An alternative explanation for the changes in erythrocyte fatty acids observed in diabetes mellitus.

Fatty acids in erythrocyte membranes and plasma were determined by capillary gas-liquid chromatography in 27 controls and 44 subjects with insulin-dependent diabetes mellitus. Significant decreases in stearic acid (P less than 0.00003) and arachidonic acid (P less than 0.001) and significant increases in palmitic acid (P less than 0.00003) were observed in erythrocytes from diabetic patients. The stearic:oleic acid ratios and arachidonic:linoleic acid ratios in erythrocytes were significantly lower in diabetic patients than in controls (P less than 0.0003 and less than 0.0007, respectively). The relative concentration of palmitic acid in plasma (as a percentage of the sum of the five major fatty acids) was increased in diabetic patients, as compared with controls (P less than 0.0125). We observed no other significant differences in fatty acids in plasma, making it unlikely that changes in fatty acids in erythrocyte membranes in diabetic patients can be accounted for simply by alterations in the fatty acids in plasma. We propose that impaired metabolic control associated with diabetes mellitus may interfere with the maintenance of fatty acid profiles in erythrocyte membranes against the concentration gradients in plasma.