Calcitonin and bone mass status in congenital hypothyroidism.
Calcitonin (CT) deficiency and its possible repercussions on bone mass were studied in a group of 9 adult patients (7 females, 2 males) with congenital hypothyroidism of dysgenetic origin. Using a new extraction method (exCT) which considerably improves the sensitivity and the specificity of the assay for CT-monomer, we measured CT levels before and after a short calcium (Ca) stimulation test (2 mg Ca/kg over 5 minutes) to evaluate C-cell secretory reserve. Mean basal plasma CT concentrations were lower in the hypothyroid women (mean +/- SEM: 0.6 +/- 0.1 pg/ml) than in 30 normal female controls (1.7 +/- 0.2 pg/ml, P less than 0.001). Serum calcium increased similarly in the two groups, but postinfusion CT levels were lower in the hypothyroid women, (1.7 +/- 0.2 pg/ml) than in normal women (16.8 +/- 2.9 pg/ml), P less than 0.001. Hypothyroid women showed a 10% reduction in bone mineral content at the diaphyseal site in the radius, 0.840 +/- 0.037 g/cm, compared with normal age-matched controls, 0.930 +/- 0.020 g/cm, (P less than 0.05). Our study demonstrates the existence of a profound CT-monomer deficiency in adult patients with thyroid agenesis or dysgenesis. Both calcitonin deficiency and thyroid hormone treatment could play a role in the observed bone loss. Attention should therefore be paid to bone metabolism during treatment of congenital hypothyroidism to avoid further bone loss.
Demeester-Mirkine
N
N
Service de Médecine, Hôpital Universitaire Brugmann, Brussels, Belgium.
Bergmann
P
P
Body
J J
JJ
Corvilain
J
J
D000293:Adolescent; D000328:Adult; D015519:Bone Density; D002116:Calcitonin / Q000097:blood / Q000172:deficiency* / Q000378:metabolism; D002118:Calcium; D003409:Congenital Hypothyroidism; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D013961:Thyroid Gland / Q000002:abnormalities
D002116:Calcitonin; D002118:Calcium