ABSTRACT
BACKGROUND: Osteopenia and osteoporosis are among the most frequent and severe complications in adolescents with anorexia nervosa. OBJECTIVE: The aim of this study was to assess the influence of nutritional therapy on bone metabolism during adolescent anorexia nervosa. DESIGN: We studied 19 anorectic patients aged 14.1 +/- 1.4 y (x +/- SD) with a body mass index (BMI; in kg/m(2)) of 14.2 +/- 1.4 and 19 age-matched control subjects aged 15.1 +/- 2.3 y with a BMI of 20.8 +/- 1.9 for 1 y. Blood samples were taken for the measurement of bone markers, insulin-like growth factor I (IGF-I), and leptin. RESULTS: BMI rose significantly from 14.2 +/- 1.4 at baseline to 17.4 +/- 0.6 (P < 0.0001) at week 15. Compared with concentrations in the control subjects, concentrations of the bone formation markers procollagen type I propeptide (PICP) and bone alkaline phosphatase (bAP) in the anorectic patients were lower at baseline (PICP: P = 0.0071; bAP: P = 0.0012), increased with nutritional therapy (PICP: P = 0.0060, bAP: P = 0.0147), and were no longer significantly different (P > 0.05) during the follow-up period. Concentrations of IGF-I and leptin were significantly lower (P < 0.0001 for both) in the anorectic patients than in the control subjects at baseline. IGF-I increased with nutritional therapy but was still significantly lower (P = 0.0036) than that in the control group and decreased again during the follow-up period (P = 0.0126). In contrast, serum C-telopeptide decreased with nutritional therapy (P = 0.0446). CONCLUSION: Nutritional therapy improves concentrations of bone formation markers in adolescent patients with anorexia nervosa.
Subject(s)
Adolescent Nutritional Physiological Phenomena , Anorexia Nervosa/diet therapy , Anorexia Nervosa/metabolism , Bone and Bones/metabolism , Insulin-Like Growth Factor I/metabolism , Leptin/blood , Adolescent , Alkaline Phosphatase/blood , Anorexia Nervosa/blood , Biomarkers/blood , Body Mass Index , Body Weight/physiology , Case-Control Studies , Collagen Type I/blood , Female , Follow-Up Studies , Humans , Inpatients , Nutrition Therapy , Nutritional Status , Osteogenesis , Treatment OutcomeABSTRACT
BACKGROUND: Many adolescents with anorexia nervosa suffer from severe osteopenia and osteoporosis. We hypothesized that individualized nutrition therapy may improve bone turnover in anorectic patients. METHODS: We studied 19 female patients [mean age, 14.2 +/- 1.4 years; mean body weight, 39.3 +/- 5.4 kg; mean body mass index (BMI), 14.2 +/- 1.4 kg/m(2)] with anorexia nervosa (International Classification of Diseases-10: F50.0, F50.1) for a period of 3 months. Nutrition therapy began at the end of the first week and included individualized hypercaloric diets, high calcium intake (2000 mg/day), and administration of vitamin D (400 IU/day). Blood samples were taken at baseline and again in weeks 3, 7, and 11. We measured serum calcium, parathyroid hormone, bone formation and resorption markers, insulin-like growth factor 1 (IGF-1), and leptin. RESULTS: Mean BMI increased significantly, from 14.2 +/- 1.4 to 17.1 +/- 0.7 kg/m(2) (P = 0.000001), during the course of treatment, whereas serum total calcium and phosphate concentrations remained unchanged. The bone formation markers procollagen-I carboxy-terminal propeptide and bone alkaline phosphatase almost doubled (P = 0.006). Both IGF-1 (P = 0.00001) and leptin (P = 0.000005) increased significantly by week 11. Parallel to this, the serum concentration of C-telopeptide, a bone resorption marker, decreased significantly (P = 0.009). CONCLUSIONS: Nutritional rehabilitation, possibly as a result of increasing IGF-1 and leptin concentrations, may increase bone formation. It therefore provides additional objective evidence of the importance of nutrition for bone.
