Higher FSH levels not linked to lower bone mineral density
MedWire News: Higher concentrations of follicle-stimulating hormone (FSH) are not associated with lower bone mineral density (BMD), US research shows.
Increased FSH is associated with lean body mass, however, indicate the findings
"These results suggest that prior unadjusted associations between FSH and BMD were not due to a direct effect of FSH on bone," report Margaret Gourlay (University of North Carolina, Chapel Hill) and colleagues in the journal Bone.
Animal model studies previously suggested that high circulating levels of FSH caused hypogonadal BMD loss, although basic science and clinical studies have failed to confirm the association.
The researchers therefore tested the association between FSH, non-bone body composition measures, and BMD in 94 postmenopausal women aged 50 to 64 years old not currently taking hormone replacement therapy.
Using dual energy X-ray absorptiometry (DXA) they found that FSH was inversely correlated with lean and fat mass.
In addition, FSH was inversely correlated with hip areal (a)BMD. They also observed that FSH was inversely correlated with volumetric (v)BMD at the ultra-distal radius, as assessed by peripheral quantitative computed tomography (pQCT).
After adjusting for age, race, years since menopause, bioavailable estradiol and testosterone, as well as multiple hormones and peptides, FSH was independently associated with lean mass.
In the fully adjusted models, however, FSH showed no statistically significant association with aBMD at any site or pQCT measures at the distal radius.
"Previously reported correlations between FSH and BMD might have been due to indirect associations via lean mass or weight," explain Gourlay and colleagues.
Race was associated with aBMD, and race and urine N-telopeptide levels were associated with bone area and vBMD.
The researchers point out that weight and age remain the most consistent clinical markers of risk for osteoporosis in postmenopausal women, and that weight can be measured in every clinic in every patient.
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