Safety of Blood Glucose Response Following Exercise Training After Bariatric Surgery.

INTRODUCTION: Safety of exercise training in relationship with the risk of hypoglycemia post-bariatric surgery is unknown. OBJECTIVE: To evaluate the safety and magnitude of changes in blood glucose levels during exercise training following bariatric surgery. MATERIAL AND METHODS: Twenty-nine severely obese patients undergoing either sleeve gastrectomy (SG) (n = 16) or biliopancreatic diversion with duodenal switch (BPD-DS) (n = 13) were prospectively enrolled. Three months after surgery, patients participated in a 12-week supervised exercise training program, (35-min aerobic training with a 25-min resistance exercises) three times a week. Capillary blood glucose (CBG) levels were measured immediately before and after each exercise session. RESULTS: Seven patients (24%) had type 2 diabetes before surgery (mean duration: 10 years); four patients still have type 2 diabetes 3 months post-bariatric surgery. A total of 577 exercise training sessions with CBG monitoring were recorded. Only seven sessions (1.2%) were associated with an episode of asymptomatic hypoglycemia (CBG ≤ 3.9 mmol/L). Patients with type 2 diabetes at baseline showed a larger decrease in CBG with pre-exercise CBG being between 6.1 and 8.0 mmol/L (- 1.6 ± 1.2 vs. - 1.1 ± 0.9 mmol/L, p = 0.02). BPD-DS patients with CBG ≥ 6.1 mmol/L showed higher reduction in CBG following exercise vs. SG patients (- 1.7 ± 1.0 vs. - 1.1 ± 1.1 mmol/L; p < 0.001 and - 4.3 ± 1.0 vs. - 2.2 ± 1.4 mmol/L, p < 0.001, respectively). CONCLUSION: Three months after bariatric surgery, exercise training program in patients without and with type 2 diabetes is safe, and is associated with a desirable glycemic profile, with few episodes of asymptomatic hypoglycemia.

Fat-Free Mass and Skeletal Muscle Mass Five Years After Bariatric Surgery.

OBJECTIVE: This study investigated changes in fat-free mass (FFM) and skeletal muscle 5 years after surgery in participants from the Longitudinal Assessment of Bariatric Surgery-2 trial. METHODS: A three-compartment model assessed FFM, and whole-body magnetic resonance imaging (MRI) quantified skeletal muscle mass prior to surgery (T0) and 1 year (T1), 2 years (T2), and 5 years (T5) postoperatively in 93 patients (85% female; 68% Caucasian; age 44.2 ± 11.6 years) who underwent gastric bypass (RYGB), sleeve gastrectomy, or adjustable gastric band. Repeated-measures mixed models were used to analyze the data. RESULTS: Significant weight loss occurred across all surgical groups in females from T0 to T1. FFM loss from T0 to T1 was greater after RYGB (mean ± SE: -6.9 ± 0.6 kg) than adjustable gastric band (-3.5 ± 1.4 kg; P < 0.05). Females with RYGB continued to lose FFM (-3.3 ± 0.7 kg; P < 0.001) from T1 to T5. A subset of males and females with RYGB and MRI-measured skeletal muscle showed similar initial FFM loss while maintaining FFM and skeletal muscle from T1 to T5. CONCLUSIONS: Between 1 and 5 years following common bariatric procedures, FFM and skeletal muscle are maintained or decrease minimally. The changes observed in FFM and muscle during the follow-up phase may be consistent with aging.

Long-Term Food Tolerance After Bariatric Surgery: Comparison of Three Different Surgical Techniques.

BACKGROUND: Food tolerance has been related to quality of life after bariatric surgery. However, long-term results about this issue are quite limited. The aim of this study was to evaluate the long-term food tolerance in obese patients submitted to surgery, comparing the results between gastric bypass (GBP), long alimentary modified biliopancreatic diversion (MBPD), and long alimentary modified duodenal switch (MDS). METHODS: A cross-sectional analytic study was performed. Food tolerance was studied with a questionnaire based on subjective alimentary satisfaction, tolerance to different foods, and frequency of vomiting and regurgitation. A food tolerance score was obtained (1 point being the worst possible tolerance and 27 points being a perfect one). Information was obtained with a telephone interview. RESULTS: One hundred ninety-six patients submitted to bariatric surgery were included. Ninety-nine patients were submitted to GBP, 54 to MBPD, and 43 to MDS. One hundred and sixty-one patients (82.1%) were not lost during a mean follow-up time of 87.9 months. Mean food tolerance score was 24.2. Tolerance satisfaction was good or excellent in 73.3% of the patients. Red meat was the worst tolerated food, but nearly 80% of the patients could tolerate it without any problem. Mean food tolerance score was 24.6, 24.0, and 23.7 for GBP, MBPD, and MDS, respectively. There were no significant differences between these procedures in food tolerance score, alimentary satisfaction, or frequency of vomiting. CONCLUSIONS: Long-term food tolerance after bariatric surgery is good. No differences between GBP, MBPD, and MDS were found.

Serum Bioavailable Vitamin D Concentrations and Bone Mineral Density in Women After Obesity Surgery.

INTRODUCTION: Low bone mass after obesity surgery may arise as a consequence of chronic malabsorption of calcium and vitamin D. However, we have not found any role of serum 25-hydroxyvitamin D or of polymorphisms in the vitamin D receptor gene in previous studies. PURPOSE: To investigate the circulating bioavailable 25-hydroxyvitamin D in women after bariatric procedures and its association with bone mass. PATIENTS AND METHODS: The study consisted of 91 women on follow-up for 7 ± 2 years after bariatric surgery. We measured bone mineral density (BMD), serum parathormone (PTH), 25-hydroxyvitamin D, and vitamin D binding protein (VDBP). All patients were genotyped for two variants in the coding region of VDBP (rs4588 and rs7041). Bioavailable 25-hydroxyvitamin D was calculated in double homozygotes. RESULTS: We found a negative correlation between bioavailable 25-hydroxyvitamin D and PTH (r = -0.373, P = 0.018), but not with BMD at lumbar spine (r = -0.065, P = 0.682) or hip (r = -0.029, P = 0.857). When adjusting by age, similar results were found for PTH (r = -0.441, P = 0.005), BMD at lumbar spine (r = -0.026, P = 0.874) and hip (r = -0.096, P = 0.561). After multivariate linear regression, forcing bioavailable 25-hydroxyvitamin D into the model resulted in a weak significant association with BMD at the lumbar spine (ß = - 0.247, P = 0.025). CONCLUSIONS: Serum bioavailable 25-hydroxyvitamin D concentrations are not associated with bone mass loss after bariatric surgery in women. The negative association with serum PTH levels suggests that vitamin D supplementation partly improves secondary hyperparathyroidism, yet other mechanisms may contribute to low bone mass after bariatric surgery.

Relationship Between Diet and Body Composition After Biliopancreatic Diversion.

BACKGROUND: Biliopancreatic diversion (BPD) has been shown to be one of the most effective techniques for losing weight, although the relationship between body composition and diet after the procedure is not well known. Our aim was to assess dietary changes and their effects on body composition. METHODOLOGY: This longitudinal study included all patients eligible for BPD who had undergone body composition analysis. Two assessments were performed: 6 weeks before and 1 year after surgery. Nutritional education was given after surgery by a registered dietitian, and dual energy X-ray absorptiometry was performed and a 3-day food record was collected for further analysis at both of the visits. RESULTS: Forty-six patients were included. The percentage of excess of weight loss was 61.03 % (SD 14.01 %), which was statistically different by gender (p = 0.045). The percentage of subjects reporting a low daily protein consumption of less than 60 g and 1.2 g/kg of ideal body weight (IBW)/day was 15.2 % before surgery and 19.6 % at 12 months (p = 0.006). The weight loss was mainly of fat mass (FM). There were differences of body composition by gender before and after surgery. A simple correlation analysis showed a significant association between daily energy intake and FM (g) only before surgery (p = 0.030), and also between daily protein intake (expressed as total g) and lean body mass (LBM) 12 months after surgery (p = 0.018), but no association was found with achieved protein goal. CONCLUSION: BPD enhanced by nutritional education seems to improve its results by achieving an adequate weight loss, preserving LBM, decreasing FM, and guaranteeing an appropriate protein intake.