Bone Mineral Density in Patients with Hepatic Glycogen Storage Diseases.

Jésica Tamara Jacoby,Lília Farret Refosco,Karina Colonetti,Poli Mara Spritzer,Carolina F M De Souza,Ida Vanessa Doederlein Schwartz,Tatiele Nalin,Roberta Hack-Mendes,Bruna Bento Dos Santos,Soraia Poloni

doi:10.3390/nu13092987

Abstract

The association between bone mineral density (BMD) and hepatic glycogen storage diseases (GSDs) is still unclear. To evaluate the BMD of patients with GSD I, IIIa and IXα, a cross-sectional study was performed, including 23 patients (GSD Ia = 13, Ib = 5, IIIa = 2 and IXα = 3; median age = 11.9 years; IQ = 10.9–20.1) who underwent a dual-energy X-ray absorptiometry (DXA). Osteocalcin (OC, n = 18), procollagen type 1 N-terminal propeptide (P1NP, n = 19), collagen type 1 C-terminal telopeptide (CTX, n = 18) and 25-OH Vitamin D (n = 23) were also measured. The participants completed a 3-day food diary (n = 20). Low BMD was defined as a Z-score ≤ −2.0. All participants were receiving uncooked cornstarch (median dosage = 6.3 g/kg/day) at inclusion, and 11 (47.8%) presented good metabolic control. Three (13%) patients (GSD Ia = 1, with poor metabolic control; IIIa = 2, both with high CPK levels) had a BMD ≤ −2.0. CTX, OC and P1NP correlated negatively with body weight and age. 25-OH Vitamin D concentration was decreased in seven (30.4%) patients. Our data suggest that patients with hepatic GSDs may have low BMD, especially in the presence of muscular involvement and poor metabolic control. Systematic nutritional monitoring of these patients is essential.

Highlights

Glycogen storage diseases (GSDs) are characterized by abnormal storage or catabolism of glycogen due to the deficient activity of enzymes that catalyze glycogen synthesis or degradation [1]
The differences observed between our cohort and other cohorts regarding the prevalence of low bone mineral density (BMD) may be due to the younger age and the higher body mass index (BMI) of our sample
We found no association between 25-OH Vitamin D levels and BMD [20,21]

Summary

Introduction

Glycogen storage diseases (GSDs) are characterized by abnormal storage or catabolism of glycogen due to the deficient activity of enzymes that catalyze glycogen synthesis or degradation [1]. Their incidence is approximately 1 in 20,000–43,000 live births worldwide. GSD III results from a deficiency of glycogen debranching enzyme [5,6], and it is classified in IIIa, which causes liver and muscular compromise, and IIIb, which causes only liver symptoms [7]. GSDIXα, caused by pathogenic variations in the phosphorylase kinase alpha 2 (PHKA2) gene, results from the absence of the liver-α subunit of the phosphorylase kinase, which causes liver symptoms only [8,9]

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