Kazuko Iba

Abnormal Calcium Metabolism in Hemodialyzed Patients with Diabetic Nephropathy

Calcium metabolism was studied in hemodialyzed patients with diabetes mellitus nephropathy (HD/DM) and in hemodialyzed nondiabetic patients with chronic glomerulonephritis (HD/non-DM). Incidence of bone changes visible in X-ray films, assessed by changes in the lamina dura and trabecular patterns of mandibulae, was less in HD/DM than in HD/non-DM patients. Serum c-terminal parathyroid hormone was significantly lower in HD/DM than that in HD/non-DM. Serum calcitonin was higher in HD/DM than that in HD/non-DM. The lower level of c-terminal parathyroid hormone would be a reason that bone changes were less in HD/DM than in HD/non-DM patients.

Characteristics of biochemical markers for bone formation in the elderly

Currently, several promising biochemical markers for bone metabolism have been postulated and expected to be applied to their clinical use. Among these markers, circulating levels of bone Gla-protein (BGP) and carboxyterminal peptide of type I procollagen (P1CP) have been established as non-invasive indices to assess bone turnover, especially bone formation. We investigated age-related effects on serum levels of both peptides and relationships between loss of bone mass and biochemical indices in the elderly. Fasting blood sample were obtained from 330 healthy volunteers to simultaneously measure serum BGP, serum P1CP and serum tartrate-resistant acid phosphatase (TRACP) as a marker for bone resorption. Serum BGP levels were found almost stable throughout life in men with a tendency to decrease in the elderly. Serum P1CP levels linearly decreased towards 50 to 60 years of age in men, followed by its constant increase with aging afterwards. Although a constant increase in serum P1CP levels were noted in women with aging, serum BGP levels were found remarkably elevated during menopausal periods of 50 to 70 years of age, followed by its wide distribution in the elderly. Both serum BGP and P1CP levels were elevated accompanied with age-related decrease in glomerular filtration rates in the elderly. In addition, a bone specific index, TRACP/BGP ratio consolidated the negative correlation between serum TRACP and % changes of bone mineral density (BMD). However, TRACP/P1CP ratio had nothing to do with % change of BMD. In conclusion, loss of bone mass could be predicted by bone specific indices, particularly in elderly women with widely distributed bone turnover.

Effect of ipriflavone on bone mineral density of lumbar spine of aged women

Aged women with osteoporosis were followed for 6 months with or without ipriflavone (IP) 600 mg/day, and lumbar bone mineral density (BMD) and bone mineral content (BMC) were evaluated by dual-photon absorptiometry. Although a significant reduction of lumbar BMD was observed in the control group at the end of the experiment, the group treated with IP showed insignificant change. The frequency of deterioration was lower in the IP group compared to the control group. Additionally, the IP effect was more apparent in patients with lower calcitonin and higher bone gla-protein (BGP) levels. These results suggest that IP effectively maintains BMD and BMC of lumbar bone among aged women with osteoporosis, and its activity may be enhanced in patients with low calcitonin and high BGP levels.

The spinal bone fracture of the aged women

The deformity or fracture of the spines, bone mineral density (BMD) of radius and spines by anterior-posterior scans and lateral scans, and metabolic bone markers were examined in the old women. The probability of fracture was less than 10% in women with L3 BMD over 0.786g/cm2, and new fractures were not found during 12 months follow-up in these patients. Among the various metabolic parameters, bone Gla protein (BGP)/hydroxyproline (Hp) excretion ratio was one of the clinically useful indices if combined with BMD. The intensive therapy may not be necessary to patients with low BMD if they show high BGP/Hp ratio. Patients with low BMD and low BGP/Hp ratio should be treated intensively in the old women.