Prediction of Whole-Body and Segmental Body Composition by Bioelectrical Impedance in Morbidly Obese Subjects

Background  

Validated equations for body composition analysis using bioelectrical impedance (BIA) in morbidly obese (MO) subjects are scarce. Thus, our aim was to develop new equations from physical and BIA parameters to estimate whole-body and segmental body composition in MO subjects, with dual-energy X-ray absorptiometry (DXA) as the reference method.     

Weight loss independently predicts urinary albumin excretion normalization in morbidly obese type 2 diabetic patients undergoing bariatric surgery

Background

Despite obesity being closely associated with two common risk factors for albuminuria, namely type 2 diabetes mellitus (T2DM) and hypertension, information on the impact of weight loss on albumin excretion rate in morbidly obese (MO) subjects is scarce.

Objective

To evaluate the independent contribution of weight loss following bariatric surgery (BS) to the improvement of the albumin-to-creatinine ratio (ACR) in MO subjects with T2DM.

Subjects and methods

Observational prospective study, including consecutive (n = 255) patients undergoing Roux-en-Y gastric bypass (GBP) or sleeve gastrectomy (SG) of whom 37.6 % (n = 96) presented with T2DM. Stepwise logistic regression analysis was used to assess the contribution of T2DM-related, hypertension-related, and weight loss-related variables, and type of surgery to normalization of ACR (<30 mg/g) at 12 and 24 months follow-up.

Results

In T2DM subjects, baseline ACR was 85.7 ± 171 mg/g with ACR ≥30 mg/g being present in 45.7 % of the cohort. At 12 months, the ACR significantly decreased in T2DM subjects (42.2 ± 142.8 mg/g; p < 0.005) with no further reduction at 24 months after surgery (44.4 ± 227.7; p = 0.862). Among T2DM subjects with ACR ≥30 mg/g at baseline, the ACR became <30 mg/g in 58.5 % and 76.9 % at 12 and 24 months, respectively (p < 0.001 relative to baseline). Body mass index (BMI) change from baseline was the only independent predictor of ACR normalization at 12 months [Exp(B) 1.373, 95 % confidence interval 1.075–1.703; p < 0.05]. None of the evaluated variables appeared as an independent predictor of ACR normalization at 24 months.

Conclusions

Our data suggest that, in MO subjects with T2DM, interventions aiming at slowing the progression of nephropathy should not only focus on optimization of glucose and blood pressure control but also include effective weight loss strategies.     

Anthropometric indexes outperform bioelectrical impedance analysis-derived estimates of body composition in identification of metabolic abnormalities in morbid obesity

BackgroundThe validity of anthropometric indexes in ascertaining the body composition (BC) in morbidly obese (MO) subjects has been questioned. Our objective was to evaluate, in MO subjects, whether bioelectrical impedance analysis (BIA) of BC is more closely associated with the metabolic syndrome (MS) and insulin resistance (IR) than are classic anthropometric measurements. The setting was a university hospital.MethodsThe association between anthropometric (body mass index, waist circumference [WC]) and BIA (total fat mass [FM] [percentage of FM], truncal FM, android FM) estimates of BC, MS, and IR was evaluated in 784 white MO subjects (212 men and 572 women). BIA estimates were calculated using equations specific for MO subjects developed by our own group and validated against dual energy x-ray absorptiometry.ResultsThe prevalence of the MS and IR was 78.6% and 88.6%, respectively. The body mass index was greater in women with the MS (P <.001) or IR (P <.001), and the WC was larger in subjects of both genders with the MS or IR (P <.001). Moreover, the WC correlated significantly with all the MS components (P <.05). In contrast, the percentage of FM, truncal FM, and android FM were significantly associated with the MS only in women. Stepwise logistic regression analysis demonstrated the WC as the only significant predictor of the MS or IR (both P <.001). Furthermore, receiver operating curve analysis showed WC was the most accurate BC parameter for the identification of subjects with the MS (area under the curve, WC = .681, P <.001) or IR (area under the curve, WC = .753, P <.001).ConclusionIn MO subjects, the BIA-derived indexes of total and central adiposity were not better predictors of the MS or IR than were traditional anthropometric measurements.     

Comparable early changes in gastrointestinal hormones after sleeve gastrectomy and Roux-En-Y gastric bypass surgery for morbidly obese type 2 diabetic subjects

Background

Sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGBP) are associated with similar type 2 diabetes mellitus (T2DM) resolution rates for morbidly obese subjects. However, the mechanisms underlying the resolution of T2DM after SG have not been clarified to date. This study aimed to compare the early changes in gastrointestinal hormones involved in insulin and glucagon secretion in morbidly obese T2DM subjects undergoing SG or RYGBP.

Methods

This prospective study investigated 12 subjects with T2DM who had undergone SG (n?=?6) or RYGBP (n?=?6). Five body mass index (BMI)-matched obese non-diabetic subjects and five BMI-matched obese diabetic subjects served as control subjects. Glucose, insulin, glucagon, glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and GLP-2 were determined after a standardized mixed liquid meal before surgery and 6?weeks afterward.

Results

After 6?weeks, five of the six subjects in each surgical group presented with T2DM remission, although the area under the curve (AUC)_0–120 of glucose was greater than that of the non-diabetic control subjects (P?0–120 of GLP-1 (P?P?P?Conclusions The data show that in a cohort of morbidly obese T2DM subjects, SG and RYGBP are associated with an early improvement in glucose tolerance, similar changes in insulin and glucagon secretion, and a similar GLP-1, GIP, and GLP-2 response to a standardized mixed liquid meal.