Effect of alendronate on bone mineral density in adult patients with Laron syndrome (primary growth hormone insensitivity).

Severe short stature resulting from a deficiency in insulin-like growth factor-I (IGF-I) is a prominent feature of Laron syndrome (LS). Whether patients with LS are osteopenic or not, and whether they need treatment with bisphosphonates, remains uncertain. The aim of this study was to investigate the action of alendronate on the IGF-I-deficient bones of adult patients with LS and osteoporosis, as determined by dual X-ray absorptiometry . Seven patients (5 women and 2 men) of mean age 40.8+/-7.6 years and mean bone mass density (BMD) 0.843+/-0.06 g/cm2 (T score -2.9+/-0.5) at the lumbar spine and 0.734+/-0.11 g/cm2 (T score -2.2+/-0.9) at the femoral neck were treated with alendronate 70 mg once/weekly over a 12-month period. Treatment led to an increase of 5.3% in BMD (p=0.038) at the femoral neck. There was a similar trend at the lumbar spine, but the difference was not statistically significant (2.3%, p=0.34). Mean total alkaline phosphatase decreased by 14% from normal range at baseline (p=0.007). Urinary deoxypyridinoline levels, which were elevated at baseline (10+/-2.3 nM/mMcre), showed a nonsignificant change during treatment. Our study suggests that treatment with alendronate may have positive effects in patients with LS and low BMD on dual X-ray absorptiometry.

Alendronate for osteoporosis in men with androgen-repleted hypogonadism.

Male hypogonadism is associated with low bone mineral density (BMD) and an increased risk of fractures. Testosterone replacement therapy improves BMD in young hypogonadal men. This effect is milder in older patients, who are at greater risk for fractures. We studied the effects of alendronate or placebo on BMD in 22 osteoporotic men, 29-69 years of age (mean, 50.2+/-11.2 years) with long-standing hypogonadism, receiving standard testosterone replacement treatment. Alendronate 10 mg daily (n=11) increased lumbar-spine BMD by 6.0 and 8.4% at 6 and 12 months, respectively, compared with -0.5% at 6 months and +3.3% at 12 months in the placebo group (n=11; P<0.005). Alendronate also increased mean femoral-neck BMD by 1.9% after 1 year, compared to a 1.4% decrease with placebo (P<0.005), and increased the total body bone mineral content by 4.4%, compared to a 0.6% decrease with placebo (P=0.07). After 6 months alendronate suppressed urinary deoxypyridinoline by 50% (P<0.005), compared to a 24% decrease in the placebo group. Both the alendronate and placebo groups continued with alendronate 70 mg once weekly for the following 2 years. Lumbar-spine BMD during this open-label study phase did not change significantly in the group originally treated with alendronate, but continued to increase in the placebo-alendronate group by 5.4, 6.5, and 6.2% after 18 (6 months of alendronate), 24 and 36 months, respectively (P<0.05). Femoral-neck BMD continued to increase in both groups receiving active therapy; in the alendronate-alendronate group by 3.7, 2.7, and 5.2% after 18, 24, and 36 months, respectively (P=0.01), and in the placebo-alendronate group by 0.7 and 1.9% at 24 (first 12 months of alendronate) and 36 months, respectively (P<0.05). Our results support the long-term administration of alendronate along with testosterone replacement to men with hypogonadism-induced osteoporosis.

Primary hyperparathyroidism in young adults.

OBJECTIVES: The purpose of this study was to compare the incidence of multiglandular disease and rate of treatment failure between younger and older patients with primary hyperparathyroidism. STUDY DESIGN AND SETTING: The medical charts of patients who underwent surgery for primary hyperparathyroidism at our tertiary-care institution between 1995 and 2001 were reviewed. RESULTS: Three hundred nineteen patients were identified, of whom 33 were aged 40 years or less. There were no statistically significant differences between the younger and older groups in the incidence of multiglandular disease (9.1% for both, P = 1.00) or in the treatment failure rate (12.1% and 8%, respectively, P = 0.43). Sonography was significantly more sensitive than technetium Tc-sestamibi in the younger group (96% vs 57%, P < 0.05). Parathyroid hormone level and gland weight were significantly higher in the older group (P = 0.004). CONCLUSION: Our results suggest that the same treatment strategy should be applied to all patients with primary hyperparathyroidism. Ultrasound appears to be the localization procedure of choice in younger patients.

Are adult patients with Laron syndrome osteopenic? A comparison between dual-energy X-ray absorptiometry and volumetric bone densities.

Severe short stature resulting from a deficiency in IGF-I is a prominent feature of Laron syndrome (LS). Although low bone mineral density (BMD) has been noted in LS patients examined by dual energy x-ray absorptiometry (DEXA), this technique does not take volume into account and may therefore underestimate the true bone density in patients with small bones. The aim of the present study was to evaluate the BMD yielded by DEXA in our LS patients using estimated volumetric values. Volumetric density was calculated with the following formulas: bone mineral apparent density (BMAD) = bone mineral content (BMC)/(area)(3/2) for the lumbar spine and BMAD = BMC/area(2) for the femoral neck. The study sample included 12 patients (mean age, 43.9 yr; mean height, 123.7 cm). Findings were compared with 10 osteopenic subjects without developmental abnormalities (mean age, 56 yr; mean height, 164.8 cm) and 10 healthy control subjects matched for sex and age to the LS patients (mean height, 165.5 cm). BMAD in the LS group was 0.201 +/- 0.02 g/cm(3) at the lumbar spine and 0.201 +/- 0.04 g/cm(3) at the femoral neck; corresponding values for the osteopenic group were 0.130 +/- 0.01 and 0.140 +/- 0.01 g/cm(3), and for the controls, 0.178 +/- 0.03 and 0.192 +/- 0.02 g/cm(3). Although areal BMD was significantly lower in the LS and osteopenic subjects compared with controls (P < 0.02) at both the lumbar spine and femoral neck, BMAD was low (P < 0.01) in the osteopenic group only. In conclusion, DEXA does not seem to be a reliable measure of osteoporosis in patients with LS.