1. ¹Institute of Medical Biology and Human Genetics, Medical University of Innsbruck, Innsbruck, Austria
2. ²Department of Medical Chemistry, Medical University of Vienna, Vienna, Austria
3. ³Department of Pediatrics, a.ö. Krankenhaus St Pölten, St Pölten, Austria
4. ⁴Institute of Epidemiology, GSF-National Research Center for Environment and Health, Neuherberg, Germany
5. ⁵Department of Clinical Chemistry, Landeskrankenanstalten Salzburg, Salzburg, Austria

Correspondence: Dr W Strobl, Department of Medical Chemistry, Medical University of Vienna, Währingerstrasse 10, Vienna A-1090, Austria. E-mail: wolfgang.strobl@univie.ac.at

Received 29 October 2003; Revised 3 May 2004; Accepted 27 June 2004; Published online 31 August 2004.

Abstract

OBJECTIVE: Apolipoprotein (apo) A-IV is an antiatherogenic apolipoprotein, which may be involved in the regulation of food intake. Plasma apoA-IV is elevated in human obesity and apoA-IV polymorphisms have been associated with the extent of obesity. Our aim was to determine the effects of weight loss on plasma apo-IV in obese adolescents and to examine the relation of apoA-IV with the degree of obesity.

DESIGN: Longitudinal intervention study of a low fat hypocaloric diet conducted in a dietary camp.

SUBJECTS: Two groups of obese adolescents (n=47 and n=29), age: 12.71.7 and 11.72.6 y, relative body mass index (RBMI): 16824 and 17534%, respectively.

MEASUREMENTS: Plasma total apoA-IV, apoA-I, apoB, plasma distribution of apoA-IV, leptin, lipids, and lipoproteins before and after 3 weeks of weight reduction.

RESULTS: Plasma apoA-IV decreased from 11.54.1 mg/dl before to 6.72.2 mg/dl after weight reduction in the first group (P<0.001) and to a similar extent in the second group. The relative amount of lipid-free apoA-IV and apoA-IV associated with apoA-I increased slightly, whereas apoA-IV associated with lipoproteins devoid of apoA-I decreased. ApoA-IV levels before and after weight reduction and the changes in plasma apoA-IV did not independently correlate with RBMI, weight loss, or plasma leptin.

CONCLUSION: Plasma apoA-IV decreases markedly in overweight adolescents undergoing short-term weight reduction. The decrease is not directly related to the degree of weight loss and the mechanisms underlying this reduction remain to be clarified.