Reduced telomere length in subjects with dementia and diabetes mellitus type 2 is independent of apolipoprotein E4 genotype

Apolipoprotein E4 gene is associated with increased risk of dementia with comorbid diabetes mellitus. Both dementia and diabetes mellitus type 2 are independently associated with telomere shortening. We assessed relative telomere length and apolipoprotein E genotype in subjects with dementia (n = 70) and cognitively normal control groups (n = 55) with and without comorbid diabetes mellitus type 2. Relative telomere length was highest in the control group (Q2 = 0.91) followed by dementia (Q2 = 0.48) and dementia with comorbid diabetes mellitus type 2 (Q2 = 0.39). Apolipoprotein E4 allele frequency was highest in dementia with comorbid diabetes mellitus type 2 (0.26). Apolipoprotein E4 allele was not significantly associated with telomere attrition in both dementia and cognitively normal group irrespective of comorbid diabetes mellitus type 2 (P > 0.05). The findings suggest that relative telomere length is unrelated to apolipoprotein E4 genotype in dementia and cognitive normal subjects with or without comorbid diabetes mellitus type 2.