Body composition in young adults with inborn errors of protein metabolism—A pilot study

Abstract

The natural history of inborn errors of protein metabolism and the long-term effects of prescribed semisynthetic therapeutic diets are largely unknown. We assessed body composition, measuring body-fat mass and distribution, fat-free mass, total body protein, total body potassium, bone density and skeletal muscle mass, in young adults (age > 18 years; 6 female, 5 male) with inborn errors of protein metabolism maintained on long-term low-protein diets, compared with controls. Female patients were significantly shorter (159.4 cm vs 169.2 cm, p = 0.013) and had higher BMI (25.3 vs 22.0 kg/m2, p < 0.05), abdominal to gluteal circumference ratio (0.84 vs 0.73, p = 0.011), percentage body fat (42.3% vs 29.5%, p < 0.005) and ratio of central to peripheral body fat (1.15 vs 0.86, p < 0.05) than controls. Male patients had lower height-adjusted total body bone mineral content (0.9 vs 1.02 g/m2, p < 0.04) and skeletal muscle mass (31.1 vs 36.3 kg, p < 0.04) than controls. Compared with controls, patients'nitrogen index was significantly lower (0.91 vs 1.03, p < 0.01), consistent with lower total body protein. Potassium index was significantly higher (121.2% vs 110.4%, p < 0.03), consistent with higher body cell mass, or intracellular water. Documentation of body composition in larger patient series is important to elucidate whether these results reflect increased risks (hence opportunities for prevention) of bone disease, metabolic syndrome and cardiovascular disease in this population.

Long‐term needs of adult patients with organic acidaemias: outcome and prognostic factors

“…Some showed the consequences of a long-term protein-restricted diet (Kerstetter et al 2003): one-third of the patients had short stature and over 60% of those evaluated had a significantly low BMD. Formal assessment of body composition would be of interest in this group (Wilcox et al 2005). Currently there are no recommendations for protein intake in adult patients with organic acidaemias.…”

Suggested guidelines for the diagnosis and management of urea cycle disorders

“…The diet needs to be adjusted for age and growth (see below) [17,47,106]. Since low protein diets may increase the risk of osteoporosis, bone density monitoring from time to time may be advisable [164,165]. …”

Cardiovascular disease biomarkers in patients with inborn errors of protein metabolism: a pilot study

“…Recent studies have shown that the Mediterranean diet was able to improve the lipid profile also in children affected with chronic diseases, such as type 1 diabetes (Cadario et al, 2012) and hypercholesterolaemia (Giannini et al, 2014). In PKU patients, the impact of the IEPM diet on various CVD risk factors was described in some studies from Mediterranean countries, such as Greece (Schulpis et al, 2002), Italy (Galluzzo et al, 1985) and Spain (Colome et al, 2001), in addition to Europe (Hvas et al, 2006), Australia (Wilcox et al, 2005) and the USA (Moseley et al, 2002). The plasma lipid profile was reported in some studies with contradictory results.…”