PubMed Health⌕ Search

Biomedical subjects

K R Fontaine

Publications and source records attributed to K R Fontaine.

At least 19 recordsLinked to original sources

A meta-analytic investigation of linkage and association of common leptin receptor (LEPR) polymorphisms with body mass index and waist circumference.

METHODS: We analyzed data pooled from nine studies on the human leptin receptor (LEPR) gene for the association of three alleles (K109R, Q223R and K656N) of LEPR with body mass index (BMI; kg/m(2)) and waist circumference (WC). A total of 3263 related and unrelated subjects from diverse ethnic backgrounds including African-American, Caucasian, Danish, Finnish, French Canadian and Nigerian were studied. We tested effects of individual alleles, joint effects of alleles at multiple loci, epistatic effects among alleles at different loci, effect modification by age, sex, diabetes and ethnicity, and pleiotropic genotype effects on BMI and WC. RESULTS: We found that none of the effects were significant at the 0.05 level. Heterogeneity tests showed that the variations of the non-significant effects are within the range of sampling variation. CONCLUSIONS: We conclude that, although certain genotypic effects could be population-specific, there was no statistically compelling evidence that any of the three LEPR alleles is associated with BMI or WC in the overall population.

Alleles↗

Estimating the consequences of anti-psychotic induced weight gain on health and mortality rate.

Many anti-psychotic medications produce marked weight gain. In this study, we estimate the expected impact of degrees of antipsychotic-induced weight gain on selected mortality rate and incidence rates of impaired glucose tolerance (IGT) and hypertension (HTN) among US adults. Using raw data from 5209 respondents from the Framingham Heart Study's public use data set and national statistics on population demographics, we estimated the expected effect of weight gain on number of deaths and incident cases of IGT and HTN for a 10-year period commencing in 1999. Results indicated that the estimated deleterious effects of weight gain were greater for people with higher BMIs at baseline, for greater degrees of weight gain, for men than women, and for older than younger persons. Because there is a 'U-shaped' relation between BMI and mortality rate, small to moderate weight gains among people with baseline BMIs less than 23 were predicted to decrease mortality rates, whereas weight gains among people with baseline BMIs above that level were expected to increase mortality rates. However, the relations of IGT and HTN with BMI are monotonically increasing. Thus, the anticipated effect of weight gain on IGT and HTN is deleterious regardless of baseline BMI. Because it is unclear whether the beneficial effects of the atypical agents on, for example, reducing suicide mortality, outweigh the putative increase in mortality due to weight gain, we estimate the beneficial effects due to decreased death from suicide with the potential deleterious effects due to a 10-kg weight gain. We found that 492 suicide deaths per 100,000 schizophrenic patients would be prevented over 10 years with the use of clozapine compared to 416 additional deaths due to antipsychotic induced weight gain. Although this estimate is rather crude and should be seen only as offering a sense of the likely situation, results suggest that the lives saved via clozapine may essentially be offset by the deaths due to weight gain. As we discuss, it is not possible to provide definitive estimates of the effect of antipsychotic-induced weight gain on health and mortality, but our findings suggest that the magnitude of weight gains induced by many antipsychotic agents is likely to have important deleterious effects on mortality and health.

Antipsychotic Agents↗

Obesity and health-related quality of life.

Although it is well documented that obesity is strongly associated with morbidity and mortality, less is known about the impact of obesity on functional status and health-related quality of life (HRQL). However, in recent years research has been conducted to estimate the impact of obesity on HRQL, and to determine the effects of weight reduction on HRQL. The majority of published studies indicate that obesity impairs HRQL, and that higher degrees of obesity are associated with greater impairment. Obesity-associated decrements on HRQL tend to be most pronounced on physical domains of functioning. Studies of the effect of obesity surgery among morbidly obese patients indicate that this procedure produces significant and sustained improvements in the majority of HRQL indices; among mild-to-moderately obese persons, modest weight reduction derived from lifestyle modification also appears to improve HRQL, at least in the short term. Additional research is needed to (1) further characterize the effect that obesity has on HRQL; (2) estimate the short- and long-term effects of various methods of weight reduction (e.g. surgery, lifestyle modification) on HRQL; (3) improve both the conceptualization and measurement of HRQL to incorporate the personal preferences and values of the patient; and (4) develop ways to enhance and sustain positive changes in HRQL, even if weight maintenance is elusive.

Health Status↗

Metabolic disharmony and mortality.

The concept of 'metabolic harmony' is introduced and conceptualized as the state in which indices of metabolic activity (i.e., serum glucose, cholesterol, systolic and diastolic blood pressure, body mass index) within an individual attain their expected values given the individual values on related variables. Its complement, 'metabolic disharmony' (i.e., the extent to which an individual's 'profile' of metabolic variables is jointly unusual in relation to their expected values) is operationalized via Mahalanbis' D(2 )statistic calculated on these indices of metabolic activity (plus age and sex). Analysis of a large (N = 5209) longitudinal (32 years) cohort study shows that, independent of the linear and quadratic effects of the aforementioned metabolic variables, the disharmony index (DI) significantly and strongly predicted hazard of death (chi(2)(1) = 20.05, P < 0.00005). That is, each 10 percentile increase in DI was associated with a 6.9% increase in the hazard rate. The association of DI to hazard rate was not materially altered when potential confounders (e.g., smoking status) were added to the model or when all subjects were included by imputing missing data. These results demonstrate that metabolic disharmony is associated with, and may cause, an increased hazard of death.

Death↗

Alternative treatments for weight loss: a critical review.

"Nontraditional" or "alternative" treatments are extremely popular, especially with respect to obesity and body composition. Although such treatments are widely used, it is not clear that these are supported by the existing data in the peer-reviewed literature. Herein, we review the data on 18 methods/products advocated as potential anti-obesity/fat-reducing agents. We have found that none have been convincingly demonstrated to be safe and effective in two or more peer-reviewed publications of randomized double-blind placebo-controlled trials conducted by at least two independent laboratories. Nevertheless, some have plausible mechanisms of action and encouraging preliminary data that are sufficiently provocative to merit further research.

Anti-Obesity Agents↗

Body weight and cancer screening among women.

Obesity increases cancer risk, yet small-scale surveys indicate that obese women delay or avoid cancer screening even more so than do nonobese women. We sought to estimate the association between body mass index (BMI) (kg/m(2)) and delayed cancer screening among adult women in a population-based survey. Subjects were women classified by BMI as underweight (<18.5), desirable weight (18.5-24.9), overweight (25-29.9), obese class I (30-34.9), obese class II (35-39.9), and obese class III (> or =40). Outcome measures were intervals (0 for < or =2 years versus 1 for >2 years) since most recent screening for Papanicolaou (Pap) smear, mammography, and clinical breast examination (CBE). Adjusting for age, race, smoking, and health insurance, we observed J-shaped associations between BMI and screening. Compared with desirable weight women, underweight women (odds ratios [OR] = 1.21, 95% confidence interval [95% CI] 1.09-1.34), overweight women (OR = 1.13, 95% CI 1.07-1.18), and obese women (OR range 1.22-1.69) were significantly more likely to delay Pap smear testing for >2 years. Underweight (OR = 1.32, 95% CI 1.13-1.54), obesity class I (OR = 1.12, 95% CI 1.02-1.23), and obesity class III women (OR = 1.32, 95% CI 1.10-1.54) were more likely to delay mammography, and overweight (OR = 1.10, 95% CI 1.01-1.19), obesity class I (OR = 1.18, 95% CI 1.08-1.30), and obesity class III women (OR = 1.47, 95% CI 1.23-1.75) were more likely to delay CBE. White women were more likely to delay CBE as a function of BMI than were non-white women. Weight may be an important correlate of cancer screening behavior, particularly for white women.

Adult↗

Health-related quality of life among obese persons seeking and not currently seeking treatment.

OBJECTIVE: To compare sociodemographic characteristics and health-related quality of life (HRQL) between groups of obese persons who sought and did not seek university-based treatment for overweight. METHOD: Three-hundred twelve consecutive obese persons sought outpatient university-based weight management treatment. The sample of obese persons (N = 89) who indicated that they were not currently trying to lose weight was derived from a larger convenience sample (N = 232) of persons surveyed in a hospital setting. Both groups completed sociodemographic and brief medical history questionnaires and the HRQL as measured by the Medical Outcomes Study Short-Form-36 Health Survey (SF-36). RESULTS: Obese persons who had sought treatment tended to be heavier, older, Caucasian, married, in white collar employment, and reported a higher prevalence of diabetes, hypertension, and pain. In multivariate analyses, both adjusted and unadjusted for these differences, obese persons who had sought treatment were significantly more impaired on the bodily pain, general health, and vitality HRQL domains than those who were not trying to lose weight. DISCUSSION: Although differences on sociodemographic and medical variables between the two groups may attenuate the obesity-HRQL relationship somewhat, obesity appears to have a pronounced impact on important dimensions of HRQL independent of whether or not the person is attempting to lose weight

Adult↗

Access and use of medical care among obese persons.

The prevalence of obesity and severe obesity is growing rapidly, along with obesity-related comorbidities and mortality. Given the increased health risks associated with obesity, it is vital that obese persons have adequate access to, and make consistent use of, medical care services. Assuming obese persons have access to medical care that is comparable to non-obese persons, one would expect to observe greater use of medical services among obese persons. In this article we briefly review empirical evidence of the access to and use of medical care among obese persons. Although certain subgroups that tend to have disproportionately high prevalences of obesity (i.e., low socioeconomic status, minority groups) have reduced access to care, no studies have specifically examined whether or not obese persons have the same access to health care as do their lean counterparts. With respect to use of health care services, however, obesity has been consistently linked with greater rates of utilization and increased health care expenditures. Both the increased use and cost appear to be largely a function of treating obesity-associated comorbidities such as diabetes and hypertension. We conclude that, although it is clear that obesity is associated with both greater use and cost of medical care, the relationship between obesity and access to medical care has not been determined.

Health Services Accessibility↗

Behavioral approaches to the problems of obesity.

Obesity is a complex and increasingly prevalent disorder that can confer a number of medical, social, and psychological difficulties. As a result, an array of treatment strategies falling under the generic umbrella of "behavior therapy" have been developed and continue to be refined and expanded. In this article, different behavioral approaches to the problems of obesity are outlined and reviewed, specifically, those that target (a) body weight or composition, (b) lifestyle factors and other health-related variables, and (c) related psychological variables such as self-esteem and assertiveness, as well as negative attitudes toward obese persons held by nonobese individuals. For each of these targets of change, approaches to both individual- and group-level interventions are considered. Suggestions for future research and clinical work are offered. Throughout, the importance of conceptualizing obesity as a multifaceted problem is underscored. The necessity for explicit target goals when attempting to modify behavior is also highlighted.

Behavior Therapy↗

Annual deaths attributable to obesity in the United States.

CONTEXT: Obesity is a major health problem in the United States, but the number of obesity-attributable deaths has not been rigorously estimated. OBJECTIVE: To estimate the number of deaths, annually, attributable to obesity among US adults. DESIGN: Data from 5 prospective cohort studies (the Alameda Community Health Study, the Framingham Heart Study, the Tecumseh Community Health Study, the American Cancer Society Cancer Prevention Study I, and the National Health and Nutrition Examination Survey I Epidemiologic Follow-up Study) and 1 published study (the Nurses' Health Study) in conjunction with 1991 national statistics on body mass index distributions, population size, and overall deaths. SUBJECTS: Adults, 18 years or older in 1991, classified by body mass index (kg/m2) as overweight (25-30), obese (30-35), and severely obese (>35). MAIN OUTCOME MEASURE: Relative hazard ratio (HR) of death for obese or overweight persons. RESULTS: The estimated number of annual deaths attributable to obesity varied with the cohort used to calculate the HRs, but findings were consistent overall. More than 80% of the estimated obesity-attributable deaths occurred among individuals with a body mass index of more than 30 kg/m2. When HRs were estimated for all eligible subjects from all 6 studies, the mean estimate of deaths attributable to obesity in the United States was 280184 (range, 236111-341153). Hazard ratios also were calculated from data for nonsmokers or never-smokers only. When these HRs were applied to the entire population (assuming the HR applied to all individuals), the mean estimate for obesity-attributable death was 324 940 (range, 262541-383410). CONCLUSIONS: The estimated number of annual deaths attributable to obesity among US adults is approximately 280000 based on HRs from all subjects and 325000 based on HRs from only nonsmokers and never-smokers.

Adult↗

Optimism and obesity treatment outcomes.

To examine the ability of the personality dimension dispositional optimism to predict short-term obesity treatment outcomes (weeks of program attendance and weight loss), 177 consecutive persons seeking outpatient treatment at a university-based weight management center completed the revised Life Orientation Test (LOT-R; Scheier, Carver, & Bridges, 1994) and underwent a comprehensive medically monitored weight loss program. The overall LOT-R and optimism subscales did not correlate with either attendance or weight loss. However, the pessimism subscale was positively associated with weeks of attendance.

Adolescent↗

Is the prevalence of successful weight loss and maintenance higher in the general community than the research clinic?

OBJECTIVE: The prevalence of successful weight loss remains unclear. In 1982, Schachter concluded that in the general population, the rate of "self-cured" obesity approached 63%-much higher than the rate from clinical trials. Several subsequent studies have addressed this issue. RESEARCH METHODS AND PROCEDURES: Our initial goal was to meta-analyze these studies to evaluate the validity of the original hypotheses and the extent to which additional investigations supported the findings. We began by restating Schachter's hypotheses in precise, testable terms. RESULTS: A systematic review of these studies found many methodological limitations and much heterogeneity among the samples studied, hypotheses addressed, and operational definitions. Some of these limitations appear to stem from the lack of clear, precise statements of the exact hypotheses tested. Differences among studies are delineated, and we outline why meta-analytic pooling of these data appears inappropriate. CONCLUSIONS: The current data are inadequate to draw any definite conclusions regarding the cure rate of obesity. Criteria for the adequate study of success rates with "self-cure" in the general population are proposed.

Female↗

Impact of weight loss on health-related quality of life.

To examine the effect of treatment-induced weight loss on Health-Related Quality of Life (HRQL), 38 mildly-to-moderately overweight persons recruited to participate in a study to examine the efficacy of a lifestyle modification treatment program completed a sociodemographic questionnaire, the Beck Depression Inventory (BDI), the Medical Outcomes Study Short-Form Health Survey (SF-36, as an assessment of HRQL), and underwent a series of clinical evaluations prior to treatment. After baseline evaluations, participants were randomly assigned to either a program of lifestyle physical activity or a program of traditional aerobic activity. Participants again completed the SF-36 and BDI after the 13-week treatment program had ended. Weight loss averaged 8.6 +/- 2.8 kg over the 13-week study. We found that weight loss was associated with significantly higher scores (enhanced HRQL), relative to baseline, on the physical functioning, role-physical, general health, vitality and mental health domains of the SF-36. The largest improvements were with respect to the vitality, general health perception and role-physical domains. There were no significant differences between the lifestyle and aerobic activity groups on any of the study measures. These data indicate that, at least in the short-term, weight loss appears to profoundly enhance HRQL.

Adult↗