Decrease of plasma apolipoprotein A-IV during weight reduction in obese adolescents on a low fat diet

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.

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

Two groups of obese adolescents (n=47 and n=29), age: 12.7+/-1.7 and 11.7+/-2.6 y, relative body mass index (RBMI): 168+/-24 and 175+/-34%, respectively.

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

Plasma apoA-IV decreased from 11.5+/-4.1 mg/dl before to 6.7+/-2.2 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.

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.