Insomnia disorder with objective short sleep duration (ISS) phenotype and cognitive performance: a systematic review and meta-analysis

The benefit of inhibitory control training for insomnia with short sleep duration phenotype: a pilot randomized trial

BACKGROUND

Two phenotypes of insomnia disorder (ID) have been identified based on objective total sleep duration (TST): one with short sleep duration (ISSD) and another with normal sleep duration (INSD). Recent proposals suggested that insomnia with objective short-sleep duration (TST < 7 h) is associated with impaired inhibitory function, leading to a dysregulation of cortical inhibition, which may underlie its prevalence. This study investigated the status of impaired response inhibition in these two phenotypes and examined the potential different effect of response inhibition training on these two phenotypes.

METHODS

Twenty-two healthy controls (HC) and eighty-one patients with ID were recruited, with IDs further categorized into ISSD and INSD (with TST ≥ 7 h). Clinical behavior measures, including the Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), Pre-sleep Arousal Scale (PSAS), objective sleep characteristics assessed by all-night sleep electroencephalography, and the accuracy of NoGo trials in the Go/NoGo task were compared among the three groups. Subsequently, within each ID phenotype, participants were divided into training and blank control sub-groups. The two training sub-groups completed Adaptive Go/NoGo training task (Through adaptive difficulty adjustment, the task trains participants' inhibitory control) 15 times over 3 weeks, and all IDs were assessed using sleep-related subjective and objective measures and Go/NoGo task before and after the intervention.

RESULTS

ISSD patients exhibited significantly longer sleep latency (p = 0.003) compared to HC, while wakefulness duration (p = 0.004) and light sleep duration (p < 0.001) were shorter than INSD. No significant differences in objective sleep characteristics were observed between INSD and HC. Following adaptive training, the ISSD training sub-group showed decreased scores in PSQI (p = 0.039) and ISI (p = 0.053) compared to their blank control sub-group. In the INSD groups, both training and blank control sub-groups demonstrated reductions in PSQI (p < 0.001), ISI (p < 0.001), and the cognitive arousal sub-dimension of the PSAS scores (p = 0.003) in the post-session test.

CONCLUSIONS

Impaired response inhibition is a characteristic of ISSD, potentially indicating dysfunctional cortical inhibition, whereas INSD pathogenesis may be related to cognitive-emotional arousal. Response inhibition training effectively alleviates sleep problems in ISSD. These findings provide new insights for developing precise intervention strategies in ID.

TRIAL REGISTRATION

The study was prospectively registered on May 30, 2024, in Chinese Clinical Trials registry (ChiCTR2400085063).

Comparing sleep measures in cancer survivors: self-reported sleep diary versus objective wearable sleep tracker

PURPOSE

Cancer survivors are increasingly using wearable fitness trackers, but it is unclear if they match traditional self-reported sleep diaries. We aimed to compare sleep data from Fitbit and the Consensus Sleep Diary (CSD) in this group.

METHODS

We analyzed data from two randomized clinical trials, using both CSD and Fitbit to collect sleep outcomes: total sleep time (TST), wake time after sleep onset (WASO), number of awakenings (NWAK), time in bed (TIB), and sleep efficiency (SE). Insomnia severity was measured by Insomnia Severity Index (ISI). We used the Wilcoxon signed rank test, Spearman's rank correlation coefficients, and the Mann-Whitney test to compare sleep outcomes and assess their ability to distinguish insomnia severity levels between CSD and Fitbit data.

RESULTS

Among 62 participants, compared to CSD, Fitbit recorded longer TST by an average of 14.6 (SD = 84.9) minutes, longer WASO by an average of 28.7 (SD = 40.5) minutes, more NWAK by an average of 16.7 (SD = 6.6) times per night, and higher SE by an average of 7.1% (SD = 14.4); but shorter TIB by an average of 24.4 (SD = 71.5) minutes. All the differences were statistically significant (all p < 0.05), except for TST (p = 0.38). Moderate correlations were found for TST (r = 0.41, p = 0.001) and TIB (r = 0.44, p < 0.001). Compared to no/mild insomnia group, participants with clinical insomnia reported more NWAK (p = 0.009) and lower SE (p = 0.029) as measured by CSD, but there were no differences measured by Fitbit.

CONCLUSIONS

TST was the only similar outcome between Fitbit and CSD. Our study highlights the advantages, disadvantages, and clinical utilization of sleep trackers in oncology.

A meta-analysis of the association between insomnia with objective short sleep duration and risk of hypertension

The aim of this meta-analysis was to examine the association between insomnia with objective short sleep duration (ISSD) with prevalent and incident hypertension in cross-sectional and longitudinal studies, respectively. Data were collected from 6 cross-sectional studies with 5914 participants and 2 longitudinal studies with 1963 participants. Odds ratios (ORs) for prevalent and risk ratios (RRs) for incident hypertension were calculated through meta-analyses of adjusted data from individual studies. Compared to normal sleepers with objective normal sleep duration (NNSD), ISSD was significantly associated with higher pooled OR for prevalent hypertension (pooled OR = 2.67, 95%CI = 1.45-4.90) and pooled RR for incident hypertension (pooled RR = 1.95, 95%CI = 1.19-3.20), respectively. Compared to insomnia with objective normal sleep duration, ISSD was associated with significantly higher pooled OR of prevalent hypertension (pooled OR = 1.94, 95%CI = 1.29-2.92) and pooled RR for incident hypertension (pooled RR = 2.07, 95%CI = 1.47-2.90), respectively. Furthermore, normal sleepers with objective short sleep duration were not associated with either prevalent (pooled OR = 1.21, 95%CI = 0.84-1.75) or incident (pooled RR = 0.97, 95%CI = 0.81-1.17) hypertension compared to NNSD. Our findings suggest that ISSD is a more severe phenotype of the disorder associated with a higher risk of hypertension. Objective short sleep duration might be a valid and clinically useful index of insomnia's impact on cardiovascular health.

Polysomnographic parameters associated with cognitive function in patients with major depression and insomnia

OBJECTIVE

To examine whether objective sleep parameters are associated with cognitive function (CF) in patients with major depressive disorder (MDD) with chronic insomnia (CI) and whether the severity of these disorders is related to CF.

METHOD

Thirty patients with MDD with CI attending a tertiary care institution underwent two consecutive nights of polysomnographic (PSG) recording and a battery of neuropsychological tests, which included episodic memory, sustained attention, working memory, and executive function. The severity of MDD and CI was assessed by clinical scales. We examined the relationship between PSG parameters and CF, as well as whether the severity of the disorders is related to CF.

RESULTS

Linear regression analysis revealed that total sleep time (TST) was positively associated with higher learning and recall of episodic memory, as well as better attention. Slow-wave sleep (SWS) showed a positive association with better working memory. Furthermore, wake after sleep onset (WASO) was negatively associated with episodic memory and lower attention. No significant relationships were found between the severity of MDD or CI with CF.

CONCLUSION

Both sleep duration and depth are positively associated with several aspects of CF in patients with MDD with CI. Conversely, a lack of sleep maintenance is negatively related to CF in these patients. These findings could help identify modifiable therapeutic targets to reduce CF impairment.

Response inhibition impairment related to altered frontal-striatal functional connectivity in insomnia disorder: A pilot and non-clinical study

BACKGROUND

It is not clear whether and how insomnia disorder (ID) impairs response inhibition ability. Fronto-striatal functional connectivity (FC) plays a critical role in response inhibition and is found be abnormal in patients with ID. In this study, we examined whether insomnia symptoms impair response inhibition in a large non-clinical sample and whether impaired response inhibition is related to abnormal fronto-striatal FC.

METHODS

One hundred and fifteen young ID patients and 160 age and sex-matched healthy controls (HC) underwent resting-state functional magnetic response imaging scans and performed the stop-signal task (SST). Performance of SST, Gray Matter Volumes (GMVs), and connections of brain regions related to fronto-striatal circuits was compared between groups. Further examined the association between response inhibition impairment and fronto-striatal FC.

RESULTS

The behavioral results showed that patients with ID had significantly longer stop-signal reaction time (SSRT) compared with the HC, reflecting the impaired response inhibition among IDs. Brain imaging results showed IDs had decreased GMVs of the Right Superior Frontal (SFG) and left Supplementary Motor area (SMA). Seed-based FC results showed that compared to HC, the ID showed decreased FC between left SMA and left Paracentral lobule, left SMA and right SMA, and right SFG and right Orbital Middle Frontal gyrus, and increased FC between right SFG and right putamen. Meanwhile, the FC between right SFG and putamen was positively correlated with SSRT in IDs.

CONCLUSIONS

The current study found significantly impaired response inhibition among ID and this impairment may be related to abnormal fronto-striatal FC in ID.

Comparing sleep measures in cancer survivors: Self-reported sleep diary versus objective wearable sleep tracker

Purpose

Cancer survivors are increasingly using wearable fitness trackers, but it's unclear if they match traditional self-reported sleep diaries. We aimed to compare sleep data from Fitbit and the Consensus Sleep Diary (CSD) in this group.

Methods

We analyzed data from two randomized clinical trials, using both CSD and Fitbit to collect sleep outcomes: total sleep time (TST), wake time after sleep onset (WASO), number of awakenings (NWAK), time in bed (TIB) and sleep efficiency (SE). Insomnia severity was measured by Insomnia Severity Index (ISI). We used the Wilcoxon Singed Ranks Test, Spearman's rank correlation coefficients, and the Mann-Whitney Test to compare sleep outcomes and assess their ability to distinguish insomnia severity levels between CSD and Fitbit data.

Results

Among 62 participants, compared to CSD, Fitbit recorded longer TST by an average of 14.6 (SD = 84.9) minutes, longer WASO by an average of 28.7 (SD = 40.5) minutes, more NWAK by an average of 16.7 (SD = 6.6) times per night, and higher SE by an average of 7.1% (SD = 14.4); but shorter TIB by an average of 24.4 (SD = 71.5) minutes. All the differences were statistically significant (all p < 0.05), except for TST (p = 0.38). Moderate correlations were found for TST (r = 0.41, p = 0.001) and TIB (r = 0.44, p < 0.001). Compared to no/mild insomnia group, participants with clinical insomnia reported more NWAK (p = 0.009) and lower SE (p = 0.029) as measured by CSD, but Fitbit outcomes didn't.

Conclusions

TST was the only similar outcome between Fitbit and CSD. Our study highlights the advantages, disadvantages, and clinical utilization of sleep trackers in oncology.