Multiple, objectively measured sleep dimensions including hypoxic burden and chronic kidney disease: findings from the Multi-Ethnic Study of Atherosclerosis.

BACKGROUND: Poor sleep may contribute to chronic kidney disease (CKD) through several pathways, including hypoxia-induced systemic and intraglomerular pressure, inflammation, oxidative stress and endothelial dysfunction. However, few studies have investigated the association between multiple objectively measured sleep dimensions and CKD. METHODS: We investigated the cross-sectional association between sleep dimensions and CKD among 1895 Multi-Ethnic Study of Atherosclerosis Sleep Ancillary Study participants who completed in-home polysomnography, wrist actigraphy and a sleep questionnaire. Using Poisson regression models with robust variance, we estimated separate prevalence ratios (PR) and 95% CIs for moderate-to-severe CKD (glomerular filtration rate <60 mL/min/1.73 m2 or albuminuria >30 mg/g) among participants according to multiple sleep dimensions, including very short (≤5 hours) sleep, Apnoea-Hypopnoea Index and sleep apnoea-specific hypoxic burden (SASHB) (total area under the respiratory event-related desaturation curve divided by total sleep duration, %min/hour)). Regression models were adjusted for sociodemographic characteristics, health behaviours and clinical characteristics. RESULTS: Of the 1895 participants, mean age was 68.2±9.1 years, 54% were women, 37% were white, 28% black, 24% Hispanic/Latino and 11% Asian. Several sleep metrics were associated with higher adjusted PR of moderate-to-severe CKD: very short versus recommended sleep duration (PR=1.40, 95% CI 1.06 to 1.83); SASHB (Box-Cox transformed SASHB: PR=1.06, 95% CI 1.02 to 1.12); and for participants in the highest quintile of SASHB plus sleep apnoea: PR=1.28, 95% CI 1.01 to 1.63. CONCLUSIONS: Sleep apnoea associated hypoxia and very short sleep, likely representing independent biological mechanisms, were associated with a higher moderate-to-severe CKD prevalence, which highlights the potential role for novel interventions.

Prevalence of Sleep Disordered Breathing in Children With Myelomeningocele.

BACKGROUND: Retrospective studies have shown high rates of sleep disordered breathing in children with myelomeningocele. However, most patients included in those studies underwent polysomnography because of symptoms, so the prevalence of sleep disordered breathing in this population is unknown. OBJECTIVE: To determine the prevalence of sleep disordered breathing in children with myelomeningocele using screening polysomnography. METHODS: In this cross-sectional study, all children with myelomeningocele seen in a multi-disciplinary spina bifida clinic between 2016 and 2020 were referred for polysomnography regardless of clinical symptoms. Included children had not previously undergone polysomnography. The primary outcome for this study was presence of sleep disordered breathing, defined as Apnea-Hypopnea Index (AHI, number of apnea or hypopnea events per hour of sleep) greater than 2.5. Clinical and demographic variables relevant to myelomeningocele were also prospectively collected and tested for association with presence of sleep apnea. RESULTS: A total of 117 participants underwent polysomnography (age 1 mo to 21 yr, 49% male). The majority were white, non-Hispanic. Median AHI was 1.9 (interquartile range 0.6-4.2). A total of 49 children had AHI 2.5 or greater, yielding a sleep disordered breathing prevalence of 42% (95% CI 33%-51%). In multivariable logistic regression analysis, children with more rostral neurological lesion levels had higher odds of sleep disordered breathing (OR for thoracic, mid-lumbar, and low-lumbar: 7.34, 3.70, 4.04, respectively, compared to sacral level, P = .043). CONCLUSION: Over 40% of a sample of children with myelomeningocele, who underwent screening polysomnography, had significant sleep disordered breathing. Routine screening polysomnography may be indicated in this population.