Morbid Obesity is Associated to Altered Fatty Acid Profile of Erythrocyte Membranes

Background: Morbid obesity is a pathologic condition associated to an increased incidence of several chronic conditions associated to increased risk of mortality. Erythrocyte fatty acid composition has been candidate as a biomarker of oxidative stress and consequently on the rate of aging and ultimately lifespan. To our knowledge, no study has investigated the total spectrum of lipid composition of erythrocyte membranes from obese individuals. The aim of this study was to compare the fatty acid composition of erythrocyte membranes derived from morbidly obese patients with healthy matched controls and long-living descendants. Methods: Gas chromatography was employed to determine fatty acid percentage of erythrocyte membranes from investigated groups. Results: Erythrocyte membranes from obese subjects had significantly lower percentage of monounsaturated fatty acids (16.0 +/- 0.8 vs. 23.0 +/- 4.5, p<0.01) and total trans fatty acid (0.2 +/- 0.1 vs. 1.3 +/- 1.2, p<0.001) than controls. Obese fatty acid profiles showed increased percent of total polyunsaturated fatty acid (36.5 +/- 1.4 vs. 27.3 +/- 10.9, p<0.001), polyunsaturated fatty acid n-3 (5.2 +/- 0.9 vs. 2.6 +/- 1.8, p <0.001) and n-6 (31.3 +/- 1.7 vs. 25.0 +/- 10.1, p<0.001). Interestingly, when obese fatty acid profiles are compared with long-living descendants, the former show opposite trends in the percentages of the main saturated and unsaturated residues of membrane phospholipids compared with nonagenarian offspring. Conclusion: This study shows that the erythrocyte membranes fatty acid composition of obese subjects differs from general population in a way opposite to the long-living descendants. If confirmed by further investigations, the fatty acid equilibration may become an additional target in the multidisciplinary strategy aimed to treat the obesity epidemic.