The effect of orlistat on the fatty acid composition of serum lipid fractions in obese subjects

Objective: To determine whether there are any changes in the fatty acid com position of serum triglycerides, cholesterol esters, and phospholipids indu ced by administration of orlistat three times a day compared with placebo a s combined with a low-fat hypocaloric diet. Methods: After 4 weeks of placebo administration, 75 obese subjects were ra ndomized to receive either one capsule (120 mg) of orlistat or placebo thre e times a day with meals for 1 year in conjunction with a nutritionally bal anced hypocaloric diet. Food records were kept to estimate the nutrient int ake. The fatty acid composition of serum Lipids were analyzed with gas chro matograph, The molar percentage proportions of fatty acids in serum Lipid f ractions were calculated. Results: Compared with placebo, there was a significant decrease in the pro portion of linoleic acid in triglycerides, cholesterol esters, and phosphol ipids in the orlistat group, even after the effect of the decrease in the l inoleic acid dietary intake (percent of energy), weight change, and gender were taken into account. However, the use of orlistat explained only 9% to 13% of the decrease in the proportion of linoleic acid in serum cholesterol esters, triglycerides, and phospholipids. Conclusion: The long-term treatment with orlistat may result in a small dec line in the proportion of diet-derived fatty acids in serum lipid fractions when used in conjunction with low-fat diet.