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Biomedical subjects

D F Williamson

Publications and source records attributed to D F Williamson.

At least 55 records · Page 3Linked to original sources
PubMed1998

The body mass index-mortality relationship in white and African American women.

OBJECTIVE: To examine the association of body mass index to all-cause and cardiovascular disease (CVD) mortality in white and African American women. RESEARCH METHODS AND PROCEDURES: Women who were members of the American Cancer Society Prevention Study I were examined in 1959 to 1960 and then followed 12 years for vital status. Data for this analysis were from 8,142 black and 100,000 white women. Body mass index (BMI) was calculated from reported height and weight. Associations were examined using Cox proportional hazards modeling with some analyses stratified by smoking (current or never) and educational status (less than complete high school or high school graduate). RESULTS: There was a significant interaction between ethnicity and BMI for both all-cause (p<0.05) and CVD mortality (p<0.001). BMI (as a continuous variable) was associated with all-cause mortality in white women in all four groups defined by smoking and education. In black women with less than a high school education, there were no significant associations between BMI mortality. For high school-educated black women, there was a significant association between BMI and all-cause mortality. Among never smoking women with at least a high school education, models using the lowest BMI as the reference indicated a 40% higher risk of all-cause mortality at a BMI of 35.9 in black women vs. 27.3 in white women. DISCUSSION: The impact of BMI on mortality was modified by educational level in black women; however, BMI was a less potent risk factor in black women than in white women in the same category of educational status.

Adult↗
PubMed1998

Relationship of childhood abuse and household dysfunction to many of the leading causes of death in adults. The Adverse Childhood Experiences (ACE) Study.

BACKGROUND: The relationship of health risk behavior and disease in adulthood to the breadth of exposure to childhood emotional, physical, or sexual abuse, and household dysfunction during childhood has not previously been described. METHODS: A questionnaire about adverse childhood experiences was mailed to 13,494 adults who had completed a standardized medical evaluation at a large HMO; 9,508 (70.5%) responded. Seven categories of adverse childhood experiences were studied: psychological, physical, or sexual abuse; violence against mother; or living with household members who were substance abusers, mentally ill or suicidal, or ever imprisoned. The number of categories of these adverse childhood experiences was then compared to measures of adult risk behavior, health status, and disease. Logistic regression was used to adjust for effects of demographic factors on the association between the cumulative number of categories of childhood exposures (range: 0-7) and risk factors for the leading causes of death in adult life. RESULTS: More than half of respondents reported at least one, and one-fourth reported > or = 2 categories of childhood exposures. We found a graded relationship between the number of categories of childhood exposure and each of the adult health risk behaviors and diseases that were studied (P < .001). Persons who had experienced four or more categories of childhood exposure, compared to those who had experienced none, had 4- to 12-fold increased health risks for alcoholism, drug abuse, depression, and suicide attempt; a 2- to 4-fold increase in smoking, poor self-rated health, > or = 50 sexual intercourse partners, and sexually transmitted disease; and 1.4- to 1.6-fold increase in physical inactivity and severe obesity. The number of categories of adverse childhood exposures showed a graded relationship to the presence of adult diseases including ischemic heart disease, cancer, chronic lung disease, skeletal fractures, and liver disease. The seven categories of adverse childhood experiences were strongly interrelated and persons with multiple categories of childhood exposure were likely to have multiple health risk factors later in life. CONCLUSIONS: We found a strong graded relationship between the breadth of exposure to abuse or household dysfunction during childhood and multiple risk factors for several of the leading causes of death in adults.

Adult↗
PubMed1998

Weight loss and mortality in persons with type-2 diabetes mellitus: a review of the epidemiological evidence.

Six epidemiological studies of weight loss and mortality in persons with diabetes are reviewed in this paper. One study found no relationship between weight loss and mortality, one study (published as an abstract) found that weight loss was associated with reduced mortality, and in two studies the results were mixed: in some groups weight loss was associated with increased mortality and in other subgroups weight loss was associated with reduced mortality. The most appropriate interpretation from this group of studies is that the relationship between weight loss and mortality in persons with diabetes is equivocal. None of these studies were designed to experimentally test the hypothesis that intentional weight loss increases survival in persons with diabetes. Because weight loss was not randomly assigned to the study participants, and because the reasons that the participants lost weight are not made clear, we can only conjecture about the potential confounding role that underlying illness plays in accounting for these results. In addition, the epidemiological evidence suggests that persons with diabetes are more likely than non-diabetics to experience both intentional and unintentional weight loss. This fact makes it especially difficult to cleanly separate the potentially opposing effects of intentional and unintentional weight loss in observational studies. Because of the important limitations and inconsistencies in the results of the studies reviewed here, the clinical community is left with little guidance on the relative role that intentional weight loss should play in the care of persons with diabetes, compared with better established treatments. Although better designed observational epidemiological studies are needed, the best test of the hypothesis that weight loss improves survival in persons with diabetes will come from randomised controlled trials.

Adult↗
PubMed1998

Population-based assessment of the level of care among adults with diabetes in the U.S.

OBJECTIVE: To estimate the levels of use of preventive care and to identify correlates of such care among people with diabetes in the U.S. RESEARCH DESIGN AND METHODS: A cross-sectional study was conducted using a sample of 2,118 adults, age > or =18 years, with self-reported diabetes in 22 states that participated in the 1994 Behavioral Risk Factor Surveillance System. Most subjects were age > or =45 years (83%), women (51%), and white (75%) and were diagnosed at ages > or =30 years (83%), had type 2 diabetes (89%), and were not using insulin (66%). RESULTS: Among all people with diabetes, 78% practiced self-monitoring of blood glucose, and 25% were aware of the term "glycosylated hemoglobin" or "hemoglobin A one C" (HbA1c). In the last year, 72% of the subjects visited a health care provider for diabetes care at least once, 61% had their feet inspected at least once, and 61% received a dilated eye examination. Controlled for age and sex, the odds ratios (ORs) for insulin use were for self-monitoring (OR [95% CI]; 4.0 [2.6-6.1]); having heard of HbA1c or receipt of a dilated eye examination (1.9 [1.4-2.5]); at least one visit to a provider (3.4 [1.9-7.2]); and feet inspected at least once (2.1 [1.5-2.9]). In addition, people <45 years, those who did not complete high school, and those without insurance coverage were high-risk groups for underuse of preventive care. Only 3% of insulin users and 1% of nonusers met all five of the American Diabetes Association standards in the previous year. CONCLUSIONS: Underuse of recommended preventive care practices is common among people with diabetes.

Adolescent↗
PubMed1997

Examination of "early mortality exclusion" as an approach to control for confounding by occult disease in epidemiologic studies of mortality risk factors.

Methods for the estimation of the effects of chronic disease risk factors on mortality continue to be an area that generates confusion and controversy. In response to the frequently observed U- or J-shaped relations between risk factors and mortality, some authors suggest that subjects dying during the first k years of follow-up (where k is some positive number less than the total length of follow-up) be excluded from statistical analyses. By excluded, the authors mean completely removed from the data set. The rationale is that persons dying during the first k years are likely to have a preexisting occult disease that confounds the relation between the risk factor under study and mortality. Excluding persons dying during the first k years of follow-up purportedly reduces this confounding. However, the authors are aware of no demonstration that this procedure effectively accomplishes its goal. They show that excluding subjects who die during the first k years of follow-up does not necessarily lead to a reduction in bias in the estimated effect of a risk factor on mortality when this relation is confounded by the presence of occult disease. Moreover, it is possible for such exclusion to exacerbate the confounding due to preexisting disease. Thus, excluding subjects dying during the first k years of follow-up is not necessarily an effective strategy for dealing with confounding due to occult disease. Investigators are encouraged to pursue alternative methods.

Confounding Factors, Epidemiologic↗
PubMed1997

Weight change and diabetes incidence: findings from a national cohort of US adults.

To examine how long-term patterns of weight change affect the risk for diabetes, especially non-insulin-dependent diabetes mellitus, the authors examined the relation of weight change over a period of about 10 years (from the baseline examination in 1971-1975 until the first follow-up examination in 1982-1984) to the 9-year incidence of diabetes mellitus (1984-1992) in a national cohort of 8,545 US adults from the National Health and Nutrition Examination Survey Epidemiologic Followup Study. Diabetes incidence was identified from death certificates, hospitalization and nursing home records, and self-report. In this cohort, 487 participants developed diabetes. The hazard ratios were 2.11 (95% confidence interval (CI) 1.40-3.18) for participants who gained 5- < 8 kg, 1.19 (95% CI 0.75-1.89) for participants who gained 8- < 11 kg, 2.57 (95% CI 1.84-3.85) for participants who gained 11- < 20 kg, and 3.85 (95% CI 2.04-7.22) for participants who gained 20 kg or more compared with participants whose weights remained relatively stable. The authors found no evidence that the results differed by age, sex, or race. They estimated that the population attributable risk was 27% for weight increases of 5 kg or more. Results from this study and other recent studies suggest that the increase in body mass index in the United States that occurred during the 1980s may portend an increase in the incidence of non-insulin-dependent diabetes mellitus with important public health consequences in future years.

Adolescent↗
PubMed1997

Parity-associated weight gain and its modification by sociodemographic and behavioral factors: a prospective analysis in US women.

OBJECTIVE: To examine how the relationship between parity increase and weight gain is modified by sociodemographic and behavioral factors. DESIGN: Prospective longitudinal data from the first National Health and Nutrition Examination Survey (NHANES I, 1971-75) and its follow-up of those aged 25 y and older, the NHANES I Epidemiologic Follow-up Survey (NHEFS, 1982-84). SUBJECTS: The analytical sample was nationally representative of the United States and included 2952 white or African-American non-pregnant women aged 25-45 y at baseline, who were re-measured approximately 10 y later. MEASUREMENTS: Statistical interactions in multiple linear and logistic regression models were examined to identify how eight sociodemographic and three behavioral factors modified the effect of parity increase on body weight change and risk of substantial weight gain. RESULTS: Factors that increased parity-associated weight gain included being African-American, living in a rural area, not working outside the home, having fewer children, lower income and lower education, and being unmarried. Among white women, being younger and having higher body weight at baseline increased parity-associated weight gain, while among African-American women, being older and having lower body weight increased parity-associated weight gain. African-American smokers gained less weight with an increase in parity, while the interactions between smoking and physical activity with parity-associated weight gain in whites were complex. CONCLUSION: The effects of sociodemographic and behavioral factors on parity-associated weight gain varied by race and parity change, with the most consistent findings being that unmarried and unemployed white women had greater parity-associated weight gain, while both white and African-American women who smoked, had higher education, or higher parity had lower parity-associated weight gain. This information may contribute to better targeting and more effective interventions to prevent postpartum weight retention.

Adult↗
PubMed1997

Secular increases in relative weight and adiposity among children over two decades: the Bogalusa Heart Study.

OBJECTIVE: To examine trends in relative weight and obesity among 5- to 24-year-olds between 1973 and 1994. DESIGN: A panel design consisting of seven cross-sectional surveys of schoolchildren and three surveys of post-high-school subjects. Anthropometric measurements included height, weight, and subscapular and triceps skinfolds. STUDY POPULATION: All schoolchildren residing in Ward 4 of Washington Parish, Louisiana, a biracial community, were considered eligible; participation rates were >80%. Young adults were eligible if they had participated previously as schoolchildren. A total of 26,371 examinations were performed on 11,564 persons. RESULTS: During the study period, substantial increases in mean levels of weight (0.2 kg/y) and skinfold thickness (0.15 mm/y) were observed; these changes were independent of height, age, and other covariates. The prevalence of overweight, defined by the 85th percentile of weight-for-height in 1973 to 1974, increased approximately twofold by 1994. Although secular increases were seen both among boys and girls and among blacks and whites, the largest increases were seen among 19- to 24-year-olds. Furthermore, the yearly increases in relative weight and obesity during the latter part of the study period (1983 through 1994) were approximately 50% greater than those between 1973 and 1982. CONCLUSIONS: The increasing prevalence of obesity in early life indicates a need for primary prevention. Additional study is needed to determine whether these trends are continuing to accelerate and to examine possible explanations, such as diet and physical activity, for these changes.

Adolescent↗
PubMed1997

Intentional weight loss: patterns in the general population and its association with morbidity and mortality.

The question of whether intentional weight loss increases the longevity of obese individuals is important, given the high prevalence of obesity and co-morbidities in industrialized countries, and the high prevalence of intentional weight loss in such populations. A number of studies suggest that both weight loss and weight fluctuation are associated with increased mortality. Factors such as smoking status and pre-existing illness, however, have to be considered in relation to these findings. A study controlled for smoking status and pre-existing illness, found that intentional weight loss by overweight, white, US women, consistently reduced mortality in those with obesity related co-morbidities. An Indian study, involving individuals with previous myocardial infarction, found that dietary intervention reduced mortality substantially. Those losing > 5 kg had the greatest reduction in both total and cardiovascular mortality. In both the above studies, weight loss was approximately 10% of initial body weight. Preliminary evidence suggests that modest intentional weight loss is associated with increased longevity in individuals with co-morbidities.

Adolescent↗
PubMed1996

Reliability of alcohol intake as recalled from 10 years in the past.

The authors assessed the reliability of alcohol intake as recalled from 10 years in the past in a cohort of 2,907 US adults. Participants reported their drinking habits in the First National Health and Nutrition Examination Survey interview during 1971-1975. During a follow-up interview in 1982-1984, they were asked to recall their drinking habits 10 years earlier and to report their current habits. In general, the correlation for recalled alcohol intake versus reported intake at baseline was good (r = 0.7). For all subgroups stratified by race, sex, education, smoking status, and disease status, the age-adjusted correlations for recalled alcohol intake versus baseline intake were equal to or higher than those for current alcohol intake versus baseline intake. The reliability of recall of alcohol intake in the past differs among subgroups with different age and education levels. Recalled alcohol intake was also highly correlated with current alcohol intake; in particular, current heavier drinkers tended to underestimate their previous amount of drinking, an effect that was independent of other factors. These data suggest that although recalled alcohol intake is a better predictor of past intake than are reports of current intake, current drinking habits may be an important influencing factor in the estimation of alcohol intake as recalled from the distant past.

Adult↗
PubMed1996

Simple anthropometric indices associated with ischemic heart disease.

In a case-control study of 217 hospitalized incident cases of ischemic heart disease and 261 controls we compared various anthropometric indices for the strength of their associations to the outcome event. The ratio of supine sagittal abdominal diameter to midthigh girth ("abdominal diameter index"; ADI) was the simple index that best discriminated cases from controls for both men (standardized difference, 0.65; p < 0.0001) and women (standardized difference, 0.95; p < 0.0001). The waist-to-thigh ratio of girths (WTR) (standardized difference, 0.57 and 0.90; p < 0.0001) was nearly as strong as the ADI and stronger than the traditional waist-to-hip ratio (standardized difference, 0.34 and 0.68; p < 0.005). After adjustments for age and race, the men's odds ratio for ischemic heart disease (tertile 3 vs. tertile 1) was 5.5 (95% CI, 2.9-10) using ADI and 5.1 (2.6-10) using the WTR. The women's odds ratio was 6.3 (1.9-20) using ADI and 8.7 (2.3-33) using the WTR. Further adjustments for body mass index and cardiovascular risk factors did not substantially change these risk estimates. Similar odds ratios were estimated by analyses restricted to 169 neighborhood-matched case-control pairs. In contrast, increased midthigh girth and subcutaneous fat mass (sum of three skinfolds) were associated with a protective effect against ischemic heart disease. Anthropometry using the ADI or WTR could offer a low-cost, noninvasive method for the clinical or epidemiologic evaluation of ischemic heart disease risk.

Anthropometry↗
PubMed1996

"Weight cycling" and mortality: how do the epidemiologists explain the role of intentional weight loss?

In the past 5 years, four prospective, epidemiologic studies of "weight cycling" found that mortality is higher for persons with unstable body weight than for persons whose body weight is relatively stable [1-3,5]. These findings have generated considerable interest and controversy in both the scientific community and the lay press because of the belief that the weight fluctuations were caused by intentional weight loss. None of these studies, however, collected information that would indicate whether the weight changes were intentional or unintentional. This review examines the reasons given by the authors of these studies to support the inference that intentional weight loss caused the increase in mortality. The authors acknowledged that weight loss can be caused by preexisting illness, and they usually made efforts to control for the confounding effects of illness in their analyses. However, they generally concluded that the weight fluctuations resulted from unsuccessful dieting, but no data were presented on the incidence or causes of weight fluctuation in the populations from which the samples were drawn. In none of the studies did the authors recommend that obese persons stop trying to lose weight. The reader is cautioned to await further studies in which intentionality of weight loss is directly assessed before concluding that dieting to reduce weight increases the risk of mortality.

Aged↗
PubMed1996

Weight loss maintenance in young adulthood: prevalence and correlations with health behavior and disease in a population-based sample of women aged 55-69 years.

OBJECTIVE: To describe the prevalence of weight loss maintenance and other weight change patterns in early adulthood (ages 18-50 years), and their association with disease prevalence in older age (average age 62 years). DESIGN: Cross-sectional survey. SUBJECTS: 17233 postmenopausal women aged 55-69 years. MEASUREMENTS: Weight change categories based on recalled body weight at age 18, 30, 40 and 50 years. RESULTS: Weight loss of 10% or more between ages 18 and 30 years followed by maintenance within 5% up to age 50 years, and weight loss of 10% or more followed by a 10% or more regain were equally common, yet rare, weight change patterns (1.6% and 1.8%, respectively). Among those who were overweight at age 18, maintaining a stable weight was associated with increased odds of diabetes (OR = 5.48) and hypertension (OR = 1.98), relative to normal weight-weight stable women. However, overweight women who lost weight had similar odds of diabetes and hypertension as normal weight-weight stable women. In both overweight and normal weight women, weight loss followed by regain was associated with higher odds of disease relative to weight stability. However, the highest odds of disease were associated with continuous weight gain or an initial weight gain that was maintained. CONCLUSIONS: Weight gain is associated with higher odds of disease compared to weight stability, which is associated with lowest odds of disease. Weight loss maintenance in the overweight is associated with lower odds of obesity-related diseases such as diabetes and hypertension.

Adolescent↗
PubMed1996

Attempted weight loss during pregnancy.

OBJECTIVE: To assess the prevalence and correlates of weight loss during pregnancy. DESIGN: Cross-sectional telephone survey from 47 states and the District of Columbia. SUBJECTS: 1794 women who reported that they were pregnant at the time of the survey. MEASUREMENTS: Self-reported weight, height, disease and behaviors. RESULTS: A minority (3.7%; 95% CI, 2.6-4.9%) of women who reported being pregnant (n = 1794) also reported trying to lose weight. However, pregnant women who reported both drinking alcohol in the past month and currently smoking had the highest prevalence of attempted weight loss (12.7%), followed by women in their first trimester (9.4%), women with reported diabetes (9.0%) and women with very high BMIs (6.9%). After adjustment for survey design and other characteristics, women in their first trimester were four times more likely to attempt weight loss than those in the third trimester. CONCLUSION: These results suggest that weight loss attempts among women who report being pregnant are uncommon, but are more likely to occur in the first trimester and possibly among women who smoke and drink, have diabetes or are very overweight.

Alcohol Drinking↗
PubMed1995

Relation of weight variability and intentionality of weight loss to disease history and health-related variables in a population-based sample of women aged 55-69 years.

The authors examined the relation of recalled weight variability and history of intentional and unintentional weight loss with disease history in 41,837 older women. Lifetime history of disease, current medication use, health-related behaviors, body weight, and intentional and unintentional weight loss episodes of at least 20 lbs (9.1 kg) were assessed by means of two surveys, completed 6 years apart. Weight variability, as measured by the root mean square error around the linear regression line of weight on age at ages 18, 30, and 40 years, was positively related to disease history. Women who reported losing > or = 20 lbs (> or = 9.1 kg) unintentionally between the ages 18 and 39 years were more likely to report a history of disease than were women who had never lost > or = 20 lbs (> or = 9.1 kg) during this age period. Intentional weight loss episodes of > or = 20 lbs (> or = 9.1 kg) between ages 18 and 39 years were also associated with higher cumulative disease prevalence. These results suggest that both unintentional and, to a lesser degree, intentional weight loss may contribute to the observed positive relation between weight loss or variability and disease. Prospective studies are needed to confirm whether weight variability is a risk factor for disease only when unintentional, or whether intentional weight loss also increases risk.

Aged↗
PubMed1995

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↗