Understanding Physical Aging in Relation to Biological Aging, Telomere Length: A Systematic Review

Telomere length (TL) serves as a marker for biological aging, influenced by chronological aging but distinct from it. This systematic review aims to synthesize the evidence on the associations between components of physical aging and TL in the elderly population. A comprehensive search was conducted in online databases of PubMed, Web of Science, ProQuest, and ScienceDirect to identify the eligible papers published until 1st August 2024. The authors independently extracted data using the standardized form. The quality of the included studies was evaluated for the risks of biases. A total of 1080 records were initially identified using the predefined search strategy. A total of 40 eligible records were included in this review. When assessing physical aging, the nature and type of measurements across studies vary, including subjective, objective, and a combination of both approaches. Subjective assessments of general health or physical limitations may be linked with TL, while frailty, whether measured subjectively or objectively, shows associations with TL in less than 35 percent of total studies. In contrast, composite measures of physical performance/ability are consistently associated with TL in the elderly population. In conclusion, we demonstrated that the associations between physical aging and TL varies depending on the type and nature of physical aging assessments. Composite measures of physical performance/ability demonstrate a strong and consistent parameter of physical aging to link with TL. Future research should prioritize standardized, multidimensional approaches to measure physical aging to understand better its association with TL to support healthy aging strategies.