Effects of individual and combined dietary weight loss and exercise interventions in postmenopausal women on adiponectin and leptin levels.

BACKGROUND: Excess body weight and a sedentary lifestyle are associated with the development of several diseases, including cardiovascular disease, diabetes and cancer in women. One proposed mechanism linking obesity to chronic diseases is an alteration in adipose-derived adiponectin and leptin levels. We investigated the effects of 12-month reduced calorie, weight loss and exercise interventions on adiponectin and leptin concentrations. METHODS: Overweight/obese postmenopausal women (n = 439) were randomized as follows: (i) a reduced calorie, weight-loss diet (diet; N = 118), (ii) moderate-to-vigorous intensity aerobic exercise (exercise; N = 117), (iii) a combination of a reduced calorie, weight-loss diet and moderate-to-vigorous intensity aerobic exercise (diet + exercise; N = 117), and (iv) control (N = 87). The reduced calorie diet had a 10% weight-loss goal. The exercise intervention consisted of 45 min of moderate-to-vigorous aerobic activity 5 days per week. Adiponectin and leptin levels were measured at baseline and after 12 months of intervention using a radioimmunoassay. RESULTS: Adiponectin increased by 9.5% in the diet group and 6.6% in the diet + exercise group (both P ≤ 0.0001 vs. control). Compared with controls, leptin decreased with all interventions (diet + exercise, -40.1%, P < 0.0001; diet, -27.1%, P < 0.0001; exercise, -12.7%, P = 0.005). The results were not influenced by the baseline body mass index (BMI). The degree of weight loss was inversely associated with concentrations of adiponectin (diet, P-trend = 0.0002; diet + exercise, P-trend = 0.0005) and directly associated with leptin (diet, P-trend < 0.0001; diet + exercise, P-trend < 0.0001). CONCLUSION: Weight loss through diet or diet + exercise increased adiponectin concentrations. Leptin concentrations decreased in all of the intervention groups, but the greatest reduction occurred with diet + exercise. Weight loss and exercise exerted some beneficial effects on chronic diseases via effects on adiponectin and leptin.

The neurocognitive connection between physical activity and eating behaviour.

As obesity rates increase worldwide, healthcare providers require methods to instill the lifestyle behaviours necessary for sustainable weight loss. Designing effective weight-loss interventions requires an understanding of how these behaviours are elicited, how they relate to each other and whether they are supported by common neurocognitive mechanisms. This may provide valuable insights to optimize existing interventions and develop novel approaches to weight control. Researchers have begun to investigate the neurocognitive underpinnings of eating behaviour and the impact of physical activity on cognition and the brain. This review attempts to bring these somewhat disparate, yet interrelated lines of literature together in order to examine a hypothesis that eating behaviour and physical activity share a common neurocognitive link. The link pertains to executive functions, which rely on brain circuits located in the prefrontal cortex. These advanced cognitive processes are of limited capacity and undergo relentless strain in the current obesogenic environment. The increased demand on these neurocognitive resources as well as their overuse and/or impairment may facilitate impulses to over-eat, contributing to weight gain and obesity. This impulsive eating drive may be counteracted by physical activity due to its enhancement of neurocognitive resources for executive functions and goal-oriented behaviour. By enhancing the resources that facilitate 'top-down' inhibitory control, increased physical activity may help compensate and suppress the hedonic drive to over-eat. Understanding how physical activity and eating behaviours interact on a neurocognitive level may help to maintain a healthy lifestyle in an obesogenic environment.

Day/night variations of high-molecular-weight adiponectin and lipocalin-2 in healthy men studied under fed and fasted conditions.

AIMS/HYPOTHESIS: Adiponectin and lipocalin-2 are adipocyte-derived plasma proteins that have been proposed to have opposite effects on insulin sensitivity. Given the epidemiological, physiological and molecular links between sleep, the circadian timing system and glucose metabolism, the aim of this study was to assess effects of the sleep/wake cycle and the fasting/feeding cycle on high-molecular-weight adiponectin (HMW-adiponectin; the biologically active form) and lipocalin-2. We also aimed to compare the 24 h rhythms in the levels of these proteins with those of cortisol, leptin, leptin-binding protein and total adiponectin. METHODS: Lean men underwent a 3 day in-laboratory study, either in the fed state (n = 8, age: 20.9 ± 2.1 years, BMI: 22.8 ± 2.3 kg/m²) or fasting state (3 day fast, n = 4, age: 25.3 ± 3.9 years, BMI: 23.3 ± 2.2 kg/m²). The sleep episode was scheduled in darkness from 23:00 to 07:00 hours. Blood was sampled every 15 min for 24 h on the third day of each study. RESULTS: While fed, HMW-adiponectin and lipocalin-2 had large daily rhythms with troughs at night (HMW-adiponectin: ~04:00 hours, peak-to-trough amplitude 36%, p < 0.0001; lipocalin-2: ~04:00 hours, 40%, p < 0.0001). On the third day of fasting, the timing and relative amplitudes were unchanged (HMW-adiponectin: ~04:00 hours, 38%, p = 0.0014; lipocalin-2: ~05:00 hours, 38%, p = 0.0043). CONCLUSIONS/INTERPRETATION: These data show that HMW-adiponectin and lipocalin-2 both have significant day/night rhythms, both with troughs at night, that these are not driven by the feeding/fasting cycle, and that it is important to report and/or standardise the time of day for such assays. Further studies are required to determine whether the daily rhythm of HMW-adiponectin levels influences the daily rhythm of insulin sensitivity.

Psychometric characteristics of the General Well-Being Schedule (GWB) with African-American women.

The General Well-Being Schedule (GWB) is a brief, reliable, and valid instrument used in population studies to assess psychological well-being, although its validity with African-Americans has yet to be established. This study evaluated the reliability, validity, and factor structure of the GWB in a sample of 599 overweight African-American women who participated in multicenter weight loss trial. The results of the factor analysis indicate that the GWB is primarily unidimensional and that the existence of the six hypothesized subscales was not supported. The GWB demonstrated evidence of concurrent and construct validity when examined in association with measures of self-concept, depression, and several health behaviors. The results of this study suggest that the GWB is a reliable and valid measure of psychological well-being in African-American women.

Treatment approaches: food first for weight management and health.

Many genetic, environmental, behavioral, and cultural factors affect health. Diet is as vital as any of them for preventing disease and promoting well-being. We know that what we eat can lead to premature disability and mortality: to obesity, coronary heart disease, type 2 diabetes, degenerative arthritis, sleep apnea, and other illnesses. Now scientific evidence points to links between dietary patterns and illness. The study of these links is a new approach to understanding the role that diet plays in chronic disease. Initial studies include those on eating patterns and risk of colon cancer. More recently, researchers have investigated all-cause mortality and leading causes of chronic disease. Novel epidemiological approaches include factorial analysis to evaluate dietary patterns and cluster analysis to examine nutrient intake, gender, and weight status across food-pattern clusters. These methods work best within groups to identify major dietary patterns, but not necessarily ideal diets. They may also differ across population groups. The success of the Dietary Approaches to Stop Hypertension and Lyon Diet Heart studies supports the value of dietary pattern analysis. At the same time, the relative failure of single-nutrient studies underscores the need for new methodologies and directions in research.

Physician's guide to popular low-carbohydrate weight-loss diets.

Low-carbohydrate weight-loss diets are very popular, but the recommendations of many of these diets are diametrically opposed to those put forth by the US Department of Agriculture, the American Heart Association, and other national organizations. Their focus on foods high in protein, fat, and cholesterol has potentially serious health implications. Physicians need to be knowledgeable about the efficacy of these programs and to talk to overweight patients about weight loss.

Low risk of significant echocardiographic valvulopathy in patients treated with anorectic drugs.

BACKGROUND: Phentermine--fenfluramine and dexfenfluramine use for weight loss has been previously associated with increased prevalence of valvular heart disease. This association was initially based on small numbers of patients, limited data on dose and duration of drug therapy, and no correlation with matched controls. METHODS: Our investigation involved 343 obese subjects enrolled in a prospective, strict weight loss, research protocol from September 1994 to September 1997. All subjects underwent transthoracic echocardiography for significant valvular lesions within a mean of 121 days from the manufacturer's announcement of the voluntary withdrawal of fenfluramine and dexfenfluramine from the market. All echocardiograms were interpreted by 2 independent readers. RESULTS: The study population included 281 females and 62 males with a mean age of 46.7+/-9.1 years and mean initial body mass index of 40.1+/-8.1 kg/m(2). Using the Food and Drug Administration's criteria, only 21 subjects (6.1%) had significant valvular lesions. Aortic regurgitation was detected in 18 subjects, mitral regurgitation in 3 subjects, and both aortic and mitral regurgitation in 1 subject; no one had severe regurgitation. Significant valvular disease did not correlate with age, gender, initial/ending body mass index, the drug dose, duration of drug therapy, or serotonin reuptake inhibitors. CONCLUSIONS: Anorexigen therapy is associated with a low prevalence of significant valvular regurgitation. Late valvular abnormalities from drug treatment await long term prospective studies.

Current status of medical and surgical therapy for obesity.

The incidence of obesity (especially childhood obesity) and its associated health-related problems have reached epidemic proportions in the United States. Recent investigations suggest that the causes of obesity involve a complex interplay of genetic, environmental, psychobehavioral, endocrine, metabolic, cultural, and socioeconomic factors. Several genes and their protein products, such as leptin, may be particularly important in appetite and metabolic control, although the genetics of human obesity appear to involve multiple genes and metabolic pathways that require further elucidation. Severe obesity is frequently associated with significant comorbid medical conditions, including coronary artery disease, hypertension, type II diabetes mellitus, gallstones, nonalcoholic steatohepatitis, pulmonary hypertension, and sleep apnea. Long-term reduction of significant excess weight in these patients may improve or resolve many of these obesity-related health problems, although convincing evidence of long-term benefit is lacking. Available treatments of obesity range from diet, exercise, behavioral modification, and pharmacotherapy to surgery, with varying risks and efficacy. Nonsurgical modalities, although less invasive, achieve only relatively short-term and limited weight loss in most patients. Currently, surgical therapy is the most effective modality in terms of extent and duration of weight reduction in selected patients with acceptable operative risks. The most widely performed surgical procedure, Roux-en-Y gastric bypass, achieves permanent (followed up for more than 14 years) and significant weight loss (more than 50% of excess body weight) in more than 90% of patients.

Obesity prevalence by age group and 5-year changes in adults residing in rural Wisconsin.

OBJECTIVE: To estimate the prevalence of overweight and obesity and weight changes over a 5-year period in a rural adult population by age group. SUBJECTS: Residents of Marinette County, Wis: 613 women and 352 men. METHODS: Age, body weight, and height data were collected during October and December 1997 in a volunteer convenience sample of white men and women (aged 20 to 74 years). Age groups in 10-year increments were defined by age in 1992. Weights obtained from medical and employment records from 1992 by medical personnel, as well as self-reported weights, were recorded for 1992 to assess weight changes from 1992 to 1997. RESULTS: In 1992 women and men had mean body weights of 72.1 and 88.4 kg, respectively. By 1997, the average weight for women in the same data set was 79.3 and that for men was 96.4 kg, a gain of 7.3 and 7.9 kg, respectively. For both women and men, those in the youngest age group (age 20 to 30 years) experienced the greatest 5-year increase in body weight: 11.0 and 12.1 kg, respectively; the next largest increase occurred in the second youngest group (age 30 to 40 years). The majority of the normal-weight subjects (58%, 229 of 393) moved into an overweight or obese category, the overweight and obese generally gained weight, and only 20 of 572 overweight or obese individuals moved from an unhealthful to a healthful body weight during the 5 years. APPLICATIONS/CONCLUSIONS: The data indicate a need for community-wide weight-gain prevention programs for young adult men and women in rural areas. Weight-reduction treatment programs should be geared toward older adults, as most have already attained an unhealthful weight, which is likely to increase.

Weight gain and antipsychotic medication.

Antipsychotic-treated patients, who tend to take combinations of psychotropic agents that may cause weight gain, are at special risk for the problems associated with being overweight or obese. Medical and psychiatric examinations should include periodic monitoring for weight change and an obesity assessment for weight-related medical illness. The assessment should involve evaluation of body mass index and waist circumference as well as medical history. Preventative strategies should be undertaken for patients who gain 5 lb (2.3 kg) or more within a 3-year period. A change in antipsychotics may be necessary for overweight patients who are unwilling or unable to lose weight. A treatment plan for overweight or obese patients should include periodic monitoring and recommendations for changes in diet and physical activity. Support groups and adjunct medication may also be helpful. The patient should be reminded of the benefits of even modest weight loss.

Nonpharmacologic and pharmacologic management of weight gain.

Obesity increases the risk of several serious health problems, including heart disease, type II diabetes mellitus, hypertension, and osteoarthritis. Patients taking certain psychotropic medications may gain a significant amount of weight (as much as a 5% increase in body weight within 1 to 2 months), placing them at risk for obesity. Body weight monitoring and prudent drug selection are the best approaches to preventing weight gain in patients taking psychotropic drugs. When weight gain (> 5% of initial body weight) is unavoidable, intervention counseling should begin. Nonpharmacologic measures for managing weight gain include a balanced deficit diet of 1000 calories and higher, depending on the patient's weight; 30 to 60 minutes of physical activity daily; and behavioral training to restrain excess caloric intake. Each of these measures requires a considerable commitment on the part of the patient and works best with support from the physician and weight-loss support groups. Drug therapy for weight loss is available (at present, sibutramine is the only approved appetite suppressant in the United States); however, for most patients already being treated with a psychotropic agent, the risks (such as drug interactions, adverse events, compliance problems) of adding an antiobesity agent probably outweigh the benefits. Surgical intervention for obesity should be reserved for morbidly obese patients whose disease is intractable to medical therapy.

Low prevalence of valvular heart disease in 226 phentermine-fenfluramine protocol subjects prospectively followed for up to 30 months.

OBJECTIVES: This investigation sought to determine the effect of phentermine-fenfluramine (phen-fen) on the prevalence of valvular heart disease in 226 obese subjects enrolled in a prospective, strict weight loss, research protocol. BACKGROUND: Early reports have suggested that the use of phen-fen for weight loss may be associated with increased valvular heart disease. Such reports were based on small numbers of patients, limited data on dose and duration of phen-fen therapy, and no correlation with matched controls. METHODS: All subjects underwent transthoracic echocardiography for significant valvular lesions within a mean of 97 days from the manufacturer's announcement of the voluntary withdrawal of fenfluramine and dexfenfluramine. All echocardiograms were interpreted by two independent readers. RESULTS: The study population included 183 women and 43 men with a mean age of 46.9 +/- 8.9 years and mean starting body mass index of 39.8 +/- 7.7 kg/m2. Using the Food and Drug Administration criteria, significant aortic regurgitation was detected in 15 subjects (6.6%) and mitral regurgitation in 3 subjects (1.3%). Only one patient had significant regurgitation of both aortic and mitral valves. No valves had severe regurgitation. Significant valvular disease did not correlate with the dose or duration of phen-fen therapy. Furthermore, the prevalence of valvular regurgitation is comparable to the normal offspring in the Framingham Heart Study, who are similar in age, gender, and geographical location. CONCLUSIONS: Phen-fen therapy is associated with a low prevalence of significant valvular regurgitation. Valvular regurgitation in our subjects may reflect age-related degenerative changes.