A meta-analysis comparing the biochemistry of primary hyperparathyroidism in youths to the biochemistry of primary hyperparathyroidism in adults.

CONTEXT: The distinctive presentation of primary hyperparathyroidism (PHPT) in adults and youths suggest that PHPT is a fundamentally different disease in these two groups.

OBJECTIVE: To understand the difference in PHPT between adults and youths we compared the biochemistry of PHPT in these two groups.

DESIGN: This study is a systematic review and meta-analysis of retrospective studies published 1966-2014 on PHPT.

DATA SOURCES: All studies were obtained through Medline (1966-2014).

STUDY SELECTION AND DATA EXTRACTION: Only studies that included post-surgical subjects and that explicitly described biochemical results from more than one decade were included. Data were extracted from each article to generate the mean and SE for multiple biochemical parameters.

DATA SYNTHESIS: We analyzed 16 studies describing 268 unique youths and 2405 adults with PHPT. Youths with PHPT had significantly (P < .05) greater serum and urinary calcium than adults with PHPT (3.2 ± 0.1 mmol/L vs 2.8 ± 0.0 mmol/L for serum calcium, and 9.95 ± 1.26 mmol/d vs 7.15 ± 0.56 mmol/d for urine calcium, [mean ± SEM]). There were no significant differences in serum intact PTH, phosphorus, or alkaline phosphatase.

CONCLUSIONS: Juvenile PHPT has greater hypercalcemia and hypercalciuria than adult PHPT at similar concentrations of serum intact PTH. These observations suggest that there are differences in the pathophysiology of PHPT between juvenile and adult patients who reflect an apparent decrease in the sensitivity of the parathyroid adenoma to negative feedback by calcium and increased sensitivity of target tissues to the effects of PTH.