Search PubMed⌕ Search

Biomedical subjects

K R Fontaine

Publications and source records attributed to K R Fontaine.

At least 19 recordsLinked to original sources
PubMed2006

Putative contributors to the secular increase in obesity: exploring the roads less traveled.

OBJECTIVE: To investigate plausible contributors to the obesity epidemic beyond the two most commonly suggested factors, reduced physical activity and food marketing practices. DESIGN: A narrative review of data and published materials that provide evidence of the role of additional putative factors in contributing to the increasing prevalence of obesity. DATA: Information was drawn from ecological and epidemiological studies of humans, animal studies and studies addressing physiological mechanisms, when available. RESULTS: For at least 10 putative additional explanations for the increased prevalence of obesity over the recent decades, we found supportive (although not conclusive) evidence that in many cases is as compelling as the evidence for more commonly discussed putative explanations. CONCLUSION: Undue attention has been devoted to reduced physical activity and food marketing practices as postulated causes for increases in the prevalence of obesity, leading to neglect of other plausible mechanisms and well-intentioned, but potentially ill-founded proposals for reducing obesity rates.

Age Factors↗
PubMed2006

Depressive mood and obesity in US adults: comparison and moderation by sex, age, and race.

OBJECTIVE: Sustained depressive mood is a gateway symptom for a major depressive disorder. This paper investigated whether the association between depressive mood and obesity differs as function of sex, age, and race in US adults after controlling for socio-economic variables of martial status, employment status, income level and education level. METHODS: A total of 44,800 nationally representative respondents from the 2001 Behavioral Risk Factor Surveillance Survey were studied. Respondents were classified as having experienced a depressive mood if they felt sad, blue, or depressed at least for 1 week in the previous month. The depressive mood was operationalized in terms of duration and sustenance, both defined based on number of days with depressive mood: 7+ and 14+ days. Age groups were classified as young (18-64 years) and old (65+ years). Obesity status was classified as: not overweight/obese (BMI<25); overweight (25 or=30). RESULTS: Prevalence of prior-month depressive mood was 14.3 and 7.8% for 7+ and 14+ days, respectively. Controlling for race and socio-economic variables, both young overweight and obese women were significantly more likely to have experienced depressive mood than nonoverweight/nonobese women. Young overweight, but not obese, men were significantly more likely to have experienced depressive mood than nonoverweight/nonobese men. Young obese women were also significantly more likely to have a sustained depressive mood than nonoverweight/nonobese women. For old respondents, depressive mood and its sustenance were not associated with obesity in either sex. DISCUSSION: The relationship between the depressive mood and obesity is dependent upon gender, age, and race. Young obese women, Hispanics in particular, are much more prone to depressive mood than nonobese women. Future studies testing associations between depression and obesity should be sensitive to the influence of these demographic and socio-economic variables.

Adolescent↗
PubMed2006

Citrus aurantium and synephrine alkaloids in the treatment of overweight and obesity: an update.

Obesity is a major health problem facing the developed and developing world. Efforts by individuals, health professionals, educators, and policy makers to combat the escalating trend of growing obesity prevalence have been multifaceted and mixed in outcome. Various dietary supplements have been marketed to reduce obesity. These products have been suggested to accomplish this by decreasing energy intake and energy absorption, and/or increasing metabolic rate. Ephedra, one such supplement, was banned from sale in the US market because of concerns about adverse events. Another substance, Citrus aurantium, which contains several compounds including synephrine alkaloids, has been suggested as a safe alternative. This review examines the evidence for safety and efficacy of C. aurantium and synephrine alkaloids as examined in animal studies, clinical weight loss trials, acute physiologic studies and case reports. Although at least three reviews of C. aurantium have been published, our review expands upon these by: (i) distinguishing and evaluating the efficacy of C. aurantium and related compounds; (ii) including results from previously unreviewed research; (iii) incorporating recent case reports that serve to highlight, in an anecdotal way, potential adverse events related to the use of C. aurantium and related compounds; and (iv) offering recommendations to guide the design of future trials to evaluate the safety and efficacy of C. aurantium. While some evidence is promising, we conclude that larger and more rigorous clinical trials are necessary to draw adequate conclusions regarding the safety and efficacy of C. aurantium and synephrine alkaloids for promoting weight loss.

Alkaloids↗
PubMed2005

Obesity and prostate cancer screening in the USA.

OBJECTIVE: To estimate the association between body mass index (BMI: kg/m2) and prostate-specific antigen (PSA) cancer screening in a nationally representative sample of US men aged 50 years and older using data from the 2001 Behavioral Risk Factor Surveillance Survey. RESPONDENTS: Men aged 50 years or older classified by BMI as healthy weight range (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: Interval since most recent screening for PSA. RESULTS: Adjusting for age, race, smoking, education, employment, income and health insurance status, we found that, compared with men in the healthy weight range, men in the overweight [odds ratio (OR)=1.13; 95% confidence interval (95% CI)=1.04-1.35], obese class I (OR=1.26; 95% CI=1.06-1.36) and obese class II (OR=1.14, 95% CI=1.02-1.26) categories were significantly more likely to have obtained a PSA test within the previous year. A similar pattern was observed when we examined other screening intervals (e.g. within past 2 years, within past 3 years, etc.). CONCLUSIONS: Among men aged 50 years and older, overweight and obesity is associated with obtaining a PSA test.

Body Mass Index↗
PubMed2003

A novel soy-based meal replacement formula for weight loss among obese individuals: a randomized controlled clinical trial.

OBJECTIVE: To assess the efficacy and safety of a low calorie soy-based meal replacement program for the treatment of obesity. DESIGN: A 12-week prospective randomized controlled clinical trial. SETTING: Outpatient weight control research unit. SUBJECTS: One hundred obese (28<BMI<or=41 kg/m(2)) volunteers between the ages of 35 and 65 y. Seventy-four participants completed the trial. INTERVENTION: Participants were randomized to either the meal replacement treatment group (n=50; 240 g/day, 1200 kcal/day) or control group (n=50). Both groups at baseline received a single dietary counseling session and a pamphlet describing weight loss practices. MAIN OUTCOME MEASURES: Weight, body fat, serum lipid concentrations. RESULTS: : By intent-to-treat analysis, the treatment group lost significantly more weight than the control group (7.00 vs 2.90 kg; P<0.001) and had a greater change in total (22.5 vs 6.8 mg/dl; P=0.013) and LDL cholesterol (21.2 vs 7.1 mg/dl; P<0.009). Among completers only, the treatment group again lost more weight (7.1 kg; n=37 vs 2.9 kg; n=37; P=0.0001) and had a greater reduction in total cholesterol (26.1 mg/dl; n=37 vs 6.7 mg/dl; P=0.0012) and a greater change in LDL cholesterol (21.6 vs 5.5 mg/dl; P=0.0025). (For any given degree of weight loss, the reduction in LDL cholesterol was significantly greater in the treatment group.) Treatment was well tolerated and no serious side effects were detected. CONCLUSIONS: Use of this soy-based meal replacement formula was effective in lowering body weight, fat mass and in reducing LDL cholesterol beyond what could be expected given the weight lost.

Adult↗
PubMed2003

Weight loss causes increased mortality: cons.

Short-term studies indicate that intentional weight loss (IWL) among obese persons significantly improves health variables that are often precursors or markers of chronic diseases (e.g. heart diseases, type-2 diabetes). Hence, it is logical to assume that IWL among obese persons would lead to increased longevity. On the whole, epidemiological studies, including recent ones that use conservative analytic approaches such as distinguishing between apparently IWL and unintentional weight loss (UWL), adjusting for potential confounders and excluding apparently unhealthy subjects, indicate that apparently IWL appears to neither increase nor decrease mortality rate. However, it is important to note that none of the existing studies were designed specifically to test the hypothesis that IWL reduces mortality rate, and given methodological problems, these studies do not provide a satisfactory way to address the body mass index (BMI)-mortality question. Several controlled clinical trials suggest that IWL may reduce mortality rate. However, even in these studies, it is important to acknowledge that subjects are randomized to conditions that produce more or less weight loss and not to distinct levels of weight loss per se. Nevertheless, while we await additional data from better designed studies, given our incomplete knowledge, we conclude that it seems more likely than not that IWL achieved by medically recommended methods does not increase and probably decreases mortality rate.

Animals↗
PubMed2002

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↗
PubMed2001

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↗
PubMed2001

Does intentional weight loss affect mortality rate?

Short-term studies indicate that intentional weight loss among obese persons significantly improves physiologic variables. Hence, it is logical to conjecture that intentional weight loss would lead to long-term benefits and increased longevity. Herein, we review recent epidemiologic studies that investigate the weight loss-mortality association using a conservative analytic approach that included distinguishing between intentional and unintentional weight loss, adjusting for potential confounders, and excluding unhealthy subjects. On balance, results indicate that intentional weight loss appears to neither increase nor decrease mortality rate. Discussion focuses on the problems of addressing this important public health question with observational data.

Journal Article↗
PubMed2001

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↗
PubMed2001

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↗
PubMed2001

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↗
PubMed2001

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↗
PubMed2001

Weight loss and exercise walking reduce pain and improve physical functioning in overweight postmenopausal women with knee osteoarthritis.

We conducted an uncontrolled pilot study to determine the effects of a weight loss and walking program on knee pain and physical function in overweight and obese (body mass index; BMI [kg/m] 25-29.9 and BMI > or = 30, respectively) postmenopausal women with knee osteoarthritis (OA). Forty-eight such women completed self-report (Western Ontario and McMaster University Osteoarthritis Index (WOMAC)) and performance-based measures of physical function ("up and go" test, 6-min walk) and enrolled in a 6-month intervention that included weekly nutrition classes and an exercise-walking program. The intervention produced an average weight loss of 5.6 +/- 4.0 kg in the 30 women who completed the program. There also were significant improvements in the 6-min walk and on VO(2max). Improvements in the timed up and go test and on the WOMAC pain and function scores, however, were restricted only to women who were classified as obese at baseline. These findings suggest that a 6-month weight loss and walking program improves measures of physical functioning and pain in overweight and obese postmenopausal women with knee OA. Among obese women, functional improvement correlated with weight loss, encouraging continued emphasis on weight loss for managing knee OA.

Journal Article↗
PubMed2000

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↗
PubMed2000

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↗