Clinical Associations with Telomere Length in Chronic Spinal Cord Injury

STUDY DESIGN: Cross-sectional study OBJECTIVES: To determine clinical factors associated with telomere length in persons with chronic spinal cord injury (SCI). SETTING: Veterans Affairs Medical Center, Boston, MA. METHODS: 278 participants with chronic SCI provided blood samples for measurement of C-reactive protein (CRP), interleukin-6 (IL-6), and telomere length, completed respiratory health questionnaires, underwent dual x-ray absorptiometry (DXA) to assess body fat, and completed spirometry. High-throughput real-time PCR assays were used to assess telomere length in leukocyte genomic DNA. Linear regression models were used to assess cross-sectional associations with telomere length. RESULTS: Telomere length was inversely related to age (p<0.0001). In age-adjusted models, gender, race, injury duration, %-total and %-trunk fat, body mass index (BMI), %-predicted forced vital capacity (FVC) and forced expiratory volume in one second (FEV(1)), chronic cough or phlegm, CRP, IL-6, wheeze, smoking, diabetes, heart disease, chronic obstructive pulmonary disease (COPD), skin ulcer, urinary tract infection (UTI), or chest illness history were not significantly associated with telomere length. There was a suggestive age-adjusted association between persons with the most severe SCI (cervical motor complete and AIS C) and shorter telomere length (p=0.055), an effect equivalent to approximately 8.4 years of premature aging. There were similar age-adjusted associations with telomere length between persons using a wheelchair (p=0.059) and persons with chronic urinary catheter use (p=0.082) compared to persons without these characteristics. CONCLUSIONS: Our results suggest that clinical characteristics such as decreased mobility and bladder dysfunction that are common in individuals with more severe SCI are associated with shorter telomere length.