Adapted Changes in Left Ventricular Structure and Function in Severe Uncomplicated Obesity

Objective: A massive amount of fat tissue, as that observed in obese subjects with BMI over 50 kg/m², could affect cardiac morphology and performance, but few data on this issue are available. We sought to evaluate cardiac structure and function in uncomplicated severely obese subjects. Research Methods and Procedures: We studied 55 uncomplicated severely obese patients, 40 women, 15 men, mean age 35.5 ± 10.2 years, BMI 51.2 ± 8.8 kg/m², range 43 to 81 kg/m², with a history of fat excess of at least 10 years, and 55 age‐matched normal‐weight subjects (40 women, 15 men, mean BMI 23.8 ± 1.2 kg/m²) as a control group. Each subject underwent an echocardiogram to evaluate left ventricular (LV) mass and geometry and systolic and diastolic function. Results: Severely obese subjects showed greater LV mass and indexed LV mass than normal‐weight subjects (p < 0.01 for all parameters). Nevertheless, LV mass was appropriate for sex, height^2.7, and stroke work in most (77%) uncomplicated severely obese subjects. In addition, no significant difference in LV mass indices and LV mass appropriateness between obese subjects with BMI ≥ 50 kg/m² and those with BMI ≤ 50 kg/m² was found. Obese subjects also showed higher ejection fraction and midwall shortening than normal‐weight subjects (p = 0.05 and p < 0.01, respectively), suggesting a hyperdynamic systolic function. No significant difference in systolic performance between obese subjects with BMI ≥ 50 kg/m² and those with BMI ≤ 50 kg/m² was seen. Discussion: Our data show that uncomplicated severe obesity, despite the massive fat tissue amount, is associated largely with adapted and appropriate changes in cardiac structure and function.     

Basal Endothelial Nitric Oxide Release Is Preserved in Overweight and Obese Adults

Objective: Impaired basal nitric oxide release is associated with a number of cardiovascular disorders including hypertension, arterial spasm, and myocardial infarction. We determined whether basal endothelial nitric oxide release is reduced in otherwise healthy overweight and obese adult humans. Research Methods and Procedures: Seventy sedentary adults were studied: 32 normal weight (BMI <25 kg/m²), 24 overweight (BMI ≥ 25 < 30 kg/m²), and 14 obese (BMI ≥ 30 kg/m²). Forearm blood flow (FBF) responses to intra‐arterial infusions of N^g‐monomethyl‐l ‐arginine (5 mg/min), a nitric oxide synthase inhibitor, were used as an index of basal nitric oxide release. Results: N^g‐monomethyl‐l ‐arginine elicited significant reductions in FBF in the normal weight (from 4.1 ± 0.2 to 2.7 ± 0.2 mL/100 mL tissue/min), overweight (4.1 ± 0.1 to 2.8 ± 0.2 mL/100 mL tissue/min), and obese (3.9 ± 0.3 to 2.7 ± 0.2 mL/100 mL tissue/min) subjects. Importantly, the magnitude of reduction in FBF (～30%) was similar among the groups. Discussion: These results indicate that the capacity of the endothelium to release nitric oxide under basal conditions is not compromised in overweight and obese adults.     

Weight Loss Expectations in Obese Patients Seeking Treatment at Medical Centers

Objective: To investigate weight loss expectations (expected 1‐year BMI loss, dream BMI, and maximum acceptable BMI) in obese patients seeking treatment and to examine whether expectations differ by sex, weight, diet and weight history, age, psychological factors, and primary motivations for weight loss. Research Methods and Procedures: 1891 obese patients seeking treatment in 25 Italian medical centers (1473 women; age, 44.7 ± 11.0 years; BMI, 38.2 ± 6.5 kg/m²) were evaluated. Diet and weight history, weight loss expectations, and primary motivation for seeking treatment (health or improving appearance) were systematically recorded. Psychiatric distress, binge eating, and body image dissatisfaction were tested by self‐administered questionnaires (Symptom CheckList‐90, Binge Eating Scale, and Body Uneasiness Test). Results: In 1011 cases (53.4%), 1‐year expected BMI loss was ≥9 kg/m², dream BMI was 26.0 ± 3.4 kg/m² (corresponding to a 32% loss), and maximum acceptable BMI was 29.3 ± 4.4 kg/m² (?23%). BMI and age were the strongest predictors of weight goals. Weight loss necessary to reach the desired targets was largely in excess of weight loss observed during previous dieting. Psychiatric distress, body dissatisfaction, and binge eating did not predict weight loss expectations. The primary motivation for weight loss was concern for future or present health; women seeking treatment to improve appearance had a lower grade of obesity, were younger, and had first attempted weight loss at a younger age. Discussion: Obese Italian patients had unrealistic weight loss expectations. There were significant disparities between patients’ perceptions and physicians’ weight loss recommendations of desirable treatment outcome.     

Postprandial Vascular Reactivity in Obese and Normal Weight Young Adults

As humans spend a significant amount of time in the postprandial state, we examined whether vascular reactivity (a key indicator of cardiovascular health) was different after a high‐fat meal in 11 obese (median BMI 46.4, age 32.1 ± 6.3 years, 7 men) and 11 normal weight (median BMI 22.6) age‐ and sex‐matched controls. At baseline and 1 and 3 h postmeal, blood pressure (BP), heart rate (HR), reactive hyperemia peripheral artery tonometry (RH‐PAT) index, radial augmentation index adjusted for HR (AIx75), brachial pulse wave velocity (PWV_b), glucose, insulin, total and high‐density lipoprotein (HDL) cholesterol, and triglycerides were measured. Brachial flow‐mediated dilatation (FMD) and, by venous plethysmography, resting and hyperemic forearm blood flows (FBFs) were measured at baseline and 3 h. At baseline, obese subjects had higher systolic BP, HR, resting FBF, insulin and equivalent FMD, RH‐PAT, hyperemic FBF, AIx75, PWV_b, glucose, total cholesterol, triglycerides, and lower HDL cholesterol. In obese and lean subjects, FMD at baseline and 3 h was not significantly different (6.2 ± 1.7 to 5.8 ± 4.3% for obese and 4.7 ± 4.1 to 4.3 ± 3.9% for normal weight, P = 0.975 for group × time). The meal did not produce significant changes in RH‐PAT, hyperemic FBF, and PWV_b in either group (P > 0.1 for the effect of time and for group × time interactions). In conclusion, the vascular responses to a high‐fat meal are similar in obese and normal weight young adults. An exaggerated alteration in postprandial vascular reactivity is thus unlikely to contribute importantly to the increased cardiovascular risk of obesity.     

Resting Metabolic Rate in Severely Obese Diabetic and Nondiabetic Subjects

Objectives : To compare the resting metabolic rate (RMR) between diabetic and nondiabetic obese subjects and to develop a predictive equation of RMR for these subjects. Research Methods and Procedures : Obese adults (1088; mean age = 44.9 ± 12.7 years) with BMI ≥ 35 kg/m² (mean BMI = 46.4 ± 8.4 kg/m²) were recruited. One hundred forty‐two subjects (61 men, 81 women) were diagnosed with type 2 diabetes (DM), giving the prevalence of DM in this clinic population as 13.7%. RMR was measured by indirect calorimetry, and several multivariate linear regression models were performed using age, gender, weight, height, BMI, fat mass, fat mass percentage, and fat‐free mass as independent variables. Results : The severely obese patients with DM had consistently higher RMR after adjustment for all other variables. The best predictive equation for the severely obese was RMR = 71.767 ? 2.337 × age + 257.293 × gender (women = 0 and men = 1) + 9.996 × weight (in kilograms) + 4.132 × height (in centimeters) + 145.959 × DM (nondiabetic = 0 and diabetic = 1). The age, weight, and height‐adjusted least square means of RMR between diabetic and nondiabetic groups were significantly different in both genders. Discussion : Severely obese patients with type 2 diabetes had higher RMR than those without diabetes. The RMR of severely obese subjects was best predicted by an equation using age, gender, weight, height, and DM as variables.     

The influence of weight loss on serum osteoprotegerin concentration in obese perimenopausal women

Objective: To assess the influence of weight reduction therapy on serum osteoprotegerin (OPG) concentration in obese patients and compare these results with normal‐weight controls. Research Methods and Procedures: Forty‐three obese women (BMI, 36.7 ± 4.1 kg/m²; mean age, 50.1 ± 4.5 years) were studied. The control group consisted of 19 normal‐weight women (BMI, 24.2 ± 2.1 kg/m²; mean age, 53.8 ± 5.2 years). In all patients, serum concentrations of OPG, C telopeptide of type I collagen containing the cross‐linking site (CTX), osteocalcin, parathormone, 25‐(OH)‐D₃ (vitamin D), and total calcium and phosphorus were assessed before and after a 3‐month weight reduction therapy. Results: In obese subjects, serum concentrations of OPG, 25‐(OH)‐D₃, osteocalcin, total calcium, and phosphorus were significantly lower, and serum concentration of parathormone was significantly higher, before weight reduction therapy in comparison with normal‐weight controls. After weight reduction, a significantly higher serum concentration of 25‐(OH)‐D₃ and CTX and significantly lower concentration of OPG were found. Discussion: Serum concentration of OPG was significantly lower in obese patients in comparison with normal‐weight controls. Weight reduction therapy resulted in further decrease in OPG serum concentrations. Therefore, OPG cannot be treated as a protective factor from bone loss in obese patients.     

Association of childhood sexual abuse with obesity in a community sample of lesbians

Objective: Our goal was to examine the association between childhood sexual abuse (CSA) and obesity in a community‐based sample of self‐identified lesbians. Research Methods and Procedures: A diverse sample of women who self‐identified as lesbian was recruited from the greater Chicago metropolitan area. Women (n = 416) were interviewed about sexual abuse experiences that occurred before the age of 18. Self‐reported height and weight were used to calculate BMI and categorize women as normal‐weight (<25.0 kg/m²), overweight (25.0 to 29.9 kg/m²), obese (30.0 to 39.9 kg/m²), or severely obese (≥40 kg/m²). The relationship between CSA and BMI was examined using multinomial logistic regression analysis. Results: Overall, 31% of women in the sample reported CSA, and 57% had BMI ≥25.0 kg/m². Mean BMI was 27.8 (±7.2) kg/m² and was significantly higher among women who reported CSA than among those who did not report CSA (29.4 vs. 27.1, p < 0.01). CSA was significantly related to weight status; 39% of women who reported CSA compared with 25% of women who did not report CSA were obese (p = 0.004). After adjusting for age, race/ethnicity, and education, women who reported CSA were more likely to be obese (odds ratio, 1.9; 95% confidence interval, 1.1–3.4) or severely obese (odds ratio, 2.3; 95% confidence interval, 1.1–5.2). Discussion: Our findings, in conjunction with the available literature, suggest that CSA may be an important risk factor for obesity. Understanding CSA as a factor that may contribute to weight gain or act as a barrier to weight loss or maintenance in lesbians, a high‐risk group for both CSA and obesity, is important for developing successful obesity interventions for this group of women.     

Effect of Internet Support on the Long‐Term Maintenance of Weight Loss

Objective: To investigate the efficacy of an Internet weight maintenance program. Research Methods and Procedures: Two hundred fifty‐five healthy overweight and obese adults (mean ± SD BMI, 31.8 ± 4.1 kg/m²) men (18%; mean ± SD age, 45.8 ± 8.9 yrs) participated in a 6‐month behavioral weight control program conducted over interactive television. Treatment was followed by a 12‐month weight maintenance program with three conditions: frequent in‐person support (F‐IPS), minimal in‐person support (M‐IPS) and internet support (IS). Main outcome measures included body weight, program adherence, and social influence components. Results: There were no significant differences among the groups in weight loss (mean ± SD) from baseline to 18 months (7.6 ± 7.3 kg vs. 5.5 ± 8.9 kg vs. 5.1 ± 6.5 kg, p = 0.23 for the IS, M‐IPS, and F‐IPS, respectively). Discussion: Participants assigned to an internet‐based weight maintenance program sustained comparable weight loss over 18 months compared with individuals who continued to meet face‐to‐face. Therefore, the internet appears to be a viable medium for promoting long‐term weight maintenance.     

Weight loss on the web: A pilot study comparing a structured behavioral intervention to a commercial program

Objective: Internet weight loss programs have become widely available as alternatives to standard treatment, but few data are available on their efficacy. This study aimed to investigate the effectiveness of a structured behavioral weight loss website (VTrim) vs. a commercial weight loss website ( eDiets.com ). Research Methods and Procedures: A randomized, controlled trial was conducted from February 2003 to March 2005, in 124 overweight and obese subjects ages 18 years and older with a BMI of 25 to 39.9 kg/m² (mean age, 47 ± 9 years; BMI, 32 ± 3 kg/m²; 20% men). Analyses were performed for the 88 subjects who had complete follow‐up data. Participants were randomly assigned to 12‐month VTrim (n = 62) or eDiets.com (n = 62) intervention. VTrim participants had access to a therapist‐led structured behavioral weight loss program delivered on‐line. eDiets.com subjects had access to a self‐help commercial on‐line weight loss program. Body weight, social support, and use of website components were measured at 0, 6, and 12 months. Results: Repeated‐measures analyses showed that the VTrim group lost significantly more weight than the eDiets.com group at 6 months (8.3 ± 7.9 kg vs. 4.1 ± 6.2 kg; p = 0.004) and maintained a greater loss at 12 months (7.8 ± 7.5 kg vs. 3.4 ± 5.8 kg; p = 0.002). More participants in the VTrim group maintained a 5% weight loss goal (65% vs. 37.5%; p = 0.01) at 12 months. Discussion: An on‐line, therapist‐led structured behavioral weight loss website produced greater weight loss than a self‐help commercial website. Because commercial sites have great potential public health impact, future research should investigate the feasibility of incorporating a more structured behavioral program into a commercial application.     

Low Plasma Leptin Concentration and Low Rates of Fat Oxidation in Weight‐Stable Post‐Obese Subjects

Objective: A low resting metabolic rate for a given body size and composition, a low rate of fat oxidation, low levels of physical activity, and low plasma leptin concentrations are all risk factors for body weight gain. The aim of the present investigation was to compare resting metabolic rate (RMR), respiratory quotient (RQ), levels of physical activity, and plasma leptin concentrations in eight post‐obese adults (2 males and 6 females; 48.9 ± 12.2 years; body mass index [BMI]: 24.5 ± 1.0 kg/m²; body fat 33 ± 5%; mean ± SD) who lost 27.1 ± 21.3 kg (16 to 79 kg) and had maintained this weight loss for ≥2 months (2 to 9 months) to eight age‐ and BMI‐matched control never‐obese subjects (1 male and 7 females; 49.1 ± 5.2 years; BMI 24.4 ± 1.0 kg/m²; body fat 33 ± 7%). Research Methods and Procedures: Following 3 days of weight maintenance diet (50% carbohydrate and 30% fat), RMR and RQ were measured after a 10‐hour fast using indirect calorimetry and plasma leptin concentrations were measured using radioimmunoassay. Levels of physical activity were estimated using an accelerometer over a 48‐hour period in free living conditions. Results: After adjustment for fat mass and fat‐free mass, post‐obese subjects had, compared with controls, similar levels of physical activity (4185 ± 205 vs. 4295 ± 204 counts) and similar RMR (1383 ± 268 vs. 1430 ± 104 kcal/day) but higher RQ (0.86 ± 0.04 vs. 0.81 ± 0.03, p < 0.05). Leptin concentration correlated positively with percent body fat (r = 0.57, p < 0.05) and, after adjusting for fat mass and fat‐free mass, was lower in post‐obese than in control subjects (4.5 ± 2.1 vs. 11.6 ± 7.9 ng/mL, p < 0.05). Discussion: The low fat oxidation and low plasma leptin concentrations observed in post‐obese individuals may, in part, explain their propensity to relapse.     

Decreased Glucagon‐like Peptide 1 Release after Weight Loss in Overweight/Obese Subjects

Objective: Postprandial glucagon‐like peptide 1 (GLP‐1) release seems to be attenuated in obese subjects. Results on whether weight loss improves GLP‐1 release are contradictory. The aim of this study was to further investigate the effect of weight loss on basal and postprandial GLP‐1 release in overweight/obese subjects. Research Methods and Procedures: Thirty‐two overweight/obese subjects participated in a repeated measurement design before (BMI, 30.3 ± 2.8 kg/m²; waist circumference, 92.6 ± 7.8 cm; hip circumference, 111.1 ± 7.4 cm) and after a weight loss period of 6 weeks (BMI, 28.2 ± 2.7 kg/m²; waist circumference, 85.5 ± 8.5 cm; hip circumference, 102.1 ± 9.2 cm). During weight loss, subjects received a very‐low‐calorie diet (Optifast) to replace three meals per day. Subjects came to the laboratory fasted, and after a baseline blood sample, received a standard breakfast (1.9 MJ). Postprandially, blood samples were taken every one‐half hour relative to intake for 120 minutes to determine GLP‐1, insulin, glucose, and free fatty acids from plasma. Appetite ratings were obtained with visual analog scales. Results: After weight loss, postprandial GLP‐1 concentrations at 30 and 60 minutes were significantly lower than before weight loss (p < 0.05). Glucose concentrations were also lower, and free fatty acids were higher compared with before weight loss. Ratings of satiety were increased, and hunger scores were decreased after weight loss (p < 0.05). Discussion: In overweight/obese subjects, GLP‐1 concentrations after weight loss were decreased compared with before weight loss, and nutrient‐related stimulation was abolished. This might be a response to a proceeding negative energy balance. Satiety and GLP‐1 seem to be unrelated in the long term.     

Long‐term effects of weight loss after bariatric surgery on functional and structural markers of atherosclerosis

Objective: Pronounced weight loss after bariatric surgery was demonstrated to have significant beneficial effects on surrogates of early atherosclerosis. The aim of this prospective examination was to investigate whether these improvements of endothelial function and vascular structure are persistent in the long‐term. Design and Methods: A total of 52 obese adults were examined before and 5 years after bariatric surgery. Carotid intima media thickness (IMT), brachial flow‐mediated dilation (FMD), abdominal fat distribution, and metabolic parameters were determined. Additional 18 months data were available from 27 patients. Results: After 5 years, mean weight loss ± SD of 25% ± 12 in all subjects was accompanied by known improvements in metabolism. Change in IMT was ?0.02 mm ± 0.007, whereas FMD improved by +1.5% ± 0.5. In the subgroup IMT decreased by 0.04 mm ± 0.06 within the first 18 months, whereas no significant change was observed between 18 month and 5 years. FMD improved by 3.8% ± 0.6 after 18 months followed by a nonsignificant decrease of ?1.4% ± 0.9. Conclusions: These long‐term results demonstrate that bariatric surgery‐induced weight loss improves both functional and structural markers of early atherosclerosis providing further evidence for the beneficial effects of weight loss on obesity‐associated alterations of the vasculature.     

A Weight Reduction Program Preserves Fat‐Free Mass but Not Metabolic Rate in Obese Adolescents

Objective: To determine the effects of a multidisciplinary weight reduction program on body composition and energy expenditure (EE) in severely obese adolescents. Research Methods and Procedures: Twenty‐six severely obese adolescents, 12 to 16 years old [mean BMI: 33.9 kg/m²; 41.5% fat mass (FM)] followed a 9‐month weight reduction program including moderate energy restriction and progressive endurance and resistance training. Body composition was assessed by DXA, basal metabolic rate by indirect calorimetry, and EE by whole‐body indirect calorimetry with the same activity program over 36‐hour periods before starting and 9 months after the weight reduction period. Results: Adolescents gained (least‐square mean ± SE) 2.9 ± 0.2 cm in height, lost 16.9 ± 1.3 kg body weight (BW), 15.2 ± 0.9 kg FM, and 1.8 ± 0.5 kg fat‐free mass (FFM) (p < 0.001). Basal metabolic rate, sleeping, sedentary, and daily EE were 8% to 14% lower 9 months after starting (p < 0.001) and still 6% to 12% lower after adjustment for FFM (p < 0.05). Energy cost of walking decreased by 22% (p < 0.001). The reduction in heart rate during sleep and sedentary activities (?10 to ?13 beats/min), and walking (?20 to ?25 beats/min) (p < 0.001) resulted from both the decrease in BW and physical training. Discussion: A weight reduction program combining moderate energy restriction and physical training in severely obese adolescents resulted in great BW and FM losses and improvement of cardiovascular fitness but did not prevent the decline in EE even after adjustment for FFM.     

Association Between the 4 bp Proinsulin Gene Insertion Polymorphism (IVS‐69) and Body Composition in Black South African Women

The objective of the study was to examine the association between a functional 4 bp proinsulin gene insertion polymorphism (IVS‐69), fasting insulin concentrations, and body composition in black South African women. Body composition, body fat distribution, fasting glucose and insulin concentrations, and IVS‐69 genotype were measured in 115 normal‐weight (BMI <25 kg/m²) and 138 obese (BMI ≥30 kg/m²) premenopausal women. The frequency of the insertion allele was significantly higher in the class 2 obese (BMI ≥35kg/m²) compared with the normal‐weight group (P = 0.029). Obese subjects with the insertion allele had greater fat mass (42.3 ± 0.9 vs. 38.9 ± 0.9 kg, P = 0.034) and fat‐free soft tissue mass (47.4 ± 0.6 vs. 45.1 ± 0.6 kg, P = 0.014), and more abdominal subcutaneous adipose tissue (SAT, 595 ± 17 vs. 531 ± 17 cm², P = 0.025) but not visceral fat (P = 0.739), than obese homozygotes for the wild‐type allele. Only SAT was greater in normal‐weight subjects with the insertion allele (P = 0.048). There were no differences in fasting insulin or glucose levels between subjects with the insertion allele or homozygotes for the wild‐type allele in the normal‐weight or obese groups. In conclusion, the 4 bp proinsulin gene insertion allele is associated with extreme obesity, reflected by greater fat‐free soft tissue mass and fat mass, particularly SAT, in obese black South African women.     

Endothelial function and weight loss: Comparison of low‐carbohydrate and low‐fat diets

Objective: The effect of weight loss on obesity‐associated endothelial dysfunction is not clear because of conflicting data, demonstrating both improvement and no change in endothelial function after weight loss in obese subjects. A 2‐year prospective study (n = 121) was conducted to examine: (1) the effect of obesity and weight loss (either a low‐carbohydrate or and low‐fat diet) on flow mediated vasodilatation (FMD), a measure of endothelial function. Design and Methods: Participants reduced body weight by 7.1% ± 4.4%, 8.7% ± 6.8%, 7.1% ± 7.8%, and 4.1% ± 7.7% at 3, 6, 12, and 24 months, respectively with no significant differences between the low‐fat and low‐carbohydrate groups. Results: Endothelial function was inversely correlated with waist circumference, triglyceride level, and directly correlated with leptin in obese persons prior to weight loss. These weight losses did not confer any improvements in FMD. There were no differences between the low‐fat and low‐carbohydrate diets in FMD at any time point. At 6 months (r = 0.26, P = 0.04) and 1 year (r =0.28, P = 0.03), there were positive correlations between change in FMD and change in leptin but not at 2 years. Conclusion: There was no significant improvement in endothelial function after 7.1% ± 7.8% weight loss at 1 year and 4.1% ± 7.7% at 2 years, achieved by either a low carbohydrate or a low fat diet.     

Effects of Diabetes and Obesity on Vascular Reactivity,Inflammatory Cytokines,and Growth Factors

We examined the influences of obesity and diabetes on endothelium‐dependent and ‐independent vasodilation, inflammatory cytokines, and growth factors. We included 258 subjects, age 21–80 years in four groups matched for age and gender: 40 healthy nonobese (BMI <30 kg·m^?2) nondiabetic subjects, 76 nonobese diabetic patients, 37 obese (BMI >30) nondiabetic subjects, and 105 obese (BMI >30) diabetic patients. The flow‐mediated dilation (FMD, endothelium‐dependent) and nitroglycerin‐induced dilation (NID, endothelium‐independent) in the brachial artery, the vascular reactivity at the forearm skin and serum growth factors and inflammatory cytokines were measured. FMD was reduced in the nonobese diabetic patients, obese nondiabetic controls, and obese diabetic patients (P < 0.0001). NID was different among all four groups, being highest in the obese nondiabetic subjects and lowest in the obese diabetic patients (P < 0.0001). The resting skin forearm blood flow was reduced in the obese nondiabetic subjects (P < 0.01). Vascular endothelial growth factor (VEGF) was higher in the obese nondiabetic subjects (P < 0.05), tumor necrosis factor–α was higher in the obese diabetic patients (P < 0.0001) and C‐reactive protein was higher in both the obese nondiabetic and diabetic subjects (P < 0.0001). Soluble intercellular adhesion molecule‐1 was elevated in the two diabetic groups and the obese nondiabetic subjects (P < 0.05). We conclude that diabetes and obesity affect equally the endothelial cell function but the smooth muscle cell function is affected only by diabetes. In addition, the above findings may be related to differences that were observed in the growth factors and inflammatory cytokines.     

Influence of Visceral Obesity and Liver Fat on Vascular Structure and Function in Obese Subjects

Endothelial dysfunction and increased intima–media thickness (IMT) have been found in obese patients. Both regional fat distribution and liver steatosis may influence these markers of subclinical atherosclerosis. We sought to determine the interrelationships of endothelial function, carotid IMT, visceral and subcutaneous adipose tissue accumulation, and liver steatosis in severely obese subjects. In 64 severely obese patients (BMI 42.3 ± 4.3 kg/m²), we determined (i) endothelial function as flow‐mediated dilation (FMD) of the brachial artery, (ii) carotid IMT, (iii) visceral fat diameter, and (iv) degree of liver steatosis using ultrasound. FMD was associated inversely with visceral fat diameter and degree of steatosis (r = ?0.577, P < 0.0001 and r = ?0.523, P < 0.0001, respectively). Carotid IMT correlated with visceral fat mass (r = 0.343, P = 0.007) but not with liver steatosis. After adjustment for conventional cardiovascular risk factors, FMD was predicted independently by the visceral fat diameter, age, and sex (r² = 0.48, P < 0.0001), but not by the degree of liver steatosis or plasma adiponectin levels. In contrast, age and sex were the only predictors of IMT (r² = 0.33, P < 0.001). In obese patients, visceral fat diameter is a major determinant of endothelial dysfunction, independent of traditional risk factors or the degree of liver steatosis and plasma adiponectin. Measurement of visceral fat diameter by ultrasound is a novel and simple method to identify subjects with an increased risk for atherosclerosis within an obese population.     

Higher protein intake preserves lean mass and satiety with weight loss in pre-obese and obese women

Objective: To examine the effects of dietary protein and obesity classification on energy‐restriction‐induced changes in weight, body composition, appetite, mood, and cardiovascular and kidney health. Research Methods and Procedures: Forty‐six women, ages 28 to 80, BMI 26 to 37 kg/m², followed a 12‐week 750‐kcal/d energy‐deficit diet containing higher protein (HP, 30% protein) or normal protein (NP, 18% protein) and were retrospectively subgrouped according to obesity classification [pre‐obese (POB), BMI = 26 to 29.9 kg/m²; obese (OB), BMI = 30 to 37 kg/m²). Results: All subjects lost weight, fat mass, and lean body mass (LBM; p < 0.001). With comparable weight loss, LBM losses were less in HP vs. NP (?1.5 ± 0.3 vs. ?2.8 ± 0.5 kg; p < 0.05) and POB vs. OB (?1.2 ± 0.3 vs. ?2.9 ± 0.4 kg; p < 0.005). The main effects of protein and obesity on LBM changes were independent and additive; POB‐HP lost less LBM vs. OB‐NP (p < 0.05). The energy‐restriction‐induced decline in satiety was less pronounced in HP vs. NP (p < 0.005). Perceived pleasure increased with HP and decreased with NP (p < 0.05). Lipid‐lipoprotein profile and blood pressure improved and kidney function minimally changed with energy restriction (p < 0.05), independently of protein intake. Discussion: Consuming a higher‐protein diet and accomplishing weight loss before becoming obese help women preserve LBM. Use of a higher‐protein diet also improves perceptions of satiety and pleasure during energy restriction.     

Impact of surgically induced weight loss on cardiovascular autonomic function: one-year follow-up

Objective: To determine the impact of surgically induced weight loss on cardiovascular autonomic function in subjects with severe obesity and examine whether the effect was comparable for persons with and without diabetes. Research Methods and Procedures: Twenty‐six severely obese individuals (BMI = 48 ± 7 kg/m²) underwent bariatric surgery (laparoscopic Roux‐en‐Y gastric bypass, n = 21; laparoscopic adjustable gastric banding, n = 5). Cardiovascular autonomic function (heart rate variation during deep breathing and the Valsalva maneuver) was assessed before and 6 and 12 months after surgery. Results: Twelve months after bariatric surgery, there was a 28% decrease in BMI. There was an increase in all parasympathetic indices of autonomic function (all assessment modalities, p < 0.05) with weight loss. The amount of improvement from baseline for all measures of autonomic function did not differ for those with or without diabetes. Discussion: Surgically induced weight loss 12 months after surgery has a favorable effect on cardiovascular autonomic function in severely obese individuals with and without diabetes.     

Regular Aerobic Exercise,Without Weight Loss,Improves Endothelium‐dependent Vasodilation in Overweight and Obese Adults

Lifestyle modification in the form of weight reduction by caloric restriction alone or in combination with regular aerobic exercise significantly improves endothelium‐dependent vasodilation in overweight and obese adults. We determined whether regular aerobic exercise, independent of weight loss, improves endothelium‐dependent vasodilation in overweight and obese adults. Twenty overweight and obese adults (age 53 ± 1 years; BMI: 30.2 ± 0.8 kg/m²) were studied before and after a 3‐month aerobic exercise training intervention. Forearm blood flow (FBF) responses were determined (via plethysmography) in response to intra‐arterial infusion of acetylcholine and sodium nitroprusside. There were no changes in body mass or composition with the intervention. FBF responses to acetylcholine were ～35% higher (P < 0.01) after (4.1 ± 0.9 to 14.7 ± 4.3 ml/100 ml tissue/min) compared with before (4.2 ± 0.8 to 11.0 ± 3 ml/100 ml tissue/min) exercise training. FBF responses to sodium nitroprusside were unchanged. These results indicate that regular aerobic exercise improves endothelium‐dependent vasodilation in overweight and obese adults, independent of changes in body mass or composition.