Treatment of obesity: an overview

Effect of educational interventions on health in childhood: A meta-analysis of randomized controlled trials

BACKGROUND

The purpose of this study was to summarize the evidences from randomized controlled trials (RCTs) investigating the effects of educational interventions in overweight/obesity childhood by using meta-analytic approach.

METHODS

PubMed, Embase, and the Cochrane Library databases were searched from the inception to April 2018. Weighted mean differences (WMDs) with corresponding 95% confidence intervals (CIs) were used to measure the effects of educational interventions during childhood in the random-effects models.

RESULTS

Thirty RCTs reporting data on 35,296 children were included in the meta-analysis. The summary WMD indicated that children received educational interventions had lower levels of body mass index (BMI) (WMD: -0.15; 95% CI: -0.24 to -0.05; P = .003), BMI z-score (WMD: -0.03; 95% CI: -0.05 to -0.02; P < .001), waist circumference (WMD: -0.97; 95% CI: -1.95 to -0.00; P = 0.050), triceps skinfold (WMD: -1.39; 95% CI: -2.41 to -0.37; P = .008), systolic blood pressure (WMD: -1.13; 95% CI: -2.20 to -0.07; P = .037), total cholesterol (WMD: -4.04; 95% CI: -7.18 to -0.90; P = .012), and triglyceride (WMD: -2.62; 95% CI: -4.33 to -0.90; P = .003). However, educational interventions were not associated with the levels of waist-to-hip ratio, diastolic blood pressure, high-density lipoprotein, and low-density lipoprotein.

CONCLUSION

The study findings elucidate the positive effects of educational interventions on BMI, BMI z-score, waist circumference, triceps skinfold, systolic blood pressure, total cholesterol, and triglyceride.

Perirenal Fat and Association With Metabolic Risk Factors: The Uberlândia Heart Study

Perirenal fat (PRF) is associated with cardiovascular risk factors. Gender differences in the correlations of cardiovascular disease risk factors and PRF in the Brazilian population are lacking.Cross-sectional study with 101 (50.49% men; mean age 56.5 ± 18, range 19-74 years) drawn from the Uberlândia Heart Study underwent ultrasonography assessment of abdominal adipose. For the PRF, a 3.5 MHz transducer was measured in the middle third of the right kidney, with the transducer positioned at the axillary midline. The examinations were always performed by the same examiner. The PRF thickness was examined in relation to waist circumference, blood pressure, and metabolic risk factors. The PRF was significantly associated with the levels of gamma-glutamyl transferase (P < 0.05, r = 0.08), fasting plasma glucose (P < 0.05, r = 0.07), waist circumference (P < 0.05, r = 0.10), and metabolic syndrome (P < 0.001, r = 0.38) in men, and with the levels of fasting plasma glucose (P < 0.05) in women.The PRF was correlated with most cardiovascular risk factors in men and only in glucose at the women.

Correction of hypothyroidism seems to have no effect on body fat

Aim. We aimed to observe the effects of L-thyroxine replacement therapy on body fat content determined with various anthropometric methods and a bioelectrical impedance analysis method in patients with hypothyroidism. Methods. Forty-two women with naive autoimmune hypothyroidism were included. Also, 40 healthy participants were enrolled as a control group. Weight, body mass index, waist circumference, and subscapulary, suprailiac, femur, biceps, and triceps skin fold thicknesses were measured. Body fat percentages were calculated and body fat measurements were performed. Euthyroidism was maintained with L-thyroxine. At the 6th and 18th month, of therapy, measurements were reperformed. Results. Mean TSH levels were 57.49 ± 36.46 mIU/L in hypothyroid group and 1.94 ± 1.12 mIU/L in control subjects at admission. In hypothyroid patients, calculated body fat percentages were greater than those of the control subjects during follow-up. Body fat percentage of each hypothyroid case decreased at 6- and 18-month controls, but the decrements were statistically insignificant. Although skin fold thicknesses measured from all sites were observed to decline, only those obtained from femur and biceps showed a significant decrease (P = 0.03 and P = 0.01, resp.). Discussion. Correction of hypothyroidism did not cause any improvement in body weight and body fat percentage. The decrease in skin fold thicknesses might probably result from the reduction in subcutaneous mucopolysaccharide deposits.

Management of the metabolic syndrome and type 2 diabetes through lifestyle modification

Sustainable lifestyle modifications in diet and physical activity are the initial, and often the primary, component in the management of diabetes and the metabolic syndrome. An energy-prudent diet, coupled with moderate levels of physical activity, favorably affects several parameters of the metabolic syndrome and delays the onset of diabetic complications. Weight loss, albeit not an absolute prerequisite for improvement, is a major determinant and maximizes effectiveness. Adopting a healthy lifestyle pattern requires a series of long-term behavioral changes, but evidence to date indicates low long-term adherence to diet and physical activity recommendations. This calls for greater research and public health efforts focusing on strategies to facilitate behavior modification.

Predictors of the metabolic syndrome and correlation with computed axial tomography

OBJECTIVE

We investigated which anthropometric variables or imaging techniques, dual-energy x-ray absorptiometric densitometry (DXA) or bioelectric impedance analysis (BIA), are the most important determinants of the metabolic syndrome. We also evaluated the correlation between anthropometric parameters and DXA and computed axial tomography (CAT) in predicting visceral fat.

METHODS

In a series of 399 overweight or obese patients (29.8% male and 70.2% female), anthropometric variables and imaging techniques (DXA or BIA) were measured and correlated with each component of the metabolic syndrome (diagnosed according to the criteria of the Third Report of the Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults of the National Cholesterol Education Program [Adult Treatment Panel III], with the exception of waist circumference). In a subpopulation of 109 patients, CAT was used to assess visceral fat and its correlation with the anthropometric variables and DXA.

RESULTS

Applying receiver operating characteristic curves, the waist/height ratio was the best determinant of the metabolic syndrome (0.758, 95% confidence interval 0.634-0.882). The intra-abdominal diameter determined by DXA (r = 0.657, P < 0.001) and the waist/hip ratio (r = 0.603, P < 0.001) had the best correlation with visceral fat as measured by CAT.

CONCLUSION

The prediction of visceral fat in overweight and obese patients, as assessed by anthropometric tests and DXA, offers a good alternative to CAT, without significant differences between them.

A multicenter, randomized, double-blind, placebo-controlled, dose-finding trial of a long-acting formulation of octreotide in promoting weight loss in obese adults with insulin hypersecretion

OBJECTIVE

To compare changes in weight in obese patients who received long-acting octreotide (octreotide LAR) at one of three dose levels (20, 40, or 60 mg) or placebo over 6 months and to identify the lowest dose of octreotide LAR that safely achieved optimal weight loss.

DESIGN

Randomized, double-blind, placebo-controlled trial of octreotide LAR at three dose levels.

PATIENTS

A total of 172 adults (28 men and 144 women) with at least moderate obesity (body mass index (BMI) range 30-65 kg/m2) and evidence of insulin hypersecretion were enrolled. Patients were predominantly either Caucasian (50.0%) or African American (45.3%). The mean age (38 +/- 11 year), weight (110.7 +/- 23 kg), and BMI (39.8 +/- 6.5 kg/m2) were similar across the four treatment groups.

MEASUREMENTS

Efficacy measures included weight, BMI, fasting serum glucose; triglycerides; percentage of total body fat and abdominal fat as measured by dual-energy X-ray absorptiometry; skin fold thickness; waist-to-hip circumference; leptin; percentage of carbohydrates, fat, and protein ingested; nutritional evaluation (including dietary analysis--3-day food record); quality of life (QoL; using the Impact of Weight on Quality of Life-Lite); Beck Depression Inventory; and Carbohydrate Craving Questionnaire. Safety measures included medical history, vital signs, physical examinations, hematology, blood chemistries, thyroid function tests, hemoglobin A1c, gallbladder ultrasound, electrocardiograms, and adverse events.

RESULTS

After 6 months of treatment, patients receiving 40 or 60 mg of octreotide LAR experienced statistically significant weight loss compared to baseline, with mean differences from placebo in percent weight change of -1.98 and -1.87%, respectively. This finding was accompanied by statistically significant mean decreases in BMI compared to baseline, that is, a mean decrease of 0.73 and 0.79 kg/m2 for the 40 and 60 mg treatment arms, respectively. The observed weight loss was progressive during the 6-month treatment in the two higher dose groups. The lowest dose to reach statistical significance in weight loss after 6 months' treatment was 40 mg. Post hoc analysis revealed a 3.5-3.8% weight loss at month 6 in the two higher dose groups among Caucasian patients having insulin secretion greater than the median of the cohort, defined as CIR(gp) (corrected insulin response at the glucose peak) > or = 1.43. There were no statistically significant changes in QoL scores, body fat, leptin concentration, Beck Depression Inventory, or macronutrient intake. Mean changes of blood glucose AUC(0-180 min) during an oral glucose tolerance test in patients taking octreotide LAR were 39-40 mg/dl h higher than those on placebo. A total of 7-21% of the patients taking octreotide LAR reached a 5% or greater decrease in body weight from Baseline, compared to 11% for the placebo group. This was not statistically significant. The most common adverse events included diarrhea, headache, cholelithiasis, nausea, and abdominal pain.

CONCLUSION

Octreotide LAR given at 40 or 60 mg resulted in statistically significant weight loss. A post hoc analysis stratifying patients by race and CIR(gp) indicated that Caucasian patients with the greater degree of insulin hypersecretion appeared to derive the most benefit from treatment. The observed safety profile was consistent with the known effects of octreotide from previous studies.

Is there an independent association between waist-to-hip ratio and cardiovascular risk factors in overweight and obese women?

BACKGROUND

This study was conducted to evaluate the relationship between waist-to-hip ratio (WHR) and cardiovascular risk factors in overweight and obese women and to determine a point of WHR above which the chances of having cardiovascular risk factors increased.

METHODS

In this cross-sectional study, 2892 pre- and postmenopausal women aged 20-78 years with body mass index (BMI) > or = 25 selected from among 5791 women of the Tehran Lipid and Glucose Study (TLGS) population (n = 15,005), by multistage cluster random sampling method, were included. Anthropometric indices were measured and BMI and WHR were calculated. Blood pressure was evaluated according to standard protocols. Biochemical indices were measured in the fasting state. Subjects were placed into the high-risk categories for cardiovascular disease on the basis of population-defined norms. Women were divided into quartiles based on their WHR: quartile 1: < 0.78, quartile 2: 0.78- < 0.83, quartile 3: 0.83- < 0.88, quartile 4: > or = 0.88 for premenopausal women, and quartile 1: < 0.84, quartile 2: 0.84- < 0.9, quartile 3: 0.9- < 0.94 and quartile 4: > or = 0.94 for postmenopausal women.

RESULTS

A lower proportion of pre- and postmenopausal women with BMI > or = 35 were in quartile 1 and a higher proportion in quartile 4. A significant increasing trend was observed for odds ratio of having low HDL-C, high triglyceride, high total-/HDL-cholesterol and high fasting blood sugar (FBS) with increasing WHR. Controlling for BMI and simultaneously adjusting for confounding variables had no effect on this trend. Although no significant increasing trends were seen for having high total cholesterol, LDL-cholesterol, systolic and diastolic blood pressure with quartiles of WHR in both pre- and postmenopausal women, subjects with higher quartiles of WHR still had higher chances for having high total cholesterol. In the case of postmenopausal women having of higher odds for high LDL-cholesterol and high systolic blood pressure in the fourth quartile of WHR should also be added to the high total cholesterol.

CONCLUSION

The results showed that in overweight and obese women, chances of having cardiovascular risk factors increased with WHR > or = 0.78 for premenopausal and with WHR > or = 0.84 for postmenopausal women.

Detection of cardiovascular risk factors by anthropometric measures in Tehranian adults: receiver operating characteristic (ROC) curve analysis

OBJECTIVE

To determine optimal cutoff points of anthropometric measures as cardiovascular indicators in an Iranian adult population.

DESIGN

: Population-based cross-sectional study.

SETTING

Tehran, the capital of Iran.

SUBJECTS

A total of 10 522 subjects (4449 men and 6073 women) aged 18-74 y.

METHODS

Demographic data were collected and anthropometric indices were measured. Blood pressure was evaluated and hypertension was defined based on JNC VI. Biochemical measurements were done. Diabetes was considered as FBS> or =126 mg/dl (> or =7.0 mmol/l) and dyslipidemia was defined according to ATP II. Risk factors were considered as: hypertension, diabetes, dyslipidemia, 'hypertension or diabetes', 'hypertension and diabetes', 'hypertension or dyslipidemia', 'hypertension and dyslipidemia', ' diabetes or dyslipidemia', 'diabetes and dyslipidemia', 'at least one risk factor' and 'at least two risk factors'. ROC curve analysis was performed to determine optimal cutoff values-where the sensitivity approximates specificity.

RESULTS

Younger men (the age category of 18-34 y) had higher WC than women. Men had higher waist-to-hip ratio (WHpR) and lower waist-to-height ratio (WHtR) than women in all age categories. Dyslipidemia, 'hypertension or dyslipidemia', 'diabetes or dyslipidemia' and 'at least one risk factor' were more prevalent risk categories in both genders. Range of areas under ROC curves for BMI and WC was 0.55-0.94 and 0.56-0.93 for men and 0.41-0.94 and 0.53-0.92 for women in various age groups, respectively. Range of areas for WHpR and WHtR in men was between 0.58-0.87 and 0.56-0.94, respectively, and for women varied between 0.53-0.91 and 0.53-0.90 in various age groups, respectively. Cutoff points of BMI for various risk factors were between 24 and 29 kg/m(2) in men and 25-31 kg/m(2) in women. Range of WHpR was between 0.86 and 0.97 in men and between 0.78 and 0.92 in women. Cutoff points for WC and WHtR were between 80 and 93 cm and 0.47 and 0.56 for men and between 79 and 96 cm and 0.50 and 0.63 for women in different age groups to detect various risk factors, respectively. In general, values were lowest for the most prevalent risk factors and highest for less prevalent conditions.

CONCLUSION

The results suggested cutoff points of anthropometric measures as indicators of cardiovascular risk factors. It seems that these cut-points are higher for Iranians than for other Asian populations.

SPONSORSHIP

Endocrine Research Center, Shaheed Beheshti University of Medical Sciences.

Is beauty in the eye of the beholder? Effects of weight and shape on attractiveness ratings of female line drawings by restrained and nonrestrained eaters

This study tested the differences between restrained and nonrestrained eaters' attractiveness perceptions of female line drawings, of their own figures, and the ideal female figure. Female line drawings varied systematically in body weight and in waist and hip circumference. Forty-six female undergraduate students, 23 nonrestrainers and 23 restrainers, rated stimuli in attractiveness, identified the figure which best represented their own body type (PAF), and the ideal body figure (IF) according to the Restraint Scale [RS; Herman, C. P., & Polivy, J. (1980). Restrained eating. In: A. Stunkard (Ed.), Obesity (pp. 208-225). Philadelphia, PA: Saunders]. Restrainers did not generally differ from nonrestrainers in attractiveness ratings or in their choice of IF. However, differences between IF and PAF were larger in restrainers than in nonrestrainers because restrainers chose PAFs with larger hips than nonrestrainers did. This difference between the restraint groups was independent of between-group differences in hip size. This discrepancy between IF and PAF may contribute to the restrainers' motivation to diet.

Methods of estimation of visceral fat: advantages of ultrasonography

OBJECTIVE

To compare methods for the assessment of visceral fat with computed tomography (CT) and establish cutoffs to define visceral obesity based on such alternative methods.

RESEARCH METHODS AND PROCEDURES

One hundred women (50.4 +/- 7.7 years; BMI 39.2 +/- 5.4 kg/m2 underwent anthropometric evaluation, bioelectrical impedance, DXA, abdominal ultrasonography (US), and CT scan.

RESULTS

Waist circumference, waist-to-hip ratio (WHR), and US-determined visceral fat values showed the best correlation coefficients with visceral fat determined by CT (r = 0.55, 0.54, and 0.71, respectively; p < 0.01). Fat mass determined by DXA was inversely correlated with visceral-to-subcutaneous-fat ratio (r = -0.47, p < 0.01). Bioimpedance-determined fat mass and skinfolds were correlated with only subcutaneous abdominal fat quantified by CT. Linear regression indicated US visceral-fat distance and WHR as the main predictors of CT-determined visceral fat (adjusted r2 = 0.51, p < 0.01). A waist measurement of 107 cm (82.7% specificity, 60.6% sensitivity) and WHR of 0.97 (78.8% specificity, 63.8% sensitivity) were chosen as discriminator values corresponding with visceral obesity diagnosed by CT. A value of 6.90 cm for visceral fat US-determined diagnosed visceral obesity with a specificity of 82.8%, a sensitivity of 69.2%, and a diagnostic concordance of 74% with CT.

DISCUSSION

US seemed to be the best alternative method for the assessment of intra-abdominal fat in obese women. Its diagnostic value could be optimized by an anthropometric measurement. Prospective studies are needed to establish CT and US cutoffs for defining visceral-fat levels related to elevated cardiovascular risk.

Risk factors for coronary heart disease in women with systemic lupus erythematosus: The Toronto Risk Factor Study

OBJECTIVE

Because women with systemic lupus erythematosus (SLE) are 5-8 times more likely to develop coronary heart disease (CHD) than are women in the general population, we assessed the prevalence of classic risk factors for CHD in women with SLE.

METHODS

Consecutive female patients with SLE who were without evidence of CHD and were attending a large lupus clinic in Toronto were studied. The control population was recruited from among age-matched subjects attending a family practice unit for an annual physical examination. The prevalence of classic CHD risk factors and the 10-year risk of a CHD-related event were determined using the Framingham risk assessment formula. Lipid subfractions, other metabolic risk factors, lifestyle variables, and demographic characteristics were also compared between the 2 groups.

RESULTS

We studied 250 SLE patients and 250 controls whose mean +/- SD age was 44.8 +/- 12 years and 44.3 +/- 15 years, respectively. Hypertension and diabetes were significantly more common among the SLE patients. Although the SLE patients had a higher mean number of CHD risk factors per patient, the 10-year risk of a CHD-related event, using the Framingham multiple risk factor assessment, was the same in SLE patients and controls (3.2%). Compared with controls, SLE patients had higher levels of very low-density lipoprotein cholesterol and total triglycerides, and had higher levels of homocysteine despite having higher folate levels. Premature menopause, sedentary lifestyle, and an at-risk body habitus were also more prevalent in SLE patients.

CONCLUSION

Women with SLE have a range of detectable coronary risk factors that are not fully reflected in the Framingham risk factor formula. These factors are likely to contribute to the loss of protection from CHD that has been observed in SLE.

Two-hour insulin determination improves the ability of abdominal fat measurement to identify risk for the metabolic syndrome

OBJECTIVE

Visceral obesity is shown to be a predictor of morbidity and mortality. We evaluated the association of measurements of generalized adiposity and visceral fat area (VFA), with abnormalities of metabolic syndrome (MS).

RESEARCH DESIGN AND METHODS

Seventy-six women (47.9 +/- 9.2 years) with BMI of 38.7 +/- 5.4 kg/m(2) underwent anthropometric measurements, laboratory procedures, bioeletrical impedance, and abdominal computed tomography (CT) scan. Diagnosis of MS was based on the presence of abdominal obesity and at least two of the following components: hypertension, dyslipidemia, and glucose intolerance and/or hyperinsulinemia.

RESULTS

BMI was correlated with both components of adipose tissue--subcutaneous (r = 0.66, P < 0.01) and VFA (r = 0.33, P < 0.02)--and leptin levels (r = 0.38, P < 0.01). In contrast, VFA was correlated with 2-h glucose and insulin levels (r = 0.32 and 0.35, P < 0.05, respectively), triglyceride, HDL cholesterol, and uric acid (r = 0.33, -0.34 and 0.24, P < 0.05, respectively). Subjects with high VFA, matched for BMI, showed greater plasma glucose area under the curve (621 +/- 127 vs. 558 +/- 129 mg x h(-1) x dl(-1), P < 0.05), 2-h insulin (804 +/- 599 vs. 579 +/- 347 pmol/l, P < 0.05), and uric acid levels (0.33 +/- 0.07 vs. 0.26 +/- 0.06 mmol/l, P < 0.05) than subjects with low VFA. In logistic regression analysis, waist circumference, VFA, and 2-h insulin were identified as independent predictors of MS. Receiver operating characteristic curve analysis pointed out the values of 104 cm for waist circumference (58.1% specificity, 84.1% sensitivity), 158.5 cm(2) for VFA (78.1% specificity, 52.3% sensitivity), and 559.8 pmol/l for 2-h insulin (71.9% specificity, 69.8% sensitivity); the presence of at least two of the three variables resulted in a degree of concordance of 76%.

CONCLUSIONS

While BMI was unable to differentiate between obese people and those at higher risk for MS, abdominal fat was shown to be associated with its metabolic abnormalities. The usefulness of abdominal fat in the identification of high-risk subjects may be improved when combined with 2-h insulin determination.

Suppression of insulin secretion is associated with weight loss and altered macronutrient intake and preference in a subset of obese adults

PURPOSE

Hyperinsulinemia is a common feature of many obesity syndromes. We investigated whether suppression of insulin secretion, without dietary or exercise intervention, could promote weight loss and alter food intake and preference in obese adults.

METHODS

Suppression of insulin secretion was achieved using octreotide-LAR 40 mg IM q28d for 24 weeks in 44 severely obese adults (89% female, 39% minority). Oral glucose tolerance testing was performed before and after treatment, indices of beta-cell activity (CIRgp), insulin sensitivity (CISI), and clearance (CP/I AUC) were computed, and leptin levels, 3-day food records and carbohydrate-craving measurements were obtained. DEXA evaluations were performed pre- and post-therapy in an evaluable subgroup.

RESULTS

For the entire cohort, significant insulin suppression was achieved with simultaneous improvements in insulin sensitivity, weight loss, and body mass index (BMI). Leptin, fat mass, total caloric intake, and carbohydrate craving significantly decreased. When grouped by BMI response, high responders (HR; DeltaBMI<-3 kg/m(2)) and low responders (LR; DeltaBMI between -3 and -0.5) exhibited higher suppression of CIRgp and IAUC than nonresponders (NR; DeltaBMI-0.5). CISI improved and significant declines in leptin and fat mass occurred only in HR and LR. Conversely, both leptin and fat mass increased in NR. Carbohydrate intake was markedly suppressed in HR only, while carbohydrate-craving scores decreased in HR and LR. For the entire cohort, DeltaBMI correlated with DeltaCISI, Deltafat mass, and Deltaleptin. DeltaFat mass also correlated with DeltaIAUC and DeltaCISI.

CONCLUSIONS

In a subcohort of obese adults, suppression of insulin secretion was associated with loss of body weight and fat mass and with concomitant modulation of caloric intake and macronutrient preference.

Clinical implications of leptin and its potential humoral regulators in long-term low-calorie diet therapy for obese humans

OBJECTIVE

To address the clinical implications of leptin and to re-examine the relationship between leptin and its potential humoral regulators such as insulin, nonesterified fatty acids (NEFA) and triiodothyronine (T3) in low-calorie diet (LCD) for obese humans.

DESIGN

Longitudinal study.

SETTING

University and foundation hospitals.

SUBJECTS

Ten obese men and 10 premenopausal obese women.

INTERVENTIONS

Five men and five women took 800 kcal/day LCD and another five men and five women took 1400 kcal/day balanced deficit diet (BDD) during 4 weeks.

RESULTS

Plasma leptin levels in the LCD group decreased more markedly (46.2+/-14.6 to 13.2+/-3.6 ng/ml) than that expected for the decrement in percentage fat (39.0+/-1.7 to 35.9+/-1.7%) and body mass index (BMI; 35.4+/-2.4 to 33.1+/-2.2 kg/m(2)), while that in the BDD group did not decrease significantly (14.9+/-3.5 to 13.4+/-2.8 ng/ml). The ratio of the decrease in leptin levels to that of BMI during the first week was significantly greater than that during the following 3 weeks (39.5+/-2.7 vs 29.3+/-2.1%, P=0.017). The plasma insulin and T3 levels also fell substantially in the first week and continued to decrease during the entire course. Plasma leptin levels measured weekly in each subject were correlated well with insulin (r=0.586, P=0.0003) and T3 (r=0.785, P=0.0004). Multiple regression analyses after adjustment for the time course and BMI revealed that serum levels of T3 were independently correlated with plasma leptin levels (r=0.928, P<0.0001). The plasma NEFA level was markedly elevated during the first 2 weeks and decreased thereafter.

CONCLUSIONS

A rapid fall in leptin during the first week of LCD, coordinated by insulin, T3 and NEFA, should be beneficial for responding to decreased energy intake. Inversely, in view of the powerful effect of leptin on energy dissipation, the present findings suggest the potential usefulness of leptin in combination with caloric restriction for the treatment of obesity.

SPONSORSHIP

The Ministry of Education, Culture, Sports, Science and Technology of Japan and the Ministry of Health, Labour and Welfare of Japan.

Dietary medium-chain triacylglycerols suppress accumulation of body fat in a double-blind, controlled trial in healthy men and women

We investigated the effect of long-term ingestion of dietary medium-chain triacylglycerols (MCT) on body weight and fat in humans. Using a double-blind, controlled protocol, we assessed the potential health benefits of MCT compared with long-chain triacylglycerols (LCT) in 78 healthy men and women [body mass index (BMI) > or = 23 kg/m(2): n = 26 (MCT), n = 30 (LCT); BMI < 23 kg/m(2): n = 15 (MCT), n = 7 (LCT)]. Changes in anthropometric variables, body weight and body fat during the 12-wk MCT treatment period were compared with those in subjects consuming the LCT diet. The subjects were asked to consume 9218 kJ/d and 60 g/d of total fat. The energy, fat, protein and carbohydrate intakes did not differ significantly between the groups. Body weight and body fat in both groups had decreased by wk 4, 8 and 12 of the study. However, in the subjects with BMI > or = 23 kg/m(2), the extent of the decrease in body weight was significantly greater in the MCT group than in the LCT group. In subjects with BMI > or = 23 kg/m(2), the loss of body fat in the MCT group (-3.86 +/- 0.3 kg) was significantly greater than that in the LCT group (-2.75 +/- 0.2 kg) at 8 wk. In addition, in subjects with BMI > or = 23 kg/m(2), the decrease in the area of subcutaneous fat in the MCT group was significantly greater than that in the LCT group at wk 4, 8 and 12. These results suggest that the MCT diet may reduce body weight and fat in individuals (BMI > or = 23 kg/m(2)) more than the LCT diet.

Ultrasonography for the evaluation of visceral fat and cardiovascular risk

Visceral fat accumulation is associated with increased cardiovascular risk. Clinical evaluation of visceral fat is limited because of the lack of reliable and low-cost methods. To assess the correlation between ultrasonography and computed tomography (CT) for the evaluation of visceral fat, 101 obese women, age 50.5+/-7.7 years with a body mass index of 39.2+/-5.4 kg/m(2), were submitted to ultrasonograph and CT scans. Visceral fat measured by ultrasonography, 1 cm above the umbilical knot, showed a high correlation with CT-determined visceral fat (r=0.67, P<0.0001). The ultrasonograph method showed good reproducibility with an intra-observer variation coefficient of <2%. Both ultrasonograph and CT visceral fat values were correlated with fasting insulin (r=0.29 and r=0.27, P<0.01) and plasma glucose 2 hours after oral glucose load (r=0.22 and r=0.34, P<0.05), indicating that ultrasonography is a useful method to evaluate cardiovascular risk. A significant correlation was also found between visceral fat by CT and serum sodium (r=0.18, P<0.05). A ultrasonograph-determined visceral-to-subcutaneous fat ratio of 2.50 was established as a cutoff value to define patients with abdominal visceral obesity. This value also identified patients with higher levels of plasma glucose, serum insulin and triglycerides and lower levels of HDL-cholesterol, which are metabolic abnormalities characteristic of the metabolic syndrome. Our data demonstrate that ultrasonography is a precise and reliable method for evaluation of visceral fat and identification of patients with adverse metabolic profile.

Subcutaneous and visceral adipose tissue: their relation to the metabolic syndrome

Methods for assessment, e.g., anthropometric indicators and imaging techniques, of several phenotypes of human obesity, with special reference to abdominal fat content, have been evaluated. The correlation of fat distribution with age, gender, total body fat, energy balance, adipose tissue lipoprotein lipase and lipolytic activity, adipose tissue receptors, and genetic characteristics are discussed. Several secreted or expressed factors in the adipocyte are evaluated in the context of fat tissue localization. The body fat distribution and the metabolic profile in nonobese and obese individuals is discussed relative to lipolysis, antilypolysis and lipogenesis, insulin sensitivity, and glucose, lipid, and protein metabolism. Finally, the endocrine regulation of abdominal visceral fat in comparison with the adipose tissue localized in other areas is presented.

Obesity, body fat distribution, and coronary artery disease

Obesity is an independent risk factor for the development of coronary artery disease (CAD). Obesity also increases risk for CAD indirectly through its association with insulin resistance, hyperlipidemia, and hypertension. An increased accumulation of fat in the intraabdominal cavity, termed visceral adiposity, is highly correlated with an adverse coronary risk profile. In patients at risk for coronary artery disease, the treatment of obesity results in an improved coronary risk profile. The prevalence of obesity is extremely high in coronary populations, yet the effect of weight loss on cardiovascular outcomes in CAD patients has received relatively little attention. Observational studies in the cardiac rehabilitation setting showed that patients who lose weight and exercise show an improvement in coronary risk profile. Further research is needed to better define the clinical effectiveness of weight loss programs and their benefits in coronary patients.

Weight gain associated with psychotropic drugs

Weight gain is a common adverse effect of psychotropic drugs. Clinically significant weight gain puts the patient at risk for coronary heart disease, hypertension, Type II diabetes, dyslipidaemia and cancer, and can lead to non-compliance, with the probability of relapse and subsequent (re)hospitalization. This review focuses on specific drug classes such as antipsychotics, antidepressants, mood stabilizers and anxiolytics that have a propensity to induce clinically significant weight gain. Patients should be informed of potential drug-induced weight gain and instructed in the importance of weight management techniques (e.g., proper nutrition, physical exercise, behaviour modification). Individual patient-risk profiles should also be assessed. To ensure adherence to treatment, a proactive physician-patient relationship is essential. Patient compliance and quality-of-life issues are addressed. For appropriate medication selection, the clinician should consider the weight gain potential of various psychotropic agents.

Body image and obesity: effects of gender and weight on perceptual measures of body image

The purpose of this study was to assess effects of gender and measures of Body Mass Index on estimates of normal body size (NBS), current body size (CBS), and discrepancies between attainable (ABS) and desirable (LTB) sizes. A total of 98 women and 74 men, shown 9 male and 9 female thin-to-heavy figure silhouette drawings, chose one drawing (or between two) indicating NBS-Male, NBS-Female, CBS, ABS, and LTB scores. Discrepancy scores were calculated as ABS-LTB. BMI within-group variances for CBS-Female scores were heterogeneous. Discrepancy scores were significantly different for groups of females. Subjects agreed on judgments of a hypothetical normal male and female figure size; men in BMI groups agreed upon a figure representing their size and felt their desired size was attainable. Normal-weight women could not consistently estimate their size. Obese and very obese females underestimated their size and felt that a desired size was unattainable.

The pharmacologic approach to the treatment of obesity

Obesity is a major risk factor for morbidity and mortality, and a series of pharmacologic approaches are available for helping to manage the problem. Obesity is caused by an imbalance between caloric intake and energy expenditure, which is influenced by both environmental and genetic factors. Pharmacologic treatments include anorexigenic agents, which fall into two broad categories: those that act via brain catecholamine pathways and those that act via serotonin pathways. The most recent oral agents approved are dexfenfluramine, which is currently being marketed, and sibutramine. Both agents inhibit the control reuptake of serotonin but in addition may have effects on thermogenesis. Under investigation are agents that increase energy expenditure: the beta 3-adrenergic receptor agonists and drugs that prevent the intestinal absorption of free fatty acids and cholesterol. In development are innovative approaches to influence leptin and its receptors, various obesity genes, and biologic substances thought to influence satiety (neuropeptide Y, enterostatin, cholecystokinin, bombesin, and amylin). Obesity has now become a major target for drug development not only for affecting obesity per se but also for managing and preventing comorbid conditions such as diabetes and cardiovascular disease.

The physiology and brain mechanisms of feeding

This article is designed as an introduction to the major theoretical models in the field of regulation of eating behavior, and a selective review of relevant neurobiological data. We first critically consider the paradigm of homeostasis as it relates to body energy content, and argue that additional theoretical constructs will be needed to account for the complexity of eating behavior in both nonhumans and humans. We then summarize some of the methods available to the neuroscientist in this area, and address some of their limitations. We review treatments and potential mechanisms that increase food intake, including deprivation, antimetabolites, norepinephrine, and several peptides including neuropeptide Y. We next review treatments that decrease food intake, including a variety of humoral, gastrointestinal, and pancreatic factors, as well as examine central pathways of satiety. This includes a discussion of leptin and other potential anorectic agents. We conclude with a discussion of human obesity and anorexias, and prospects for pharmacotherapy of eating disorders. We emphasize throughout that most regions of the human brain probably make some contribution to feeding behavior, and so a focus on any one area of transmitter/hormone is an unrealistic approach both in basic and applied areas.

Bodyweight change as an adverse effect of drug treatment. Mechanisms and management

A number of drugs are capable of changing bodyweight as an adverse effect of their therapeutic action. Bodyweight gain is more of a problem than bodyweight loss. As bodyweight gain during drug treatment for any kind of disease may be the reflection of improvement of the disease itself, we will try to separate these effects from those due to drug-induced alterations of the mechanisms regulating bodyweight. Bodyweight gain may jeopardise patient compliance to the prescribed regimen and it may pose health risks. The body mass index (BMI) is determined by dividing bodyweight in kilograms by height in metres squared. A BMI of > or = 27 kg/m2 warrants therapeutic action; nutritional counselling and programmed physical exercise can be used as a basis. In general, if basic therapeutic measures are unsuccessful at controlling bodyweight gain then a change of drug might help. Finally, an anoretic drug may serve to support dietary measures. However, safety and efficacy has been demonstrated for only a few anorectic drugs when used as an adjunct to caloric restriction in the treatment of drug-induced obesity. Bodyweight is determined by complex mechanisms regulating energy balance. A number of neurotransmitter systems acting in several hypothalamic nuclei are pivotal to the regulation of body fat stores. Most drugs that are capable of changing bodyweight interfere with these neurotransmitter systems. The increment is dependent on the type and dose of the drug concerned. Some antidepressant drugs induce bodyweight gain, which may amount to 20 kg over several months of treatment. Monoamine oxidase inhibitors appear to cause less bodyweight change than tricyclic antidepressants. Selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitors cause bodyweight loss instead of bodyweight gain. Lithium may cause large increases in bodyweight. Generally speaking, the bodyweight change induced by antipsychotics is more often of clinical significance than the bodyweight change associated with the use of antidepressants. Again, the changes of bodyweight are dependent upon the type and dose of the antipsychotic drug involved. Although almost all antipsychotics induce bodyweight gain, molindone and loxapine appear to induce bodyweight loss. Anticonvulsants, especially valproic acid (sodium valproate) and carbamazepine, induce bodyweight gain in a considerable percentage of patients. Treatment with corticosteroids is associated with dose-dependent bodyweight gain in many patients. Corticosteroid-induced obesity aggravates other corticosteroid-associated health risks. Insulin therapy in diabetic patients usually increases bodyweight. Finally, sulphonurea derivatives, antineoplastic agents used for the treatment of breast cancer and several drugs used in migraine prophylaxis may cause bodyweight gain as well.

Current views on obesity

Although the disorders associated with obesity have been extensively studied, little attention has been paid to the fact that obesity is itself a chronic disease. This misunderstanding of the nature of obesity has contributed to the stigmatization of obese persons and to the use of inappropriate or inadequate treatment regimens. Although the etiology of obesity is still unclear, genetic, metabolic, and social factors are all believed to play a role in its development and progression. Behavioral therapy, exercise, very-low-calorie diets, drug therapy, and surgery affect the treatment of obesity of differing levels of severity. The regaining of weight following treatments other than surgery is very frequent, in part because periods of weight loss are rarely followed by maintenance programs. An increasing awareness of the chronic, multifactorial nature of obesity will ideally lead to the development of new long-term treatment programs that are safe and effective. Such programs are urgently needed in light of new data that show that the prevalence of obesity is increasing in the United States, as much as 30% in the last decade.

Prozac (fluoxetine, Lilly 110140), the first selective serotonin uptake inhibitor and an antidepressant drug: twenty years since its first publication

In this review, we describe the evolutionary process involved in the discovery of the selective 5-HT uptake inhibitor, fluoxetine, and summarize some of the large body of scientific research performed on fluoxetine in the 20 years since the first publication. The historical background of the proposed involvement of 5-HT in psychiatric disorders and the activity of tricyclic antidepressants in depression is reviewed. The effects of fluoxetine in various in vitro assays and in animal studies including receptor down-regulation, neurochemical and behavioral models are summarized. In addition, the clinical effectiveness of fluoxetine in depression and obsessive compulsive disorders and its potential use in other disorders are examined.

The lipoprotein lipase HindIII polymorphism modulates plasma triglyceride levels in visceral obesity

The aim of this study was to investigate the potential interaction between the lipoprotein lipase (LPL) HindIII polymorphism and visceral adipose tissue (AT) accumulation in the modulation of triglyceride levels in visceral obesity. The LPL-HindIII genotype was determined by polymerase chain reaction in 52 min. Twenty-three subjects were heterozygous (+/-) and 28 were homozygous (+/+) for the presence of the restriction site. One subject who was homozygous for the--allele was excluded from analysis. Body mass index (BMI), fasting insulin level, and visceral AT area as measured by computed tomography were positively correlated with triglyceride levels only in subjects homozygous for the + allele. Furthermore, whereas these variables were negatively correlated with plasma HDL2 cholesterol concentrations in the +/+ group, these associations were not found in +/- heterozygotes, with the exception of BMI. To further investigate the interaction of the LPL-HindIII polymorphism with visceral obesity and hyperinsulinemia, the two genotype groups were further subdivided on the basis of BMI (low versus high), fasting insulin level (low versus high), and visceral AT area (low versus high), and their lipoprotein profiles were compared. Elevated levels of abdominal visceral AT were significantly associated with increased triglyceride concentrations in +/+ homozygous men, suggesting that visceral obesity may lead to hypertriglyceridemia in the presence of the +/+ genotype. In the +/- group, variation in the amount of visceral AT was not associated with differences in triglyceride concentration. However, hypertriglyceridemia and an increased cholesterol-to-HDL cholesterol ratio were observed in the hyperinsulinemic state irrespective of LPL-HindIII genotype status.(ABSTRACT TRUNCATED AT 250 WORDS)

Dyslipidaemia and obesity

Obesity is frequently associated with a dyslipidaemic state. Several metabolic and epidemiological studies published in the 1980s have, however, emphasized the importance of considering the regional distribution of body fat in the assessment of the health hazards of obesity. The development of imaging techniques such as computed tomography has also allowed it to be established that the fat located in the abdominal cavity, i.e. the visceral adipose tissue, was the critical correlate of the metabolic complications found in abdominal obesity which include insulin resistance and hyperinsulinaemia, glucose intolerance, hypertriglyceridaemia, hypoalphalipoproteinaemia and increased concentrations of dense LDL particles. Furthermore, since several genes are involved in the regulation of plasma lipoprotein-lipid levels and they have been reported to show polymorphism, visceral obesity should be considered as a permissive factor that exacerbates an individual's susceptibility to dyslipidaemia and premature coronary heart disease rather than a primary regulator of the dyslipidaemic state observed in visceral obese patients. Finally, as insulin resistance and the level of visceral adipose tissue are two main correlates of the dyslipidaemic state which characterizes abdominal obesity, treatment should be aimed at reducing visceral fat and improving insulin sensitivity. Prospective studies are clearly warranted to evaluate the potential benefits of such interventions on the incidence of coronary heart disease.

Therapy for obesity--today and tomorrow

Obesity poses a serious health hazard and its treatment is often disappointing. Besides conservative methods, the place of pharmacotherapy, very-low-calorie diets, and even, in selected cases, mechanical means or surgery can be considered. Effective drug treatment for obesity must reduce energy intake, or increase energy expenditure, or increase energy losses in faeces. All these possibilities have potential activities but also serious limitations. Current pharmacotherapy essentially uses anorectic drugs and the other approaches, although promising, are still under investigation. Of the anorectic compounds currently available, serotoninergic agents, like dexfenfluramine and fluoxetine, appear to have the most suitable pharmacological profile. Very-low-calorie diets could help in the short-term but should be associated with other approaches to increase the rate of long-term success. They must be well-balanced as macronutrients and micronutrients are concerned, be prescribed in well-selected patients under careful medical supervision, and not be followed longer than a few weeks. Surgery can provide palliation for severe obesity when all medical approaches have failed. It may consist in decreasing food intake (gastric procedures), affecting calorie absorption (intestinal shunting, biliopancreatic bypass), or removing localized excess fat (lipectomy, liposuction). Gastric reduction operations are safe and effective provided they are performed by experienced surgeons in well-selected patients. They can be considered now as the best option for a minority of patients with morbid and refractory obesity. Finally, in very selected patients, mechanical means (such as the waist cord) may also help losing weight and/or avoiding weight regain. Even if all these therapeutic approaches can be helpful, at least in some obese individuals, they also have important limitations so that prevention remains up to now the 'treatment' of choice for obesity.

Waist circumference and abdominal sagittal diameter: best simple anthropometric indexes of abdominal visceral adipose tissue accumulation and related cardiovascular risk in men and women

The amount of abdominal visceral adipose tissue measured by computed tomography is a critical correlate of the potentially "atherogenic" metabolic disturbances associated with abdominal obesity. In this study conducted in samples of 81 men and 70 women, data are presented on the anthropometric correlates of abdominal visceral adipose tissue accumulation and related cardiovascular disease risk factors (triglyceride and high-density lipoprotein cholesterol levels, fasting and postglucose insulin and glucose levels). Results indicate that the waist circumference and the abdominal sagittal diameter are better correlates of abdominal visceral adipose tissue accumulation than the commonly used waist-to-hip ratio (WHR). In women, the waist circumference and the abdominal sagittal diameter also appeared more closely related to the metabolic variables than the WHR. When the samples were divided into quintiles of waist circumference, WHR or abdominal sagittal diameter, it was noted that increasing values of waist circumference and abdominal sagittal diameter were more consistently associated with increases in fasting and postglucose insulin levels than increasing values of WHR, especially in women. These findings suggest that the waist circumference or the abdominal sagittal diameter, rather than the WHR, should be used as indexes of abdominal visceral adipose tissue deposition and in the assessment of cardiovascular risk. It is suggested from these data that waist circumference values above approximately 100 cm, or abdominal sagittal diameter values > 25 cm are most likely to be associated with potentially "atherogenic" metabolic disturbances.

Obesity, anorexia, and bulimia

Eating disorders are common in our society. They represent a heterogeneous group of disorders with respect to pathophysiology (biological, social-cultural, psychological, familial, and developmental), presentation, and treatment. The patient may have superimposed comorbid psychiatric illnesses and may even exhibit features common to both anorexia and bulimia. Regardless, the health care provider must remain cognizant of these illnesses to be able to offer prompt referral to an appropriate center with expertise in treating these pervasive illnesses.

Genetic aspects of susceptibility to obesity and related dyslipidemias

Obesity has a multifactorial origin. However, although environmental variables undoubtedly play a role in the development of obesity, it is now clear that genetic variation is also involved in the determination of an individual's susceptibility to body fat accumulation. In addition, it is also widely accepted that obesity is not a single homogeneous phenotype. It is also heterogeneous regarding its causes and metabolic complications. The regional distribution of body fat appears to be an important correlate of the metabolic complications that have been related to obesity. Due to their higher accumulation of abdominal fat, men are generally more at risk for the metabolic complications of obesity than women whereas some obese women, with large gluteal-femoral adipose depots may have a cosmetic problem which may not necessarily require medical intervention. Several studies have been conducted to understand the mechanisms by which abdominal obesity is related to diabetes, hypertension and cardiovascular disease. It appears that the increased risk of abdominal obesity is the result of complex hormonal and metabolic interactions. Studies in genetic epidemiology have shown that both total body fatness and the regional distribution of body fat have a significant genetic component. Standardized intervention studies using an identical twin design have shown that individuals that have the same genetic background tend to show similar changes in body fat and in plasma lipoprotein levels when exposed to standardized caloric excess or energy restriction. Finally, although abdominal obesity is a significant risk factor for cardiovascular disease, not every abdominal obese subject will experience metabolic complications, suggesting that some obese individuals may be more susceptible than others. Variation in several genes relevant to lipid and lipoprotein metabolism may alter the relation of abdominal obesity to dyslipoproteinemias. Abdominal obesity should therefore be considered as a factor that exacerbates an individual's susceptibility to cardiovascular disease.

Treatment for obesity: a nutrient balance/nutrient partition approach

This paper examines the treatment of obesity, using a feedback model of nutrient regulation. A feedback model contains afferent signals and a central controller that transduces afferent information into efferent signals that modulate the controlled system. Using this model and the receptor hypothesis for drug action, a variety of current and potential therapeutic approaches are discussed. Among the more promising approaches would be cholecystokinin agonists, small molecules that mimic ketoacids, agonists to corticotropin-releasing hormone, beta-3 agonists, antagonists to opioid peptides, antagonists to neuropeptide Y, glucocorticoid receptor antagonists, and growth hormone agonists. Since a number of mechanisms can influence body fat and nutrient partitioning, it is likely that optimal therapy will involve use of more than one pharmacologic agent.

Serotonin in human eating disorders

The onset and progression of symptomatology in patients with anorexia nervosa and bulimia nervosa is complex. It is unlikely that dysregulation of a single neurotransmitter system would be sufficient to explain the pathophysiology of these disorders. The studies reviewed above provide preliminary evidence that decreased central serotonin function may contribute to the onset or persistence of binge eating episodes in patients with bulimia nervosa, including low weight anorexic patients with bulimic symptoms. Future clinical studies will benefit from the availability of selective serotonin receptor agonists and antagonists. Longitudinal studies through progressive phases of treatment and clinical remission will be important to clarify the contribution of dietary and body weight changes to results of neurotransmitter studies with eating disorder patients.

Management strategies for weight control. Eating, exercise and behaviour

Obesity is a major health and social problem worldwide for which no single satisfactory treatment exists. Because of the prevalence of the disease, numerous therapeutic strategies have been attempted--often unsuccessfully. Weight loss programmes based on dietary restriction of caloric intake and nutritional education, exercise, surgical (gastroplasty, gastric bypass) and procedural (gastric balloon, waist cord, jaw wiring, liposuction) intervention and pharmacotherapy (appetite suppressants, thermogenic agents, bulking agents) used alone or in combination, have produced weight loss in the short to medium term; however, weight is generally regained on discontinuation of treatment. Behaviour modification programmes appear to offer the highest success rate in the long term. Weight loss is not rapid, although losses of 10 to 15 kg have been achieved after 6 months, and this may be increased when behaviour modification therapy is combined with more aggressive treatments such as severe caloric restriction or jaw wiring. Behaviour modification is particularly beneficial in special patient groups such as the obese elderly, children or adolescents, and disabled patients. Thus, although it appears that each of the treatments developed for the management of obese patients has its place, the cornerstone of therapy for most patients remains a programme of dietary restriction, combined with exercise and behaviour modification.