Although weight loss is recommended for obese patients, it remains questionable how much weight loss is optimal. A novel index that accurately determines the risk of cardiovascular diseases (CVDs) in terms of weight loss is needed. The modified Atherogenic Index of Plasma (AIP), presented here is unique in the literature. It is calculated based on data for anti-atherogenic, high-density lipoprotein cholesterol (HDL-C) fractions, instead of the total HDL-C. This study investigates whether weight loss correlates with CVD risk, and whether the modified AIP allows more accurate diagnostics in obese/overweight people. According to the increase or decrease of AIP during weight loss, 52 Polish patients were subdivided into two groups: group I (increased AIP; n = 16) and group II (decreased AIP; n = 36). The patients' body mass composition and fasting serum lipid parameters (total cholesterol, triglycerides, HDL-C, and LDL-C (low-density lipoprotein cholesterol)), and cholesterol in 21 lipoprotein sub-fractions were determined. Over six months, all patients reduced their body mass by about 10%. There were no significant differences in anthropometric measures between groups. Increases in large and intermediate HDL-C fractions 1 to 6 and decreases in smaller fractions 7 to 10 were observed in group II. In group I, HDL-C fractions 1 and 10 decreased, while cholesterol in other fractions increased. Increases were observed in the antiatherogenic HDL-C of 52% of group II and 4% of group I. As for atherogenic HDL-C, a decrease of 24% was observed in group II and an increase of 9% in group I. In group I, increases of very-low-density lipoprotein (VLDL), intermediate-density lipoprotein (IDL), and large LDL fractions were noticed, and the reverse in group II. The results show that the modified AIP is a more accurate indicator of CVD risk than existing indices, and that uncontrolled weight reduction does not necessarily have a beneficial influence, and may adversely affect the cardiovascular system.
Keywords: Atherogenic Index of Plasma (AIP); LDL-C; anthropometric measures; cardiovascular diseases; sub-fractions of HDL-C; weight loss.