Psychomotor Performance in Patients with Obstructive Sleep Apnea Syndrome

Abstract

Purpose

Determinants of obstructive sleep apnea (OSA) are hypoxemia and hypercapnia, as well as (micro) arousals from sleep, resulting in chronic sleep fragmentation, sleep deprivation, and excessive daytime sleepiness (EDS). All of the above-mentioned factors might contribute to psychomotor impairment seen in OSA patients. Additionally, this study aimed to assess the contribution of BMI, age, EDS assessed with Epworth sleepiness scale (ESS), and severity of OSA assessed with apnea-hypopnea index (AHI) to the reaction time on chronometric tests in OSA patients and controls. It is hypothesized that moderate and severe OSA have adverse effects on reaction time of perception to visual stimulus, of solving simple arithmetic operations, and of psychomotor limbs coordination assessed by chronometric psychodiagnostic test battery.

Patients and Methods

This study was conducted on 206 male participants; 103 of them had moderate or severe OSA diagnosed by whole-night polysomnography/polygraphy. Control participants (N=103), matched to patients with OSA by age and BMI, had no reported OSA in their medical history, no increased risk for OSA, nor EDS. All participants were assessed with three chronometric psychodiagnostic tests, measuring the reaction time of perception to visual stimulus, of solving simple arithmetic operations, and of psychomotor limbs coordination.

Results

Participants from the OSA group achieved impaired results compared to control participants in minimum single task solving time in speed of solving simple arithmetic operations (3±0.9 and 2.6±0.6, P<0.001), and in minimum solving time of a single task in complex psychomotor limbs coordination (0.69±0.2 and 0.61±0.1, P=0.007). Regression analysis revealed no significant contribution of daytime sleepiness to the results achieved in each of the tests.

Conclusion

It is concluded that severe OSA impaired speed of perception, convergent, and operative thinking. Moreover, it is suggested that EDS did not contribute to poor psychomotor outcome in patients with OSA in this study, when age was controlled for.

Keywords:

• obstructive sleep apnea syndrome
• overnight polysomnography
• psychomotor performance
• psychodiagnostic test
• daytime sleepiness

Abbreviations

OSA, obstructive sleep apnea; EDS, excessive daytime sleepiness; CRD, Complex Reactionmeter Drenovac; CPAP, continuous positive airway pressure; MAD, mandibular advancement device; BMI, body mass index; PSG, polysomnography; PG, polygraphy; AHI, apnea-hypopnea index; ESS, Epworth sleepiness scale; CRD 311, speed of perception to visual stimulus; CRD 411, speed of complex psychomotor limbs coordination; CRD 11, speed of solving simple arithmetic operations; MinT, minimum (best) single task solving time; MedT, median time for task solving; TTST, total test solving time; TB, total ballast; SB, start ballast; EB, end ballast; ODI, oxygen index desaturation.

Ethics Approval

Ethical standards of the institutional research committee and the 1964 Helsinki declaration with its later amendments were applied to the protocol of the study. Ethics approval was obtained from the Ethics Committee for Biomedical Research at the University of Split School of Medicine.

Informed Consent

Following Ethics Committee for Biomedical Research and institutional approvals at the University of Split School of Medicine, all participants were informed about the procedures and the aims of the study, and signed the informed consent forms.

Acknowledgments

The authors are thankful for the technical assistance of Jelena Baricevic. The authors acknowledge Assistant Professor Shelly Pranic, PhD, for her assistance with proofreading the manuscript. An abstract of this paper was presented at the ESRS meeting in Basel 2018 as a conference talk with interim findings. The abstract is cited as: Pavlinac Dodig, I., Pecotic, R., Valic, M., Lusic, L. and Dogas, Z. Moderate and severe OSA in males impair psychomotor reaction times assessed by CRD-series testing. 24th Congress of the European Sleep Research Society, Basel, Switzerland, 25–28 September 2018. DOI: 10.1111/jsr.12751.

Author Contributions

All authors made substantial contributions to conception and design, acquisition of data, or analysis and interpretation of data; took part in drafting the article or revising it critically for important intellectual content; gave final approval of the version to be published; and agree to be accountable for all aspects of the work.

Disclosure

The authors declare they have no conflict of interest. No competing interests were reported by the authors for any financial interests or commercial associations held by the authors or their family members.

Additional information

Funding

Croatian Science Foundation (HRZZ) supported this research via grant TIHO2_SLEEP_BREATH 5935, which was obtained by Professor Zoran Dogas.