Discussion
insomnia, sleep loss
REMISSION
The current study examined whether a randomized clinical trial to treat insomnia among older adults could result in modification of a hallmark of biological aging, namely cellular senescence. Older adults assigned to a cognitive behavioral therapy for insomnia had no increases over 2 years in the expression of the gene for p16One in four older adults suffer from moderate to severe clinical insomnia [Another feature of this study that may have strengthened the results is the characteristics of the cohort. As aged systems are thought to be less resilient to challenges such as sleep loss, our intervention may have a stronger effect in an older adult sample than if the intervention was delivered to younger adults with insomnia. Additional research will be necessary to test vulnerability and resilience to the efficacy of the intervention to slow biological aging across the lifespan.Of note, our marker of cellular senescence captures aging within the circulating immune system, which has implications for immunity [Despite many strengths of the current study design including a randomized clinical trial, detailed assessments of insomnia status and covariates, and a longitudinal follow up of 2 years, a few limitations of the current study should be noted. First, our sample was comprised of moderately mobile and healthy older adults and may not generalize to those with multimorbidity, frailty, or chronic inflammatory conditions. Second, as our sample was comprised of older adults, the results need to be replicated in other age groups. Last, the sample was representative of the nearby community of patients at our institution, predominantly Caucasian and of upper middle income, and results of the trial may differ when applying it to other socioeconomic or ethnic/racial groups with divergent risk. Further research is needed to understand the role of insomnia remission at slowing biological aging in populations of different racial and ethnic make-up, ages, regions of the US and other countries, and economic backgrounds.