Skeletal responsiveness to parathyroid hormone in pseudohypoparathyroidism.
BACKGROUND
Although there have been some case reports suggesting that bone in patients with pseudohypoparathyroidism (PHP) might respond to parathyroid hormone (PTH), no information is available as to whether serum PTH concentration is related to bone metabolic markers or to bone mineral density (BMD) in PHP.


OBJECTIVE
To address these relationships, by comparing intact serum PTH, bone metabolic markers and BMD in patients with PHP with those in patients with idiopathic hypoparathyroidism (IHP) and postoperative hypoparathyroidism (OHP).


METHODS
Intact serum PTH, bone metabolic markers (osteocalcin, tartrate-resistant acid phosphatase, pyridinoline, deoxypyridinoline) and BMD by dual-energy X-ray absorptiometry or single-photon absorptiometry were measured in patients with PHP Ia (n=2) and PHP Ib (n=8). The results were compared with those in patients with IHP (n=5) and OHP (n=14).


RESULTS
All bone metabolic markers measured were present in significantly greater amounts in patients with PHP Ib than in those with IHP+OHP. The Z score (standard deviation of average BMD at each age) of the BMD of femoral neck was significantly lower in patients with PHP Ib than in those with IHP+OHP. The Z scores of BMD of lumbar spine and radius were also lower in patients with PHP Ib than in those with IHP+OHP, but the difference was not significant. Moreover, the intact serum PTH concentrations were significantly and positively related to bone metabolic marker levels in all patients, and the intact serum PTH concentrations were significantly and negatively related to BMD of lumbar spine in PHP patients.


CONCLUSIONS
These results suggest that PTH stimulates bone turnover in PHP Ib patients, resulting in a relatively lower BMD in PHP Ib patients than in IHP+OHP patients. The present study indicates that bones of most cases of PHP could respond to PTH.
Third Division, Department of Medicine, Kobe University School of Medicine, Kobe 650, Japan.
M
M
Kanatani
T
T
Sugimoto
H
H
Kaji
K
K
Ikeda
K
K
Chihara
D000135:Acid Phosphatase / Q000097:blood; D000328:Adult; D000368:Aged; D000596:Amino Acids / Q000097:blood; D015415:Biomarkers / Q000097:blood; D015519:Bone Density / Q000187:drug effects*; D002762:Cholecalciferol / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D003404:Creatinine / Q000097:blood; D000242:Cyclic AMP / Q000652:urine; D004910:Erythrocyte Membrane / Q000187:drug effects / Q000378:metabolism; D005260:Female; D019205:GTP-Binding Protein alpha Subunits, Gs / Q000378:metabolism; D006801:Humans; D007011:Hypoparathyroidism / Q000097:blood / Q000188:drug therapy; D007527:Isoenzymes / Q000097:blood; D007668:Kidney / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D015675:Osteocalcin / Q000097:blood; D010281:Parathyroid Hormone / Q000097:blood / Q000494:pharmacology* / Q000627:therapeutic use*; D010710:Phosphates / Q000652:urine; D011183:Postoperative Complications / Q000097:blood / Q000188:drug therapy; D011547:Pseudohypoparathyroidism / Q000097:blood / Q000188:drug therapy* / Q000652:urine; D000071681:Tartrate-Resistant Acid Phosphatase
D000596:Amino Acids; D015415:Biomarkers; D007527:Isoenzymes; D010281:Parathyroid Hormone; D010710:Phosphates; D015675:Osteocalcin; D002762:Cholecalciferol; C015484:pyridinoline; C036020:deoxypyridinoline; D003404:Creatinine; D000242:Cyclic AMP; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase; D019205:GTP-Binding Protein alpha Subunits, Gs