This article is more than 5 years old. Information may no longer be current.
Growth hormone reduces osteoporotic fracture risk in older women
Click Here to Manage Email Alerts
Older women with osteoporosis treated with growth hormone showed a reduced risk for fracture and improved bone density that continued for years after stopping treatment, according to research in The Journal of Clinical Endocrinology & Metabolism.
In a randomized, double blind, placebo-controlled trial, researchers found that the women assigned GH injections for 36 months reduced their rate of osteoporotic fracture by 50% compared with women who received a placebo injection for 18 months.
“Years after treatment stopped, women who were treated with [GH] still experienced improved bone density and reduced fracture risk,” Emily Krantz, MD, of Sdra lvsborgs Hospital in Borås, Sweden, said in a press release.
Krantz and colleagues analyzed data from 80 women aged 50 to 70 years with osteoporosis who were receiving estrogen hormone therapy for at least 9 months, and a random sample of 120 aged-matched controls. Researchers randomly assigned participants 1 U or 2.5 U of GH or placebo for 18 months. Those assigned placebo then stopped injections, whereas the women assigned GH continued therapy for another 18 months. All participants received 750 mg calcium and 400 U vitamin D during and after the study. All women also completed a quality-of-life questionnaire. Women underwent DXA scanning for bone mineral density at baseline and every 6 months until the 48-month follow-up, and then at 60, 72, 96 and 120 months. Researchers followed all women for 7 years after the end of GH treatment.
Before receiving GH, 56% of participants experienced a fracture; that number dropped to 28% 7 years after GH stopped. The fracture rate for controls rose from 8% before placebo to 32% at the 7-year follow-up.
Women who received the larger dose of GH also had higher BMD and bone mineral content levels in all areas vs. women who received a lower dose of GH or placebo, according to researchers.
Lifestyle factors were unchanged across groups over 10 years, and quality of life did not change significantly during GH administration, according to researchers.
“The findings indicate the beneficial effects of [GH] remained long after the treatment ceased,” Krantz said. – by Regina Schaffer
Disclosure: The researchers report no relevant financial disclosures.
Perspective
Back to TopRoberto Salvatori, MD
Krantz and colleagues studied the effect of growth hormone supplementations on fractures and quality of life in 80 women with postmenopausal osteoporosis. It must be pointed out that these were not GH-deficient women with pituitary pathology. They received either placebo or two different doses (5 or 13 mcg/kg/day) for 3 years in a double-blinded fashion. All subjects were on estrogen replacement, calcium and vitamin D supplementation. They were followed for a total of 10 years, and the prevalence of fractures was compared with the one observed in a random age-matched population of women. As expected, GH caused a dose-dependent increase in serum insulin-like growth factor-I, with women in the higher-dose group reaching supra-physiological levels. More dramatic increase was probably prevented by oral estrogen, which is known to cause GH-resistance. IGF-I promptly retuned to baseline after GH was discontinued. Bone mineral density increased in dose-dependent fashion at years 4 and 5, and returned to baseline by year 10 in the low-dose group, while remaining higher than the other two groups in the high-dose GH group. Despite this, there was no difference in the incidence of fractures among the three groups (placebo, low- and high-dose GH). All three groups showed a reduction in incidence of fractures, while the control group showed an increase in fractures. There was no effect of any of the treatments on quality of life, measured by the 36-item Short Form Questionnaire.
This work is experimental, and GH should not be seen as a possible treatment for osteoporosis. The long-term effects of bringing serum IGF-I above normal or in the upper part of normal in non-GH deficient patients are unknown. More importantly, the incidence of fractures reduced by the same rate in all three treatment groups, irrespectively from whether the women received GH or placebo. This is a non-specific clinical trial effect, possibly due to counseling on fall avoidance. In summary, a 3-year GH treatment in non-GH deficient postmenopausal women does not reduce fracture any better than placebo. GH should be reserved for women who have biochemically proven GH deficiency in the setting of pituitary or hypothalamic pathologies.
Click Here to Manage Email Alerts