Abdominal Fat SIRT6 Expression and Its Relationship with Inflammatory and Metabolic Pathways in Pre-Diabetic Overweight Patients.

: The role of sirtuin 6 (SIRT6) in adipose abdominal tissue of pre-diabetic (pre-DM) patients is poorly known. Here, we evaluated SIRT6 expression in visceral abdominal fat of obese pre-diabetic patients and the potential effects of metformin therapy. Results indicated that obese pre-DM subjects showed low SIRT6 protein expression and high expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), peroxisome proliferator-activated receptor gamma (PPAR-γ), and sterol regulatory element-binding transcription factor 1 (SREBP-1). Obese pre-DM patients showed high values of glucose, insulin resistance (HOMA-IR), C reactive protein (CRP), nitrotyrosine, tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6), and low values of insulin (p < 0.05). Of note, abdominal fat tissue of obese pre-DM patients treated with metformin therapy presented higher SIRT6 expression and lower NF-κB, PPAR-γ, and SREBP-1 expression levels compared to pre-DM control group. Collectively, results show that SIRT6 is involved in the inflammatory pathway of subcutaneous abdominal fat of obese pre-DM patients and its expression responds to metformin therapy.

Endotoxinemia contributes to steatosis, insulin resistance and atherosclerosis in chronic hepatitis C: the role of pro-inflammatory cytokines and oxidative stress.

PURPOSE: Endotoxin is a component of the outer membrane of gram-negative bacteria that live in the intestine. Endotoxinemia is reported in non-alcoholic fatty liver disease and in cirrhotic patients, causing various biological and clinical effects in the host. It is not known whether endotoxinemia occurs in chronic hepatitis C patients (CHC), therefore we evaluated the occurrence of endotoxinemia and its effect on inflammation, liver damage, insulin resistance (IR) and atherosclerosis. METHODS: Consecutive CHC patients assessed by liver biopsy were enrolled. Endotoxinemia was evaluated by LAL test. IR was estimated by HOMA-IR. Serum TNF-α, IL-8, adiponectin and MCP-1 were measured with ELISA tests. Oxidative stress was estimated by circulating IgG against malondialdehyde adducts with human serum albumin (MDA-HAS). Carotid atherosclerosis was assessed by ultrasonography. RESULTS: Endotoxinemia was found in 60% of the 126 patients enrolled. A serum level-dependent association between endotoxinemia, steatosis (p < 0.001) and HOMA-IR (p < 0.006) was observed. Patients with endotoxinemia showed significant increase in TNF-α and IL8 levels. TNF-α correlated with steatosis (p <  0.001) and HOMA-IR (p < 0.03), whereas IL8 correlated with steatosis (p =  <0.001), TNF-α (p < 0.04) and atherosclerosis (p < 0.01). The highest levels of endotoxinemia were associated with oxidative stress and a higher prevalence of carotid atherosclerosis. Multivariate logistic regression analysis showed that the independent factors associated with endotoxinemia were hepatic steatosis, HOMA-IR, IL8 and MDA-HAS. CONCLUSIONS: Endotoxinemia occurs with high frequency in CHC patients and contributes to the development of hepatic steatosis, IR and atherosclerosis through increased pro-inflammatory cytokines and oxidative stress. Anti-endotoxin treatment could be of clinical relevance.

In routine clinical practice, few physicians use early viral kinetics to guide HCV dual therapy treatment decisions.

BACKGROUND & AIMS: PROPHESYS is a large, multinational, non-interventional prospective cohort study of chronic hepatitis C patients treated with peginterferon alfa/ribavirin. This subanalysis assesses rates of premature treatment discontinuation stratified by on-treatment virological response (VR). METHODS: This PROPHESYS subanalysis is restricted to treatment-naive, hepatitis C virus (HCV) genotype (G)1/2/3 mono-infected patients who received peginterferon alfa-2a (40KD)/ribavirin with intended treatment duration of 48 (G1) or 24 weeks (G2/3). Early virological responses were classified into four mutually exclusive categories [rapid VR (RVR), complete early VR (cEVR), partial EVR (pEVR), no RVR/EVR], using standard criteria. RESULTS: The likelihood for shortening treatment owing to good efficacy was highest among patients with an RVR and HCV RNA≤400 000 IU/ml (G1 10.0%; G2/3 5.8%) whereas for poor efficacy, it was highest in G1 non-RVR/EVR patients with HCV RNA>400 000 IU/ml (56.6%). Factors significantly associated with early treatment discontinuation as a result of good efficacy in G1 patients included RVR vs. no RVR/EVR and, at baseline, lower HCV RNA, lower FIB-4 score, HCV infection via injection drug use. For G2/3 patients, factors included lower baseline HCV RNA and G2 vs. G3 infection. Most patients started with the recommended peginterferon alfa-2a dose, but a high proportion received a higher-than-recommended ribavirin dose. CONCLUSIONS: Despite international guidelines, few physicians used early viral kinetics to abbreviate treatment. Therefore, relatively few patients with an RVR and low baseline HCV RNA abbreviated treatment. In addition, there were deviations in ribavirin starting doses, suggesting that physicians tailor treatment according to local guidelines or previous experience.

Inflammatory Cytokines and SIRT1 Levels in Subcutaneous Abdominal Fat: Relationship With Cardiac Performance in Overweight Pre-diabetics Patients.

Objectives: In obese patients the superficial adipose tissue expresses cytokines, and sirtuins, that may affect myocardial function. In this study, we investigated the effect of metformin therapy added to a hypocaloric diet on the inflammatory pattern and cardiac performance (MPI) in obese patients with pre-diabetic condition. Materials and Methods: Fifty-eight obese patients that were enrolled for abdominoplastic surgery were divided into patients with pre-diabetic condition (n 40) and normo-glycemic patients (n18). Patients with pre-diabetic condition were randomly assigned to metformin therapy added to a hypocaloric diet (group 1, n 20) or to a hypocaloric diet therapy alone (group 2, n20). Patients with normo-glycemic condition were assigned to a hypocaloric diet therapy. Results: During enrollment, obese patients with a pre-diabetic condition (group 1 and 2) presented higher glucose values, lower values of insulin, and higher values of the homeostasis model for the assessment of insulin resistance (HOMA-IR) than obese patients with normo-glycemic condition(group 3). In addition, they had higher values of C Reactive protein (CRP), interleukin 6 (IL6), and lower values of sirtuin 1(SIRT1). In the 12th month of the follow-up, metformin therapy induced in patients with pre-diabetic condition (group 1) a significant reduction of glucose values, HOMA-IR, and inflammatory markers such as CRP (1.04 ± 0.48 vs. 0.49 ± 0.02 mmol/L, p < 0.05), IL6 (4.22 ± 0.45 vs. 3.33 ± 0.34 pg/ml, p < 0.05), TNFα (6.95 ± 0.59 vs. 5.15 ± 0.44 pg/ml, p < 0.05), and Nitrotyrosine (5,214 ± 0,702 vs. 2,151 ± 0,351 nmol/l, p < 0.05). This was associated with a significant reduction of Intima-media thickness (1.01 ± 0.15 vs. 0.86 ± 0.15 mm, p < 0.05), Septum (14 ± 2.5 vs. 10.5 ± 2 mm, p < 0.05), Posterior wall (11 ± 1.5 vs. 8 ± 1 mm, p < 0.05), LV mass (192.5 ± 49.5 vs. 133.2 ± 37.6 g, p < 0.05) and of MPI (0.58 ± 0.03 vs. 0.38 ± 0.02, p < 0.05). At 12 months of follow-up, group 2 experienced only a reduction of cholesterol (4.15 ± 0.94 vs. 4.51 ± 0.88 mmol/L, p < 0.05) and triglycerides (1.71 ± 1.18 vs. 1.83 ± 0.54 mmol/L, p < 0.05). At 12 months of follow-up, group 3 experienced a significant reduction of inflammatory markers, and also of echographic parameters, associated with amelioration of myocardial performance. To date, IL6 expression was related to higher values of left ventricle mass (R-value 0.272, p-value 0.039), and to higher IMT (R-value 0.272, p-value 0.039), such as those observed for CRP (R-value 0.308, p-value 0.021), for glucose blood values (R-value 0.449, p-value 0.001), and for HOMA-IR (R-value 0.366, p-value 0.005). An inverse correlation was found between subcutaneous fat expression of SIRT1 and myocardial performance index (R-value-0.236, p-value 0.002). Conclusion: In obese patients with pre-diabetic condition a metformin therapy may reduce inflammation and oxidative stress, and this may be associated with the amelioration of the cardiac performance. Clinical research trial number: NCT03439592.

Comparative study on the occurrence of polycyclic aromatic hydrocarbons in breast milk and infant formula and risk assessment.

The study compared the polycyclic aromatic hydrocarbons (PAH) profile of human milk collected from Italian mothers and different brands of infant formula available on Italian market. Levels of 14 PAHs most frequently occurred in food, PAH markers listed by Commission Regulation (EC) No. 1881/2006, and carcinogenic PAHs classified by the International Agency for Research on Cancer, were determined by high-pressure liquid chromatography with fluorescence detector. The average concentrations of total PAHs were 114.93 in breast milk and 53.68 µg kg-1 in infant formula. Furthermore, Benzo(a)pyrene (BaP) and the sum of ∑PAH4 markers (BaP, Chrysene, Benzo(a,h)anthracene and Benzo(b)fluoranthene) were higher than the permissible limit of 1 µg kg-1 in 43% and 86% for breast milk and in 10% and 76% for infant formula samples, respectively. Breast milk showed higher levels (P < 0.05) of carcinogenic, and possible carcinogenic hydrocarbons than infant formula samples. Both in human and commercial milk, data showed the occurrence of low and high molecular weight PAHs, respectively from petrogenic and pyrolytic environmental sources, characterizing the infant and mother exposure. Particularly, waste incineration could have represented an important exposure source for infants during breastfeeding, through exposition of mothers resident in some areas of Southern Italy. High PAH levels detected in infant formula enriched with LC-PUFA might be related to the contamination of the vegetable oils added as ingredients. Results showed a high percentage of samples of both breast milk and infant formulas with margin of exposure (MOE) value indicating a potential concern for consumer health.

Relationship between autonomic cardiac activity, beta-cell function, anthropometrics and metabolic indices in type II diabetics.

OBJECTIVE: Recent studies have demonstrated that C-peptide exerts beneficial effects on the diabetic state, including improvements in kidney and nerve function. Thus, we investigated the effect of residual pancreatic C-peptide secretion on the cardiac autonomic nervous system in well- and poorly controlled type II diabetic patients. DESIGN: Randomised cross-sectional study. PATIENTS: Forty type II diabetic patients free from diabetic neuropathy, with similar anthropometric parameters, volunteered for our study. MEASUREMENTS: Insulin action, residual pancreatic C-peptide secretion and the cardiac autonomic nervous system were investigated by euglycaemic hyperinsulinaemic clamp, glucagon bolus test and heart rate variability, respectively. M-values were used as an index of insulin sensitivity. High frequency (HF) and low frequency (LF) oscillations in heart rate were analysed. RESULTS: The patients were categorized into those with good (HbA1c < or = 7.0) and poor (HbA1c > or = 8.0) metabolic control. The patients with good metabolic control had fasting plasma glucose and C-peptide levels, plasma area under the curve (auc) insulin and C-peptide levels, M-values, LF values and LF/HF ratio significantly lower than patients with poor metabolic control. In contrast, RR interval, total power and HF values had an opposite trend. Basal plasma C-peptide correlated with LF/HF in patients with good (r = -0.42; P < 0.05) and poor metabolic control (r = -0.45; P < 0.05). An even stronger correlation between auc C-peptide and LF/HF in patients with good (r = -0.53, P < 0.002) and poor metabolic control (r = -0.49; P < 0.03), as well as in the whole group (r = -0.83; P < 0.001) was found. By multiple regression analyses performed in all patients, LF/HF were independently associated with auc C-peptide (t = -8.618; P < 0.001) but not basal C-peptide levels (t = -0.137; P < 0.88). CONCLUSION: Our study demonstrated that preserved C-peptide secretion is associated with a well balanced cardiac autonomic activity in type II diabetic patients.