The long and the short of it: Salivary telomere length as a candidate biomarker for hypertension and age-related changes in blood pressure

Hypertension becomes more prevalent with increasing age. Telomere length (TL) has been proposed as a candidate biomarker and can be accessibly extracted from saliva. However, clarity is needed to evaluate the suitability of using TL as a predictor in such instances. This study investigated salivary TL in a cohort of older adults from the 2008 Health and Retirement Study (n = 3329; F: 58%, mean age: 69.4, SD: 10.3 years) to examine any associations with blood pressure (BP). A Bayesian robust regression model was fit using weakly informative priors to predict the effects of TL with age, sex, systolic BP (SBP), diastolic BP (DBP), and treatment status. There were small effects of treatment (β: −0.07, 95% CrI [−0.33, 0.19], pd: 71.91%) and sex (β: −0.10, 95% CrI [−0.27, 0.07], pd: >86.78%). Population effects showed a reduction of 0.01 log2 units in TL with each year of advancing age (95% CrI [−0.01, −0.00]). Conditional posterior predictions suggest that females, and treated individuals, experience greater change in TL with increasing age. Bayes R2 was ~2%. TL declines with increasing age, differs between sexes, and appears to be influenced by antihypertensive drugs. Overall, all effects were weak. The data do not currently support the suitability of salivary TL as a biomarker to predict or understand any age-related changes in BP.