Clinical and metabolic effects of first-line treatment with somatostatin analogues or surgery in acromegaly: a retrospective and comparative study.

To evaluate the metabolic effects of first-line somatostatin analogues or surgery in acromegaly. Retrospective, comparative, 12-month follow-up. Two hundred and thirty one patients (123 men, age 47.32 ± 14.63 years) with active acromegaly, first line treatments were somatostatin analogues in 151 (65.4%) and surgery in 80 (34.6%). Metabolic syndrome (MS) parameters, glucose, insulin and GH during oral glucose tolerance test, stimulated insulin sensitivity by insulin sensitivity index (ISI Matsuda), early and total insulin-secretion rate by insulinogenic index and AUC(INS), visceral adiposity function, expressed by visceral adipose index (VAI). Somatostatin analogues treatment improved all MS parameters and significantly reduced fasting glucose (P < 0.001), HbA1c (P = 0.014) and the prevalence of DM (P = 0.003) when disease control was achieved. Both somatostatin analogues and surgery improved ISI Matsuda (P < 0.001) and reduced AUC(INS) (P < 0.001) and VAI (P < 0.001 and P = 0.003, respectively). Only in controlled somatostatin analogues-treated patients a significant reduction in insulinogenic index (P = 0.010) was observed. ISI Matsuda showed a significant independent correlation with IGF-1 levels (ß = -0.258; P = 0.001) and VAI score (ß = -0.430; P < 0.001). VAI was independently correlated with IGF-1 (ß = 0.183; P = 0.004). Both somatostatin analogues and surgery can safely be used as first-line therapy in acromegaly, without any untoward effects on glucose tolerance. The control of acromegaly is the main determinant of beneficial effects on general features of insulin sensitivity. VAI could represent an additional link between disease control and insulin sensitivity.

Visceral adiposity index is associated with histological findings and high viral load in patients with chronic hepatitis C due to genotype 1.

UNLABELLED: Metabolic factors have been associated with liver damage in patients with genotype 1 chronic hepatitis C (G1 CHC). We tested visceral adiposity index (VAI), a new marker of adipose dysfunction in G1 CHC, patients to assess its association with host and viral factors and its link to both histological findings and sustained virological response (SVR). Two hundred thirty-six consecutive G1 CHC patients were evaluated by way of liver biopsy and anthropometric and metabolic measurements, including insulin resistance (IR), homeostasis model assessment (HOMA), and VAI using waist circumference, body mass index, triglycerides, and high-density lipoprotein cholesterol. All biopsies were scored by one pathologist for staging and grading and graded for steatosis, which was considered moderate to severe if ≥ 30%. Multiple linear regression analysis revealed that VAI score was independently associated with higher HOMA score (P = 0.009), log10 hepatitis C virus RNA levels (P = 0.01), necroinflammatory activity (P = 0.04), and steatosis (P = 0.04). Multiple logistic regression analysis revealed that IR (OR 3.879, 95% CI 1.727-8.713, P = 0.001), higher VAI score (OR 1.472, 95% CI 1.051-2.062, P = 0.02), and fibrosis (OR 2.255, 95% CI 1.349-3.768, P = 0.002) were linked to steatosis ≥ 30%. Logistic regression analysis revealed that older age (OR 1.030, 95% CI 1.002-1.059, P = 0.03), higher VAI score (OR 1.618, 95% CI 1.001-2.617, P = 0.04), and fibrosis (OR 2.608, 95% CI 1.565-4.345, P < 0.001) were independently associated with moderate to severe necroinflammatory activity. No independent associations were found between VAI score and both fibrosis and SVR. CONCLUSION: In G1 CHC patients, higher VAI score is independently associated with both steatosis and necroinflammatory activity and has a direct correlation with viral load.

The oligomenorrhoic phenotypes of polycystic ovary syndrome are characterized by a high visceral adiposity index: a likely condition of cardiometabolic risk.

BACKGROUND: Women with polycystic ovary syndrome (PCOS) frequently exhibit central obesity, glucose intolerance, atherogenic dyslipidemia and hypertension, which are characteristic features of a condition of cardiometabolic risk. Our objective was to investigate the relationship between visceral adiposity index (VAI) and phenotypic characteristics in women with PCOS. METHODS: We conducted a cross-sectional case-control study in our Endocrinology Outpatients Clinic. A total of 220 women with PCOS (Rotterdam definition) and 144 age- and BMI-matched healthy women were studied. We evaluated hyperandrogenemia and clinical hyperandrogenism, ovarian morphology, hypothalamic-hypophyseal axis and metabolic syndrome parameters. An oral glucose tolerance test (75 g glucose) measured areas under the curve (AUC) for insulin (AUC(2h-insulin)) and for glucose (AUC(2h-glucose)). Homeostasis model assessment of insulin resistance, the Matsuda index of insulin resistance and VAI were determined. RESULTS: Of all the variables examined, at multivariate analysis, only AUC(2h-insulin) [odds ratio (OR): 1.00; 95% confidence interval (CI): 1.00-1.00; P = 0.003] and VAI score (OR: 1.81; 95% CI: 1.20-2.73; P = 0.005) showed an independent association with PCOS. All phenotypes with oligomenorrhea showed a higher VAI score than the control group (oligomenorrhea + hyperandrogenism: 2.49 ± 1.46 versus 1.62 ± 0.84, P < 0.001; oligomenorrhea + polycystic ovary morphology: 2.25 ± 1.4 versus 1.62 ± 0.84, P = 0.001; complete phenotype: 2.45 ± 1.63 versus 1.62 ± 0.84, P < 0.001). CONCLUSIONS: Our data suggest that VAI could be an easy and useful tool in daily clinical practice and in population studies for the assessment of cardiometabolic risk associated with PCOS.

Cut-off points of the visceral adiposity index (VAI) identifying a visceral adipose dysfunction associated with cardiometabolic risk in a Caucasian Sicilian population.

BACKGROUND: The Visceral Adiposity Index (VAI) is a sex-specific mathematical index, based on Waist Circumference (WC), Body Mass Index (BMI), triglycerides (TG) and HDL cholesterol (HDL) levels, indirectly expressing visceral adipose function and insulin sensitivity. Our aim was to find the optimal cut-off points of VAI identifying a visceral adipose dysfunction (VAD) associated with cardiometabolic risk in a Caucasian Sicilian population. METHODS: Medical check-up data of 1,764 Primary Care patients (PC patients) were retrospectively and cross-sectionally examined using a receiver-operating characteristic (ROC) curve to determine appropriate stratified-for-age cut-off of VAI, for the identification of PC patients with Metabolic Syndrome (MetS) according to the NCEP-ATP III criteria. The PC patients with higher VAI scores were subdivided into three groups according to VAI tertiles (i.e. PC patients with mild VAD, moderate VAD or severe VAD). Finally, VAD classes were compared to classical cardio- and cerebrovascular risk factors as independent predictors of coronary heart disease and/or myocardial infarction, transient ischemic attack and/or ischemic stroke. RESULTS: Moderate and severe VADs proved to be independently associated with cardiovascular events [(OR: 5.35; 95% CI: 1.92-14.87; p = 0.001) and (OR: 7.46; 95% CI: 2.64-21.05; p < 0.001) respectively]. Mild, moderate and severe VADs were found to be independently associated with cerebrovascular events [(OR: 2.73; 95% CI: 1.12-6.65; p = 0.027), (OR: 4.20; 95% CI: 1.86-9.45; p = 0.001) and (OR: 5.10; 95% CI: 2.14-12.17; p < 0.001) respectively]. CONCLUSIONS: Our study suggests that among Caucasian Sicilian subjects there are clear cut-off points of VAI able to identify a VAD strongly associated with cardiometabolic risk.

Low estradiol-to-testosterone ratio is associated with oligo-anovulatory cycles and atherogenic lipidic pattern in women with polycystic ovary syndrome.

OBJECTIVE: The estradiol-to-testosterone (E2/T) ratio has been investigated in different diseases but few in vivo data are available with regard to its role in women with ovary syndrome (PCOS). The aim of this study was to evaluate the role of the E2/T ratio in the ovulatory function and metabolic pattern in such women. METHODS: We retrospectively evaluated hyperandrogenemia, clinical hyperandrogenism, ovarian morphology, hypothalamo-hypophyseal axis and metabolic syndrome parameters in a cohort of 202 consecutive women affected by PCOS. An oral glucose tolerance test measured areas under the curve for insulin (AUC(2hIRI)), for glucose (AUC(2hglucose)), and the HOMA-IR and Matsuda index of insulin resistance were evaluated. Serum progesterone (Pg) was determined from day 20 to day 24 of the menstrual cycle and chronic oligo-anovulation was established if two consecutive cycles were anovulatory. RESULTS: Women with PCOS with normal ovulation [66/202 (32.7%)] showed a significantly higher E2/T ratio than women with PCOS with chronic oligo/anovulation [136/202 (67.3%)] (p < 0.05). Using a series of multiple linear regression models, we also investigated which variables correlated with the E2/T ratio. The analysis showed a strongly positive correlation of the E2/T ratio with Pg (ß = 0.473, p < 0.001) and a negative correlation with total cholesterol (ß = -0.433, p < 0.001). CONCLUSIONS: Our data suggest that in women with PCOS a low E2/T ratio is not only associated with chronic oligo-anovulation, but is also a determinant factor of the atherogenic lipid profile.

The evaluation of metabolic parameters and insulin sensitivity for a more robust diagnosis of the polycystic ovary syndrome.

BACKGROUND: Polycystic ovary syndrome (PCOS) is considered predominantly as a hyperandrogenetic syndrome and the evaluation of metabolic parameters and insulin sensitivity is not mandatory. CONTEXT: PCOS diagnostic criteria [National Institute of Health (NIH), Rotterdam Consensus (ROT), Androgen Excess Society (AES)] are unanimous recognized. We aimed to assess in women with suspected PCOS whether the application of the three diagnostic criteria differently characterizes the metabolic profile and insulin sensitivity. DESIGN: Retrospective study in a cohort of women admitted to our Outpatient Clinic for suspected PCOS. PATIENTS: Two hundred and four women with suspected PCOS in comparison to a group of normal, age-matched Sicilian women (N = 34) without signs of metabolic syndrome. MEASUREMENTS: We evaluated hyperandrogenaemia and clinical hyperandrogenism, ovarian morphology, hypothalamo-hypophyseal axis and metabolic syndrome parameters. An oral glucose tolerance test (OGTT; 75 g glucose) measured areas under the curve (AUC) for insulin, C peptide and homeostasis model assessment of insulin-resistance (HOMA-IR) were performed. RESULTS: The prevalence of PCOS was 51% according to NIH, 83% to ROT and 70.6% to AES, and only 100 patients were qualified simultaneously under these three criteria. The prevalence of the metabolic syndrome in PCOS women was 26.92% (NIH), 21.77% (ROT) and 23.61% (AES), respectively. In comparison to healthy women, PCOS women showed increased fasting insulinaemia (PCOS/ROT: P = 0.028; PCOS/NIH: P = 0.007; PCOS/EAS: P = 0.023), 120 min insulin after OGTT insulinaemia (for the three criteria: P < 0.001), AUC(2h) insulin (for the three criteria: P < 0.001) and AUC(2h) C peptide (for the three criteria: P < 0.001). CONCLUSIONS: Our study highlights the fact that regardless of the diagnostic criteria used, evaluation of the metabolic parameters and insulin sensitivity is important for a correct diagnosis of PCOS and a therapeutic approach.

Use of glargine in pregnant women with type 1 diabetes mellitus: a case-control study.

BACKGROUND: Insulin glargine is a once-daily basal insulin analog with prolonged duration of action and absence of an evident peak. Glargine is associated with reduced frequency of hypoglycemic episodes (mostly nocturnal) as well as effective glycemic control. Maintenance of good metabolic control before conception and throughout pregnancy is essential to lower the risk of fetal malformations. Glargine might be a valuable alternative in the management of pregnancies complicated by diabetes mellitus. However, because its clinical utility has not been established, the use of glargine is not currently recommended during pregnancy. OBJECTIVE: The aim of this study was to retrospectively evaluate (years 2004-2007) the effectiveness and safety of insulin glargine compared with neutral protamine Hagedorn (NPH) in women affected by type 1 diabetes mellitus (T1DM) during pregnancy. METHODS: The study comprised pregnant women affected by T1DM who were followed up in the Diabetes and Pregnancy Outpatient Clinic at the University of Palermo, Palermo, Italy, within 8 +/- 3.4 weeks subsequent to a positive pregnancy test. All patients with T1DM were treated with conventional basal-bolus insulin therapy (aspart or lispro analogs at the 3 main meals plus glargine or NPH at bedtime). Healthy pregnant women were used as controls for fetal and neonatal parameters. Patients were consecutively enrolled. In all women, metabolic status was determined daily by mean glycemic values (2-hour postprandial blood glucose) and glycosylated hemoglobin (HbA1c) values (at 3-month intervals). Fetal measurements (<50th and >90th centiles of the head circumference, abdomen circumference, and femoral length) were evaluated by ultrasound at second and third trimesters. Weight and femoral length were assessed at birth, and neonates were classified according to the fetal growth curve for the Italian population (<10th centile = small for gestational age; and >90th centile = large for gestational age (LGA). RESULTS: A total of 73 pregnant women (30 with T1DM and 43 healthy [control]) were included in the study. Of the 30 diabetic pregnant women included in the study, 15 (mean [SD] age, 27.4 [5.2] years; mean pregravidic weight, 59.7 [11.7] kg) maintained their preconception therapy with glargine, and 15 (mean age, 30.1 [2.4] years; mean pregravidic weight, 60.7 [8.7] kg) with NPH. No significant difference was observed between the glargine-treated group and the NPH-treated group with regard to pregravidic hypertension, third-trimester preeclampsia, maternal complications and/or their progression during pregnancy (diabetic retinopathy, micro- or macroalbuminuria) and episodes of mild hypoglycemia, severe hypoglycemia, and ketosis. There were no significant between group differences in insulin requirements (IU/kg of body weight) and glycemic profile, with the exception of better fasting and 2 hours after breakfast glycemic values in the glargine group during the first (P = 0.008 and P < 0.001, respectively) and the second (P = 0.015 and P = 0.016) trimesters, confirmed by the lower HbA1c levels in the first trimester (P = 0.037). The frequency of femoral length <50th centile at both second and third trimesters was 4/15 (26.7%) in the glargine-treated group (P = 0.033 and P = 0.013, respectively, vs control), 3/15 (20.0%) and 1/15 (6.7%), respectively, in the NPH-treated group (both, P = NS vs control), and 2/43 (4.7%) and 1/43 (2.3%), respectively, in the control group. The prevalence of LGA was 7/15 (46.7%) in the glargine group (P < 0.001 vs control), 4/15 (27.6%) in the NPH group (P = 0.033 vs control), and 2/43 (4.7%) in the control group. CONCLUSIONS: Although our retrospective study involved only a small number of participants, no significant difference was found in glycemic control between glargine and NPH treatments. Use of glargine was associated with a significantly higher frequency of femoral length <50th centile. Further larger prospective studies are necessary to assess the safety profile of glargine in T1DM during pregnancy.

Insulin resistance and polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in humans, affecting approximately 7-8% of women of reproductive age. Despite the criteria adopted, PCOS is considered to be a predominantly hyperandrogenetic syndrome and the evaluation of metabolic parameters and insulin sensitivity is not mandatory. Most women with PCOS also exhibit features of the metabolic syndrome, including insulin resistance, obesity and dyslipidaemia. While the association with type 2 diabetes is well established, whether the incidence of cardiovascular disease is increased in women with PCOS remains unclear. Acknowledging the strong impact of insulin-resistance in the genesis of PCOS could be helpful not only to make the diagnosis more robust, but also for conferring better cardiovascular risk prevention. Several current studies support a strong recommendation that women with PCOS should undergo comprehensive evaluation for the metabolic syndrome and recognized cardiovascular risk factors, and receive appropriate treatment as needed. Lifestyle modifications remain the first-line therapy for all obese women with PCOS. However, many of these women do not lose weight easily. Insulin-sensitizing drugs are discussed as a promising and unique therapeutic option for the chronic treatment of PCOS.

Fine-needle aspiration molecular analysis for the diagnosis of papillary thyroid carcinoma through BRAF V600E mutation and RET/PTC rearrangement.

OBJECTIVE: To evaluate BRAF(V600E) mutation on consecutive fine-needle aspiration biopsy (FNAB) specimens in order to assess FNAB's usefulness in preoperative papillary thyroid carcinoma (PTC) diagnosis with the contemporaneous analysis of RET/PTC1 and RET/PTC3 rearrangements obtained from ex vivo thyroid nodules. DESIGN: Thyroid FNABs from 156 subjects with nodules and 49 corresponding surgical samples were examined for the presence of BRAF mutation by real-time allele-specific polymerase chain reaction, confirmed with the use of a laser pressure catapulting system. Samples were also examined for RET/PTC rearrangements. The results were compared with the cytological diagnosis and histopathology. MAIN OUTCOMES: 13/156 cytological examinations were diagnostic for PTC and 19/156 showed suspicious/indeterminate FNAB (12.2%). FNAB-BRAF(V600E) mutation was detected in 11/16 (69%) cases with histological confirmation of PTC. In our series, RET/PTC rearrangement was detected in only one case of PTC, whereas it was not present in any case of adenoma, goiter, or Hashimoto's thyroiditis. No PTC case was found positive at the same time for BRAF mutation and RET/PTC rearrangements. CONCLUSION: BRAF(V600E) mutation detected on FNAB specimens, more than RET/PTC rearrangements, is highly specific for PTC and its routine research might well be an adjunctive and integrative diagnostic tool for the preoperative diagnostic iter.

Lower insulin sensitivity differentiates hirsute from non-hirsute Sicilian women with polycystic ovary syndrome.

OBJECTIVE: It is well known that hyperandrogenism and insulin-resistance with or without compensatory hyperinsulinism are closely associated, but the Rotterdam Consensus has concluded that principally obese women with polycystic ovary syndrome (PCOS) should be evaluated for the metabolic syndrome. Our aim was to study insulin sensitivity in PCOS women with hirsutism regardless of obesity. METHODS: Clinical characteristics, sex hormones and fasting- and after OGTT-glycemia and insulinemia, homeostatic model of insulin resistance (HOMA IR), and Matsuda index of insulin sensitivity were analyzed in 130 women with PCOS. Hirsutism has been evaluated through the Ferriman-Gallwey (FG) map scoring system. RESULTS: PCOS women with hirsutism (57.7% of participants) showed significant higher values of total testosterone levels (P = 0.016), free testosterone (P = 0.027), DHEA sulfate (P = 0.017), and Delta4androstenedione (P = 0.018). They had similar body mass index (BMI) (P = 0.073) and were significantly less insulin sensitive (P = 0.002) than those without hirsutism (42.3% of participants). In women with PCOS and hirsutism, there was a significant correlation between FG score and insulin-sensitivity indexes (HOMA IR, rho = 0.33, P = 0.005; Matsuda index, rho = -0.34, P = 0.003) but not with the androgen levels. Moreover, women with hirsutism showed a significantly greater insulin (P = 0.019), C-peptide (P = 0.002), and glucose (P = 0.024) areas under the curve (auc2h). CONCLUSIONS: Our study suggests that the increased responsiveness of the pilo-sebaceous unit to androgens seems to be influenced by insulin sensitivity and that insulin resistance should be assessed in all hirsute women with PCOS regardless of their BMI, as insulin resistance was found in hirsute women irrespective of whether they were overweight or obese.

Transient chylomicronemia preceding the onset of insulin-dependent diabetes in a young girl with no humoral markers of islet autoimmunity.

OBJECTIVE: We investigated the possible causes of diabetes in a young child who presented with hyperglycemia associated with severe hypertriglyceridemia (>166 mmol/l), hypercholesterolemia (>38 mmol/l) and fasting chilomicrons. RESULTS: The patient did not have any of the HLA and autoantibody markers typically associated with type 1 diabetes. A glucose clamp failed to demonstrate insulin resistance (peripheral glucose utilization rate (M)=4.3 mg/kg per min) and there was no family history of type 2 diabetes or maturity onset diabetes in youth. Both fasting and stimulated C-peptide levels, including those in response to i.v. glucagon, were below the limit of detection. This is consistent with loss of beta-cell function. The family history did not reveal the existence of relatives with lipid abnormalities, coronary heart disease, and pancreatitis. We did not find any abnormality of plasma apoCII, lipoproteinlipase and hepatic lipase activities. The patients had a epsilon3/epsilon3 apoE genotype and she rapidly cleared an oral fat load after normalization of plasma lipids. CONCLUSIONS: The mild hyperglycemia seems an unlikely explanation for both the severe hypertriglyceridemia and chylomicronemia. A more plausible explanation is transient lipoproteinlipase deficiency. This rare condition, occasionally associated with a high-fat diet, could have caused the rapid and dramatic hypertriglyceridemia observed in this patient, which in turn might have led to the beta-cell destruction by direct lipid toxicity.

Janus kinase (JAK) 2 V617F mutation as the cause of primary thrombocythemia in acromegaly with severe visceromegaly and divergence between growth hormone and insulin-like growth factor-1 concentrations during the follow-up: causal or casual association?

OBJECTIVE: An increased prevalence of hematological abnormalities is reported in acromegaly, but to date no reports about the presence of the Janus Kinase (JAK) 2 mutation in acromegalic patients have been described. DESIGN: We report the complex clinical presentation of the unique case, never described, of acromegaly due to GH-secreting pituitary adenoma associated with JAK2 V617F mutation. RESULTS: The patient shows primary thrombocythemia and myelofibrosis, due to JAK2 V617F mutation, severe visceromegaly and a peculiar clinical course of the disease characterized by discrepant values of GH and IGF-1 during somatostatin analog (SA) treatment despite a significant reduction in pituitary adenoma size and therapeutic resistance both to SA and pegvisomant. CONCLUSIONS: The presence of JAK2 V617F mutation is a cause of primary thrombocythemia and myelofibrosis in acromegaly. In this patient, a peculiar clinical course of acromegaly was observed, with the difficulty in controlling the disease. More data, on a larger cohort of patients, could clarify whether JAK2 V617F mutation has a serious impact on the clinical features and course of acromegaly.

In vitro generation of pancreatic endocrine cells from human adult fibroblast-like limbal stem cells.

Stem cells might provide unlimited supply of transplantable cells for ß-cell replacement therapy in diabetes. The human limbus is a highly specialized region hosting a well-recognized population of epithelial stem cells, which sustain the continuous renewal of the cornea, and the recently identified stromal fibroblast-like stem cells (f-LSCs), with apparent broader plasticity. However, the lack of specific molecular markers for the identification of the multipotent limbal subpopulation has so far limited the investigation of their differentiation potential. In this study we show that the human limbus contains uncommitted cells that could be potentially harnessed for the treatment of diabetes. Fourteen limbal biopsies were obtained from patients undergoing surgery for ocular diseases not involving the conjunctiva or corneal surface. We identified a subpopulation of f-LSCs characterized by robust proliferative capacity, expressing several pluripotent stem cell markers and exhibiting self-renewal ability. We then demonstrated the potential of f-LSCs to differentiate in vitro into functional insulin-secreting cells by developing a four-step differentiation protocol that efficiently directed f-LSCs towards the pancreatic endocrine cell fate. The expression of specific endodermal, pancreatic, islet, and ß-cell markers, as well as functional properties of f-LSC-derived insulin-producing cells, were evaluated during differentiation. With our stage-specific approach, up to 77% of f-LSCs eventually differentiated into cells expressing insulin (also assessed as C-peptide) and exhibited phenotypic features of mature ß-cells, such as expression of critical transcription factors and presence of secretory granules. Although insulin content was about 160-fold lower than what observed in adult islets, differentiated cells processed ∼98% of their proinsulin content, similar to mature ß-cells. Moreover, they responded in vitro in a regulated manner to multiple secretory stimuli, including glucose. In conclusion, f-LSCs represent a possible relevant source of autologous, transplantable, insulin-producing cells that could be tested for the reversal of diabetes.

In vitro phenotypic, genomic and proteomic characterization of a cytokine-resistant murine ß-TC3 cell line.

Type 1 diabetes mellitus (T1DM) is caused by the selective destruction of insulin-producing ß-cells. This process is mediated by cells of the immune system through release of nitric oxide, free radicals and pro-inflammatory cytokines, which induce a complex network of intracellular signalling cascades, eventually affecting the expression of genes involved in ß-cell survival.The aim of our study was to investigate possible mechanisms of resistance to cytokine-induced ß-cell death. To this purpose, we created a cytokine-resistant ß-cell line (ß-TC3R) by chronically treating the ß-TC3 murine insulinoma cell line with IL-1ß + IFN-γ. ß-TC3R cells exhibited higher proliferation rate and resistance to cytokine-mediated cell death in comparison to the parental line. Interestingly, they maintained expression of ß-cell specific markers, such as PDX1, NKX6.1, GLUT2 and insulin. The analysis of the secretory function showed that ß-TC3R cells have impaired glucose-induced c-peptide release, which however was only moderately reduced after incubation with KCl and tolbutamide. Gene expression analysis showed that ß-TC3R cells were characterized by downregulation of IL-1ß and IFN-γ receptors and upregulation of SOCS3, the classical negative regulator of cytokines signaling. Comparative proteomic analysis showed specific upregulation of 35 proteins, mainly involved in cell death, stress response and folding. Among them, SUMO4, a negative feedback regulator in NF-kB and JAK/STAT signaling pathways, resulted hyper-expressed. Silencing of SUMO4 was able to restore sensitivity to cytokine-induced cell death in ß-TC3R cells, suggesting it may play a key role in acquired cytokine resistance by blocking JAK/STAT and NF-kB lethal signaling.In conclusion, our study represents the first extensive proteomic characterization of a murine cytokine-resistant ß-cell line, which might represent a useful tool for studying the mechanisms involved in resistance to cytokine-mediated ß-cell death. This knowledge may be of potential benefit for patients with T1DM. In particular, SUMO4 could be used as a therapeutical target.

Predictors of microvascular complications in type 1 diabetic patients at onset: the role of metabolic memory.

BACKGROUND: Several epidemiological studies showed a close association between metabolic control and microvascular complications in type 1 Diabetes Mellitus (T1DM). The aim of our longitudinal observational study was to evaluate the predictive role of the main clinical and biochemical parameters in determining microvascular complications. METHODS: 376 T1DM patients, hospitalized in our division from 1991 to 2005 (mean follow-up=10.93±4.26 years) were studied. Stepwise Cox regression analysis was used to identify the influence of residual ß-cell function, ß-cell autoimmunity, HbA1c levels and other clinical and laboratory parameters in the development of microalbuminuria and retinopathy. RESULTS: The probability of developing microalbuminuria was higher in males than in females (HR 1.82; 95% CI 1.01-3.28; p=0.044), in patients with higher mean HbA1c values (HR 2.80; 95% CI 1.63-4.83; p<0.001), longer duration of disease (HR 1.98; 95% CI 1.10-3.57; p=0.022) and younger age of diabetes onset (HR 0.53; 95% CI 0.03-0.92; p=0.026). An increased probability of developing retinopathy was found in patients with higher mean HbA1c levels during follow-up (HR 2.35; 95% CI 1.34-4.12, p=0.003), as well as at onset (HR 1.85; 95% CI 1.06-3.24; p=0.030). CONCLUSIONS: Our study suggests that among the clinical, metabolic, immunological and biochemical factors evaluated at onset, only HbA1c is predictive for the microangiopathy development in T1DM.

BRAFV600E mutation, TIMP-1 upregulation, and NF-κB activation: closing the loop on the papillary thyroid cancer trilogy.

BRAF(V600E) is the most common mutation found in papillary thyroid carcinoma (PTC). Tissue inhibitor of metalloproteinases (TIMP-1) and nuclear factor (NF)-κB have been shown to play an important role in thyroid cancer. In particular, TIMP-1 binds its receptor CD63 on cell surface membrane and activates Akt signaling pathway, which is eventually responsible for its anti-apoptotic activity. The aim of our study was to evaluate whether interplay among these three factors exists and exerts a functional role in PTCs. To this purpose, 56 PTC specimens were analyzed for BRAF(V600E) mutation, TIMP-1 expression, and NF-κB activation. We found that BRAF(V600E) mutation occurs selectively in PTC nodules and is associated with hyperactivation of NF-κB and upregulation of both TIMP-1 and its receptor CD63. To assess the functional relationship among these factors, we first silenced BRAF gene in BCPAP cells, harboring BRAF(V600E) mutation. We found that silencing causes a marked decrease in TIMP-1 expression and NF-κB binding activity, as well as decreased invasiveness. After treatment with specific inhibitors of MAPK pathway, we found that only sorafenib was able to increase IκB-α and reduce both TIMP-1 expression and Akt phosphorylation in BCPAP cells, indicating that BRAF(V600E) activates NF-κB and this pathway is MEK-independent. Taken together, our findings demonstrate that BRAF(V600E) causes upregulation of TIMP-1 via NF-κB. TIMP-1 binds then its surface receptor CD63, leading eventually to Akt activation, which in turn confers antiapoptotic behavior and promotion of cell invasion. The recognition of this functional trilogy provides insight on how BRAF(V600E) determines cancer initiation, progression, and invasiveness in PTC, also identifying new therapeutic targets for the treatment of highly aggressive forms.

OCT is not useful for detection of minimal diabetic retinopathy in type 1 diabetes.

Optical coherence tomography (OCT) has been proven useful in measuring retinal thickness (RT) in patients with diabetes, although with discordant results in different studies. We examined RT in patients with type 1 diabetes (T1D) with or without minimal diabetic retinopathy (MDR) to test whether OCT is able to identify early retinal changes and potential correlations with metabolic parameters. RT of 102 patients with T1D (53 females, 49 males, aged 27.03 +/- 7.4 years) and of 42 healthy controls was examined, with analysis of nine different sectors (fovea, four pericentral and four peripheral sectors). According to the results of basal fundus photography, patients were divided into two groups, without MDR (48 cases) and with MDR (54 cases). Patients with proliferative DR or macular edema were excluded. No difference was found between patients with or without MDR and the control group for all OCT parameters investigated. Mean HbA1c of the last 5 years (P < 0.001), microalbuminuria (P = 0.002), total (P = 0.046) and LDL cholesterol (P = 0.007) and triglyceride (P < 0.001) levels were higher in patients with MDR, along with higher prevalence of hypertension (P = 0.013), younger age at diagnosis (P = 0.018) and longer diabetes duration (P < 0.001) with regard to the patients without MDR and controls, although no significant correlation between these parameters and RT was found. Our study suggests that MDR without macular edema in patients with T1D cannot be detected with OCT. Therefore, the conventional diagnostic methods are mandatory to detect early DR.

Visceral Adiposity Index: a reliable indicator of visceral fat function associated with cardiometabolic risk.

OBJECTIVE: To individuate a novel sex-specific index, based on waist circumference, BMI, triglycerides, and HDL cholesterol, indirectly expressing visceral fat function. RESEARCH DESIGN AND METHODS: Visceral adiposity index (VAI) was first modeled on 315 nonobese healthy subjects. Using two multiple logistic regression models, VAI was retrospectively validated in 1,498 primary care patients in comparison to classical cardio- and cerebrovascular risk factors. RESULTS: All components of metabolic syndrome increased significantly across VAI quintiles. VAI was independently associated with both cardiovascular (odd ratio [OR] 2.45; 95% CI 1.52-3.95; P < 0.001) and cerebrovascular (1.63; 1.06-2.50; P = 0.025) events. VAI also showed significant inverse correlation with insulin sensitivity during euglycemic-hyperinsulinemic clamp in a subgroup of patients (R(s) = -0.721; P < 0.001). By contrast, no correlations were found for waist circumference and BMI. CONCLUSIONS: Our study suggests VAI is a valuable indicator of "visceral adipose function" and insulin sensitivity, and its increase is strongly associated with cardiometabolic risk.

Adrenal morphology and function in acromegalic patients in relation to disease activity.

Visceromegaly is a common consequence of acromegaly. However, few studies investigated the chronic effects of growth hormone on adrenal glands. Our aim was to evaluate adrenal morphology and function in a cohort of acromegalic patients in relation to disease activity. Twenty-six acromegalics (10 males and 16 females) and 21 healthy subjects were investigated. Gland morphology was evaluated by computerized axial tomography, measuring central, lateral, and medial adrenal segments. Uncontrolled acromegalics showed increased volume of all adrenal segments, higher urinary free cortisol (UFC), and lower morning adrenocorticotropic hormone in comparison with healthy subjects. However, normal cortisol levels after low-dose dexamethasone suppression test indicated a preserved regulation of the hypothalamic-pituitary-adrenal axis. In addition, uncontrolled patients showed greater medial segment of right gland, higher UFC, and aldosterone levels with respect to controlled patients. All acromegalics did not show any difference in adrenal size when grouped according to UFC/24 h levels. In addition, no difference was found in any of the parameters between normotensive and hypertensive patients. In conclusion, our findings confirm that acromegaly affects adrenal size as well as other organs. In addition, we report a stimulatory effect of growth hormone on adrenal function, although the regulation of the hypothalamic-pituitary-adrenal axis is preserved.

Identification of tyrosine phosphatase 2(256-760) construct as a new, sensitive marker for the detection of islet autoimmunity in type 2 diabetic patients: the non-insulin requiring autoimmune diabetes (NIRAD) study 2.

OBJECTIVE: The presence of autoantibodies to islet antigens GAD and/or tyrosine phosphatase 2 (IA-2) in type 2 diabetic patients (latent autoimmune diabetes in adults [LADA]) identifies subjects at high risk to develop insulin dependency. The aim of this study was to dissect humoral anti-IA-2 immune response in Caucasian LADA patients, identifying the most sensitive construct to evaluate IA-2 immunoreactivity and comparing LADA IA-2 epitope specificities to those found in type 1 diabetes. RESEARCH DESIGN AND METHODS: We analyzed 177 LADA and 978 type 2 diabetic patients with different disease duration, collected in a nationwide Italian survey, the Non-Insulin Requiring Autoimmune Diabetes (NIRAD) study aimed at assessing prevalence and characteristics of autoimmune diabetes in type 2 diabetic patients and 106 newly diagnosed type 1 diabetic patients (53 children, 53 adults). By radioimmunoassay, we analyzed humoral immunoreactivity to seven IA-2 constructs: IA-2(PTP (687-979)), IA-2((761-964)), IA-2((256-760)), IA-2(JM (601-630)), IA-2(IC (605-979)), IA-2(BDC (256-556:630-979)), and IA-2(FL (1-979)). RESULTS: IA-2((256-760)) fragment was identified as the marker with the highest sensitivity for detection of humoral IA-2 immunoreactivity in LADA patients, identifying IA-2 autoantibodies in approximately 30% of GAD antibody (GADA)-positive LADA patients and in 3.4% of GADA-negative type 2 diabetic patients. LADA IA-2((256-760))A positivity was associated with an increased frequency of autoimmune diabetes HLA-susceptible genotypes and with a higher risk for developing thyroid autoimmunity compared with autoantibody-negative type 2 diabetic patients. At disease diagnosis, adult-onset type 1 diabetic and LADA patients showed a lower IA-2 COOH-terminal immunoreactivity compared with childhood-onset type 1 diabetic patients. CONCLUSIONS: IA-2 immunoreactivity in LADA patients has thus far been underestimated, and IA-2((256-760)) autoantibody detection may represent a novel diagnostic tool for the identification of islet autoimmunity in these patients.