Bariatric surgery in obesity: changes of glucose and lipid metabolism correlate with changes of fat mass.

BACKGROUND AND AIM: Bariatric surgery induces significant weight loss and improves glucose metabolism in obese patients (BMI>35 kg/m(2)). Our aim was to compare restrictive (LAGB, laparoscopic gastric banding) and malabsorptive approaches (BIBP, biliary-intestinal bypass) on the loss of fat-free mass (FFM), fat mass (FM), and on changes of glucose and lipid metabolism. METHODS AND RESULTS: Body composition (bio-impedance analysis, BIA), blood glucose (BG), insulin, triglycerides, total- and HDL-cholesterol, liver enzymes (AST and ALT) were measured at baseline and 1 year after surgery in patients undergoing LAGB, BIBP, and in diet-treated control patients. In the main study, with patients matched for initial BMI (43-55 kg/m(2), LAGB=24, BIBP=12, controls=6), decreases of BMI, FM, BG and cholesterol were greater in patients with BIBP than with LAGB (p<0.01), while decreases of FFM, insulin, HOMA-IR and triglycerides were similar. No effects on BMI, FM, FFM, BG, insulin, HOMA-IR or cholesterol were observed in the control patients. Decreases of BG, insulin, HOMA-IR, cholesterol and triglycerides correlated with FM but not with FFM decrease. Similar results were obtained in an additional study in patients with a different initial BMI (LAGB=25, BIBP=6, controls=24) and when considering all subjects together. A decrease of liver enzymes (ALT) was greater with LAGB than with BIBP, and HDL-cholesterol increased with LAGB and decreased with BIBP. CONCLUSION: BMI, FM, BG and cholesterol decrease more with malabsorptive than with restrictive surgery, while FFM, insulin, HOMA-IR and triglycerides decrease in a similar way. FFM loss is of low entity. Changes of glucose and lipid metabolism are proportional to a decrease of fat mass but not of fat-free mass.

Effect of weight loss through laparoscopic gastric banding on blood pressure, plasma renin activity and aldosterone levels in morbid obesity.

BACKGROUND AND AIMS: Several mechanisms are probably involved in obesity-related hypertension. This study was aimed to investigate the effect of significant weight loss on blood pressure and plasma renin activity (PRA) and aldosterone levels, other then on metabolic profile, in normotensive and hypertensive obese subjects. METHODS AND RESULTS: Forty hypertensive and 55 normotensive obese subjects were studied under basal conditions and again 1 year after significant weight loss obtained through laparoscopic adjustable gastric banding (LAGB). Weight, waist circumference, blood glucose, insulin, electrolytes (Na and K), lipids and supine and upright PRA and aldosterone were evaluated. All parameters evaluated improved, except for total cholesterol, and electrolytes that did not change. Blood pressure decreased in hypertensive subjects, with a concordant decrease in PRA and supine aldosterone levels, not observed in normotensive patients. CONCLUSION: Weight loss is associated with reduction of blood pressure and of PRA and aldosterone levels in obese hypertensive subjects.

Ultrasound measurement of visceral and subcutaneous fat in morbidly obese patients before and after laparoscopic adjustable gastric banding: comparison with computerized tomography and with anthropometric measurements.

BACKGROUND: There are now a variety of methods to assess body fat distribution, anthropometric (waist circumference and waist/hip W/H ratio), computed tomography (CT), and ultrasound (US) measurements, with CT considered as the reference method. Bariatric surgery leads to a significant and usually durable weight loss in morbidly obese patients; when assessing its results, it is of interest to measure changes of total fat tissue and of body fat distribution. METHODS: In this study, we compared anthropometric, US, and CT measurements of body fat distribution under basal conditions and 1 year after laparoscopic adjustable gastric banding (LAGB); 120 morbidly obese patients were considered at baseline, and 40 patients were re-evaluated 1 year after LAGB. RESULTS: Thickness of visceral and subcutaneous fat measured through CT and US methods was superimposable both under basal conditions and 1 year after LAGB, and the highest correlation was found between CT and US data on visceral fat, followed by CT and US data on subcutaneous fat; a fair correlation was also found between CT and US data on visceral fat and waist circumference. CONCLUSION: We suggest that evaluation of body fat distribution is accomplished by US instead of CT measurement, because of its lower cost and low exposure risk. Waist circumference stands as a reasonable surrogate of both methods, while W/H ratio is poorly correlated with other measures of body fat distribution.

Efficacy and safety of acarbose in the treatment of Type 1 diabetes mellitus: a placebo-controlled, double-blind, multicentre study.

AIMS: The aim of the study was to evaluate the efficacy and safety of acarbose in patients with Type 1 diabetes mellitus (DM). METHODS: A multicentre double-blind, randomized, placebo-controlled study was performed. After a 6-week run-in, 121 patients were randomized to acarbose or placebo and to high- or low-fibre diet for 24 weeks. Acarbose dose was 50 mg t.d.s. for the first 2 weeks and 100 mg t.d.s. for the subsequent weeks. RESULTS: At the end of 24 weeks of treatment the intention to treat analysis showed that acarbose compared with placebo decreased 2 h postprandial plasma glucose levels (12.23 +/- 0.83 vs. 14.93 +/- 0.87 mmol/l; F = 6.1, P < 0.02) (least square means +/- SEM). No significant effect of acarbose was recorded on HbA1c or on the number of hypoglycaemic episodes. The effect of acarbose on blood glucose control was not influenced by the amount of carbohydrate and/or fibre intake. The incidence of adverse events were 75% and 39% in acarbose and placebo groups, respectively; they were mild and confined to the gastrointestinal tract. CONCLUSIONS: The use of acarbose in combination with insulin reduces postprandial plasma glucose levels in Type 1 diabetic patients who are not satisfactorily controlled with insulin alone but without significant effect on HbA1c.

Bioelectrical impedance in the evaluation of the nutritional status of hemodialyzed diabetic patients.

Bioelectrical impedance is a technique allowing a quick, repeatable and reliable assessment of body composition. This method was applied to detect total body water (TBW), fat (FAT) and fat-free mass (FFM) in 80 normal subjects, 65 diabetic (45 insulin-dependent [IDD], 20 non insulin-dependent [NIDD]) and 34 uremic diabetic patients (20 IDD, 14 NIDD) submitted to hemodialysis three times a week. Uremic patients were tested at the end of the dialytic session. Multivariated analysis adjusted for age, sex and disease showed the following results: body mass index (BMI) increased with age (p < 0.005) and in the presence of NIDD (p < .001); TBW was lower in nephropathic patients (p < 0.05) and in the female sex (p < 0.0001); FFM decreased with age (p < 0.005), female sex (p < 0.0001) and in nonuremic NIDD (p < 0.001). Correspondingly FAT increased with age (p < 0.005), female sex (p < 0.0001) and in nonuremic NIDD (p < 0.001). Sixteen uremic subjects, randomly selected from both IDD and NIDD groups, tested at the beginning and at the end of the same hemodialytic session, showed a significant decrease of TBW which corresponded to the correction of their overhydratation. In our patients uremia does not seem to influence the nutritional status and the bioelectrical analysis could be applied to determine the real dry weight in hemodialyzed diabetic patients.

[Evaluation of an impedance measurement method for determining body composition in diabetic subjects and normal controls]. / Validazione di una metodica di rilevazione impedenziometrica per la valutazione della composizione corporea in soggetti diabetici e controlli normali.

The reproducibility of impedance measurements made using the Human-IM system (Dietosystem, Milan-Italy) was assessed in a group of normal and diabetic subjects on the basis of three tests made under the same experimental conditions on three consecutive days. A total of 22 normal subjects, 29 insulin-dependent (IDD) and 6 noninsulin dependent (NIDD) diabetic patients were included in the study. The coefficient of variation between the three successive tests ranged between 0 and 2.7% (normals 1.1 +/- 0.7%, IDD 1.6 +/- 0.7%, NIDD 1.1 +/- 0.4%), thus confirming the good reproducibility of the method in all groups. There was no significant difference between impedance measurement tests in the two group of diabetic patients with regard to TBW, FAT and FFM. NIDD patients differed from normal subjects due to higher FAT levels, whereas there was no significant difference between IDD patients and normal subjects.