Cognitive performance in patients with implantable cardioverter defibrillators: Associations with objective sleep duration, age and anxiety

Preliminary investigation of interactive associations of sleep and pain with cognition in sedentary middle-aged and older adults

STUDY OBJECTIVES

The objective of this study was to examine independent and interactive associations between self-reported sleep (sleep efficiency and total sleep time [TST]) and pain with cognition in sedentary middle-aged and older adults.

METHODS

Seventy-five sedentary adults at least 50 years of age (Mage = 63.24, standard deviation = 8.87) completed 14 daily diaries measuring sleep and pain. Weekly average sleep efficiency, TST, and pain were computed. Participants also completed computerized cognitive tasks: Letter Series (reasoning), N-back (working memory), Symbol Digit Modalities Test (processing speed, attention), and Number Copy (processing speed). Multiple regression analyses were conducted to determine independent and interactive (with pain) associations of sleep efficiency and TST with cognition, controlling for age, education, and sex.

RESULTS

Sleep efficiency and pain interacted in their associations with Letter Series performance and N-back difference scores (2-back minus 1-back). Specifically, higher sleep efficiency was associated with better reasoning and working memory in those with highest pain but not average or lowest pain. TST and pain also interacted in their associations with Letter Series performance. Specifically, longer TST associated with worse reasoning in those with lowest (not average or highest) pain.

CONCLUSIONS

Preliminary results show that in sedentary middle-aged and older adults, pain and sleep interact in their associations with executive function tasks. Higher sleep efficiency may be associated with better reasoning and working memory in those with highest pain. Lower TST may be associated with better reasoning in those with lowest pain. Studies evaluating temporal associations between sleep, pain, and cognition are needed.

Associations between pain, objective sleep efficiency and cognition in patients with implantable cardioverter defibrillators

INTRODUCTION

Patients with implantable cardioverter defibrillators (ICDs) frequently experience sleep disruption. Prior work shows associations between objective (actigraphic) sleep and cognition in these patients, but whether pain affects associations between measures of sleep fragmentation (eg, sleep efficiency, SE) and cognition is unknown. The present study examined independent and interactive associations between objective SE and pain on cognitive performance in patients with ICDs.

METHODS

A total of 37 patients with ICDs (M_age = 60.0, SD = 12.4) and self-reported sleep disturbance completed 14 days of actigraphy. Average SE was computed [(average total sleep time/average time in bed) × 100%]. Patients completed the Short Form 36 Health Survey pain section, and computerized tasks measuring executive functioning (letter series, N-Back task), sustained attention/processing speed (symbol digit modalities test, SDMT), and simple reaction time. Multiple linear regressions examined whether SE independently predicted or interacted with pain ratings to predict cognitive performance.

RESULTS

SE interacted with pain to predict SDMT performance, accounting for 12% unique variance. In patients reporting worse pain, higher SE was associated with better SDMT performance. Similar patterns of association on SDMT were not observed in patients with average or low pain. SE and pain ratings did not independently predict SDMT performance. Performance on other cognitive tasks was not associated with any predictors.

CONCLUSION

Better sleep efficiency may play an important role in improving sustained attention/processing speed in patients with ICDs and perceived severe pain. Future research should examine whether interventions aimed at improving sleep fragmentation provide benefit to lower order cognition, particularly in patients with worse pain.