ACTA ENDOCRINOLOGICA (BUC)

Background. Chronic kidney disease (CKD) and type 2 diabetes mellitus (T2DM) are associated with disturbed mineral homeostasis and serum bone biomarkers. The interplay between T2DM and CKD on serum bone turnover markers (BTM) is unclear. Our aim was to describe the BTM in patients with T2DM, CKD or both. Methods. In this observational, single-centre, prospective study, we included 320 patients over 40 years, divided into four groups: T2DM and normal kidney function (n=142), T2DM and CKD (n=36), CKD and normal glucose metabolism (n=29) and healthy controls (n=113). We excluded patients treated for osteoporosis and with secondary osteoporosis. Patients were compared by age, levels of glycated hemoglobin, PTH, alkaline phosphatase, osteocalcin (OC), CTx and 25 OH vitamin D. Results. Univariate analysis showed that GFR correlated significantly with PTH (r=0.37), OC (r=0.43) and CTX (r=0.45) in the diabetes group but only with PTH (r=0.34) in the non-T2DM group. Multivariate analysis showed that GFR remained significantly correlated with the same bone markers even after adjustment for age, sex or 25(OH)D levels. Diabetics seem to have lower levels of alkaline phosphatase (68±22.1 U/L) and CTX (0.37±0.24 ng/mL) than those without diabetes (76.7±29.6. U/L and 0.5±0.19 ng/mL, respectively). There was no correlation between BTM and glycated hemoglobin. Conclusions. Bone turnover markers correlate with GFR, particularly in patients with T2DM. However, alkaline phosphatase is lower in T2DM than in non-T2DM.

Renal osteodystrophy and low bone mass are frequently found in patients with end-stage renal disease (ESRD). Our aim was to identify the independent predictors of age - and sex-adjusted bone mineral density (BMD), measured at different traditional sites, in patients with ESRD treated by hemodialysis (HD) or peritoneal dialysis (PD). Patients and Methods. We consecutively assessed 23 patients with ESRD (17 on HD and 6 on PD). Patients treated with 1,25 dihydroxyvitamin D, vitamin D derivates (paricalcitol) or calcimimetics were excluded. Serum parathormone and 25OH vitamin D were measured in all patients. In HD patients all biochemical measurements were done in the day between dialysis sesions. BMD was assessed at following sites: femoral neck, total proximal femur, 1/3 radius, ultradistal (UD) radius and total radius. Radial BMD was assessed in the forearm without arteriovenous fistula. BMD Z-score provided by the manufacturer was used. Results. In patiens undergoing PD the femoral neck BMD Z-score was significantly higher than in HD patients (difference -0.77 DS, 95% CI for difference -1.48 to -0.06). PTH correlated significantly with BMD Z-score at the 1/3 (r=-0.664, p<0.001) and total (r=-0.583, p=0.002) radius levels. Total proximal femur and UD radius BMD Z-scores did not correlate with any of the proposed variables. Years of dialysis, 25OH vitamin D and body mass index did not correlate with BMD Z-score at any site. Conclusion. In patients with ESRD PTH correlates strongly with BMD Z-score at cortical sites. PD seems to be less harmful to BMD than HD.