Effects of competitive physical activity on serum irisin levels and bone turnover markers.

BACKGROUND: Irisin, a myokine, is a polypeptide derived from the cleavage of the extracellular domain of fibronectin domain-containing protein 5, a receptor that is present on different tissues (skeletal muscle, pericardium, myocardium, and brain), whose functions are not yet fully defined. PURPOSE: The main aim of our study was to evaluate the effect of competitive physical activity on serum irisin levels and bone turnover markers. METHODS: Fifteen male footballers and an equal number of subjects of the same age and gender, but with a predominantly sedentary lifestyle, had their serum levels of irisin and bone turnover markers measured. Bone mineral status was evaluated in both groups by quantitative bone ultrasound of the calcaneus. In addition, only in footballers, biochemical analyses were repeated after 3 months. RESULTS: We did not observe significant differences in the serum levels of calcium, phosphorus, and parathyroid hormone between the two groups. The footballers had significantly higher quantitative bone ultrasound, 25-OH vitamin D, and creatinine values than the controls. There were also no significant differences in the bone alkaline phosphatase, carboxy-terminal telopeptide of type I collagen, osteoprotegerin, sclerostin or Dkk-1 values, while the irisin levels (+ 89%, p < 0.001) and RANKL were significantly higher in the footballers compared to those in the controls. CONCLUSION: Our study shows that footballers have significantly higher serum irisin values than the general population. Irisin could be the "trait d'union" between bone health and physical activity.

Inflammation and ventricular-vascular coupling in hypertensive patients with metabolic syndrome.

BACKGROUND AND AIMS: Metabolic syndrome (MetS) is currently considered to raise the risk for type 2 diabetes and cardiovascular events. It has been suggested that part of this risk excess may be due to a cluster of additional factors associated with MetS. We aimed to investigate the role of inflammation on the ventricular-vascular coupling in patients with MetS. METHODS AND RESULTS: We enrolled a total of 227 hypertensive patients (106 with MetS and 121 without MetS) matched for age and gender. Aortic pulse wave velocity (aPWV), intima-media thickness (IMT) and high sensitivity C-reactive protein (CRP) increased according to the number of MetS components. Patients with MetS showed increased aPWV (11.5 ± 3.7 vs. 10.3 ± 2.5 m/s, P = 0.03) compared with controls. In a model adjusted for age, sex, heart rate and mean blood pressure, aPWV resulted increased in patients with CKD (beta 1.29 m/s, 95%CI 0.61-1.96 m/s, P < 0.001) and MetS (beta 0.89 m/s, 95%CI 0.28-1.51 m/s, P = 0.005). After additional adjustment for CRP and IMT, the slope of aPWV was respectively reduced by 16% and 62%, suggesting that inflammation and intima-media thickening could contribute to aortic stiffening in patients with MetS. In these patients, aPWV was also associated with left-ventricular mass index (beta 0.79 g/m2.7, 95%CI 0.05-1.52 g/m2.7, P = 0.05). CONCLUSION: MetS is characterized by an inflammation-dependent acceleration in cardiovascular ageing. This pattern of pathophysiological abnormalities may contribute to amplify the burden of cardiovascular risk in patients with MetS.

Proton pump inhibitors and symptomatic hypomagnesemic hypoparathyroidism.

Hypomagnesemia is a common but often overlooked problem in hospitalized patients. Unrecognized hypomagnesemia can cause serious complications. The association of hypokalemia and hypocalcemia is strongly evocative of a magnesium deficiency. Research into the causes of hypomagnesemia is imperative, as it will definitely change the approach, treatment and prognosis. We report the case of a 65-year-old man with chronic hypocalcemia and hypokalemia associated with cerebellar syndrome, a solitary seizure and cerebellar hyperintensities on magnetic resonance imaging. After the detection and treatment of hypomagnesemia with oral supplements of magnesium and the replacement of pantoprazole with ranitidine, we observed immediate relief of the symptoms. In conclusion, in clinical practice, magnesium depletion should be investigated in elderly patients with hypocalcemia treated with proton pump inhibitors for many years, in particular in the presence of neurological disorders.

Sodium-glucose linked transporter-2 inhibitors in chronic kidney disease.

SGLT2 inhibitors are new antihyperglycaemic agents whose ability to lower glucose is directly proportional to GFR. Therefore, in chronic kidney disease (CKD) the blood glucose lowering effect is reduced. Unlike many current therapies, the mechanism of action of SGLT2 inhibitors is independent of insulin action or beta-cell function. In addition, the mechanism of action of SGLT2 inhibitors is complementary and not alternative to other antidiabetic agents. SGLT2 inhibitors could be potentially effective in attenuating renal hyperfiltration and, consequently, the progression of CKD. Moreover, the reductions in intraglomerular pressure, systemic blood pressure, and uric acid levels induced by SGLT inhibition may potentially be of benefit in CKD subjects without diabetes. However, at present, only few clinical studies were designed to evaluate the effects of SGLT2 inhibitors in CKD. Consequently, safety and potential efficacy beyond blood glucose lowering should be better clarified in CKD. In this paper we provide an updated review of the use of SGLT2 inhibitors in clinical practice, with particular attention on subjects with CKD.

[Phosphorus: a new cardiovascular risk factor?]. / Il Fosforo: nuovo fattore di rischio cardiovascolare?

Phosphorus is an essential mineral in the regulation of many metabolic processes. However, is known as alterations in serum phosphate levels, compared to the normal range, have clinical relevance: many studies about phosphorus and cardiovascular risk have shown that high serum phosphate levels are associated with clinical and subclinical cardiovascular disease, in CKD and non-CKD patients. In recent years, serum phosphate level within the upper limits of normal range is also identified as a "stealthier killer", and has emerged as a risk factor of cardiovascular mortality and progression of CKD. This mounting evidence suggests the possibility that lowering serum phosphate levels may be a future target of cardiovascular disease management, also through the use of early biomarkers of phosphate overload, such as FGF23, Klotho or the urinary fractional excretion of phosphate. The goal must be an early diagnosis and treatment of disordered phosphorus metabolism, before end-organ damage occurs. Since the western diet is rich in phosphate, a dietary restriction associated with the use of phosphate binders, as well as the use of intervention such as calcitriol supplementation, certainly will have a positive influence on the phosphate-regulatory axis.

Resistive intrarenal index: myth or reality?

In renal diagnosis, the B-mode ultrasound is used to provide an accurate study of the renal morphology, whereas the colour and power Doppler are of strategic importance in providing qualitative and quantitative information about the renal vasculature, which can also be obtained through the assessment of the resistive index (RI). To date, this is one of the most sensitive parameters in the study of kidney diseases and allows us to quantify the changes in renal plasma flow. If a proper Doppler ultrasound examination is carried out and a critical analysis of the values obtained is performed, the RI measurement at the interlobar artery level has been suggested in the differential diagnosis between nephropathies. The aim of this review is to highlight the pathological conditions in which the study of intrarenal RI provides useful information about the pathophysiology of renal diseases in both the native and the transplanted kidneys.

[Nephrological paradox]. / Il paradosso nefrologico.

Patients that are followed by nephrologists from the beginning of the illness, they show a deceleration in the progression of the Chronic Kidney Disease towards dialysis and a better quality of life (less osteodystrophy, anaemia and fluids overload, better pressure management). However, in 2013 it still exists a great lack of knowledge about the professional figure of nephrologist. Residents of Nephrological School of Catania decided to conduct a survey to evaluate common knowledge of renal diseases and their treatments. The survey was conducted in two cities of Sicily. The results show that people are generally uninformed and disoriented about renal illness and their risks.

Oxidative stress, glutathione status, sirtuin and cellular stress response in type 2 diabetes.

Oxidative stress has been suggested to play a main role in the pathogenesis of type 2 diabetes mellitus and its complications. As a consequence of this increased oxidative status a cellular adaptive response occurs requiring functional chaperones, antioxidant production and protein degradation. This study was designed to evaluate systemic oxidative stress and cellular stress response in patients suffering from type 2 diabetes and in age-matched healthy subjects. Systemic oxidative stress has been evaluated by measuring plasma reduced and oxidized glutathione, as well as pentosidine, protein carbonyls lipid oxidation products 4-hydroxy-2-nonenal and F2-isoprostanes in plasma, and lymphocytes, whereas the lymphocyte levels of the heat shock proteins (HSP) HO-1, Hsp72, Sirtuin-1, Sirtuin-2 and thioredoxin reductase-1 (TrxR-1) have been measured to evaluate the systemic cellular stress response. Plasma GSH/GSSG showed a significant decrease in type 2 diabetes as compared to control group, associated with increased pentosidine, F2-isoprostanes, carbonyls and HNE levels. In addition, lymphocyte levels of HO-1, Hsp70, Trx and TrxR-1 (P<0.05 and P<0.01) in diabetic patients were higher than in normal subjects, while sirtuin-1 and sirtuin-2 protein was significantly decreased (p<0.05). In conclusion, patients affected by type 2 diabetes are under condition of systemic oxidative stress and, although the relevance of downregulation in sirtuin signal has to be fully understood, however induction of HSPs and thioredoxin protein system represent a maintained response in counteracting systemic pro-oxidant status. This article is part of a Special Issue entitled: Antioxidants and Antioxidant Treatment in Disease.