Excessive generalized and visceral adiposity is associated with a higher prevalence of diabetic retinopathy in Caucasian patients with type 2 diabetes.

BACKGROUND AND AIMS: Type 2 Diabetes Mellitus (T2D) has heterogeneous clinical phenotypes related to different risk of developing diabetes complications. We investigated the correlation between generalized and abdominal adiposity and the prevalence of both micro- and macrovascular complications in Caucasian patients with T2D. METHODS AND RESULTS: We evaluated 769 individuals with T2D consecutively referred to our diabetes center. Body mass index (BMI), waist circumference (WC), waist to hip (W/H) ratio, glycated hemoglobin (HbA1c), systolic and diastolic blood pressure, lipid profile, smoking habit, diabetes therapy, and micro- and macrovascular complications were recorded. Patients were divided into three groups based on BMI and WC: non-obese with normal WC (nWC, n = 220), non-obese with excess of abdominal fat (AF, n = 260) and obese (Ob, n = 289). We found that nWC, compared with AF and Ob individuals, were predominantly males (p<0.01), had lower HbA1c (p<0.01), diastolic blood pressure (p<0.01), triglycerides (p<0.01), and showed a significantly lower prevalence of diabetic retinopathy (DR) (p = 0.01). The rate of proliferative DR was significantly higher in Ob (13.2 %) compared to the other groups (p = 0.03). Multivariate analyses showed a significantly decreased prevalence of DR in nWC compared to both AF (OR 0.58, 95 CI 0.34-0.96; p = 0.03) and Ob (OR 0.57, 95 CI 0.33-0.98; p = 0.04) individuals. Conversely, DR was associated, mainly in women, to higher WC and W/H ratio. The prevalence of the other diabetes-related complications was similar among the studied groups. CONCLUSIONS: In our population, nWC subjects showed a lower prevalence of DR. An increased generalized and abdominal adiposity was associated to a higher prevalence of DR, especially among females.

Impact of unhealthy childhood and unfavorable parents' characteristics on adiposity in schoolchildren.

BACKGROUND: Childhood obesity is encouraged by low physical activity (PA), time spent using screens (screen time, ST), and by sugar-sweetened beverage consumption (SSBc). It is also influenced by unfavorable parents' characteristics, such as a high body mass index (BMI) and low education level (EL). Our aim was to evaluate the overall and specific influence of these factors on childhood adiposity. MATERIAL AND METHODS: Anthropometric parameters including BMI z-score, waist circumference (WC), waist to height ratio (WtHR), and fat mass were measured in a cohort of 1702 schoolchildren (6.0-14.5 years, mean 10.7 ± 1.8) and questionnaires concerning children's PA, ST, and SSBc, and parent's BMI and EL were administered to parents. RESULTS: Overweight/obesity prevalence was higher (P < .0001) in males (57%) than in females (43%). Less physically active children (28.9%) had a higher prevalence of overweight/obesity and higher BMI z-score, WC, WtHR, and fat mass relative to more physically active children (P < .05). PA was negatively associated with the BMI z-score (r = 0.18, P < .0001) and fat mass percentage (r = 0.18, P < .0001). Children with more ST had higher WC and WtHR than non-ST viewers (P < .05) but not BMI. Moreover, SSBc did not influence the anthropometric parameters. At multivariate analysis, male gender, less PA, and parental risk factors (parent's overweight/obesity and low/medium EL) were independently associated with overweight and obesity among childhood with a progressively increasing odds ratio (1.65, 1.40, and 1.80, respectively). CONCLUSIONS: Male gender, behavioral risk factors (particularly low PA), and parent's characteristics are important correlates of obesity in children.

Adipose Tissue, Obesity and Adiponectin: Role in Endocrine Cancer Risk.

Adipose tissue has been recognized as a complex organ with endocrine and metabolic roles. The excess of fat mass, as occurs during overweight and obesity states, alters the regulation of adipose tissue, contributing to the development of obesity-related disorders. In this regard, many epidemiological studies shown an association between obesity and numerous types of malignancies, comprising those linked to the endocrine system (e.g., breast, endometrial, ovarian, thyroid and prostate cancers). Multiple factors may contribute to this phenomenon, such as hyperinsulinemia, dyslipidemia, oxidative stress, inflammation, abnormal adipokines secretion and metabolism. Among adipokines, growing interest has been placed in recent years on adiponectin (APN) and on its role in carcinogenesis. APN is secreted by adipose tissue and exerts both anti-inflammatory and anti-proliferative actions. It has been demonstrated that APN is drastically decreased in obese individuals and that it can play a crucial role in tumor growth. Although literature data on the impact of APN on carcinogenesis are sometimes conflicting, the most accredited hypothesis is that it has a protective action, preventing cancer development and progression. The aim of the present review is to summarize the currently available evidence on the involvement of APN and its signaling in the etiology of cancer, focusing on endocrine malignancies.

Efficacy of High-dose Liraglutide 3.0 mg in Patients with Poor Response to Bariatric Surgery: Real-world Experience and Updated Meta-analysis.

PURPOSE: Poor response to bariatric surgery, characterized by insufficient weight loss (IWL) or weight regain (WR), poses a significant challenge in obesity treatment. This study aims to assess the effectiveness of liraglutide in addressing this issue. MATERIALS AND METHODS: A retrospective, multicenter cohort study investigated the impact of liraglutide 3 mg on weight loss in adults with suboptimal responses or weight regain after bariatric surgery (BS). Additionally, a systematic review and meta-analysis were conducted for a comprehensive evaluation. RESULTS: A total of 119 patients (mean age 41.03 ± 11.2 years, 71.4% female) who experienced IWL or WR after BS received pharmacologic therapy with liraglutide 3 mg. Mean percent weight loss in the entire cohort was 5.6 ± 2.6% at 12 weeks and 9.3 ± 3.6% at 24 weeks with a significant reduction in waist circumference (p < 0.0001). No serious side effects were reported. A meta-analysis, utilizing the fixed effect model with the metafor package in R, included 6 and 5 papers for the change in body weight and BMI after liraglutide treatment, respectively. The analysis demonstrated a considerable reduction in body weight (7.9; CI - 10.4; - 5.4, p < 0.0001) and BMI (3.09; CI 3.89; - 2.28, p < 0.0001). CONCLUSION: Liraglutide 3 mg emerges as a viable option for significant weight loss in patients experiencing IWL or WR after BS. Its inclusion in a multimodal, sequential obesity treatment approach proves promising.

High-dose liraglutide improves metabolic syndrome in poor responders to bariatric surgery.

Background: Bariatric surgery (BS) represents the most effective therapy for obesity class III, or class II with at least one weight-related comorbidity. However, some patients have insufficient weight loss or clinically relevant weight regain after a successful primary procedure. This study aimed to assess the efficacy of liraglutide treatment on weight loss, body composition and improvement of metabolic syndrome (MS) in patients defined as poor responders after BS. Methods: The study involved 59 non-diabetic adults with obesity (M/F: 17/42, age: 38.6 ± 11.8 years, BMI 38.3 ± 5.5 kg/m2) who had been treated with BS and experienced a poor response, categorized as either IWL (insufficient weight loss) or WR (weight regain). All patients were prescribed pharmacological therapy with liraglutide and attended nutritional counseling. Anthropometric and clinical measurements, body composition and the presence of MS defined according to the ATP-III classification were evaluated before starting liraglutide and after 24 weeks of treatment. Results: After 24 weeks of treatment with liraglutide, the mean weight loss was 8.4% ± 3.6% with no difference between gender, bariatric procedure, or type of poor response (IWL or WR). A significant decrease in fat mass, free-fat mass and total body water was documented. After 24 weeks, patients presented significantly lowered fasting glucose, total cholesterol, triglycerides, AST and ALT. The prevalence of MS was reduced from 35% at baseline to 1.6% after 24 weeks. No patients discontinued the treatment during the study. Conclusion: In patients who experience poor response after BS, liraglutide is well tolerated and promotes significant weight loss, ameliorates cardiometabolic comorbidities, and reduces the prevalence of MS.

New paradigm for the management of cardio-nephro-metabolic syndrome: multidisciplinary approach and role of telemedicine.

Heart failure (HF), type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD) are some of the most important health problems of this century, and these three conditions often coexist, one worsening the prognosis of the other two. No disease is more important than the others in the composition of risk, which is significantly increased by their overlap. Thus, it would be more appropriate to refer to this cluster as cardio-nephro-metabolic syndrome. The aim of this review is to promote the development of an integrated multidisciplinary approach to the treatment of HF, T2DM and CKD in a perspective of paradigm shift from an individual management among different specialists to a shared one. Nowadays, this is achievable thanks to telemedicine and optimized therapy consisting in the new drugs with pleiotropic effect available today. The need is to have technological solutions, which also include telemedicine, for the management of patients affected by all three diseases to consider their fragility, sometimes due to a wrong, partial, or incomplete treatment. Multicentric, multidisciplinary trials on cardio-nephro-metabolic syndrome and new telemedicine/telemonitoring technologies could help place the chronic and fragile patient at the center of such multidimensionally integrated care.

Pharmacological treatment of nonresponders following bariatric surgery: a narrative review of the current evidence.

INTRODUCTION: Obesity is a complex chronic disease and requires a long-term multidisciplinary management. Even patients undergoing bariatric surgery, one the most effective treatments for obesity, can have insufficient weight loss (IWL) than expected (primary non responder) or weight regain (WR) after a successful primary procedure (secondary non responder). A poor response represents a challenge of bariatric surgery that can induce persistence or recurrence of obesity-related comorbidities, prejudicing benefits of surgery. Increasing evidence suggests that weight loss medications represent a useful strategy in obesity care also after bariatric surgery procedures. EVIDENCE ACQUISITION: This narrative review summarizes the evidence concerning anti-obesity therapy in the management of no-responders to primary bariatric surgery. Available data on liraglutide (one randomized double-blind placebo-controlled trial, three prospective and three retrospective studies), naltrexone/bupropion (three retrospective studies), orlistat (one case control prospective and one retrospective studies) and topiramate and phentermine (5 retrospective studies) have been considered. EVIDENCE SYNTHESIS: Available data suggest that weight loss medications could offer a significant adjunctive benefit to lifestyle and behavioral modifications in the life-long management of obesity. CONCLUSIONS: Newer treatment modalities including the use of anti-obesity drugs provide patients and healthcare providers with more options in the management of poor response after bariatric surgery.

Identification of the Inappropriate Clinical Actions (DON'T) to Improve the Management of Patients with Type 2 Diabetes Failing Basal Insulin Supported Oral Treatment: Results of Survey for a Panel of Diabetes Specialists in Italy.

INTRODUCTION: Despite the development of several recommendations, glycemic control in a large proportion of patients with type 2 diabetes, including those treated with insulin, remains suboptimal. This study is aimed to identify a set of actions to promote the reduction of inappropriate clinical practices in type 2 diabetes failing basal insulin supported oral therapy (BOT). METHODS: A panel of diabetes specialists was assembled to identify a list of ten corrective actions, "things not to do," for the management of type 2 diabetes: five concerning treatments, procedures and diagnostic tests and five about relationship, communication and information. The Choosing Wisely methodology and approach were the inspiration. RESULTS: A total of 73/73 (100%) panelists responded to the survey. Twenty-four actions were proposed. The final list of inappropriate actions deemed most important to improve the management of patients with type 2 diabetes failing BOT were: (1) do not use secretagogues-do not neglect the use of innovative glucose-lowering agents; (2) do not underestimate the risk of lack of hypoglycemia awareness; (3) do not underestimate the benefit of personalization of therapy; (4) do not delay insulin intensification; (5) do not delay modification of the therapeutic regimen. In the area of patient communication, the following actions were identified: (1) do not fail to train in the management of hypoglycemia; (2) do not underestimate whether the patient has understood the modification of therapy; (3) do not prescribe injection therapy without adequately instructing the patient to titrate it; (4) do not ignore the patient's adherence; (5) do not stop listening to the patient and verify learning. CONCLUSION: A set of corrective experience-based actions to enact in a timely manner, which can assist physicians in improving clinical outcomes and patients' needs in terms of communications and interaction, is proposed. The list is intended to promote discussions among diabetes specialists to provide high-value diabetes care.

ENPP1 Q121 variant, increased pulse pressure and reduced insulin signaling, and nitric oxide synthase activity in endothelial cells.

OBJECTIVE: Insulin resistance induces increased pulse pressure (PP), endothelial dysfunction (ED), and reduced bioavailability of endothelium-derived nitric oxide (NO). The genetic background of these 3 cardiovascular risk factors might be partly common. The ENPP1 K121Q polymorphism is associated with insulin resistance and cardiovascular risk. METHODS AND RESULTS: We investigated whether the K121Q polymorphism is associated with increased PP in white Caucasians and with ED in vitro. In 985 individuals, (390 unrelated and 595 from 248 families), the K121Q polymorphism was associated with PP (P=8.0 x 10(-4)). In the families, the Q121 variant accounted for 0.08 of PP heritability (P=9.4 x 10(-4)). This association was formally replicated in a second sample of 475 individuals (P=2.6 x 10(-2)) but not in 2 smaller samples of 289 and 236 individuals (P=0.49 and 0.21, respectively). In the individual patients' data meta-analysis, comprising 1985 individuals, PP was associated with the Q121 variant (P=1.2 x 10(-3)). Human endothelial cells carrying the KQ genotype showed, as compared to KK cells, reduced insulin-mediated insulin receptor autophosphorylation (P=0.03), Ser(473)-Akt phosphorylation (P=0.03), and NO synthase activity (P=0.003). CONCLUSIONS: Our data suggest that the ENPP1 Q121 variant is associated with increased PP in vivo and reduced insulin signaling and ED in vitro, thus indicating a possible pathogenic mechanism for the increased cardiovascular risk observed in ENPP1 Q121 carriers.

Laparoscopic sleeve gastrectomy for morbid obesity. Our initial experience.

AIM OF THE STUDY: The outcomes and initial results of laparoscopic sleeve gastrectomy (LSG) were evaluated at our Institution. METHODS: A retrospective analysis of the initial 6 patients who underwent laparoscopic sleeve gastrectomy (LSG), between November 2006 and May 2008, was performed. The aim of this study was to assess the safety and short-term efficacy of LSG as a treatment option for weight reduction. Data collected included operative time, postoperative complications, length of hospital stay and degree of weight reduction. RESULTS: Our 6 morbidly obese patients, who underwent LSG had an average preoperative BMI 58.2 kg/m2. There were 2 women and 4 men, with mean age 45 (range 41 to 55 years). Indication for LSG was related to BMI, high perioperative risk, and body habitus for five patients. One patient underwent LSG as an alternative to laparoscopic adjustable gastric banding (LAGB). Mean operative time was 2 hours (range 1.5-2.5). We had no conversion to open procedure. There were neither postoperative complications nor mortality. Median hospital stay was 2 days. For our first 4 patients Average %EWL and BMI were 24% and 44.5 kg/m2 at 6 months and % 31.2 and 41.2 kg/m2 at 1 year respectively. No patients have subsequently undergone a second-stage procedure. CONCLUSIONS: In our initial experience, LSG is a safe and effective treatment option for the high-risk and super super-obese patient. Follow-up will be necessary to evaluate long-term results when performed as single stage operation for morbid obesity.

The novel loss of function Ile354Val mutation in PPARG causes familial partial lipodystrophy.

AIMS: Familial partial lipodystrophy (FPLD) is a rare autosomal dominant disorder, mostly due to mutations in lamin A (LMNA) or in peroxisome proliferator-activated receptor gamma (PPARG) genes. In the present study, we aimed to identify and functionally characterize the genetic defect underlying FPLD in an Italian family presenting with several affected individuals in three consecutive generations. METHODS: Mutational screening by direct Sanger sequencing has been carried out on both LMNA and PPARG genes. In silico analyses and functional in vitro studies on transfected cell lines have been also performed to evaluate the biological impact of the identified mutation. RESULTS: We identified a novel PPARG missense mutation (i.e., PPARγ2 Ile354Val) segregating with FPLD in the study family. In silico analyses and in vitro experiments showed that probably altering the PPARγ2 ligand binding domain conformation, the Ile354Val aminoacid change leads to a significant reduction (i.e., ~ 30-35%) of transcriptional activity in the mutant receptor, with no evidences of a dominant negative effect on the wild-type receptor. CONCLUSIONS: Our present data extend the spectrum of PPARG mutations responsible for FPLD3 and reinforce the notion that even loss of function mutations affecting transcriptional activity to an extent lower than that observed in the case of haploinsufficiency are able to cause a severe FPLD3 phenotype.

Prevalence and Clinical Characteristics of Children and Adolescents with Metabolically Healthy Obesity: Role of Insulin Sensitivity.

Obesity represents a major risk factor for metabolic disorders, but some individuals, "metabolically healthy" (MHO), show less clinical evidence of these complications, in contrast to "metabolically unhealthy" (MUO) individuals. The aim of this cross-sectional study is to assess the prevalence of the MHO phenotype in a cohort of 246 overweight/obese Italian children and adolescents, and to evaluate their characteristics and the role of insulin resistance. Homeostasis model assessment-insulin resistance (HOMA-IR), insulin sensitivity index (ISI), insulinogenic index (IGI) and disposition index (DI) were all calculated from the Oral Glucose Tolerance Test (OGTT). MHO was defined by either: (1) HOMA-IR < 2.5 (MHO-IRes), or (2) absence of the criteria for metabolic syndrome (MHO-MetS). The MHO prevalence, according to MHO-MetS or MHO-IRes criteria, was 37.4% and 15.8%, respectively. ISI was the strongest predictor of the MHO phenotype, independently associated with both MHO-IRes and MHO-MetS. The MHO-MetS group was further subdivided into insulin sensitive or insulin resistant on the basis of HOMA-IR (either < or ≥ 2.5). Insulin sensitive MHO-MetS patients had a better metabolic profile compared to both insulin resistant MHO-MetS and MUO-MetS individuals. These data underscore the relevance of insulin sensitivity to identifying, among young individuals with overweight/obesity, the ones who have a more favorable metabolic phenotype.

Loss-of-function mutation of the GPR40 gene associates with abnormal stimulated insulin secretion by acting on intracellular calcium mobilization.

BACKGROUND: Free fatty acids (FFAs) acutely stimulate but chronically impair glucose-stimulated insulin secretion from beta-cells. The G protein-coupled transmembrane receptor 40 (GPR40) mediates both acute and chronic effects of FFAs on insulin secretion and plays a role in glucose homeostasis. Limited information is available on the effect of GPR40 genetic abnormalities on insulin secretion and metabolic regulation in human subjects. STUDY DESIGN AND RESULTS: For in vivo studies, we screened 734 subjects for the coding region of GPR40 and identified a new single-nucleotide mutation (Gly180Ser). The mean allele frequency was 0.75%, which progressively increased (P < 0.05) from nonobese subjects (0.42%) to moderately obese (body mass index = 30-39.9 kg/m2, 1.07%) and severely obese patients (body mass index > or = 40 kg/m2, 2.60%). The relationship between the GPR40 mutation, insulin secretion, and metabolic alterations was studied in 11 Gly/Ser mutation carriers. In these subjects, insulin secretion (insulinogenic index derived from oral glucose tolerance test) was significantly lower than in 692 Gly/Gly carriers (86.0 +/- 48.2 vs. 183.7 +/- 134.4, P < 0.005). Moreover, a case-control study indicated that plasma insulin and C-peptide responses to a lipid load were significantly (P < 0.05) lower in six Gly/Ser than in 12 Gly/Gly carriers. In vitro experiments in HeLa cells cotransfected with aequorin and the mutated Gly/Ser GPR40 indicated that intracellular Ca2+ concentration increase after oleic acid was significantly lower than in Gly/Gly GPR40-transfected cells. This fact was confirmed using fura-2 acetoxymethyl ester. CONCLUSIONS: This newly identified GPR40 variant results in a loss of function that prevents the beta-cell ability to adequately sense lipids as an insulin secretory stimulus because of impaired intracellular Ca2+ concentration increase.

The allelic variant of LAR gene promoter -127 bp T-->A is associated with reduced risk of obesity and other features related to insulin resistance.

Insulin resistance, which is pathogenic for type 2 diabetes (T2D), is under the control of largely unknown genetic determinants. LAR, a protein-tyrosine phosphatase which inhibits insulin signalling, is overexpressed in animal and human models of insulin resistance. We studied the entire sequence of the LAR gene by SSCP analysis and automatic DNA sequencing, with the aim of verifying whether its sequence variants might be associated with insulin resistance. In the 276 bp sequence upstream of the transcriptional start site (i.e. a region we have identified as having basal promoter activity) a -127 bp T-->A SNP (5% frequency) was associated with lower body mass index (BMI) ( P=0.03), waist circumference ( P=0.01), blood pressure ( P=0.01) and urinary albumin/creatinine ratio ( P=0.04) in 589 non-diabetic unrelated individuals from the Gargano region (central east coast of Italy). To quantify the risk for a high body weight conferred by the -127 T-->A SNP, the whole cohort was divided into tertiles according to the individual BMI. The risk of belonging to the heavier tertile, as compared to the leaner one, was reduced by approximately 60%. In a population from East Sicily ( n=307), T/A genotype carriers ( n=13) showed lower triglyceride levels ( P=0.04) and higher insulin sensitivity as indicated by lower plasma glucose ( P=0.03) and serum insulin ( P=0.006) during oral glucose tolerance testing (OGTT). Promoter activity, studied by cDNA transfection experiments, was similar for the A and T alleles. In conclusion, a genetic variant of the LAR gene promoter is consistently associated with features of insulin resistance in two different Caucasian populations. Although the biological relevance of this variant has yet to be determined, this finding underlines the potential importance of the LAR gene in dysregulation of insulin sensitivity and related disorders.

Chronic lymphocytic thyroiditis: could it be influenced by a petrochemical complex? Data from a cytological study in South-Eastern Sicily.

INTRODUCTION: In genetically predisposed individuals, exogenous factors (including pollution) influence the development of Hashimoto's thyroiditis/chronic lymphocytic thyroiditis (CLT). CLT may also be a risk factor for associated thyroid cancer. Few data are available on the role of pollution from petrochemical complexes, one of which is located in the Siracusa province (South-Eastern Sicily), in the pathogenesis of CLT. AIMS: i) To study the frequency of CLT in fine-needle aspiration cytology (FNAC)-interrogated thyroid nodules from patients who were stably resident in their zones, comparing it in patients living in the petrochemical complex area (zone A) with that of patients from a control area (zone B). ii) To study the frequency of CLT in the FNAC categories of malignancy risk, comparing the two zones. PATIENTS AND METHODS: We retrospectively evaluated cytologically adequate slides of 1323 nodules in 1013 outpatients who underwent ultrasound-guided FNAC from 2006 to 2012. We stratified by area of residence, gender, and FNAC categories of malignancy risk. RESULTS: CLT was detected with significantly greater frequency in either patients or nodules from zone A compared with zone B (32.0% vs 23.1%, P=0.002 or 28.2% vs 18.8%, P=0.0001), with a female preponderance (F=35.2% vs M=21.1% or 30.4% vs 20.4%, zone A and F=26.5% vs 12.3% or 21.6% vs 9.5%, zone B). Regardless of zone, CLT was approximately twofold more frequent in the suspiciously malignant+malignant classes (TH4+THY5=47.6%, zone A and 32.4%, zone B) compared with the benign+intermediate classes (THY2+THY3=27.3%, zone A and 18.2%, zone B), but with a clear stepwise THY2 through THY5 increase only in zone A (THY2=25.3%, THY5=66.7%; THY2=18.6%, THY5=28.6% in zone B). CONCLUSIONS: The petrochemical complex-related pollution is an environmental factor involved in the development of CLT and, likely, in the CLT association with thyroid neoplasms.

Strong evidence of sexual dimorphic effect of adiposity excess on insulin sensitivity.

AIMS: Our aims were to investigate in several large samples, with a wide range of adiposity, whether: (1) the effect of BMI on insulin sensitivity is different between sexes; (2) also waist circumference plays a sex-specific role on insulin sensitivity; and (3) serum adiponectin and resistin are mediators of such sex-dimorphic effect. METHODS: Samples used were: Gargano study 1 (GS1), GS2 and Catania study (CS) comprising 3274 individuals. Adiponectin and resistin were measured by ELISA. Associations between variables were tested by linear models. RESULTS: In all samples, relationship between BMI and HOMAIR was steeper in males than in females (BMI-by-sex interaction p = 0.04-0.0007). No interaction was observed on serum adiponectin and resistin (p = 0.40-059), which are therefore unlikely to mediate the sex-dimorphic effect of BMI on insulin resistance. Relationship between waist circumference and HOMAIR was similar between sexes in GS1 and GS2 but not in CS (waist-by-sex interaction p = 0.01), comprising much heavier individuals. This suggests that a sex-dimorphic effect of abdominal adiposity on insulin resistance is observable only in the context of high BMI. CONCLUSIONS: Our findings represent a proof of concept that BMI and insulin sensitivity are associated in a sex-specific manner. This may explain why females are protected from diabetes and cardiovascular disease, compared to males of similar BMI.

Adiponectin relationship with lipid metabolism is independent of body fat mass: evidence from both cross-sectional and intervention studies.

Adiponectin influences insulin sensitivity and lipid metabolism, but it is not clear whether these effects are correlated with fat mass or distribution. We studied the relationship between plasma adiponectin and leptin levels, insulin sensitivity, and serum lipids by a cross-sectional study (n = 242 subjects) and by an intervention study (95 of 242) to evaluate the effect of weight loss (WL). Considering all subjects both together and subdivided into nonobese (n = 107) and obese (n = 135) groups, plasma adiponectin, but not plasma leptin, was significantly (P < 0.01) correlated with insulin sensitivity [homeostasis model assessment of insulin-resistance index (HOMAIR), insulin sensitivity index (ISI) at oral glucose tolerance test, and clamp in 115 of 242 individuals], high-density lipoprotein cholesterol, and triglycerides. These relationships were still significant (P < 0.01) after adjusting for age, gender, body mass index (BMI), and ISI. After WL (-16.8 +/- 0.8%), plasma adiponectin increased, and plasma leptin decreased (P < 0.0001 for both). Their changes (Delta) were significantly correlated with Delta-BMI (P < 0.05 for both). Delta-Adiponectin, but not Delta-leptin, significantly (P < 0.001) correlated with Delta-high-density lipoprotein cholesterol and Delta-triglycerides; these correlations were independent of age, gender, Delta-BMI, and Delta-ISI (P < 0.005). In conclusion, both cross-sectional and intervention studies indicate that plasma adiponectin level correlates with serum lipids independently of fat mass. The intervention study also suggests that adiponectin increase after WL is correlated with serum lipid improvement independently of insulin sensitivity changes.

An ATG repeat in the 3'-untranslated region of the human resistin gene is associated with a decreased risk of insulin resistance.

Resistin is overexpressed in human adipose tissue of obese individuals and is likely to modulate insulin sensitivity. Resistin is, therefore, a candidate gene for insulin resistance. We searched for polymorphisms in the resistin gene by single strand conformation polymorphism and direct sequencing. An ATG triplet repeat in the 3'-untranslated region was identified and considered for association with insulin resistance. Three alleles were identified (allele 1: 8 repeats, allele frequency, 0.3%; allele 2: 7 repeats; allele frequency, 94.5%; allele 3: 6 repeats; allele frequency, 5.2%). Two hundred and three unrelated white Caucasian nondiabetic subjects from Sicily and 456 from the Gargano area (center east coast of Italy) were analyzed. Among Sicilians, subjects carrying allele 3 had a lower fasting insulin and insulin resistance index (homeostasis model assessment of insulin resistance; P < 0.001 for both) and glucose (P = 0.025) and insulin (P = 0.002) levels during the oral glucose tolerance test. In subjects from Gargano, those carrying allele 3 had lower fasting plasma glucose levels and serum triglycerides (P = 0.01 for both). When the 2 populations were analyzed together, subjects carrying allele 3 had lower fasting insulin levels (P < 0.005), homeostasis model assessment of insulin resistance (P < 0.005), and serum triglycerides (P = 0.01). In conclusion, our data suggest that subjects carrying allele 3 of the resistin gene are characterized by relatively high insulin sensitivity.

Very severely obese patients have a high prevalence of type 2 diabetes mellitus and cardiovascular disease.

The prevalence of very severe obesity has increased progressively and faster than other classes of obesity over the last years. It is unclear whether the prevalence of obesity-related complications and health risks increases progressively or reaches a plateau above a certain degree of obesity. The aim of our study was to investigate whether the severity of obesity was correlated with the prevalence of type 2 diabetes mellitus (T2DM), impaired fasting glucose, impaired glucose tolerance (IGT), metabolic syndrome (MS), and cardiovascular diseases (CVDs) in a large cohort of patients with different degrees of obesity. A cross-sectional study was conducted in 938 obese patients without a previous diagnosis of diabetes. Patients were assigned to different categories of obesity: mild-moderate obesity (BMI 30-39.9 kg/m(2)), morbid obesity (BMI 40-49.9 kg/m(2)), and super-obesity (SO, BMI ≥50 kg/m(2)). The prevalence of IGF, IGT, screen-detected T2DM, MS, and CVD was higher in SO patients than in the other groups. Interestingly, the association between SO and either MS or CVD was independent of glucose tolerance status, indicating that factors other than glucose metabolism also favor cardio-metabolic complications in obese patients. In patients without screen-detected T2DM (n = 807), insulin sensitivity and secretion OGTT-derived indexes indicated that SO patients had the worst glucose homeostasis relative to the other categories of obesity, which was indicated by the most reduced disposition index in these patients, a predictor of future T2DM. In conclusion, SO patients have an extremely high prevalence of glucose metabolism deterioration, and cardio-metabolic complications are more prevalent in these patients compared to less obese patients.

Joint effect of insulin signaling genes on insulin secretion and glucose homeostasis.

CONTEXT: Reduced insulin signaling in insulin secreting ß-cells causes defective insulin secretion and hyperglycemia in mice. OBJECTIVE: We investigated whether functional polymorphisms affecting insulin signaling (ie, ENPP1 K121Q, rs1044498; IRS1 G972R, rs1801278; and TRIB3 Q84R, rs2295490) exert a joint effect on insulin secretion and abnormal glucose homeostasis (AGH). DESIGN: Insulin secretion was evaluated by 1) the disposition index (DI) from an oral glucose tolerance test (OGTT) in 829 individuals; 2) insulin secretion stimulation index (SI) in islets from nondiabetic donors after glucose (n = 92) or glibenclamide (n = 89) stimulation. AGH (including impaired fasting glucose and/or impaired glucose tolerance or type 2 diabetes; T2D) was evaluated in case-control studies from the GENetics of Type 2 Diabetes in Italy and the United States (GENIUS T2D) Consortium (n = 6607). RESULTS: Genotype risk score, obtained by totaling individual weighted risk allele effects, was associated with the following: 1) DI (P = .005); 2) glucose and glibenclamide SI (P = .046 and P = .009); or 3) AGH (odds ratio 1.08, 95% confidence interval 1.03-1.13; P = .001). We observed an inverse relationship between genetic effect and age at AGH onset, as indicated by a linear correlation between AGH-genotype risk score odds ratios and age-at-diagnosis cutoffs (R(2) = 0.80, P < .001). CONCLUSIONS: Functional polymorphisms affecting insulin signaling exert a joint effect on both in vivo and in vitro insulin secretion as well as on early-onset AGH. Our data provide further evidence that abnormal insulin signaling reduces ß-cell function and impairs glucose homeostasis.