Is Telomeric Length in Cell Subtypes Related to Frailty Syndrome in Community-dwelling Older Adults?

Abstract

Abstract Leukocyte telomere length in the older adults has been associated with cell aging and the relationship with frailty syndrome is unclear. Factors that interfere with telomere shortening could be similar to those linked to frailty. The aims of this study were to compare the relative telomeric length (RTL) in DNA extracted from whole blood leukocytes, mononuclear cells and granulocytes of the community-dwelling older adults classified as frail, non-frail, and pre-frail, and to evaluate if there is a relationship between telomeric length in subpopulations of cells classified in frailty subgroups in community-dwelling older adults. This is an observational, cross-sectional, multicentric study conducted with older Brazilian adults. Sample characterization was performed using a sociodemographic clinical questionnaire. Telomere length was evaluated by quantitative polymerase chain reaction and frailty was classified by phenotypic criteria proposed by Fried et al. 2001. A total of 111 older adults (age 70.4 ± 5.4 years) were enrolled in this study. The mononuclear cell RTLs were shorter than granulocytes RTL and whole blood leukocyte RTL. No significant differences were found between whole blood leukocyte RTL and granulocyte RTL. Also, no significant association was found between frailty classification groups and any cell population. Although telomere shortening was not directly attributed to frailty syndrome, the shorter mononuclear cell RTL may be linked to the immunosenescent status which is one of the components of frailty syndrome. The lack of relationship between mononuclear cell RTL and frailty syndrome could be explained by the physical phenotypic feature of the classification in frailty subgroups. This study may contribute to clarifying the telomere length of cell subtypes and its association with immunosenescence and frailty syndrome, enabling the advancement of knowledge about aging process.