Insulin resistance, but not insulin response, during oral glucose tolerance test (OGTT) is associated to worse histological outcome in obese NAFLD.

BACKGROUND AND AIM: Obese subjects are at high risk of nonalcoholic fatty liver disease (NAFLD) and diabetes (T2D) due to insulin resistance (IR). Since high glucose levels are as toxic as lipids for hepatic metabolism, we hypothesize that altered response to oral glucose tolerance test (OGTT) is associated to more severe NAFLD with significant/advanced liver damage. METHODS AND RESULTS: We studied 90 subjects with morbid obesity (73F/17M, BMI = 43.2 ± 5,9 kg/m2) undergoing bariatric surgery and intraoperative liver biopsy, and measured HbA1c, HOMA-IR (fasting Glucose x Insulin/22.5), OGTT glucose and insulin profile, and calculated OGIS (muscle insulin sensitivity), hepatic-IR (glucose [AUC0-30] x insulin [AUC0-30]) during OGTT, insulin response as (insulin [dAUC0-120]/glucose [dAUC0-120] or Insulinogenic Index (IGI = (I30-I0)/(G30-G0)). Patients were divided in 3 groups according to liver biopsy: A (no-NAFLD, 23%), B (simple steatosis (SS), 53%) and C (NASH, 24%) with similar age, gender and BMI. Diabetes was 0% in no-NAFLD, 13% in SS, 35% in NASH. During OGTT, OGIS decreased from A to C (422 vs 360 vs 338, p < 0.01). Increased insulin concentrations, HbA1c, HOMA-IR and OGIS, not Hep-IR, were strongly associated to hepatic steatosis (p = 0.03, p = 0.0001 and p = 0.01 respectively). Hepatic fibrosis stage was mild as most of the patients had fibrosis grade-1 (69% vs. 8% no fibrosis) and associated to fasting insulin, HbA1c and HOMA-IR. dAUC-I/dAUC-G was similar in the 3 groups, while only AUC-I was strongly associated to steatosis (r = 0.35, p = 0.005), but not to fibrosis. CONCLUSIONS: In morbid obesity indexes of IR, and not of insulin response, are markers of histological severity of liver disease.

Noninvasive assessment of hepatic steatosis and fibrosis in patients with severe obesity.

PURPOSE: In morbid obesity nonalcoholic fatty liver disease (NAFLD) is endemic. Aim of this study is to evaluate the diagnostic accuracy of the most common noninvasive methods for identify NAFLD and fibrosis in a cohort of morbid obese population. METHODS: Ninety morbid obese patients undergoing bariatric surgery (BS) and intraoperative liver biopsy were evaluated preoperatively with Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) and serum biomarkers for steatosis and fibrosis and liver stiffness measurement (LSM) using acoustic radiation force impulse (ARFI) elastography. All nondiabetic patient (n = 77) underwent OGTT and calculation of Oral Glucose Insulin Sensitivity index (OGIS). RESULTS: In the entire cohort prevalence of NAFLD was 77%, NASH 24%, moderate/severe steatosis 50%, and significant fibrosis 14%. New cut-offs were evaluated for all steatosis score assessed in this population. In all patients with moderate/severe steatosis HOMA IR was significantly greater than 3.5. ALT, GGT, Triglycerides, HOMA IR, and ARFI increased with fibrosis grade (p 0.03, p 0.008, p 0.04, p 0.05, respectively) and AST to Platelet ratio (APRI) was the only noninvasive fibrosis score significantly increased in significant fibrosis (p 0.04). A combination of 1/OGIS and VAI was able to discriminate NASH from simple steatosis (NAFL) (p 0.02). CONCLUSIONS: In morbid obese subjects, we calculated new cut-offs of the most common steatosis indexes and found that a score based on insulin resistance (1/OGIS) and abdominal obesity (VAI) could represent a way to identify morbid obese subjects at risk of NASH.

Long-term Metabolic Effects of Laparoscopic Sleeve Gastrectomy.

OBJECTIVE: Obesity is one of the major health challenges throughout the world. The association between obesity and diabetes is well established because 90% of patients with type 2 diabetes mellitus (T2DM) show excess body weight. The aim of the study was to evaluate the effect of laparoscopic sleeve gastrectomy (LSG) on morbid obesity and type 2 diabetes (T2DM) in the long-term follow-up. METHODS: One hundred ninety-five obese patients, 78 with T2DM, were evaluated before and after LSG up to 10 years, to identify complete diabetes remission (FPG < 100 mg/dl, A1c < 6.0%), partial remission (FPG 100-125 mg/dl, A1c < 6.5%), or relapse. RESULTS: Before surgery, body weight and BMI were 123 ± 21 kg and 44.6 ± 6.8 kg/m2 respectively; at a mean follow-up of 7 years (range 4-10), body weight was 104.9 ± 18 kg and BMI 37 ± 6 kg/m2. Minimum weight was reached after 2 years. T2DM remission was observed in 66, 57, and 52% at short (< 2 years), medium (2-5 years), and long-term (> 5 years) follow-up respectively. Furthermore, 45.2% maintained complete remission for at least 5 years and about 36% showed a persistent but improved diabetes. None of the patients cured from diabetes had a duration disease greater than 8 years and a glycemic control requiring insulin. The prevalence of hypertension and dyslipidemia significantly decreased from 49 to 35% and from 51 to 40% respectively. CONCLUSIONS: LSG significantly improves body weight, diabetes, hypertension, and dyslipidemia in long-term follow-up.

Search for Genetic Variant in the Apelin Gene by Resequencing and Association Study in European Subjects.

AIMS: Apelin is a peptide produced and secreted by white adipose tissue. It is synthesized as preproapelin, a protein containing 77 aminoacids which is then cleaved to shorter active fragments. As an adipokine, apelin plays a role in the regulation of many biological functions, including body energy homeostasis and glucose metabolism, water balance, and immunity. We have recently demonstrated that subjects with type 2 diabetes (T2D) have significantly higher serum apelin levels compared with controls, and that these levels associate with fasting glucose, basal disposition index, age, and diagnosis of T2D. The first aim of this study was to search for sequence variants in the apelin gene (APLN), located on chromosome Xq25-q26.1 that may associate with serum levels of apelin. The second aim was to analyze the possible association between diabetes and diabetes-related traits and APLN variants. METHODS: We designed a two-step genetic association study. Step one consisted of an initial screen of 100 individuals selected from the extremes of the apelin distribution levels wherein we sequenced the APLN gene to identify common variants. In step two, the rs181301686 with a minor allele frequency >0.2 was genotyped in 917 individuals to explore its association with T2D and diabetes-related traits. RESULTS: Five sequence variations were found across the APLN gene. To test for association with apelin levels, the rs181301686 and rs2281069 single-nucleotide polymorphisms were genotyped in 256 subjects for whom serum apelin levels were available. No significant differences were observed in apelin levels between genotypes. Association analysis in 917 individuals did not show significant differences between APLN genotypes and diabetes and diabetes-related traits. CONCLUSIONS: Resequencing of the apelin gene in subjects stratified by low or high apelin levels identified five APLN variants in an European population. No association was found between the most frequent variant, diabetes, and metabolic parameters.

Very low-carbohydrate ketogenic diet before bariatric surgery: prospective evaluation of a sequential diet.

BACKGROUND: We evaluated the effectiveness of a sequential diet regimen termed the obese preoperative diet (OPOD) in morbidly obese patients with and without type 2 diabetes mellitus (T2DM) scheduled for laparoscopic bariatric surgery. METHODS: Fifty patients (body mass index 53.5 ± 8.4 kg/m(2)) scheduled for bariatric surgery, including 14 with T2DM, were prospectively enrolled and followed the OPOD regimen: a very low-calorie ketogenic diet for 10 days, followed by a very low-calorie diet for 10 days, and then a low-calorie diet for 10 days. Patients were evaluated at baseline (T0) and after 10 days (T1), 20 days (T2), and 30 days (T3). RESULTS: Body weight, body mass index, waist circumference, and neck circumference were significantly lower at T1, T2, and T3 than at T0 in the 48 patients who completed the OPOD. Two patients discontinued the OPOD after 4-7 days. In patients with T2DM, fasting plasma glucose levels decreased significantly, enabling reduction of diabetic medications. Plasma and urine ketone levels increased at T1 but were all <1 mmol/L, and hunger decreased during the diet period. CONCLUSIONS: OPOD, including 10 days of a VLCKD, was safe and effective in morbidly obese patients, and it seems to be promising in morbidly obese patients with and without T2DM scheduled for laparoscopic bariatric surgery.

Obesity, type 2 diabetes mellitus, and other comorbidities: a prospective cohort study of laparoscopic sleeve gastrectomy vs medical treatment.

OBJECTIVE: To compare the effect of sleeve gastrectomy vs medical therapy on type 2 diabetes mellitus and other obesity-related comorbidities (obstructive sleep apnea syndrome, hypertension, and dyslipidemia) in prospectively enrolled and matched obese patients with type 2 diabetes. DESIGN: A prospective cohort study. Morbidly obese patients with type 2 diabetes who either underwent sleeve gastrectomy or conventional therapy were followed up and assessed for their diabetic state and other comorbidities every 3 months for 18 months. SETTING: Centre for the Surgical-Medical Treatment of Morbid Obesity, Policlinico "Umberto I," University of Rome "Sapienza," Italy. PATIENTS: A total of 30 morbidly obese patients with type 2 diabetes who underwent sleeve gastrectomy (group A) and a total of 30 morbidly obese patients with type 2 diabetes who underwent conventional therapy (group B). RESULTS: In group A, the preoperative mean (SD) body mass index, fasting plasma glucose level, and hemoglobin A1c level were 41.3 (6.0), 166.6 (68.1) mg/dL, and 7.9% (2.1%), respectively, and, at 18 months, these values were 28.3 (5.4), 96.2 (29.4) mg/dL, and 6.0% (1.5%), respectively. For 80% of patients, diabetes was resolved. With regard to other comorbidities, the prevalence of obstructive sleep apnea syndrome dropped from 50% to 10%, and patients reduced significantly their use of medication for hypertension and dyslipidemia. In group B, the preoperative mean (SD) body mass index, fasting plasma glucose level, and hemoglobin A1c level were 39.0 (5.5), 183.7 (63.5) mg/dL, and 8.1% (1.7%), respectively, and, at 18 months, these values were 39.8 (5.0), 150 (48) mg/dL, and 7.1% (1.3%), respectively. All patients remained diabetic and continued or increased their level of hypoglycemic therapy. With regard to other comorbidities, we observed an increase in the use of medication for hypertension and dyslipidemia, and the prevalence of obstructive sleep apnea syndrome did not change. CONCLUSIONS: This study confirms the efficacy of sleeve gastrectomy in the treatment of morbidly obese type 2 diabetic patients when compared with conventional medical treatment.

Association of FTO polymorphisms with early age of obesity in obese Italian subjects.

Obesity is recognized as a major health problem worldwide. Genetic factors play a major role in obesity, and genomewide association studies have provided evidence that several common variants within the fat mass- and obesity-associated (FTO) gene are significantly associated with obesity. Very limited data is available on FTO in the Italian population. Aims of our study are to investigate: (1) the association of FTO gene SNPs rs9939609 and rs9930506 with body mass index (BMI) and obesity-related parameters in a large cohort (n = 752) of Italian obese subjects; (2) the association between the two FTO SNPs and age of onset of obesity. Our results demonstrate a strong association between FTO SNPs rs9939609 (P < 0.043) and rs9930506 (P < 0.029) with BMI in the Italian population. FTO rs9930506 was significantly associated with higher BMI in a G allele dose-dependent manner (BMI + 1.4 kg/m² per G allele). We also observed that the association with BMI of the two FTO variants varied with age, with the carriers of the risk alleles developing an increase in body weight earlier in life. In conclusion, our study further demonstrates a role of the genetic variability in FTO on BMI in a large Italian population.

Type 2 diabetes in obese patients with body mass index of 30-35 kg/m2: sleeve gastrectomy versus medical treatment.

BACKGROUND: Type 2 diabetes mellitus (T2DM) and obesity are diseases of epidemic proportions. Long-term realistic weight loss by nonsurgical methods has a variable effect on glycemic control, and only a proportion of patients with T2DM have a worthwhile response. Laparoscopic sleeve gastrectomy (LSG) has been proposed as an advantageous bariatric procedure for patients with a lower body mass index (BMI). Our objective was to compare the effects of LSG and medical therapy on patients with T2DM and a BMI of <35 kg/m(2). METHODS: A total of 18 nonmorbidly obese patients with T2DM, diagnosed according to the American Diabetes Association guidelines, were consecutively enrolled. Of these patients, 9 underwent LSG (group A) and 9 underwent conventional medical therapy (group B). The 2 groups were matched for BMI, glycated hemoglobin (HbA1c) and C-peptide levels, pretrial therapy type, and number of patients with a T2DM duration of >10 years. RESULTS: In group A, T2DM resolution was achieved in 8 (88.8%) of the 9 patients (T2DM duration 5.2 yr). Hypertension was controlled in all 8 of 9 patients. Dyslipidemia was corrected. In 1 patient, obstructive sleep apnea syndrome improved. In group B, all 9 patients continued to have T2DM and required hypertensive and hypolipemic therapies throughout the observation period. At baseline, 3 patients were affected by obstructive sleep apnea syndrome and remained affected 1 year later. CONCLUSION: The results of the present study have confirmed the efficacy of LSG in the treatment of nonmorbidly obese T2DM patients, with a remission rate of 88.8% without undesirable excessive weight loss. The results in this group of patients add to those obtained by us in patients with a BMI >35 kg/m(2).

Lack of effect of apolipoprotein C3 polymorphisms on indices of liver steatosis, lipid profile and insulin resistance in obese Southern Europeans.

BACKGROUND: Apolipoprotein C3 (APOC3) is a component of triglyceride-rich lipoproteins, and APOC3 rs2854116 and rs2854117 polymorphisms have been associated with non-alcoholic fatty liver disease, hypertriglyceridaemia, and insulin-resistance. OBJECTIVE: To determine if the APOC3 variants alter the susceptibility of obese subjects to develop liver damage, hypertrigliceridaemia, and insulin-resistance. METHODS: The study was carried out on 585 unrelated obese Italians (median body mass index BMI = 41 kg/m2) who were genotyped for the rs2854116 and rs2854117 variants. All participants underwent oral glucose tolerance tests (OGTT), with measurement of glucose, insulin, lipid parameters. Indices of insulin-resistance (HOMA and ISI) were calculated. Alanine transaminase (ALT) and aspartate transaminase (AST) were used as markers of liver injury. RESULTS: The study subjects were divided into two groups: those homozygous for the wild-type alleles at both SNPs (-482C and -455T alleles) and those who were carriers of at least one variant allele or both (-482T, -455C or both). Also each SNP was analysed independently. No significant differences were found in ALT and AST levels and in the lipid profile between the two groups. Insulin concentrations, glucose tolerance and insulin sensitivity were similar in the two groups. CONCLUSION: We did not identify any significant association between APOC3 polymorphisms and fatty liver disease, lipids, and insulin-resistance in obese subjects, thus not confirming the suggested role of these APOC3 gene sequence variants.