Biomedical subjects

F Dutto

Publications and source records attributed to F Dutto.

2 recordsLinked to original sources

PubMed1996

Effects of mineral composition of drinking water on risk for stone formation and bone metabolism in idiopathic calcium nephrolithiasis.

1. To assess whether the mineral content of drinking water influences both risk of stone formation and bone metabolism in idiopathic calcium nephrolithiasis, 21 patients were switched from their usual home diets to a 10 mmol calcium, low-oxalate, protein-controlled diet, supplemented with 21 of three different types of mineral water. Drinking water added 1, 6 and 20 mmol of calcium and 0.5, 10 and 50 mmol of bicarbonate respectively to the controlled diet. 2. The three controlled study periods lasted 1 month each and were separated by a 20 day washout interval. Blood and urine chemistries, including intact parathyroid hormone, calcitriol and two markers of bone resorption, were performed at the end of each study period. The stone-forming risk was assessed by calculating urine saturation with calcium oxalate (beta CaOx), calcium phosphate (beta bsh) and uric acid (beta UA). 3. The addition of any mineral water produced the expected increase in urine output and was associated with similar decreases in beta CaOx and beta UA, whereas beta bsh varied marginally. These equal decreases in beta CaOx, however, resulted from peculiar changes in calcium, oxalate and citrate excretion during each study period. The increase in overall calcium intake due to different drinking water induced modest increases in calcium excretion, whereas oxalate excretion tended to decrease. The changes in oxalate excretion during any one study period compared with another were significantly related to those in calcium intake. Citrate excretion was significantly higher with the high-calcium, alkaline water. 4. Parathyroid hormone, calcitriol and markers of bone resorption increased when patients were changed from the high-calcium, alkaline to the low-calcium drinking water. 5. We suggest that overall calcium intake may be tailored by supplying calcium in drinking water. Adverse effects on bone turnover with low-calcium diets can be prevented by giving high-calcium, alkaline drinking water, and the stone-forming risk can be decreased as effectively as with low-calcium drinking water.

Adult↗

PubMedDate not supplied

[Intact whole bioactive parathormone: problems arising from comparing different methods].

BACKGROUND: Parathyroid hormone (PTH) has important applications in the nephrological clinical practice. Because assays of Intact PTH (I-PTH) are liable to interferences by N-truncated fragments, a novel method for whole-(1-84) PTH has been proposed. This study is aimed at comparing the latter with some of the previous I-PTH assays. For each method the results are referred to pertinent markers of mineral metabolism. METHODS: We enrolled 171 subjects, including 56 healthy controls (C), 65 calcium stone- formers (CaSF), 40 haemodialysis patients (HD), 10 with primary hyperparathyroidism (PHP). On blood samples we measured: I-PTH by four methods (N-Tact, Advantage, Elecsys, Scantibodies), whole-(1-84) PTH, defined as CAP (Cyclase Activating PTH), total and ionised calcium, phosphate, vitamin D, osteocalcin and Crosslaps. The difference between I-PTH and CAP Scantibodies is defined as CIP (Cyclase Inhibiting PTH). RESULTS: Despite relating to each other (r>0.97) PTH values varied remarkably among methods. For all methods, the reference intervals differed from those provided by the producer. Assuming these new ranges, 10 CaSF had over-range values not always associated with abnormalities of mineral metabolism. One of the PHP patients was normal for I-PTH with 2/4 methods. In HD the differences among methods were even greater, there were inverse (p<0.05) and direct (p<0.001) relationships with ionised calcium and osteocalcin-crosslaps, respectively. The CAP/CIP ratio was lower in low bone turnover patients, but the two subgroups widely overlapped. CONCLUSIONS: This study indicates that the reliability of I-PTH assays is still unsatisfactory, and none of the four methods emerged as the best. Assay for CAP only improves diagnostic efficiency, whereas the CAP/CIP ratio does not exhibit powerful discriminating capacity. Our suggestion is that each Centre should establish its own reference ranges. PTH assay should always be coupled with measurements of other markers of mineral metabolism as well as renal function.

Adult↗