests. We analysed 1030 standardised 75 g tests. Although mean fasting values did not differ, post-load values did: adjusted mean 2 h glucose concentration was 1.03 mmol/L lower at lower (5-14 degrees C) than at higher (25-31 degrees C) temperatures (p < 0.001). The occurrence of abnormal glucose tolerance doubled on warmer days. The diagnostic accuracy of the glucose tolerance test showed clinically significant temperature-associated variation. These variations, if confirmed, call for temperature standardisation during glucose tolerance testing and/or alternative strategies for use when standardisation is not feasible.

Adult↗

PubMed1994

B-mode-detected carotid artery plaque in a general population. Atherosclerosis Risk in Communities (ARIC) Study Investigators.

BACKGROUND AND PURPOSE: There is little information on the distribution of atherosclerotic lesions of the extracranial carotid artery wall in free-living populations. The purpose of the present study was to describe the prevalence from 1987 through 1989 of extracranial carotid artery plaque and plaque with acoustic attenuation (shadowing) lesions in a general population of white and black adults from four US communities. METHODS: B-mode ultrasound was used to characterize wall lesions in the common and internal carotid arteries and at the carotid artery bifurcation in 14,046 men and women 45 to 64 years old who participated in the Atherosclerosis Risk in Communities Study baseline survey. RESULTS: Thirty-four percent of participants had plaque and 6.4% had plaque with acoustic shadowing. The prevalence of plaque with acoustic shadowing increased steadily with age from 2.5% at ages 45 to 49 to 12.4% at ages 60 to 64. Overall, whites had more plaque with acoustic shadowing lesions than blacks (odds ratio [OR], 1.22; 95% confidence interval [CI], 1.02 to 1.46), and men had more than women (OR, 1.42; 95% CI, 1.22 to 1.63). However, plaque lesions in the common carotid artery were less common among whites than among blacks, and no racial difference was observed in the prevalence of plaque with acoustic shadowing at this segment. CONCLUSIONS: Although these prevalence rates are likely to be underestimated because of the emphasis on arterial boundary visualization of the scanning protocol, they show a large, mostly asymptomatic burden of atherosclerosis in these populations, especially among older individuals. Site-specific frequency rates of plaque varied between blacks and whites. Among those with plaque, however, whites had more lesions with acoustic shadowing attenuation.

Adult↗

PubMed1993

[Myocardial infarct and cerebral vascular disorders associated with high temperature and carbon monoxide in a metropolitan area of southeastern Brazil].

Many studies have been published about the relationship between life style and genetic risk factors and stroke and heart attack, but there have been few about the relationship between atmospheric pollution, specifically with carbon monoxide, and temperature and stroke and heart attack. With a view to filling this gap the relationship between values of carbon monoxide concentration in the air, maximum and average by day, and maximum temperature by day and the number of new cases of CVA and IM admitted as emergencies at the biggest hospital complex of S. Paulo city was analysed. If was concluded, by the use of multivariable regression analysis, that 2.1% and 4.9% of heart attack admissions were due to carbon monoxide air pollution and high temperature, respectively. 2.8% of stroke admissions were due high temperature. Stroke and carbon monoxide were not associated in this population.

Brazil↗

PubMed1993

[Risk factors for non-communicable diseases in a metropolitan area in the south of Brazil. Prevalence and simultaneity].

Three-quarters of deaths in Rio Grande do Sul State, Brazil, are due to non-communicable diseases-cardiovascular diseases, alone, being responsible for 35% of them. To evaluate the prevalence of risk factors for these diseases, a household survey of 1,157 randomly sampled individuals between 15 and 64 years of age was undertaken in 1986 and 1987 in census tracts of 4 areas of the city of Porto Alegre. The age- and sex-adjusted prevalence of smoking was 40%, hypertension 14%, obesity 18%, overall sedentary life-style 47%, and excessive alcohol consumption 7%. Thirty-nine percent of the sample presented two or more of these five risk factors, and only 22% of men and 21% of women had none of them. The high frequencies and simultaneous presence of these risk factors indicate their importance for programs aimed at the prevention of non-communicable diseases and the promotion of adult health.

Adolescent↗

PubMed1993

Validity of self-reported weight--a study of urban Brazilian adults.

In order to evaluate the validity of self-reported weight for use in obesity prevalence surveys, self-reported weight was compared to measured weight for 659 adults living in the Porto Alegre county, RS Brazil in 1986-87, both weights being obtained by a technician in the individual's home on the same visit. The mean difference between self-reported and measured weight was small (-0.06 +/- 3.16 kg; mean +/- standard deviation), and the correlation between reported and measured weight was high (r = 0.97). Sixty-two percent of participants reported their weight with an error of < 2 kg, 87% with an error of < 4 kg, and 95% with an error of < 6 kg. Underweight individuals overestimated their weight, while obese individuals underestimated theirs (p < 0.05). Men tended to overestimate their weight and women underestimate theirs, this difference between sexes being statistically significant (p = 0.04). The overall prevalence of underweight (body mass index < 20) by reported weight was 11%, by measured weight 13%; the overall prevalence of obesity (body mass index > or = 30) by reported weight was 10%, by measured weight 11%. Thus, the validity of reported weight is acceptable for surveys of the prevalence of ponderosity in similar settings.

Adolescent↗

PubMed1993

Socioeconomic distribution of noncommunicable disease risk factors in urban Brazil: the case of Pôrto Alegre.

The study reported here sought to assess the degree to which the prevalences of five risk factors for noncommunicable diseases--hypertension, smoking, obesity, sedentary lifestyle, and excessive alcohol consumption--varied individually and in combination for urban Brazilians with differing socioeconomic status in terms of educational achievement, income, and social class. For this purpose, 1986-1987 data from a cross-sectional household survey of 1,157 randomly selected adults 15-64 years of age residing in the major Brazilian city of Pôrto Alegre were analyzed. In general, it was found that less privileged socioeconomic situations tended to be associated with higher risk factor prevalences. However, this was not the case for obesity and sedentary lifestyle among men, and may not have been the case with respect to hypertension among women. When the effects of education, income, and social class were considered simultaneously, higher risk factor prevalences were most strongly associated with low educational attainment. Important exceptions to this rule were found for smoking among women and excessive alcohol consumption among men, where higher risk factor prevalences were most associated with social class. Once the effects of education and social class were accounted for, low income generally tended to be associated with lower prevalences of the risk factors studied.

Adolescent↗