Obstructive sleep apnoea is more prevalent in men with schizophrenia compared to general population controls: results of a matched cohort study

How sleep in patients with serious mental illness is recorded and treated, and its impact on service engagement

BACKGROUND

Sleep and mental health share a bidirectional relationship whereby problems in one exacerbate the other. Accordingly, sleep problems are frequent and severe in serious mental illness (SMI) populations, exacerbating SMI symptoms. This study examined the documentation and treatment of sleep problems within anonymised clinical records of SMI patients, and their association with attendance rates and number of appointments scheduled.

METHODS

Patient records between 01.09.2021 and 31.08.2022 were identified and relevant records (n = 229) extracted from an NHS Trust database. Content analysis was used to assess documentation and treatment of sleep problems and Chi-square tests were used to assess demographic differences. Mann-Whitney U tests were used to compare attendance rates and number of appointments scheduled between patients with/without sleep problems.

RESULTS

Most (n = 170; 84 %) patients with sleep problems had no or minimal assessment of the sleep problem within their records. Patients were primarily offered no (n = 115; 57 %) or non-recommended (n = 69; 34 %) sleep treatment. More outpatients were offered no sleep treatment (n = 89; 64 %) than inpatients (n = 26; 41 %) (p = .002) whilst more inpatients were offered non-recommended sleep treatments (n = 33; 52 %) than outpatients (n = 36; 26 %) (p < .001). No significant associations were found between sleep and attendance or appointments scheduled.

CONCLUSIONS

There is a lack of routine clinical attention to sleep assessment and treatment in SMI groups. Where sleep is addressed, treatment often conflicts with guidelines. Improved sleep assessment and treatment could significantly enhance current SMI patient care.

Sleep apnea in schizophrenia: Estimating prevalence and impact on cognition

Undertreated medical illnesses can compound the disabling cognitive deficits of schizophrenia. Obstructive sleep apnea (OSA) impairs cognitive domains also affected by schizophrenia, is common, and is treatable. The effects of sleep apnea on cognition in schizophrenia, however, are not well understood. We estimated the prevalence of OSA in a previously characterized sample of 3942 Veterans with schizophrenia by self-report and with a predictive model to identify individuals at high risk for OSA. We then compared neuropsychological and functional capacity assessment results between those who reported OSA versus those who did not, and between those predicted to have OSA versus predicted to not have OSA. We expected that many Veterans not reporting sleep apnea would be predicted to have it, and that both reported and predicted sleep apnea would be associated with lower cognitive and functional performance. The reported prevalence of OSA in the sample was 14%, whereas 72% were predicted to be at high risk of OSA. Interestingly, participants who reported having OSA had better cognitive and functional capacity performance (p's < 0.001) compared to those who did not report OSA, particularly on speed of processing assessments (p < 0.001). Predicted OSA, by contrast, was associated with lower speed of processing, verbal learning and working memory test scores (p's < 0.001). One possible interpretation of these results is that people with higher cognitive capacity may be more likely to seek medical care, while those with cognitive impairments are at greater risk for having untreated co-occurring medical conditions that further compromise cognition.

Assessing the causal relationship between psychiatric disorders and obstructive sleep apnea: a bidirectional Mendelian randomization

Background

Extensive observational evidence suggests an association between psychiatric disorders (PDs) and obstructive sleep apnea (OSA), but their causal relationship remains unexplored. The objective of this study was to examine the causal relationship between PDs and OSA.

Methods

Mendelian randomization (MR) analysis was conducted with summary genetic data from the FinnGen and Psychiatric Genomics Consortium (PGC). Inverse-variance weighted (IVW), MR-Egger, weighted median, and weighted mode methods were employed to ascertain causal influence. Sensitivity analysis employing various methodologies assessed the robustness of the findings. Furthermore, multivariable Mendelian randomization (MVMR) was used to clarify if the exposures independently caused OSA.

Results

MR analysis showed that genetically determined major depressive disorder (MDD) increased the risk of OSA (IVW odds ratio [OR]: 1.377, 95% confidence interval [CI]: 1.242-1.526, P = 1.05×10-9). Sensitivity analysis showed no evidence of pleiotropy and heterogeneity. In MVMR, the significant association persisted after adjusting for BMI, smoking, and alcohol consumption. No conclusive evidence indicated the causal impact of other psychological characteristics on OSA. In the reverse MR analyses, there was no causal effect of OSA on PDs.

Conclusion

This study suggests a causal effect of MDD on OSA risk. Further research is needed to confirm these findings and understand how MDD contributes to OSA development, potentially aiding in reducing OSA incidence.

Multivariate patterns of disrupted sleep longitudinally predict affective vulnerability to psychosis in 22q11.2 Deletion Syndrome

22q11.2 deletion syndrome (22q11DS) contributes dramatically to increased genetic risk for psychopathology, and in particular schizophrenia. Sleep disorders, including obstructive sleep apnea (OSA), are also highly prevalent, making 22q11DS a unique model to explore their impact on psychosis vulnerability. Still, the contribution of sleep disturbances to psychosis vulnerability remains unclear. We characterized the sleep phenotype of 69 individuals with 22q11DS and 38 healthy controls with actigraphy and sleep questionnaires. Psychiatric symptoms were measured concomitantly with the baseline sleep assessment and at longitudinal follow-up, 3.58±0.85 years later. We used a novel multivariate partial-least-square-correlation (PLSC) approach to identify sleep patterns combining objective and subjective variables, which correlated with psychiatric symptoms. We dissected longitudinal pathways linking sleep disturbances to psychosis, using multi-layer-network-analysis. 22q11DS was characterized by a non-restorative sleep pattern, combining increased daytime fatigue despite longer sleep duration. Non-restorative sleep combined with OSA symptoms correlated with both emotional and psychotic symptoms. Moreover, a sleep pattern evocative of OSA predicted longitudinal worsening of positive and negative symptoms, by accentuating the effects of emotional dysregulation. These results suggest that sleep disturbances could significantly increase psychosis risk, along an affective pathway. If confirmed, this suggests that systematic screening of sleep quality could mitigate psychosis vulnerability in 22q11DS.

Risk of obstructive sleep apnea in patients with schizophrenia: a nationwide population-based cohort study

PURPOSE

Patients with schizophrenia (SCZ) have a higher prevalence of known risk factors for obstructive sleep apnea (OSA). This study aims to determine if SCZ patients are at increased risk of incident OSA.

METHODS

A total of 5092 newly diagnosed SCZ patients and 5092 non-SCZ controls matched by gender, age, and index year were included between 2000 and 2012 and followed to 2013. Participants newly diagnosed with OSA were defined as incidents. Cox regression analysis was used to calculate the hazard ratio (HR) with 95% confidence intervals (CI) of the OSA incidence rate between the two groups studied.

RESULTS

SCZ patients were at increased risk of OSA compared to non-SCZ controls after adjusting for gender, age, comorbidities, and duration of antipsychotic use (2.12 versus 1.01 per 1000 person-years, HR: 1.97, 95% CI: 1.36-2.85). Also, this study confirmed the existence of some known risk factors for OSA, including male gender (HR 1.65, 95% CI 1.14-2.37), obesity (HR 2.62, 95% CI 1.19-5.80), hypertension (HR 1.61, 95% CI 1.06-2.47), hyperlipidemia (HR 1.55, 95% CI 1.04-2.38), diabetes (HR 1.53, 95% CI 1.01-2.38), and antipsychotic use (duration < 1 year (HR 1.57, 95% CI 1.13-2.37), 1-3 years (HR 1.62, 95% CI 1.06-2.82), and 3-5 years (HR 1.45, 95% CI 1.06-2.44)).

CONCLUSION

This study shows SCZ patients are at increased risk of OSA, and there is still an association with higher risk of OSA after controlling for known risk factors, indicating that it is necessary to develop targeted interventions in SCZ patients to reduce the negative impact of OSA on health.

Screening for obstructive sleep apnoea in an early psychosis cohort: a pilot study

OBJECTIVE

Rates of obstructive sleep apnoea (OSA) appear to be lower in the youth population (< 4%) compared to the general population (6%-17%); rates in people with psychotic illness are estimated at 13.5%-57.1%. We hypothesised that this comorbidity extends to early psychosis (EP) populations, and used previously validated OSA questionnaires to screen for OSA in an EP cohort.

METHOD

Fifty-three patients were screened using the OSA50 and STOP-Bang questionnaires with collection of anthropometric measures. Patients who screened positively were referred for polysomnography.

RESULTS

Fifteen per cent (8/53) screened positively; most frequently endorsed measures included BMI > 25, snoring, hypertension, neck circumference (> 40 cm) and male gender. Only 2/8 patients accepted polysomnography.

CONCLUSIONS

Screening indicates OSA may be more prevalent in EP populations than age-equivalent cohorts, but ongoing research is required.

Cognition in schizophrenia improves with treatment of severe obstructive sleep apnoea: A pilot study

Previous studies have shown that people with schizophrenia have high rates of Obstructive Sleep Apnoea (OSA). Despite this, intervention studies to treat OSA in this population have not been undertaken. The ASSET (Assessing Sleep in Schizophrenia and Evaluating Treatment) pilot study investigated Continuous Positive Airway Pressure (CPAP) treatment of severe OSA in participants recruited from a clozapine clinic in Adelaide. Participants with severe untreated OSA (Apnoea-Hypopnoea Index (AHI) > 30), were provided with CPAP treatment, and assessed at baseline and six months across the following domains: physical health, quality of sleep, sleepiness, cognition, psychiatric symptoms and CPAP adherence. Six of the eight ASSET participants with severe OSA accepted CPAP. At baseline, half of the cohort had hypertension, all were obese with a mean BMI of 45, and they scored on average 1.47 standard deviations below the normal population in cognitive testing. The mean AHI was 76.8 and sleep architecture was markedly impaired with mean rapid eye movement (REM) sleep 4.1% and mean slow wave sleep (SWS) 4.8%. After six months of treatment there were improvements in cognition (BACS Z score improved by an average of 0.59) and weight loss (mean weight loss 7.3 ± 9 kg). Half of the participants no longer had hypertension and sleep architecture improved with mean REM sleep 31.4% of the night and mean SWS 24% of the night. Our data suggests CPAP may offer novel benefits to address cognitive impairment and sleep disturbance in people with schizophrenia.