Apolipoprotein E genotype is a determinant of low-density lipoprotein cholesterol and of its response to a low-cholesterol diet in type 1 diabetic patients with elevated urinary albumin excretion

The effect of the apolipoprotein (apo) E genotype on the lipoprotein respon se to a 1 year low cholesterol diet (200 mg cholesterol per day) was evalua ted in 36 patients with Type 1 diabetes mellitus with albuminuria between 1 0 and 200 mu g min(-1). Apo E genotype was characterized by polymerase chai n reaction and restriction isotyping. In 11 IDDM patients with at least one epsilon 4 allele (apo E4 group), baseline serum total and low density lipo protein (LDL) cholesterol were higher (p < 0.05 for both) than in 25 patien ts without an epsilon 4 allele and with at least one epsilon 3 allele (apo E3 group). Dietary counselling resulted in a similar decrease in cholestero l intake in both groups, whereas linoleic acid did not change. in the apo E 4 group, serum total and LDL cholesterol at follow-up fell (p < 0.01 for bo th) to levels that were not different from those in the apo E3 group, and t he changes in these parameters were greater (p < 0.02) than those in the ap o E3 group. We conclude that the apo E4 allele is associated with atherogen ic lipoprotein abnormalities in Type 1 DM patients with minor elevations in albuminuria when they use their habitual diet. Apo E4 carrying patients re spond better to a low cholesterol diet. (C) 1998 John Wiley & Sons, Ltd.