Longevity in Untreated Congenital Growth Hormone Deficiency Due to a Homozygous Mutation in the GHRH Receptor Gene

Abstract

CONTEXT: Reduced longevity observed in hypopituitarism has been attributed to GH deficiency (GHD). It is, however, unclear whether GHD or other confounding factors cause this early mortality. OBJECTIVE: The aim was to study longevity in subjects from a large kindred with untreated, lifetime isolated GHD (IGHD) due to a homozygous mutation in the GHRH receptor gene and in heterozygous carriers of the mutation. DESIGN, SETTING, AND PARTICIPANTS: We carried out a retrospective cohort study on three groups. We first compared mortality risk of 65 IGHD individuals and their 128 unaffected siblings from 34 families. We then compared mean age of death of the IGHD to the general population. A transversal study was carried out to compare the rate of heterozygosity for the mutation in two groups of young (20-40 yr old) and old (60-80 yr old) normal-appearing subjects from the same county. MAIN OUTCOME MEASURE: We measured longevity. RESULTS: The risk of death of IGHD subjects was not different from their siblings. Life span in IGHD individuals was shorter than the general population. When stratified by sex, this difference persisted only in females, due to a high frequency of IGHD deaths in females aged 4-20. There was no significant difference in life span between IGHD subjects and siblings or the general population when analyzing subjects who reached age 20. The prevalence of heterozygosity did not differ in young and old groups, suggesting no survival advantage or disadvantage. CONCLUSIONS: In a selected genetic background, lifelong untreated IGHD does not affect longevity.