Bony density in adolescents after surgical repair of tetralogy of Fallot: a comparative study with healthy adolescents

Abstract

Background: Adverse influences arising in fetal life or immediately after birth have a permanent effect on body structure, physiology and metabolism. Evidence is now accumulating that programming of bone growth might be an important contributor to the later risk of osteoporosis. Long-term morbidity and mortality associated with tetralogy of Fallot is not completely known. The aim of the present study was to evaluate the state of the bones in adolescents after surgical repair of tetralogy of Fallot, so as to ascertain any possible repercussions of the disease on bone mineralization. Material and methods: We studied 34 adolescents with repaired tetralogy of Fallot, between the ages of 11 and 18 years, to establish their nutritional status, in terms of height, weight, and skinfolds, their body composition using an anthropometric method, their sexual maturity according to Tanner, and their food-habits as based on 24-hour recall. Bone density was evaluated by lumbar dual-energy X-ray absorptiometry. We included 34 healthy eutrophic adolescents, matched for gender and age, as controls. Results: No significant differences were observed between the patients and their controls concerning nutritional status, body composition, total energy intake and nutritional supply in macronutrients, calcium, phosphorus, magnesium and vitamin D. Bone mineral density, expressed in Z-score and g/cm², was significantly higher in patients with tetralogy of Fallot (p < 0.01). The age at the time of the first surgical procedure, or at complete surgical repair, and the total number of surgical procedures, had no significant influence on nutritional status or bone mineralization. Gender, chronological age, sexual maturity and the index of body mass are the major determinants of bone density for both samples. Obese adolescents with repaired tetralogy of Fallot had a significantly higher bone density (p < 0.05) compared to undernourished or euthrophic patients. Conclusions: Being born with tetralogy of Fallot has no significant repercussion, by the stage of adolescence, on nutritional status, pubertal progression, and accretion of bone minerals subsequent to surgical repair. Nutritional status is the major influence on the accretion of bone mass.