Exercise Induces White Adipose Tissue Browning Across the Weight Spectrum in Humans.

While the effect of exercise on white adipose tissue browning and metabolic improvement in rodents is clear, there are few studies in humans with inconclusive results. Thus, the aim of the study was to assess whether an exercise intervention promotes subcutaneous adipose tissue browning in humans, and whether this response is associated with metabolic improvement in three groups of individuals defined by body mass index (BMI) (kg/m2). Sedentary adult subjects with different BMI were enrolled in a 12-week bicycle-training program (3 times per week, intensity 70-80% HRmax). Brown and beige gene expression in subcutaneous adipose tissue (scWAT) biopsies, and serum glucose, insulin, lipid, adipokine, and myokine levels were compared before and after the exercise intervention. Thirty-three non-diabetic subjects (mean age 30.4 ± 4.6 years; 57.57% female; 13 normal weight, 10 overweight and 10 with obesity) completed the exercise intervention. Without any significant change in body composition, exercise improved several metabolic parameters, most notably insulin resistance and particularly in the overweight group. Circulating adiponectin, apelin, and irisin exercise-induced changes predicted 60% of the insulin sensitivity improvement. After exercise UCP1, TBX1, CPT1B scWAT expression significantly increased, along with P2RX5 significant positive staining. These changes are compatible with scWAT browning, however, they were not associated with glucose metabolism improvement. In conclusion, 12-weeks of exercise training produced brown/beige gene expression changes in abdominal scWAT of non-diabetic individuals with different BMI, which did not contribute to the metabolic improvement. However, this result should not be interpreted as a lack of effect of browning on metabolic parameters. These findings suggest that a bigger effect is needed and should not preclude the development of more effective strategies of browning. Furthermore, exercise-induced changes in adiponectin, apelin, and irisin predicted insulin sensitivity improvement, supporting the important role of adipokines and myokines in metabolism homeostasis.

Differences in Body Composition in Patients with Obesity 1 Year After Roux-En-Y Gastric Bypass: Successful Vs. Unsuccessful Weight Loss.

AIM: The aim of this study is to compare the differences in body composition in patients with obesity with successful weight loss (SWL) and unsuccessful (USWL) 1 year after Roux-en-Y gastric bypass (RYGB). METHODS: We included 36 women and 22 men. After stratifying patients according with SWL (defined as ≥ 50% of excess weight loss), fat-free mass (FFM) and fat mass (FM) trajectories were analyzed in each group. RESULTS: The %FM in SWL women (78%) was lower than USWL (36 vs. 44, p < 0.001). The %FM in SWL men (77%) was lower than USWL (27 vs. 38, p < 0.05). A lower %FM before surgery increased the probability of success (p < 0.05). CONCLUSIONS: SWL patients have a lower %FM, and those with lower pre-surgical %FM are more likely to have SWL 1 year after RYGB.

Impact of Body Mass Index >50 on Cardiac Structural and Functional Characteristics and Surgical Outcomes After Bariatric Surgery.

BACKGROUND: Body mass index (BMI) ≥50.0 kg/m2 has been associated with increased surgical complications and mortality. We assessed echocardiographic characteristics and bariatric surgery complications of patients with BMI ≥50.0 kg/m2 vs. those in less severe obesity. METHODS AND RESULTS: A retrospective analysis in patients who underwent gastric bypass was performed. Pre-surgery structural characteristics analyzed included left atrial dimension (LA), left ventricle mass (LVM), LVM indexed for height2.7 (LVMI), and LV hypertrophy (LVH). Functional characteristics included LV diastolic and systolic function. Degree of obesity was correlated with cardiac parameters, comorbidities, and surgical complications. Data on 312 patients (75.3 % women, age 39.3 ± 0.6 years, BMI 50.2 ± 0.5 kg/m2) were analyzed. Cardiac parameters on the basis of BMI (<50 kg/m2 vs. ≥50 kg/m2) were LA 39.6 ± 4.8 vs. 41.9 ± 5.2 mm, LVM 161 ± 46 vs. 194 ± 56 g, LVMI 43.6 ± 0.9 vs. 51.8 ± 1.3 g/ht2.7, and systolic pulmonary pressure 43.7 ± 10.1 vs. 50.5 ± 11.3 mmHg, respectively (all p < 0.001). LVMI was correlated with BMI (p < 0.001), 2-h glucose on a glucose tolerance test (p = 0.01), and ejection fraction (p = 0.01). Surgical complications were not different among groups. Presence of LVH was independently associated with BMI ≥50 kg/m2 and female sex, after adjusting for age, diabetes, hypertension, and pulmonary hypertension. CONCLUSION: Body mass index ≥50 kg/m2 was independently associated with female sex and LVH but not with hypertension, diabetes, or a higher rate of surgical complications.