Fatty acid binding to serum albumin in Type I insulin-dependent diabetes mellitus

Abstract

Equilibria of binding of long-chain fatty acids to albumin in sera from type I diabetic patients and healthy adults were studied by dialysis exchange rate determinations and described by, p*, the reserve albumin concentration for binding of fatty acid, C*/p*, the total availability of fatty acids, where C* is the total concentration of non-esterified fatty acid, and L*, the fatty acid binding property of albumin, which is L* = p*/P + 0.05 C*/P, where P is the albumin concentration. Studies in samples from 81 diabetic patients and 99 healthy adults showed that availability of fatty acids increased with increasing fatty acid concentrations, equally in the two groups. Some diabetics had higher fatty acid concentrations, and thus higher fatty acid availabilities, than the normals. It is shown that the fatty acid binding property of serum albumin is individually variable, ranging about the same mean value in normal and diabetic persons but with a larger variation in the latter. The fatty acid binding property of albumin in serum, L*, and sixteen clinical parameters were measured in 42 of the 81 diabetic patients. Regression analysis indicated that L* was correlated to serum cholesterol concentration (probability of 0-hypothesis, p = 0.01) and to serum triglyceride concentration (p = 0.05). Values of L* were slightly correlated to age, age on diagnosis, duration, Body Mass Index (BMI), diastolic blood pressure, albumin excretion rate, serum creatinine concentration, and serum non-esterified fatty acid concentration with p-values varying from 0.10 to 0.50. For sex, retinopathy, hemoglobin A1c, systolic blood pressure, daily insulin dose, and blood glucose concentration no correlation to L* was found, p-values ranging from 0.56 to 0.96. Non-enzymatic glycosylation of serum albumin did not decrease binding affinity for fatty acid in vitro.