Abstract
Context
Type 1a and 1b glycogenosis [glycogen storage disorder (GSD)1a, GSD1b] are rare diseases generally associated with malnutrition. Although abnormal substrate oxidation rates and elevated energy expenditures might contribute to malnutrition, this issue has not been investigated.
Objective
To investigate whether abnormal resting energy expenditure (REE) and substrate oxidation rate characterize patients with GSD1.
Design
Cross-sectional study
Setting
Outpatient referral center for rare diseases and laboratory of clinical nutrition at the University Hospital of Palermo
Patients
Five consecutive patients with GSD1 (4 type a, 1 type b; 3 men, 2 women; age range, 19 to 49 years)
Main Outcome Measures
The usual clinical procedures for patients with malnutrition, including REE and basal substrate oxidation rate (both indirect calorimetry), body composition (bioimpedance method), muscle strength (hand-grip test), and the usual laboratory tests, were performed.
Results
Malnutrition was clearly diagnosed in 2 patients (1 GSD1a and 1 GSD1b), with REE elevated in all five patients, and especially, in the two malnourished patients (+124% and +32.1% vs predictive values using Harris-Benedict equations). The two malnourished patients also exhibited lower basal protein oxidation rates (7.7% and 6.6%) than the nourished patients (range, 12.1% to 24.7%), with higher carbohydrate or lipid oxidation rates. Additionally, the two malnourished patients exhibited higher blood concentrations of lactic acid than the nourished patients.
Conclusions
According to data obtained from our small sample of patients with GSD1, elevated REEs seem to be a common characteristic that might contribute to malnutrition. Low basal protein oxidation rates and elevated blood lactic acid concentrations appear to be associated with malnutrition.
Resting energy expenditure and substrate oxidation rates in cystic fibrosis.
