Bone turnover in postmenopausal osteoporosis. Effect of calcitonin treatment.

UNLABELLED: To investigate the effectiveness of calcitonin treatment of postmenopausal osteoporosis in relation to bone turnover, we examined 53 postmenopausal osteoporotic women before and after one year of therapy with salmon calcitonin (sCT), at the dose of 50 IU every other day. Baseline evaluation revealed that 17 (32%) patients had high turnover (HTOP), and 36 (68%) normal turnover osteoporosis (NTOP) as assessed by measurement of whole body retention (WBR) of 99mTc-methylene diphosphonate. The two groups did not differ in terms of bone mineral content (BMC) measured by dual photon absorptiometry at both lumbar spine and femoral diaphysis. However, HTOP patients had higher levels of serum osteocalcin (OC) and urinary hydroxyproline excretion (HOP/Cr). Multivariate regression analysis showed no correlation between parameters of bone turnover (WBR, OC, HOP/Cr) and both femoral and vertebral bone density; the latter being negatively correlated only with the years elapsed since menopause (R2 = 0.406). Treatment with sCT resulted in a significant increase of vertebral BMC in the 53 patients taken as a whole group (+/- 7%, P less than 0.001). When the results obtained in HTOP and NTOP were analyzed separately, only those with HTOP showed a marked increment of spinal BMC (+22%, P less than 0.001), NTOP subjects neither gained nor lost bone mineral during the study. Femoral BMC decreased in the whole group after sCT therapy (-3%, P less than 0.003). However, HTOP patients maintained initial BMC values, whereas those with NTOP lost a significant amount of bone during the study period (-5%, P less than 0.001). The increase of vertebral bone mass was associated with a marked depression of bone turnover detectable in both subsets of patients and in the whole group. IN CONCLUSION: (a) assessment of bone turnover cannot help predict the severity of bone loss in postmenopausal osteoporosis; (b) calcitonin therapy appears to be particularly indicated for patients with high-turnover osteoporosis, resulting in a net gain of bone mineral in the axial skeleton and a slowing of bone loss in the appendicular bones.

Metabolic and clinical effects of ipriflavone in established post-menopausal osteoporosis.

Twenty patients with post-menopausal osteoporosis were randomly divided into two groups of ten patients and treated under double-blind conditions with ipriflavone (Osteofix) or placebo. The dosage was 600 mg/day given in three doses and treatment lasted 6 months. All the patients received an oral calcium supply (1 g per day). At baseline and then after 3 and 6 months, the following parameters were controlled: bone mineral content at the lumbar spine, distal radius and femoral shaft; parameters of bone metabolism (alkaline phosphatase, PTH, osteocalcin, calcitonin, calciuria and hydroxyprolinuria); clinical conditions (pain at rest and on movement, motility). Ipriflavone facilitated the conservation of bone mass, that increased in one of the tested areas (distal radius). On the contrary, a bone mineral loss was found in the group treated with placebo, which was significant in the spine. Pain and motility significantly improved in the group treated with ipriflavone; there was an initial improvement in the control group, followed by a sharp worsening. The parameters investigated showed a significant reduction of osteocalcin in the ipriflavone group that indicates a modulation on bone turnover. The drug was well tolerated and compliance to oral treatment was excellent.

[Serum ionized calcium, parathormone and plasma renin activity in essential arterial hypertension]. / Calcio ionizzato sierico, paratormone, attività reninica plasmatica nell'ipertensione arteriosa essenziale.

Given the significance of the calcium ion in the pathogenesis of essential arterial hypertension, blood levels of total and ionised calcium, phosphorus, parathormone, blood renin activity as well as urinary calcium and phosphorus were assayed in a group of hypertensives and a comparable control group with normal blood pressure. The results showed reduced ionised calcium in the blood of the hypertensives together with hyperparathyroidism and increased calciuria. In addition, the link between parathormone and mean blood pressure levels suggests that parathormone itself play a primary role in the genesis of high blood pressure. Finally the connection between renin activity in the plasma and ionised calcium in the serum suggests that the two hormone systems are closely linked and may interact via the calcium ion.

Effects of one-year treatment with estrogens on bone mass, intestinal calcium absorption, and 25-hydroxyvitamin D-1 alpha-hydroxylase reserve in postmenopausal osteoporosis.

A double-blind, placebo-controlled study on 21 postmenopausal osteoporotic women was performed in order to assess the effects of 1 year estrogen therapy (Premarin, 1.25 mg/day) on bone mass, intestinal calcium absorption, and mineral metabolism. Bone mineral content (BMC), measured by dual photon absorptiometry on the vertebral bodies and the femoral shaft, increased in both areas, but the changes were more evident at the former site, which is predominantly trabecular (+8.3%, P less than 0.05), than at the latter, which is mainly cortical (+2.6%, P less than 0.05). An improvement of intestinal calcium absorption was also detected at the end of the study (P less than 0.05) in the estrogen-treated group. Parameters of bone metabolism showed a decrease in hydroxyproline/creatinine ratio and osteocalcin, an increase in calcitonin, and no significant changes in parathyroid hormone (PTH) and alkaline phosphatase. Serum 1,25-dihydroxycholecalciferol (1,25(OH)2D3) levels increased after estrogen therapy, whereas 25-hydroxycholecalciferol (25OHD3) remained stable during the study period. Renal 25-hydroxyvitamin D 1 alpha-hydroxylase reserve, assessed by the PTH-stimulation test, showed a more rapid response in producing a 1,25(OH)2D3 peak in the estrogen-treated patients compared with the control subjects. However, estrogens did not induce an absolute improvement in the secretory reserve. This study demonstrates that 1 year treatment with estrogens improves both intestinal calcium absorption and BMC in postmenopausal osteoporotic women. The latter effect appears to be induced by an inhibition of bone resorption, associated to an increased secretion of calcitonin, whereas vitamin D metabolites do not seem to contribute substantially to the mediation of estrogen action on bone.

Abnormalities in calcium metabolism in sarcoidosis.

In sarcoidosis the excess of calcitriol of extrarenal origin induces changes in calcium metabolism (CM), specifically hypercalciuria and less often hypercalcemia. We report the results of the study of CM in 44 sarcoidosis patients (mean age 43.7 +/- 11 years, M +/- SD, 21 males). 25% were on steroid therapy at the time of the tests. 34% of the patients had hypercalciuria, this figure rose to 39% if only untreated patients were considered. Hypercalcemia was found in only 2.2%. Chronic forms and extrathoracic involvement (mostly skin) were more frequent in the hypercalciuric patients than in the normocalciuric.