Analysis of telomere length and subtelomeric methylation of circulating leukocytes in women with Alzheimer’s disease

Backgrounds and aims Telomere attrition proceeds with the aging process, and is also associated with aging disease conditions, such as Alzheimer’s disease (AD). The aging process also affects subtelomeric methylation status. In the present study, the telomere length and the subtelomeric methylation status in female AD patients were analyzed to see how AD affects telomere structure. Methods Terminal restriction fragment length of 23 AD patients’ peripheral leukocytes was analyzed with methylation sensitive- and insensitive-isoschizomer by Southern blot. Results AD patients were found to have normal mean telomere lengths (controls; 6.4 ± 0.9 kb, AD; 6.1 ± 0.8 kb, p = 0.131), a proportionally decreased number of the longest telomeres (>9.4 kb) (controls; 30.3 ± 7.9 %, AD; 24.4 ± 8.3 %, p = 0.013), increased medium-sized telomeres (controls; 51.7 ± 3.3 %, AD 55.5 ± 6.4 %, p = 0.015) and unchanged numbers of the shortest telomeres (