The Impact of Disrupted Sleep Schedules on Frontal Lobar Executive Functioning, Cognitive Flexibility, Inhibitory Control and Autonomic Reactivity among Nursing Students: A Cross-sectional Study

Introduction: Disrupted sleep schedules particularly in night shift workers like nurses are known to impair attention and psychomotor performance, however its impact on frontal lobe executive function, inhibitory control and autonomic reactivity to a cognitive load remain highly unexplored. Aim: To evaluate the influence of 12 hours of sleep deprivation due to night shift work on sleep quality, cognitive flexibility, inhibitory control, and autonomic reactivity and frontal lobe functions among nurses, and compare their findings with the day shift working nurses of a tertiary hospital. Materials and Methods: A cross-sectional study was conducted from August 2021- April 2022 on 72 nursing students out of which 36 were working night shifts at a KLE’S Prabhakar Kore tertiary care hospital and MRC, Belgaum, Karnataka, India and 36 serving as daytime controls. The Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality. Iowa Trail Making Test (ITMT), Frontal Assessment Battery (FAB) and computerised Go-NO Go test were administered to measure visual scanning, attention, cognitive flexibility, executive functions, and inhibitory control. For autonomic reactivity heart rate and blood pressures (SBP and DBP) were measured at baseline as well as during Go/No-Go task (Cognitive stressor). Group comparisons were performed using Student’s t-test and One-way Analysis of Variance (ANOVA). Results: The groups were comparable in age (21.1±1.97 years vs 21.2±2.01 years; p-value=0.64) and gender distribution. Baseline heart rate and blood pressure values did not differ significantly between the groups (p-value>0.05). Shift workers had poor sleep quality with higher scores (19±2.1) on the PSQI, compared to controls. ITMT completion times were significantly prolonged for shift workers on both part A (27±8.9 vs 19±4.2, p-value=0.001) and part B (176±7.54 vs 101±5.55, p-value =0.04). The FAB scores was significantly lower in shift workers (12.21±0.4) compared to controls (18.±0.9, 180.24, p-value =0.004). Conclusion: Night shift nurses experience poor sleep quality, impairments in frontal executive functions, disinhibition, and heightened sympathetic reactivity increasing cognitive errors in safety-critical clinical settings. Evidence based duty roster and sleep schedules are therefore essential from an occupational health point of view.