Effects of Six-Month Aerobic Exercise Intervention on Sleep in Healthy Older Adults in the Study: A Pilot Study.

BACKGROUND

Sleep disturbances have been shown to be associated with the presence of the apolipoprotein () 4 allele, the well-known genetic risk factor for late-onset sporadic Alzheimer's disease (AD).

OBJECTIVE

This study quantifies the effects of a six-month aerobic exercise intervention on objective and subjective sleep quality in middle-aged to older individuals including those at increased genetic risk for late-onset sporadic Alzheimer's disease (AD), who carry the apolipoprotein () 4 risk allele.

METHODS

199 sedentary men and women without significant cognitive impairments were enrolled in the study, a quasi-experimental single group pre-test/post-test study with no control group. Participants completed a six-month aerobic exercise intervention and consented to genetic testing. Genotyping of confirmed that 54 individuals were carriers of the 4 allele. Participants' subjective quality of sleep was assessed with the Pittsburgh Sleep Quality Index (PSQI) pre- and post-intervention. A convenience sample of participants ( = 29, 4+ = 7) consented to undergo two nights of in-home polysomnography (PSG) pre- and post intervention. Sleep architecture and respiratory variables were assessed.

RESULTS

The six-month aerobic exercise intervention significantly improved participants' total PSQI score, sleep efficiency, and sleep latency in the full sample ( = 199). PSG results showed that total sleep time and sleep onset latency significantly improved over the course of the exercise intervention only in individuals who carried the 4 allele. These results are, however, exploratory and need to be carefully interpreted due to the rather small number of 4+ in the PSG subgroup.

CONCLUSIONS

The six-month aerobic exercise intervention significantly improved participants' sleep quality with beneficial effects on PSG shown in individuals at increased genetic risk for late-onset sporadic AD.