Effects of Diet on Bile Acid Metabolism and Insulin Resistance in Type 2 Diabetic Rats after Roux-en-Y Gastric Bypass.

BACKGROUND: Roux-en-Y gastric bypass (RYGB) is effective for the treatment of type 2 diabetes mellitus; however, the mechanism remains unclear. METHODS: The effects of RYGB on postprandial responses to three different diets (low carbohydrate (CH)-rich diet, high CH-rich diet, and fat-rich diet) of different nutritional composition in a Goto-Kakizaki (GK) diabetic rat model were assessed by measuring glucose tolerance, insulin resistance, incretin responses, and bile acid (BA) metabolism. RESULTS: GK-RYGB group rats lost weight and preferred low CH-rich diet, but there were no significant differences in BW among the different diets. Glucose tolerance and insulin resistance were improved in rats who underwent RYGB, together with higher levels of circulating BAs, plasma GLP-1, and PYY levels. GK-RYGB rats fed high CH-rich or fat-rich diet showed increased glucose level and insulin resistance, together with high plasma BA, GIP, and PYY levels compared to those fed a low CH-rich diet. CONCLUSION: RYGB improves glucose tolerance and insulin resistance which may be related to BA metabolism and hormone levels, and the nutrient composition of the diet affects the treatment effect of RYGB on T2DM.

Changes of Ghrelin/GOAT axis and mTOR pathway in the hypothalamus after sleeve gastrectomy in obese type-2 diabetes rats.

AIM: To examine the changes of the ghrelin/ghrelin O-acyltransferase (GOAT) axis and the mammalian target of rapamycin (mTOR) pathway in the hypothalamus after sleeve gastrectomy. METHODS: A total of 30 obese type-2 diabetes Sprague-Dawley (SD) rats, 6 wk of age, fed with high-sugar and high-fat fodder for 2 mo plus intraperitoneal injection of streptozotocin were randomly divided into three groups: non-operation group (S0 group, n = 10), sham operation group (Sh group, n = 10) and sleeve gastrectomy group (SG group, n = 10). Data of body mass, food intake, oral glucose tolerance test (OGTT), acylated ghrelin (AG) and total ghrelin (TG) were collected and measured at the first day (when the rats were 6 wk old), preoperative day 3 and postoperative week 8. The mRNA expression of preproghrelin, GOAT and neuropeptide Y (NPY), and protein expression of ghrelin, GOAT, GHSR and the mTOR pathway (p-Akt, p-mTOR and p-S6) were measured in the hypothalamus. RESULTS: SG can significantly improve metabolic symptoms by reducing body mass and food intake. The obese rats showed lower serum TG levels and no change in AG, but the ratio of AG/TG was increased. When compared with the S0 and Sh groups, the SG group showed decreased TG (1482.03 ± 26.55, 1481.49 ± 23.30 and 1206.63 ± 52.02 ng/L, respectively, P < 0.05), but unchanged AG (153.06 ± 13.74, 155.37 ± 19.30 and 144.44 ± 16.689 ng/L, respectively, P > 0.05). As a result, the ratio of AG/TG further increased in the SG group (0.103 ± 0.009, 0.105 ± 0.013 and 0.12 ± 0.016, respectively, P < 0.05). When compared with the S0 group, SG suppressed mRNA and protein levels of preproghrelin (0.63 ± 0.12 vs 0.5 ± 0.11, P < 0.05) and GOAT (0.96 ± 0.09 vs 0.87 ± 0.08, P < 0.05), but did not change NPY mRNA expression (0.61 ± 0.04 vs 0.65 ± 0.07, P > 0.05) in the hypothalamus. The protein levels of p-Akt, p-mTOR and p-S6 were higher in the SG group, which indicated that the hypothalamic mTOR pathway was activated after SG at the postoperative week 8. CONCLUSION: The reduction of ghrelin expression and activation of the mTOR pathway might have opposite effects on food intake, as SG improves obesity and T2DM.

A meta-analysis of short-term outcomes of patients with type 2 diabetes mellitus and BMI ≤ 35 kg/m2 undergoing Roux-en-Y gastric bypass.

BACKGROUND: Roux-en-Y gastric bypass (RYGB) is effective for type 2 diabetes mellitus (T2DM) patients with a body mass index (BMI) >35 kg/m(2). It is unknown whether it benefits those with a BMI ≤ 35 kg/m(2). In the last decade, the effect of bariatric procedures on metabolic outcomes in individuals who underwent surgery outside National Institutes of Health (NIH) guidelines (BMI ≤ 35 kg/m(2)) was both interesting and controversial. OBJECTIVE: We performed a systematic analysis evaluating the effect of RYGB for T2DM patients with a BMI ≤ 35 kg/m(2). METHODS: We searched databases (Embase, Ovid, PubMed, China National Knowledge Infrastructure [CNKI], and Cochrane Library) and relevant journals between January 1980 and October 2013. Keywords used in electronic searching included 'diabetes', 'gastric bypass', 'BMI', and 'body mass index'. Inclusion criteria were as follows: (1) patients who underwent RYGB; (2) sample size ≥ 15; (3) patients with a BMI ≤ 35 kg/m(2); and (4) follow-up ≥ 12 months. Exclusion criteria were as follows: (1) data extracted from a database; (2) trials for sleeve gastrectomy; (3) trials for laparoscopic banding; (4) trials for bilio-pancreatic diversion; and (5) trials for duodenojejunal bypass. Participants and intervention type 2 diabetes patients with BMI ≤ 35 kg/m(2) who underwent RYGB. Two investigators reviewed all reported studies independently. Data were extracted according to previously defined endpoints. A meta-analysis was performed for these parameters, with homogeneity among different trials. RESULTS: Nine articles fulfilled inclusion criteria. After 12 months, patients with T2DM had a significant decrease in their BMI postoperatively (p < 0.00001, weighted mean difference [WMD] -7.42, 95 % confidence interval [CI] -8.87 to -5.97), and remission of diabetes (glucose: p < 0.00001, WMD -59.87, 95 % CI -67.74 to -52.01; hemoglobin A1c p < 0.00001, WMD -2.76, 95 % CI -3.41 to -2.11). There were no deaths in all trials, and the complication rate was between 6.7 and 25.9 %. Mean length of hospital stay was 2.00 to 3.20 days, and mean operative time was from 72.8 to 112.0 min. In terms of study limitations, publication and selection bias were unavoidable. Trials with small sample sizes were excluded, which may lead to a selection bias. CONCLUSION: RYGB was effective for T2DM patients with BMI ≤ 35 kg/m(2). Further clinical studies with long-term follow-up data are necessary to clarify this issue.

[Analysis of risk factors for cerebral infarction after hip arthroplasty].

OBJECTIVE: To investigate the independent risk factors for cerebral infarction so as to provide a theoretical basis for the prevention of cerebral infarction after total hip arthroplasty. METHODS: A retrospective analysis of 571 patients for hip arthroplasty was conducted from January 2003 to September 2008. Twenty-three patients were found with cerebral infarction postoperatively. Single-factor and multi-factor correlation analyses were tested for the patients with cerebral infarction after hip arthroplasty. RESULTS: The single-factor analysis for hip arthroplasty revealed that age (P = 0.001) and femoral neck fracture (P = 0.008) were the main factors for cerebral infarction. Furthermore, age was considered a risk factor for cerebral infarction after hip arthroplasty in multi-factor analysis (P = 0.029, OR = 1.054, 95%CI: 1.005 - 1.105). CONCLUSION: Advanced age (> 70 yr) and femoral neck fracture are the main independent risk factors for cerebral infarction after hip arthroplasty.