Non-thyroidal illness syndrome in chronic diseases: role of irisin as modulator of antioxidants.

OBJECTIVE: Non-thyroidal-illness syndrome (NTIS) refers to condition found in chronic diseases that is an adaptive mechanism. However, oxidative stress is related to NTIS in a vicious circle, due to deiodinases alteration and negative effects of low T3 on antioxidant levels or activity. Muscle is one of the main targets of thyroid hormones and it can secrete a myokine named irisin, which is able to induce the browning of white adipose tissue, energy expenditure and protect against insulin resistance. Inconclusive data have been reported about irisin role in chronic diseases. Moreover, no correlation with antioxidants has been investigated. Therefore, we performed a case-control study with the primary endpoint to evaluate irisin levels in two models of NTIS, such as chronic heart failure (CHF) and chronic kidney disease (CKD) during haemodialytic treatment. The secondary endpoint was the correlation with total antioxidant capacity (TAC) to establish a possible role of irisin in the modulation of antioxidant systems. PATIENTS AND METHODS: Three groups of subjects were enrolled. Group A included CHF patients (n=18; aged 70.22 ± 2.78 ys; BMI ± 27.75 ± 1.28 kg/m2); Group B included CKD patients (n=29; aged 67.03 ± 2.64; BMI 24.53 ± 1.01); finally, 11 normal subjects (Group C) have been enrolled as controls. Irisin has been evaluated by ELISA method and Total Antioxidant Capacity (TAC) by spectrophotometric method. RESULTS: Irisin was significantly higher in Group B vs. A and C groups (Mean ± SEM: 20.18 ± 0.61 ng/ml vs. 2.77 ± 0.77 and 13.06 ± 0.56, respectively; p<0.05); a significant correlation between irisin and TAC was observed in group B. CONCLUSIONS: These preliminary data suggest a possible role of irisin in the modulation of antioxidants in two chronic syndromes with low T3 (i.e., CHF and CKD) with differential pattern in these two models studied. Further insights are needed to confirm this pilot study, which could be the basis for a longitudinal investigation, to assess a prognostic role of irisin with possible therapeutic implications.

Hormonal deficiencies in heart failure with preserved ejection fraction: prevalence and impact on diastolic dysfunction: a pilot study.

OBJECTIVE: In heart failure with reduced ejection fraction, catabolic mechanisms have a strong negative impact on mortality and morbidity. The relationship between anabolic hormonal deficiency, thyroid function, and heart failure with preserved ejection fraction (HFpEF) has still been poorly investigated. Therefore, we aimed to define the multi-hormonal deficiency prevalence in HFpEF patients and the relationships between hormonal deficiency and echocardiographic indexes. PATIENTS AND METHODS: Plasma levels of N-terminal pro-brain natriuretic peptide, fasting glucose, thyroid-stimulating hormone, free triiodothyronine (T3), free thyroxine, insulin-like growth factor-1, dehydroepiandrosterone-sulfate (DHEA-S), total testosterone (only in male subjects) in 40 patients with HFpEF were evaluated. An echocardiographic evaluation was performed. RESULTS: One (2.5%) patient (2.5%) had no hormonal deficiencies; 8 (20%) patients had deficits of one hormone, 18 patients (45%) of two axes, 12 patients (30%) of three axes, and one patient (2.5%) of all four axes. Among them, 97.5% had DHEA-S deficiency, 67.5% IGF-1 deficiency, 37% testosterone deficiency, 22.5% a "Low T3 syndrome", and 20% subclinical hypothyroidism. Patients with IGF-1 deficit showed higher left atrial volume values, systolic pulmonary artery pressure (SPAP), tricuspid peak velocity (TPV), and lower tricuspid annular plane systolic excursion (TAPSE) and TAPSE/SPAP ratio values. Patients with testosterone deficiency had higher SPAP and TPV. Patients with low T3 syndrome had higher value of right ventricular mid cavity diameter. Hormonal dysfunction was independent from the presence of comorbidities and no difference between male and female subjects was noted. CONCLUSIONS: Multi-hormonal deficiencies are associated with right ventricular dysfunction and diastolic dysfunction in patients with HFpEF.

Anthracycline and trastuzumab-induced cardiotoxicity in breast cancer.

OBJECTIVE: Breast cancer is the most common cancer among women. In the last twenty years early diagnosis, neoadjuvant and adjuvant systemic treatment that targeted to specific molecular targets have significantly reduced the mortality from breast cancer. However, the increase in survival has allowed to observe the cardiotoxic effects of anticancer therapy and increased mortality from cardiovascular causes, resulting in a large literature where experts try to identify the correct management of this critical problem. Even thought the increased attention in this field, many questions have not yet answers and new studies are needed. MATERIALS AND METHODS: We conducted a broad search of the English-language literature in Medline using the following search terms: cardiotoxicity, anthracyclines, trastuzumab, breast cancer, left ventricular dysfunction, heart failure. A manual examination of the articles found has been performed. RESULTS: We provide a comprehensive assessment of the current knowledge about cardiotoxicity induced by anthracycline plus trastuzumab in women affected by breast cancer. CONCLUSIONS: Early identification and prompt treatment of subclinical cardiotoxicity may improve cardiologic prognosis of these patients and may allow oncologists to avoid withdrawal of chemotherapy. That is why it becomes always more important the creation of multidisciplinary teams where cardiologists and oncologists work together to ensure optimal care to oncologic patients treated with cardiotoxic agents.

Molecular mechanisms of diabetes reversibility after bariatric surgery.

OBJECTIVE: Insulin resistance is a strong biological marker of both obesity and type 2 diabetes. Abnormal fat deposition within skeletal muscle has been identified as a mechanism of obesity-associated insulin resistance. Biliopancreatic diversion (BPD), inducing a massive lipid malabsorption, leads to a reversion of type 2 diabetes. To elucidate the mechanisms of diabetes reversibility, the expression of genes involved in glucose and free fatty acids (FFAs) metabolism was investigated in skeletal muscle biopsies from obese, type 2 diabetic subjects. Peripheral insulin sensitivity and insulin secretion was also measured. SUBJECTS: Eight Caucasian obese diabetic patients (BMI 52.1+/-1.85 kg/m(2)) were studied before and 3 years after BPD. MEASUREMENTS: The mRNA levels were estimated by quantitative real-time reverse transcription polymerase chain reaction (RT-PCR), insulin sensitivity by the euglycemic-hyperinsulinemic clamp and insulin secretion using a model describing the relationship between insulin secretion and glucose concentration. RESULTS: Whole-body glucose uptake (M), normalized by fat-free mass, significantly increased in post-obese subjects (P<0.0001). Total insulin output decreased (P<0.05) in association with a significant improvement of beta-cells glucose sensitivity (P<0.05). mRNA levels of FABP3 (P<0.05), FACL (P<0.05), ACC2 (P<0.05), HKII (P<0.05) and PDK4 (P<0.05) were significantly decreased, while SREBP1c mRNA increased (P<0.05) after BPD. CONCLUSION: Reversibility of type 2 diabetes after BPD is dependent on the improvement of skeletal muscle insulin sensitivity, mediated by changes in the expression of genes regulating glucose and fatty acid metabolism in response to nutrient availability.