Determinants of homocysteine during weight reduction in obese children andadolescents

homocysteine levels have been shown to be associated with indexes of obesit y and insulin resistance in obese children and adolescents. We, therefore, investigated the contribution of changes in body composition, markers of in sulin resistance, folate, and vitamin B-12 to changes in homocysteine durin g a weight reduction program in obese children and adolescents. Thirty-seve n obese white girls (mean SD; age, 12 +/- 1.8 years, body mass index [BMI], 26.9 +/- 5.25) and 19 obese white boys (age, 11.9 +/- 1.7 years; BMI, 26.2 +/- 5.2) were investigated for body composition, fasting total plasma homo cysteine (tHcy), insulin, C-peptide, folate, and vitamin B-12 before and af ter a 3-week weight reduction program including physical activities. During weight reduction BMI, fat mass (FM), percentage fat mass, insulin, and C-p eptide decreased significantly, whereas homocysteine and vitamin B-12 showe d a significant increase. Folate and lean body mass (LBM) remained unchange d. tHcy concentration before weight reduction was a function of age, folate , and C-peptide, whereas tHcy concentration after weight reduction was a fu nction of folate and baseline LBM. Changes in tHcy during weight reduction correlated significantly with baseline LBM and were related inversely to ch anges in LBM during weight reduction. Children who increased LBM showed low er increases in tHcy compared with children who lost LBM. In multiple linea r regression analysis, only baseline LBM contributed independently and sign ificantly to changes in tHcy. Our study suggests that LBM has a significant impact on tHcy metabolism during weight reduction. Copyright (C) 2001 by W .B. Saunders Company.