ACTA ENDOCRINOLOGICA (BUC)

Context. The undercarboxylated form of osteocalcin (ucOC) and osteoprotegerin (OPG) are bonederived molecules involved in the endocrine crosstalk governing the bone, the adipose tissue and the pancreas. In addition, glucocorticoids are major determinants of both insulin resistance and osteoporosis. Objective. We aimed to investigate the response of ucOC and OPG to dysglycemia and/or dexamethasone (DXM) in primary human osteoblastic cell (HOC) cultures. Design and methods. Third-passage sub-confluent primary HOC cultures were treated with glucose: 2.8 mmol/L, 5.6 mmol/L, 11.1 mmol/L and 28 mmol/L, respectively. Alternatively, HOC cultures were subjected to DXM 1 μmol/L. In more complex experiments, HOC cultures were pre-treated with glucose (5.6 mmol/L) with/without insulin (1 pmol/L) followed by DXM (1 μmol/L). 24-hours posttreatment, culture medium ucOC and OPG were measured by ELISA. Results. ucOC production differed significantly (p<0.05) between cell groups, decreasing in a dosedependent manner as glucose concentration in the medium increased. Insulin prevented this effect. OPG levels appeared not to be significantly influenced by the hyperglycemic culture medium and were not related to ucOC concentration (p>0.05). Addition of DXM resulted in significantly lower ucOC concentrations compared to vehicle-treated cells (p<0.05). However, the effect of insulin co-treatment on ucOC was not counteracted by DXM (p<0.05). Conclusions. An obvious alteration of OC production/metabolism was observed as glucose levels changed in the bone microenvironment, to potentially be involved in diabetes-related osteopenia. DXM suppressed ucOC levels however not in insulin-rich environment.

Background. Vascular calcifications (VCs) represent an important complication in dialysis patients. It is still a subject of debate whether VCs are associated with low or high intact parathormone (iPTH), or if it is not any relation.\r\nThe purpose of this study was to assess the predictive value of iPTH and other mineral markers for VCs development.\r\nMethods. The study evaluated peripheral VCs in haemodialysis (HD) and peritoneal dialysis (PD) patients using radiographies. We counted a semiquantitative score ranging from 0 to 8. Each category was divided into two groups according to VCs score. We assessed the relationship between the VCs score and mineral markers.\r\nResults. A VC score=2 was positively associated with male gender, serum Ca, P, CaxP, ALP and iPTH levels in HD patients. There was no correlation with age, HD vintage, received treatment. In PD patients, did CaxP have a higher significance with VC score>/2; were iPTH, CaxP and P of higher significance for a score=5.\r\nConclusions. Hyperparathyroidism can be considered a predictor for VCs development in dialysis patients. Other risk factors are increased serum Ca, P, CaxP and ALP levels. In PD patients, high iPTH could predict VCs only for severe calcifications, but the CaxP could even predict for less extended VCs.

Context. Angiotensin converting enzyme 2 (ACE2) is highly expressed in the kidney and cleaves angiotensin II to Angiotensin (1–7), annihilating the deleterious effects of angiotensin II which is known to be a strong activator of oxidative stress. Objective. We aimed to evaluate the relationship of oxidative stress to urinary ACE2 (uACE2) in type 2 diabetes mellitus (T2DM) patients. Design. We included consecutive normo or microalbuminuric T2DM patients in an observational transversal study. Routine laboratory investigations, plasma malondialdehyde (MDA, fluorimetric thiobarbituric method) as a marker of prooxidant capacity and superoxide dismutase (SOD, cytochrome reduction method) and catalase (CAT) activity (in erythrocyte lysate by the modification of absorbance method) as two measures of serum antioxidant capacity and uACE2 (ELISA method) were assessed. Results. MDA showed a negative correlation with SOD (r=-0.44, p=0.001), CAT (r=-0.37, p=0.006), uACE2 (r=-0.33, p=0.016) and a positive correlation with glycated haemoglobin (HbA1c) (r=0.49, p<0.001) and associated cardiovascular disease (r=0.42, p=0.001). CAT as also positively correlated to uACE2 (r=0.29, p=0.037). SOD was also negatively correlated with glycemia (r=-0.71, p<0.001) and HbA1c (r=-0.53, p<0.001). Patients with lower MDA (when divided according to median value of 3.88 nmol/ mL) had higher uACE2 57.15(40.3-71.2) pg/mL compared to 38.5(31.8-45.95) pg/mL in patients with higher MDA (p<0.001). In multivariate logistic regression uACE2 was the only predictor for MDA above or below its median (OR=0.94, 95%CI[0.90-0.98], p=0.002). Conclusion. Increased prooxidant serum capacity is associated with lower uACE2 levels in T2DM patients.

Background. Recent experimental data show that increased plasma adiponectin in chronic kidney disease could be a response to inflammation.\r\nObjective. To identify factors influencing adiponectinemia in patients with type 2 diabetes (T2DM) and microalbuminuria or low grade proteinuria.\r\nDesign. 32 patients with urinary albumin excretion rate (UAER)> 30 mg/g creatinine but without significant proteinuria (< trace COMBUR) were included and compared to 59 normalbuminuric T2DM controls. History, anthropometric measurements, laboratory analysis, total plasma adiponectin were obtained.\r\nResults. In our patients with UAER of 273.51?57.26 mg/g creatinine and estimated glomerular filtration rate (eGFR) 64.92?4.56 mL/min, in simple regression, adiponectinemia\r\ncorrelates inversely to eGFR (p=0.02, r= -0.38), triglyceridemia (p=0.03, r=-0.37) and hemoglobin\r\n(Hb -p= 0.01, r=-0.45) and positively to HDL cholesterol (p=0.001, r=0.54) and UAER (p<0.0001, r=0.71); the two latter parameters remain significant in multiple regression. In controls, adiponectinemia correlates inversely to age (p=0.04, r=-0.26) and BMI (p=0.04, r=-0.24); these and UAER predict adiponectinemia in multiple regression. 11 patients have UAE superior to 300 mg/g creatinine and 21 are strictly microalbuminuric (mean UAER 653.16?97.02 and 83.68?10.28mg albumin/g creatinine respectively). In microalbuminuric patients serum C reactive protein (CRP) correlates positively (p=0.0008, r=0.68) and Hb negatively (p=0.04, r=-0.41) to adiponectinemia; in multiple regression adiponectinemia only depends on CRP. In proteinuric patients CRP and\r\nglycated Hb correlate to adiponectinemia in stepwise multiple regression.\r\nConclusion. Adiponectinemia is mainly predicted by UAER in our cohort whereas it depends on age and BMI in normalbuminuric T2DM controls; in strictly microalbuminuric\r\npatients CRP is a major predictor of adiponectinemia.

Background Supplementation of Lcarnitine is associated with improvement in some abnormalities present in hemodialysis (HD) patients. Objective. The study aim was to analyze the effect of oral L-carnitine supplementation on endothelial dysfunction (ED), oxidative stress (OS), inflammation and anemia in HD patients. Design. A prospective, longitudinal and observational study was performed in a single dialysis unit. Subjects and methods.We studied 31 HD patients: 21 patients formed the Lcarnitine supplementation group (group 1) and 10 entered the control group (group 2). At baseline and after 3 months of L-carnitine supplementation (500mg/day) we determined endothelial-dependent flow-mediated vasodilatation (FMD) and nitroglycerin induced endothelium independent vasodilatation, involving ultrasonographic brachial artery measurements, serum visfatin, malondialdehyde, body mass index, systolic blood pressure, diastolic blood pressure, interdialytic body weight gain, C-reactive protein, albumin, cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides, ferritin, transferrin saturation, hemoglobin, erythropoietin dose, calcium (Ca), phosphorus (P), parathormone and Kt/V . Results. In group 1, FMD (8.9 (4.5-12.5) to 10.6 (6.7-18), p=0.04) and Ca (8.4±0.6 to 8.8±0.5 mg/dL, p<0.001) significantly increased after L-carnitine supplementation, while visfatin (1.0 (0.2-1.3) to 0.4 (0-0.9) pg/mL, p=0.03), malondialdehyde (2.8 (2.4- 3.2) to 1.3 (1.2-1.5) nmol/mL, p<0.001) and P (5.6±1.3 to 5.0±1.2 mg/dL, p=0.005) significantly decreased. Albumin increased significantly in both groups (3.9±0.3 to 4.2±0.3 mg/dL, p<0.001 in group 1 and 3.7±0.3 to 4.0±0.3 mg/dL, p=0.02 in group 2). There were no other significant variations of the studied parameters. Conclusions. L-carnitine supplementation reduces ED, visfatin levels and markers of OS, but has no effect on inflammation, nutrition and anemia in HD patients.

Introduction. Recent studies suggest that nutritional status can modify the association\r\nbetween high iPTH and mortality, especially in diabetics and older hemodialysis patients (HDP).\r\nAim. To assess the impact of mineral metabolism parameters in the survival of HDP\r\nin our area and to evidence the factors that influence iPTH levels in our HDP, which are\r\nyounger and have less frequently diabetic nephropathy as the cause of chronic renal failure\r\nthan in most published studies.\r\nPatients and Methods. A prospective cohort study of 126 HDP was recorded for\r\ndemographic, clinical and laboratory data, and after 24 months, the general mortality. Patients\r\nwere divided in two groups, survivors and non-survivors, and each of groups classified according\r\nto the time on hemodialysis (THD). The groups of non-survivors and survivors with THD more\r\nthan 10 year-period were compared to the groups with less than 10 year vintage, regarding the\r\nalbumin levels, iPTH levels, phosphate-calcium metabolism markers, age and sex.\r\nResults. We observed the better survival only for calcium phosphate product less than 55\r\nmg?/dL? (p=0,02). The iPTH level seems to be conditioned by albumin levels. For THD<10\r\nyears, iPTH levels are greater in survivors (p=0.01); in this subgroup we observed higher levels\r\nof serum albumin (p<0.001), the patients were younger (p<0.001), and had 5-fold lower\r\nfrequency of diabetes. For THD>10 years, iPTH levels are greater in non-survivor patients\r\n(p=0.02), as well as calcium, phosphorus and calcium phosphorus product.\r\nConclusions. Calcium-Phosphorus product is a better indicator for survival in HDP in our\r\narea than immunoreactive PTH levels. Immunoreactive PTH as prognostic factor might be\r\nbetter evaluated in association with calcium phosphorus metabolism parameters and albumin\r\nlevels too, even in younger and lower percent-diabetic HDP groups.

We studied the incidence, risk factors, presentation, treatment and prognosis of calcific uremic arteriolopathy (CUA) in 140 of our hemodialysis patients. Methods. Patients with CUA in the past 3 years have been compared to controls in a cross-sectional survey of 140 hemodialysis patients. Results. Prevalence of CUA was 6/140 (4.28%); common presentation was ulcerated acral necrosis. Age, sex ratio, BMI, prevalence of diabetes were similar in case (n=6) and control (n=134) patients. CUA patients had higher serum calcium (9.58?1.25 mg/dL vs. 8.50?1.03 mg/dL, p=0.01), calcium-phosphate product (71.06?19.67 mg2/dL2 vs. 58.73?17.20 mg2/dL2, p=0.01) and parathormone levels (1854?1407 pg/mL vs. 654?776 pg/mL, p=0.0002). Differences in ingestion of calcium, active vitamin D and non-calcium containing phosphate binders in the year prior to the assessment were not significant. CUA patients had higher CRP values in the 6 preceding months than non CUA patients (6.61?9.68 mg/dL vs. 1.97?4.20 mg/dL, p=0.01); logistic regression disclosed CRP as the only predictive factor for CUA (p=0.03). 4 (66%) of the CUA patients died due to sepsis, as compared to 3(2.23%) of the control group (p=0.001). 2 of 3 parathyroidectomised patients survived. In conclusion, this is, to our knowledge, the first series of CUA reported from Eastern Europe. In our center acral, ulcerated forms of CUA in patients with severe hyperparathyroidism are predominant.