Interaction between obstructive sleep apnea and shortened telomere length on brain white matter abnormality

Study Objectives: Age-related brain white matter changes (WMC) have been associated separately with obstructive sleep apnea (OSA) and short telomere length (TL). No studies have examined their interaction effect on WMC. Methods: This is a cross-sectional study with a community-based sample of 420 participants (mean age, 61.3 ± 7.2) from the Korean Genome and Epidemiology Study during 2011-2012. An overnight fasted blood sample was taken to determine glucose and blood lipid levels at the sleep laboratory of Korea University Ansan Hospital. The status of brain WMC was determined using structural magnetic resonance imaging at 1.5 Tesla. Overnight polysomnography was performed, and leukocyte TL was measured. OSA was determined based on apnea-hypopnea index, and short TL was defined as the lowest quartile of the study participants. Results: Adjusting for age, sex, BMI, smoking, drinking, snoring, and hypertension, odds ratio (OR) of brain WMC was estimated using multivariate logistic regression. The odds ratio was significant for cardiovascular disease (OR, 4.5; 95% CI, 1.2-16.3) and OSA (OR, 4.0; 95% CI, 1.0-15.2) among those with short TL; and for diabetes (OR, 3.0; 95% CI, 1.3-13.0) and age (OR, 1.1; 95% CI, 1.0-1.1) among those with longer TL. Interaction effect of OSA and short TL (OR, 4.3; 95% CI, 1.4-13.8) was significant, compared to those with neither OSA nor short TL. Conclusions: This study provides a first evidence of mediated interaction of short TL with OSA on brain WMC in a community-based sample. The results generate new hypotheses regarding mechanisms of impaired brain health in sleep apnea.