Atherogenic phenotype remains in elderly diabetic patients

Aim: It is known that plasma low-density lipoprotein cholesterol (LDL-C) levels tend to decrease with age. Thus, most elderly diabetic patients often show normal LDL-C levels. Therefore, the present study was carried out to examine whether elderly diabetic patients show "the atherogenic phenotype" even if their LDL-C is not elevated. Methods: The study participants consisted of 236 patients. They were separated into four groups according to their age (below 64years and above 65years) and an association of type2 diabetes. A total of 88 middle-aged diabetic, 34 middle-aged non-diabetic, 64 elderly diabetic and 50 elderly non-diabetic participants were enrolled. LDL-C, small dense LDL-C (sLDL-C) were investigated. ANOVA were used for comparison of LDL-C, sLDL-C and the sLDL-C/LDL-C ratio between the four groups. Multivariate regression analysis was carried out in order to find the independent factors associated with the sLDL-C/LDL-C ratio. Results: Among the four groups, the LDL-C of the elderly diabetic group showed lower LDL-C levels compared with that of middle-aged diabetic group, although the difference was not significant (128.6±38.7 vs 138.4±35.8mg/dL). In contrast, sLDL-C and the sLDL-C/LDL-C ratio in the elderly diabetic group were both higher than those of the elderly non-diabetic group (47.0±24.2mg/dL and 0.36±0.14mg/dL, vs 21.4±16.7mg/dL and 0.19±0.11mg/dL, P<0.05). Multivariate regression analysis showed that age, sex, the presence of diabetes mellitus and plasma triglyceride were the independent factors determining the sLDL-C/LDL-C ratio. Discussion: It is concluded from the present data that the atherogenic phenotype remains in elderly diabetic patients even if their LDL-C is not elevated.