Long-term treatment with cinacalcet and conventional therapy reduces parathyroid hyperplasia in severe secondary hyperparathyroidism.
BACKGROUND
The effect of cinacalcet on the structural pattern of hyperplastic parathyroid glands was evaluated, using high-resolution colour Doppler (CD) sonography, in haemodialysis patients with severe, inadequately controlled, secondary hyperparathyroidism (sHPT).


METHODS
Nine patients (6 males, 3 females; mean age +/- SD, 55.5 +/- 12.6 years) received cinacalcet, with adaptation of existing concomitant therapies. Biochemical parameters and the morphology and vascular pattern of hyperplastic parathyroid glands were measured at baseline and every 6 months thereafter, for a follow-up period of 24-30 months.


RESULTS
At baseline, 28 hyperplastic glands were identified. Cinacalcet led to a reduction in glandular volume during the course of the study: 68% in glands with a baseline volume <500 mm(3) and 54% in glands with a baseline volume >or=500 mm(3). The mean volume +/- SD of glands <500 mm(3) changed significantly from the baseline (233 +/- 115 mm(3)) to the end of follow-up (102 +/- 132 mm(3), P = 0.007). Levels of mean serum phosphorus, calcium and calcium-phosphorus product decreased, but not significantly, whereas there were significant decreases in mean parathyroid hormone +/- SD levels (1196 +/- 381 pg/ml versus 256 +/- 160 pg/ml; P < 0.0001) and alkaline phosphatase +/- SD levels (428 +/- 294 versus 223 +/- 88 IU/l; P = 0.04), accompanied by an improvement in a subjective clinical score.


CONCLUSIONS
Cinacalcet, in combination with conventional treatments, led to an improvement in biochemical and clinical parameters of sHPT and reduced glandular volume in patients with severe sHPT. Volume reduction was more evident in smaller glands. Longer term, larger, randomized clinical trials are needed to confirm these preliminary findings and to further define a more systematic approach in the treatment of sHPT.
Meola
Mario
M
Department of Internal Medicine, S Anna School of Advanced Studies, Nephrology and Dialysis Unit, University of Pisa, Italy. mmeola@int.med.unipi.it
Petrucci
Ilaria
I
Barsotti
Giuliano
G
D000328:Adult; D000368:Aged; D000069449:Cinacalcet; D015331:Cohort Studies; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000188:drug therapy* / Q000209:etiology / Q000473:pathology; D006965:Hyperplasia / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology; D007676:Kidney Failure, Chronic / Q000150:complications* / Q000000981:diagnostic imaging / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009281:Naphthalenes / Q000008:administration & dosage*; D010280:Parathyroid Glands / Q000000981:diagnostic imaging / Q000473:pathology*; D044169:Receptors, Calcium-Sensing / Q000037:antagonists & inhibitors; D006435:Renal Dialysis; D018615:Ultrasonography, Doppler, Color
D009281:Naphthalenes; D044169:Receptors, Calcium-Sensing; D000069449:Cinacalcet