Longitudinal study of the effect of calcium pidolate on bone mass in eugonadal women.

Seventy-two eugonadal women, mean age 39 +/- 4 years, with a z score for total body bone mineral content (BMC) of less than -1.5 (mean -1.80 +/- 0.12) were selected from a previous screening study of normal values of total body and regional BMC in women using dual-energy X-ray absorptiometry. The women were distributed into two groups: 36 women undergoing treatment with 1 g/day of elemental calcium in the form of calcium pidolate and 36 women not treated. One year later, total body BMC, regional BMC in arms, legs and trunk, 24-hour urinary calcium excretion (Ca 24 hour), fasting urinary calcium/creatinine ratio, and serum tartrate-resistant acid phosphatase concentration were measured in both groups. There was a significant increase in total body and regional BMC (P < 0.001) in the group taking calcium pidolate. The increase was greater in arms and legs (2.5%) than in trunk (1.7%), being 2.6% for total body BMC. The z score increased from -1.81 +/- 0.13 to -1.52 +/- 0.12 (16%, P < 0.001). The corporal index did not change, and total body BMC corrected for fat-free body mass increased by 6.7% (P < 0.001). These changes were accompanied by an increase in 24-hour urinary calcium excretion and a decrease in urinary calcium/creatinine ratio and serum tartrate-resistant acid phosphatase concentration (P < 0.05 for all). There was a correlation between cumulative calcium dose at the end of treatment and gain in total body BMC (r2 = 0.925, P < 0.001). The untreated group showed no changes.(ABSTRACT TRUNCATED AT 250 WORDS)