Low-back pain in morbidly obese patients and the effect of weight loss following surgery.

BACKGROUND: Although low-back pain (LBP) is a common health problem and a source of significant discomfort, disability and work absences, its incidence, severity and outcome have not been extensively investigated in morbidly obese patients undergoing bariatric surgery. METHODS: 50 morbidly obese candidates for vertical banded gastroplasty (VBG) were asked to fill in a questionnaire, to assess the incidence and severity of any existing LBP symptoms. 50 non-obese patients, admitted to our surgical unit for management of several benign conditions, were also asked to fill in the same questionnaire and served as controls. 24 months after VBG, the morbidly obese patients were again evaluated for their LBP symptoms. RESULTS: LBP was identified in 29 morbidly obese patients (58%) preoperatively and in only 12 (24%) of the lean controls (P<0.01). 2 years after VBG, with a significant excess weight loss (P<0.0001), only 10 patients continued to have LBP but less frequently and requiring reduced doses of medications compared with the preoperative condition. In the remaining 19 patients with preoperative positive LBP history, the postoperative weight loss was associated with complete resolution of the symptoms. CONCLUSION: The frequency of LBP is significantly higher in morbidly obese patients than in lean subjects. Surgical weight reduction results in significant improvement and even disappearance of this obesity co-morbidity.

Human exposure to endocrine disrupters: consequences of gastroplasty on plasma concentration of toxic pollutants.

BACKGROUND: Body weight loss occurring after a hypoenergetic diet or a gastroplasty could be followed by an increase in blood concentration of potentially toxic pollutants that can interfere with the hormonal system (endocrine disrupters). DESIGN: Thirty obese individuals recruited for gastroplasty were compared before and after treatment with 45 normal-weight people. MEASUREMENTS: Blood samples were analyzed for DDT, DDE, HCB and PCBs no. 28, 52, 101, 118, 138, 153 and 180, by gas chromatography-mass spectrometry. RESULTS: The results indicate clearly that body weight loss occurring after gastroplasty increases plasma concentration of lipophilic pollutants. CONCLUSION: Gastroplasty increases plasma concentration of organochlorine pesticides and PCBs, which could be a risk factor of endocrine disruption. Future longitudinal research will have to determine if the advantages of body weight loss are reduced by this potentially harmful effect.

Anthropometric evolution during hospitalization of severe malnourished children with persistent diarrhea receiving standardized nutritional supportIn order to estimate the nutritional rehabilitation (NR) during admission of malnourished children with persistent diarrhea (PD) receiving standardized nutritional support (NS), we prospectively evaluated the weight, height, head circumference and arm measurements (AM) of 20 children, 19 below 1 year, admitted to the ward with weigh/age -2.89 to -5.21 standard deviation. Four infants comprised the death group (DG) and 16 survived (SG). The SG was separated, according to initial weight behavior, into weight gain (WG) or weight loss (WL). Compared to SG at admission, DG only had lower AM and more metabolic-infectious alterations (p<05). The survivors presented NR but this was evident for WL only when considering the minimum weight. DG received less calories than SG and weight loss during the pre-death period was higher than for WL (p<05). It was concluded that very altered AM, severe metabolic-infectious insults, low caloric input and high weight loss velocity are associated to bad prognosis; severely malnourished infants with PD began NR during hospitalization while receiving adequate NS, but minimum weight must be considered for this evaluation; AM must be obtained at admission, due to its prognostic value, and adequate NS as well as anthropometric follow-up during the hospital stay are essential.

Results of laparoscopic gastric bypass in patients with cirrhosis.

BACKGROUND: The safety and efficacy of bariatric surgery in patients with cirrhosis has not been well studied. METHODS: A retrospective review was conducted of patients with cirrhosis who underwent weight-loss surgery at a single institution. RESULTS: Out of a total of 2119 patients who underwent laparoscopic Roux-en-Y gastric bypass (RYGBP), 30 patients (1.4%) with cirrhosis were identified.When compared with the entire cohort, patients with cirrhosis were significantly more prone to be heavier (BMI 53 vs 48), older in years (age 50 vs 45), more likely to be male (RR=1.3), and have a higher incidence of diabetes (70% vs 21%) and hypertension (67% vs 21%), P<0.05. The diagnosis of cirrhosis was made intra-operatively in 90% of patients. There were no perioperative deaths, conversions to laparotomy, or liver-related complications. Early complications occurred in 9 patients and included anastomotic leak (1), acute tubular necrosis (4), prolonged intubation (2), ileus (1), and blood transfusion (2). Mean length of hospital stay was 4 days (2-18). There was one late unrelated death and one patient with prolonged nausea and protein malnutrition. The average follow-up time was 16 months (1-48). For patients >12 months postoperatively (n=15), the average percent excess weight loss was 63+/-15%. CONCLUSION: Laparoscopic RYGBP in the cirrhotic patient has an acceptable complication rate and achieves satisfactory early weight loss. Patients tend to be heavier, older, male and more likely to have diabetes and hypertension. Long-term studies are necessary to examine how weight loss impacts established cirrhosis.

Lactation, weaning, and calcium supplementation: effects on body composition in postpartum women.

BACKGROUND: Concern that long-term weight retention after pregnancy contributes to obesity underscores the need to identify factors that facilitate postpartum weight loss. Lactation is believed to facilitate postpartum weight loss and fat loss. Calcium intake also has been hypothesized to promote weight loss and fat loss. OBJECTIVE: We addressed the following questions: 1) whether lactation enhances loss of fat mass, and 2) whether loss of fat mass during lactation and after weaning is greater in women receiving calcium supplementation than in women receiving placebo. DESIGN: We used data from 87 lactating and 81 nonlactating women enrolled in a randomized, double-blind, calcium supplementation trial from 2 wk to 6 mo postpartum and data from 76 previously lactating and 82 nonlactating women enrolled in a parallel trial from 6 to 12 mo postpartum. Body fat and lean masses were measured by using dual-energy X-ray absorptiometry. RESULTS: Nonlactating women lost whole-body, arm, and leg fat at a faster rate than did lactating women between 2 wk and 6 mo postpartum (lactation group x time effect, P < or = 0.01). Fat mass of the trunk, arms, and legs decreased between 6 and 12 mo postpartum regardless of previous lactation status (time effect, P < or = 0.001). Calcium supplementation did not affect postpartum fat loss. CONCLUSIONS: Body-composition changes occur differently in nonlactating and lactating women during the first 6 mo postpartum and occur at some sites until 12 mo postpartum regardless of previous lactation status. Clinicians should use caution when advising lactating mothers about expected rates of postpartum fat loss. Calcium supplementation (1 g/d) does not promote postpartum weight loss or fat loss.

Effect of weight loss on VLDL-triglyceride and apoB-100 kinetics in women with abdominal obesity.

The effects of obesity and weight loss on lipoprotein kinetics were evaluated in six lean women [body mass index (BMI): 21 +/- 1 kg/m(2)] and seven women with abdominal obesity (BMI: 36 +/- 1 kg/m(2)). Stable isotope tracer techniques, in conjunction with compartmental modeling, were used to determine VLDL-triglyceride (TG) and apolipoprotein B-100 (apoB-100) secretion rates in lean women and in obese women before and after 10% weight loss. VLDL-TG and VLDL-apoB-100 secretion rates were similar in lean and obese women. weight loss decreased the rate of VLDL-TG secretion by approximately 40% (from 0.41 +/- 0.05 to 0.23 +/- 0.03 micromol x kg fat-free mass(-1) x min(-1); P < 0.05). The relative decline in VLDL-TG produced from nonsystemic fatty acids, derived from intraperitoneal and intrahepatic TG, was greater (61 +/- 7%) than the decline in VLDL-TG produced from systemic fatty acids, predominantly derived from subcutaneous TG (25 +/- 8%; P < 0.05). weight loss did not affect VLDL-apoB-100 secretion rate. We conclude that weight loss decreases the rate of VLDL-TG secretion in women with abdominal obesity, primarily by decreasing the availability of nonsystemic fatty acids. There is a dissociation in the effect of weight loss on VLDL-TG and apoB-100 metabolic pathways that may affect VLDL particle size.

Comparison of methods for assessing body composition changes during weight loss.

PURPOSE: Four cross-sectional studies have reported that percent body fat (%BF) measured by dual-energy x-ray absorptiometry (DXA) is significantly higher compared with values obtained with air displacement plethysmography (ADP) using the Bod Pod(R) in normal-weight individuals. This study was performed to confirm these findings in an overweight population and to assess whether DXA and ADP detected similar changes in body composition after moderate weight loss. METHODS: Twelve women (42 +/- 8 yr) and 10 men (40 +/- 11 yr) had their %BF, fat mass (FM), and fat-free mass (FFM) measured using DXA and ADP before and after an 8-wk weight-loss program involving moderate energy restriction and exercise. RESULTS: Body weight decreased significantly in women (-4.3 +/- 3.4 kg) and men (-4.7 +/- 3.1 kg). There were significant method (ADP vs DXA) and time (pre and post) effects but no method by time or gender interactions. Methods were significantly different in estimating %BF, FM, and FFM with ADP estimates of %BF and FM being lower and estimates of FFM higher than corresponding DXA values (P = 0.000). There were significant correlations accounting for a high degree of the shared variance between DXA and ADP (r = 0.98 to 0.99) for %BF, FM, and FFM and lower correlations for the changes in %BF (r = 0.66), FM (r = 0.86), and FFM (r = 0.34). In response to weight loss, the mean changes in %BF, FM, and FFM were not significantly different between methods (P > 0.05). CONCLUSION: Both DXA and ADP measure changes in body composition after small to moderate weight loss to the same extent and with similar sensitivity.

Decreased mitochondrial proton leak and reduced expression of uncoupling protein 3 in skeletal muscle of obese diet-resistant women.

weight loss in response to caloric restriction is variable. Because skeletal muscle mitochondrial proton leak may account for a large proportion of resting metabolic rate, we compared proton leak in diet-resistant and diet-responsive overweight women and compared the expression and gene characteristics of uncoupling protein (UCP)2 and UCP3. Of 1,129 overweight women who completed the University of Ottawa Weight Management Clinic program, 353 met compliance criteria and were free of medical conditions that could affect weight loss. Subjects were ranked according to percent body weight loss during the first 6 weeks of a 900-kcal meal replacement protocol. The highest and lowest quintiles of weight loss were defined as diet responsive and diet resistant, respectively. After body weight had been stable for at least 10 weeks, 12 of 70 subjects from each group consented to muscle biopsy and blood sampling for determinations of proton leak, UCP mRNA expression, and genetic studies. Despite similar baseline weight and age, weight loss was 43% greater, mitochondrial proton leak-dependent (state 4) respiration was 51% higher (P = 0.0062), and expression of UCP3 mRNA abundance was 25% greater (P < 0.001) in diet-responsive than in diet-resistant subjects. There were no differences in UCP2 mRNA abundance. None of the known polymorphisms in UCP3 or its 5' flanking sequence were associated with weight loss or UCP3 mRNA abundance. Thus, proton leak and the expression of UCP3 correlate with weight loss success and may be candidates for pharmacological regulation of fat oxidation in obese diet-resistant subjects.