Body composition of adults with an energy metabolism disorder
Patients with a metabolic disorder have an increased risk of malnutrition, because of frequently occurring nutritional problems and lower BMI. BMI is not a reliable measure of nutritional status in neuromuscular disorders. Despite a normal BMI, a reduced muscle mass and increased fat mass can exist.
This study describes the body composition of adults with a metabolic disorder and compares the results with reference values in healthy people.
This cross-sectional study in patients with a metabolic disorder recorded length (m), weight (kg), mid upper arm circumference (MUAC, cm), upper arm muscle circumference (UAMC, cm), triceps skinfold (mm) and waist circumference (WC, cm). Fat-free Mass Index (FFMI, kg/m2), body fat percentage and Fat Mass Index (FMI, kg/m2) were calculated with the results of bio-impedance analysis. Differences in BMI, FFMI and FMI between patients and healthy references were evaluated with the one-sample t-test (p < 0.05).
85 patients with a metabolic disorder (age: 46±12 years; male: n = 27) signed informed consent. 7% had a BMI <18.5 kg/m2, 40% > 25 kg/m2. The average VVMI was lower than the P50 value of the reference population, 17.6±2.4 vs. 19.3 kg/m2 for men (p = 0.01) and 15.3±1.6 vs. 16.1 kg/m2 for women (p < 0.001). The average FMI was higher than the reference population (6.6±3.3 vs. 4.9 kg/m2 for men (p = 0.02) and 9.0±3.1 vs. 6.2 kg/m2 for women (p < 0.001). The average UAMC of male patients (n = 7) was lower than the P50 value of the reference population (p = 0.02). 39% of the patients had a low muscle mass based on low FFMI, while 64% had central obesity based on a high WC, 19% had a low muscle mass combined with a high fat mass.
Patients with a metabolism disorder (also those with a normal BMI) have a different body composition healthy reference population, namely a lower FFMI and a higher FMI than the.
Key words: Upper arm circumference, metabolic disease, body composition, waist circumference, neuromuscular disorder, Nutritional assessment, Fat Free Mass Index (FFMI)