Objective: To evaluate the nutritional status of vitamin D in urban populations of healthy elderly people living at home, in different regions of Argentina. Design: Cross-sectional study. Subjects: In total, 386 ambulatory subjects over 65 y of age from seven cities (between latitude 261S and 551S) were asked to participate between the end of winter and the beginning of spring. Of these, 369 accepted, 30 were excluded because of medical history or abnormal biochemical determinations. Finally, 339 subjects (226 women and 113 men) (X7s.d.) (71.37 5.2 y) were included. Results: Serum 25OHD levels were lowest in the South (latitude range: 411S-551S): 14.275.6 ng/ml (Po0.0001vs North and Mid regions); highest in the North (261S-271S): 20.777.4 ng/ml (Po0.03 vs Mid, Po0.0001vs South); and intermediate in the Mid region (331S-341S) 17.978.2 ng/ml. Serum mid-molecule PTH (mmPTH) and 25OHD were inversely related: (r ¼ À0.24, Po0.001). A cutoff level of 25OHD at which serum mmPTH levels began to increase was established at 27 ng/ml. A high prevalence (87-52%) of subjects with 25OHD levels in the deficiency-insufficiency range (25OHD levels o20 ng/ml) was detected. Conclusion: This study shows that vitamin D deficiency/insufficiency in the elderly is a worldwide problem. Correction of this deficit would have a positive impact on bone health of elderly people. Sponsorship: Asociació n Argentina de Osteología y Metabolismo Mineral (AAOMM).

Some studies based on bone biopsy have demonstrated that in patients with tumor‐induced osteomalacia (TIO) the mineralization process of the bone matrix is profoundly disturbed. However, the interrelationship between clinical and biochemical features and bone microarchitecture in this disease needs further analysis. With this purpose in mind, we set out three objectives: (i) to determine bone microarchitecture and estimated bone strength in a group of patients with tumor‐induced osteomalacia using high‐resolution peripheral quantitative computed tomography (HR‐pQCT) and finite element analysis (FEA), (ii) to investigate correlations between duration of disease, biochemical features, bone density, HR‐pQCT and FEA parameters, and (iii) to compare HR‐pQCT and FEA parameters with a healthy control group. Ten patients with TIO were included. All patients had non‐resolved disease. At the distal radius, all bone microarchitecture parameters were significantly affected in patients with TIO in comparison with healthy controls. At the distal tibia, all parameters were significantly impaired, except for trabecular thickness. All the parameters were more affected in the distal tibia than in the distal radius. Women with TIO (n = 7) had significantly lower bone strength parameters than healthy controls. In men (n = 3), bone strength parameters were significantly lower than in the control group at the distal tibia. Alkaline phosphatase levels exhibited a negative correlation with microarchitecture parameters, failure load, and stiffness. Higher levels of parathyroid hormone correlated with poorer microarchitecture parameters. We believe that in TIO, hormonal disturbances and the lack of mechanical stimulus specially converge to generate an extremely harmful combination for bone health. © 2021 American Society for Bone and Mineral Research (ASBMR).

No abstract

Pamidronate (APD), a third-generation bisphosphonate, has proven to be useful in haemodialysis (HD) patients with ectopic calcifications and hypercalcaemia. Little is known about bisphosphonates clearance in patients undergoing HD. The authors' main objective was to study HD removal and clearance of APD. In total, 23 HD-requiring anuric end-stage renal disease (ESRD) adult individuals (12 men) aged 61.7 +/- 13 (mean +/- SD) years were admitted into the study. APD clearance and elimination were evaluated by (99m)Technetium APD (half-life 6 h). In total, 1 mg of labelled APD was injected via the arteriovenous graft prior to the start of HD. Blood samples were then drawn from the arterial (predialyser) and venous (postdialyser) lines of the extracorporeal circuit 2 h after the HD onset. In a subgroup of patients (n: 15) the dialysate was collected and quantified during the three initial HD hours. Venous APD concentrations (postdialyser) were 72 + 7% of arterial (predialyser) concentrations. Mean APD clearance was 69.3 + 16.6 mL/min, and mean APD extraction during dialysis session was 31.6 + 10.1%. In the present study involving HD-requiring anuric ESRD patients APD was successfully eliminated by HD. At the dose administered here none of the participants reported adverse events. APD is a potentially useful drug to be administered to HD-requiring ESRD patients, the understanding of its removal during HD as well as its dialytic clearance allows for a safer management of a drug that is usually eliminated by renal excretion.

No abstract