Introduction: Previous data from our group suggested a role for the GH/IGF1 axis in the pathophysiology of osteoporosis in thalassemia (Clin Endocrinol 69:202, 2008). The present study was aimed at evaluating the relationships between circulating IGFs and bone metabolism and density in a very large series of adult thalassemic patients.
Study design: One hundred and thirty-nine patients affected by thalassemia major (mean age 32.3±7.87 years) underwent the following evaluations: assessment of lumbar and femoral BMD by DEXA; measurement of serum osteocalcin and CTx, and urinary NTx; measurement of serum IGF1 and IGF2; assessment of the GH response to GHRH+arginine.
Results: Lumbar osteoporosis and femoral osteoporosis were detected in 54.3 and 58.1% of patients, respectively. IGF1 was low in 86.7% of subjects, whereas none of them displayed low IGF2. Severe GH deficiency was documented in 27.9% of subjects. In the whole group of patients, IGF1 was positively correlated with GH peak (P<0.01), osteocalcin (P<0.0001), CTx (P<0.0001) and NTx (P<0.0001), and negatively correlated with age (P<0.0001), but was not correlated with either lumbar or femoral T-scores. No correlations were found between IGF2 and any of the above parameters, with the exception of age (negative correlation, P<0.05). The same picture of correlations held true when considering the subset of osteoporotic patients.
Conclusions: Our study confirms the high prevalence of both osteoporosis and GH/IGF1 deficiency in thalassemic adults. GH and IGF1 secretory status, but not circulating IGF2, appears to positively affect bone turnover in this clinical condition. Further, GH secretory status, but not circulating IGFs, is likely to influence also bone mineralization.