Resting Energy Expenditure Is Decreased in Pseudohypoparathyroidism Type 1A.

Abstract

Pseudohypoparathyroidism type 1A (PHP1A) is caused by loss-of-function mutations on the maternally inherited GNAS allele and is associated with early-onset obesity, neurocognitive defects, and resistance to multiple hormones. The role of energy intake vs central regulation of energy expenditure in the pathophysiology of obesity remains unclear. The aim of this study was to evaluate resting energy expenditure (REE) in participants with PHP1A. We assessed REE, biochemical, endocrine, and auxological status of 12 participants with PHP1A who had normal or elevated body mass index; controls were a cohort of 156 obese participants. This study took place at Children's Hospital in Philadelphia and Sick Children's Hospital in Toronto. REE as a percent of predicted REE was the outcome measure. PHP1A participants had normal endocrine status while receiving appropriate hormone replacement therapy, but had significantly decreased REE as a percent of predicted REE (using the modified Schofield equation). Our results are consistent with REE being the principal cause of obesity in PHP1A rather than it being caused by excessive energy intake or endocrine dysfunction.