Obstructive sleep apnea (OSA) in young patients results in pathophysiologic changes associated with aging, according to study results recently published in Annals of the American Thoracic Society.
Previous studies have shown that OSA may induce cellular and molecular changes that are associated with the aging process. In addition, these changes may be more significant in younger patients compared with older patients. However, these mechanisms have not been well characterized. The goal of this study was to evaluate specific indicators of aging and their association with OSA and to see whether these changes are consistent in patients across different age ranges.
Researchers recruited 599 patients with suspected sleep apnea who were referred to sleep units in 4 hospitals for this multicenter, observational and prospective study. All patients underwent a polysomnographic sleep study. To establish the relationship between the hallmarks of aging and OSA, the dose-response relationships of various OSA parameters were studied. OSA parameters included the apnea-hypopnea index (AHI; defined as the number of apneic and hypopneic events per hour of sleep), arousal index, and time with oxygen saturation less than 90%. To investigate the association of OSA and aging across different age ranges, patients were divided into 4 groups according to AHI and age (median, 50 years).
To investigate the effects of OSA on the aging process, 5 markers of aging that were previously identified were studied: alteration of cellular communication as measured by C-reactive protein (CRP), deregulation of nutrient sensing as measured by insulin resistance, telomere attrition as measured by telomeric length, mitochondrial dysfunction as measured by leukocytic mitochondrial DNA content, and genomic instability as measured by urinary concentration of 8-hydroxy-2’-deosxguanosine (8-OHdG).
Of the 599 recruited patients, 150 were categorized as “non-OSA” and 449 as OSA. Patients were primarily men, middle-aged, and overweight/obese. The linear relationship between OSA severity and hallmarks of aging was studied. The nonlinearity of the relationships was evaluated using generalized additive model (GAM) models. There was an association between all parameters of OSA and cellular communication, deregulation of nutrient sensing, and mitochondrial dysfunction. There was an association between AHI and arousal index and genomic instability when adjusted for confounding factors. There was no association between OSA and telomere attrition.
The association between OSA and hallmarks of aging was also evaluated by age group. In patients younger than 50, after adjusting for confounding factors there was an association between OSA and alteration of intercellular communication, deregulation of nutrient sensing, and genomic instability. There was no significant association between OSA and hallmarks of aging in older patients.
The authors acknowledged several limitations of the study, including the fact that not all age ranges were equally represented, onset of OSA was not available, the number of patients in each group was not homogenous, the patients studied were referred for OSA and as such may not be generalized to the global population, and not all markers of aging were studied.
In conclusion, the researchers wrote that their findings suggest a need for early diagnosis and intervention to prevent accelerated aging and its consequences. These findings are consistent with previous studies linking OSA to aging. However, additional studies are needed to clearly distinguish correlative and causal observations in the potential association between OSA and aging.
Pinilla L, Santamaria-Martos F, Benítez ID, et al; on behalf of the Spanish Sleep Network. Association of obstructive sleep apnea with the aging process. Ann Am Thorac Soc. Published online March 4, 2021 doi:10.1513/AnnalsATS.202007-7710C