Approximate prediction of life expectancy in the older people using a revised equation for estimating somatic telomere length from clinical blood data

Abstract

We previously proposed an equation for estimating somatic telomere length (TL) from peripheral blood test values. Here, we reexamined data from a larger number of individuals and found that the hemoglobin levels in men and serum albumin levels in women were well correlated with the measured TL values. We developed a new simplified estimated TL (eTL) equation that incorporates these test values. We analyzed the relationship between eTL derived from this revised equation based on the test values from a single day and life expectancy until death among residents of elderly care facilities, thereby exploring the correlation between eTL and life expectancy. The results revealed that the eTL values exhibited a significant negative correlation with the number of days until death due to senility. This data suggests that the eTL values can also be used as a tool for assessing the progression of senility in the very elderly. Furthermore, this correlation was no longer significant in populations in which the eTL values exceeded the TL values predicted by age-based regression. Therefore, this discrepancy between eTL and life expectancy may be more pronounced in old individuals who do not live in nursing homes. Furthermore, among elderly residents of nursing homes, serum albumin levels and serum cholesterol levels in men with shorter eTLs were positively correlated with eTLs in both men and women. The relationship between TL maintenance and nutritional status in the elderly is a topic that should be investigated further.

Keywords: Aging, life expectancy, telomere, clinical laboratory data, elderly, geriatric health services facility