Effect of nutritional support on mitochondrial complex I activity in malnourished patients with anorexia nervosa

Previous studies have shown a reduction in lymphocyte mitochondrial complex I activity (CIA) in malnourished patients, which is restored after refeeding. Our aim was to evaluate the usefulness of CIA as an indicator of nutritional status in anorexia nervosa patients. Twelve malnourished anorexia nervosa females (mean age, 24.5 years) were admitted to the Eating Disorders Unit. Basal and weekly anthropometrics, bioelectric impedance (BIA), body composition, and CIA were performed until discharge. Patients were matched to 25 healthy females and refeeding was adjusted according to the Unit's protocol. Statistics were used as appropriated and significance was reached at p < 0.05. Patients showed a significant reduction in body mass index, fat mass and fat free mass (FFM), triceps skinfold, and waist circumference on admission as compared with the control group. Parameters improved during hospitalization, but they failed to reach normal values at discharge. Compared with controls, CIA was significantly lower in patients on admission (2.16 vs. 5.68 nmol.min(-1).mg protein(-1)). Refeeding and weight gain did not restore CIA. A positive association (r(2) = 0.69) was found between FFM and CIA in patients at discharge. Malnourished females with anorexia nervosa have lower CIA than controls that is not recovered after refeeding. This could be because of a low FFM exacerbated by physical inactivity while in hospital.