Comparison of telomere length of vocal folds with different tissues: a physiological measurement of vocal senescence.

The objective of this article is to determine telomere length, a measure of biological age, in true vocal fold (TVF), false vocal fold (FVF), and five other tissue types, to ascertain whether there is tissue-specific telomere shortening. The study design is that of a prospective, basic science study. Tissue samples were obtained from the TVF, FVF, skin from the back of hand, skin from thigh, aorta, blood, and bone marrow from 12 patients ages 54 to 76 years. Genomic DNA was isolated from each sample, and telomere lengths were calculated with real-time polymerase chain reaction. In our small age group, age was not significantly associated with telomere length across tissue types, nor were there any linear correlations within tissue types and age. Controlling for age, significant differences were found between the following tissues: aorta and blood (P < 0.000), aorta and bone marrow (P = 0.033), aorta and FVF (P = 0.015), aorta and hand skin (P = 0.004), blood and thigh skin (P = 0.012), and blood and TVF (P = 0.048). A significant linear correlation between telomere length and tissue type without considering donor age was established between bone marrow and hand skin (P < 0.05, R2 = 0.766), thigh skin and hand skin (P < 0.01, R2 = 0.926), TVF and blood (P < 0.01, R2 = 0.836), and thigh skin and TVF (P < 0.05, R2 = 0.624). Our findings indicate that surrogate tissue for measurement of telomere length of TVF includes FVF, bone marrow, skin, and aorta. These findings have implications for understanding vocal fold aging at the cellular level.