Endocrine Abstracts

Introduction: Hypoparathyroidism is the only endocrine deficiency for which replacement therapy with the missing hormone is not part of the clinical practice. High quality evidence on the use of PTH 1-34 or PTH 1-84 in hypoparathyroidism is missing.

Objective: We aim to evaluate the efficacy and safety of PTH 1-34 and PTH 1-84, and to compare the two treatments when possible.

Methods: We searched databases up to March 2021 for randomized control trials or prospective studies on PTH 1-34 and 1-84 in hypoparathyroidism. Three reviewers screened eligible publications (2070) and extracted the outcomes. Other performed quality control and all assessed the risk of biases.

Data synthesis: 36 studies were selected for inclusion in meta-analysis, but 11 were excluded due to population overlap. Both PTH 1-34 and PTH 1-84 allowed a significant reduction in calcium and calcitriol supplementation, and many patients could discontinue conventional treatments. Metanalysis of biochemical profile showed stable calcium levels, while both treatments reduced serum phosphate levels, 25(OH) vitamin D and urinary calcium excretion. Calcium-phosphate product was decreased under PTH 1-84 only. Bone turnover markers and bone mineral density at lumbar spine increased after PTH treatment. Quality of life was also improved in patients receiving PTH. Safety evaluation did not show significant differences between patients and controls in the incidence of adverse events, but total number of adverse events was higher in PTH 1-84.

Conclusions: PTH therapy demonstrates promising efficacy in the management of hypoparathyroidism, reducing the need for other supplements and improving serum and urinary electrolytes profile, without safety concerns. However, further studies on additional outcomes, comparison between treatments and the inclusion of patients not controlled with conventional supplementation will help in expanding current knowledge on PTH replacement in hypoparathyroidism.