Severe vitamin D deficiency in chronic renal failure patients on peritoneal dialysis.

UNLABELLED: The aim of this study was to evaluate the prevalence of vitamin D deficiency in chronic renal failure (CRF) patients on peritoneal dialysis (PD) and to correlate the findings with various demographic and renal osteodystrophy markers. METHOD: This cross-sectional, multicenter study was carried out in 273 PD patients with a mean age of 61.7 +/- 10.9 years and mean duration of PD 3.3 +/- 2.2 years. It included 123 female and 150 male patients from 20 centers in Greece and Turkey, countries that are on the same latitude, namely, 36-42 degrees north. We measured 25(OH)D3 and 1.25(OH)2D3 levels and some other clinical and laboratory indices of bone mineral metabolism. RESULTS: Of these 273 patients 92% (251 patients) had vitamin D deficiency i.e. serum 25(OH)D3 levels less than 15 ng/ml, 119 (43.6%) had severe vitamin D deficiency i.e., serum 25(OH)D3 levels, less than 5 ng/ml, 132 (48.4%) had moderate vitamin D deficiency i.e., serum 25(OH)D3 levels, 5-15 ng/ml, 12 (4.4%) vitamin D insufficiency i.e., serum 25(OH)D3 levels 15 - 30 ng/ml and only 10 (3.6%) had adequate vitamin D stores. We found no correlation between 25(OH)D3 levels and PTH, serum albumin, bone alkaline phosphatase, P, and Ca x P. In multiple regression analyses, the independent predictors of 25(OH)D3 were age, presence of diabetes (DM-CRF), levels of serum calcium and serum 1.25(OH)2D3. CONCLUSION: We found a high prevalence (92%) of vitamin D deficiency in these 273 PD patients, nearly one half of whom had severe vitamin D deficiency. Vitamin D deficiency is more common in DM-CRF patients than in non-DM-CRF patients. Our findings suggest that these patients should be considered for vitamin D supplementation.

Response of uremic osteoid to vitamin D.

Three patients with nutritional osteomalacia and three with the osteomalacia of chronic renal failure were treated with small doses of vitamin D for 4 to 10 months. The plasma concentration of 25-OH vitamin D rose to and remained within the normal range throughout the study. There was similar increase in the extent of calcification front in the osteoid lamellae lying immediately adjacent to calcified bone in the two groups of patients. The associated histologic appearances of hyperparathyroidism improved in the patients with nutritional osteomalacia but did not change or became worse in the patients with the osteomalacia of chronic renal failure.

The 'shrinking man' syndrome.

3 men presented with loss of height. Quantitative bone histology revealed all the features of hyperparathyroidism, yet the plasma calcium and hand radiographs were normal. 2 of the patients had been on maintenance haemodialysis for over 10 years (a group in whom osteopenia is described) and the third was elderly. It is probable that in these 3 patients the loss of height was due to wedging of vertebrae as a result of the hyperparathyroidism. It is suggested that in all 3 the disease became manifest clinically because the vertebrae may have been osteopenic for other reasons.

The role of parathyroidectomy in the management of hyperparathyroidism in patients on maintenance haemodialysis and after renal transplantation.

Between March 1964 and March 1980, 36 (34 dialysis, 2 transplant) of 327 patients accepted for the maintenance dialysis/transplantation programme at Charing Cross Hospital were submitted to parathyroidectomy. There were four main indications: persistent hypercalcaemia, progressive phalangeal erosions, aseptic necrosis of the femoral head and height loss with abnormal bone biopsy despite normal hand radiographs. At parathyroidectomy, 4 glands were removed in 1 patient, 3 1/2 glands in 24, 3 glands in 7, 2 glands in 3 and a single large gland in 1 patient. The operation was followed by improvement in 28 patients, no change in 5, and progression of hyperparathyroidism in 3.2 of the 28 patients who improved later relapsed and were treated with 1,25-(OH)2 vitamin D3. 4 patients were submitted to a further parathyroidectomy and improved considerably. We would conclude that, although parathyroidectomy is an effective and safe procedure, it is to be hoped that careful monitoring of bone state and early administration of 1,25-(OH)2 vitamin D3 may reduce the need for parathyroidectomy.

Double-blind trial of oral 1,25-dihydroxy vitamin D3 versus placebo in asymptomatic hyperparathyroidism in patients receiving maintenance haemodialysis.

Fifty-seven patients who had been receiving maintenance haemodialysis for a mean of 4.6 years were given 0.25-0.5 microgram oral 1,25-dihydroxy (1,25-(OH)2) vitamin D3 or a placebo in a double-blind manner for one to two years. In patients with normal radiographs (mean plasma parathyroid hormone concentration 205 microliterEq/ml) 1,25-(OH)2 vitamin D3 prevented the development of the radiological appearances of hyperparathyroidism. In patients with abnormal radiographs (mean plasma parathyroid concentration 709 microliterEq/ml) 1,25-(OH)2 vitamin D3 arrested or reversed the radiological changes of hyperparathyroidism. Nevertheless, the response was slow and the concentration of the hormone remained considerably raised (mean 445 microliterEq/ml). It is concluded from these results that giving 1,25-(OH)2 vitamin D3 to patients receiving maintenance haemodialysis who have normal hand radiographs or minimal erosions is beneficial. In patients with more advanced hyperparathyroidism parathyroidectomy should be considered unless there is a rapid response.