TNFα G308A polymorphism is associated with resilience to sleep deprivation-induced psychomotor vigilance performance impairment in healthy young adults

Abstract

Cytokines such as TNFα play an integral role in sleep/wake regulation and have recently been hypothesized to be involved in cognitive impairment due to sleep deprivation. We examined the effect of a guanine to adenine substitution at position 308 in the TNFα gene (TNFα G308A) on psychomotor vigilance performance impairment during total sleep deprivation. A total of 88 healthy women and men (ages 22-40) participated in one of five laboratory total sleep deprivation experiments. Performance on a psychomotor vigilance test (PVT) was measured every 2-3h. The TNFα 308A allele, which is less common than the 308G allele, was associated with greater resilience to psychomotor vigilance performance impairment during total sleep deprivation (regardless of time of day), and also provided a small performance benefit at baseline. The effect of genotype on resilience persisted when controlling for between-subjects differences in age, gender, race/ethnicity, and baseline sleep duration. The TNFα G308A polymorphism predicted less than 10% of the overall between-subjects variance in performance impairment during sleep deprivation. Nonetheless, the differential effect of the polymorphism at the peak of performance impairment was more than 50% of median performance impairment at that time, which is sizeable compared to the effects of other genotypes reported in the literature. Our findings provided evidence for a role of TNFα in the effects of sleep deprivation on psychomotor vigilance performance. Furthermore, the TNFα G308A polymorphism may have predictive potential in a biomarker panel for the assessment of resilience to psychomotor vigilance performance impairment due to sleep deprivation.

Keywords: Biomarker; Cognitive impairment; Genotype; Inter-individual differences; Phenotype; Psychomotor vigilance test (PVT); Sleep deprivation; Trait vulnerability; Tumor necrosis factor (TNF).

Fig. 1

Schematic of the days of each laboratory study relevant to the analyses of individual subjects’ vulnerability to sleep loss. Test bouts on the PVT are indicated by asterisks. Test bouts in the 24-h period used to quantify vulnerability to sleep loss are enclosed in gray boxes. Black indicates sleep periods; light gray indicates scheduled wakefulness. Note that in studies 4 and 5, the sleep deprivation period continued beyond the days shown here.

Fig. 2

Average number of PVT lapses as a function of genotype. The panels on the left show performance across 24 h of TSD (top) and at baseline (bottom). The panels on the right show performance during the first 12-h period of TSD (22:00–10:00; top) and the second 12-h period of TSD (10:00–22:00; bottom), where times of day during the second 12-h period correspond to those of the baseline period. Error bars denote standard error.

Fig. 3

Average number of PVT lapses across consecutive 6-h intervals of sustained wakefulness for subjects with the G/G genotype versus subjects with the A/G or A/A genotypes. Error bars denote standard error. Intervals that are part of the 24-h period used to quantify vulnerability to sleep loss are enclosed in the gray box (cf. Fig. 1). For reference, the average number of PVT lapses across consecutive 6-h intervals is also shown for the most vulnerable, intermediate, and most resilient tertiles of our sample irrespective of genotype.