Prematurity: A Prognostic Factor for Increased Severity of Pediatric Obstructive Sleep Apnea

Phenotypical Characterization of Obstructive Sleep Apnea in Premature Infants using Polysomnography

OBJECTIVE

To use objective quantification of polysomnographic (PSG) parameters in premature infants to define the severity and nature of obstructions (partial hypopnea vs. total obstruction), along with the impact on sleep fragmentation and oxygenation patterns.

METHODS

Retrospective comparison of PSG features in 207 infants (<12 months) referred for sleep disordered breathing. Our study groups included term (> = 37 weeks GA, n = 162) and premature (<37 weeks GA, n = 45) infants. Groups were compared for OSA sleep-stage-specific apnea hypopnea (AHI) indexes (REM and NREM), hypopnea indexes (HI), obstructive apnea indexes (OI) and arousal indexes. Oxygenation was assessed as % of time with SpO2  < 90%, nadir with apneic events and frequency of SpO2 desaturations (>3%) calculated as stage-specific O2 desaturation indexes.

RESULTS

Overall, premature infants had greater apnea severity (AHI premature 13.9/h vs. Term 7.9/h, p = 0.018). Additional analyses showed that the primary difference between premature and term infants is seen in the group with partial obstructions (HI index) and severe OSA (OAHI> = 10/h). Premature infants also had greater arousal indexes (premature 13.8/h vs. term 10.5/h, p = 0.003). Although the percentage of time <90% at night and the median SpO2 nadir during apneic events was similar in premature vs. term, O2 desaturation indexes were greater in premature infants (10.3/h in term vs. 18.3/h in prematurity, p = 0.03).

CONCLUSIONS

Children born premature have an OSA phenotype in infancy characterized by greater severity mostly due to frequent partial obstructions (hypopneas) rather than full obstructions (obstructive apnea). Prematurity is also associated with more intermittent hypoxemia and sleep fragmentation.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:1933-1938, 2024.

Untangling the relationship between childhood risk factors and obstructive sleep apnoea in adulthood

See related article

Occurrence of sleep-disordered breathing in children with pulmonary hypertension

BACKGROUND

Obstructive sleep apnea (OSA) has been associated with pulmonary hypertension (PH) through a complex and bidirectional relationship. The prevalence of OSA and other forms of sleep-disordered breathing (SDB) among children with PH is not well understood. A better understanding could help elucidate contributing factors for PH, guide diagnostic testing, and inform therapies. We therefore determined the proportion of SDB codiagnosis and OSA risk factors among a cohort of children with PH.

METHODS

Retrospective chart review was performed for children 0-21 years old with PH who underwent polysomnography (PSG) between 1 January 2010 and 31 August 2020. The primary outcome was OSA occurrence and risk based on demographics, diagnoses, and PH classification. The secondary outcome was occurrence and risk of other SDB diagnoses based on PH classification.

RESULTS

Among 89 children identified, diagnoses included OSA (N = 79, 89%), central sleep apnea (N = 11, 12%), sleep-related hypoventilation (N = 6, 7%), and non-apneic hypoxemia (N = 28, 31%). Trisomy 21 diagnosis (N = 38, 43%) was associated with increased OSA risk (RR: 1.24, 95% CI: [1.09-1.42]) and age >12 months at PSG was associated with decreased OSA risk (N = 52, 58%, RR: 0.60, 95% CI: [0.45-0.81]). There was no difference in SDB risk based on Group 1 (N = 56, 63%) or Group 3 (N = 33, 37%) PH and no difference in OSA severity based on demographics and diagnoses.

CONCLUSION

OSA was diagnosed among a majority of children with PH, and other SDB diagnoses were identified in a significant proportion of children. These findings support routine screening for SDB with PSG in children with PH.

Early life predictors of obstructive sleep apnoea in young adults: Insights from a longitudinal community cohort (Raine study)

OBJECTIVE

Early-life obstructive sleep apnoea (OSA) predictors are unavailable for young adults. This study identifies early-life factors predisposing young adults to OSA.

METHODS

This retrospective study included 923 young adults and their mothers from the Western Australian Pregnancy Raine Study Cohort. OSA at 22 years was determined from in-laboratory polysomnography. Logistic regression was used to identify maternal and neonatal factors associated with OSA in young adulthood.

RESULTS

OSA was observed in 20.8% (192) participants. Maternal predictors of OSA included gestational diabetes mellitus (odds ratio (OR) 9.54, 95% confidence interval (CI) 1.7, 58.5, P = 0.011), preterm delivery (OR 3.18, 95%CI 1.1,10.5, P = 0.043), preeclampsia (OR 2.95, 95%CI 1.1,8.0, P = 0.034), premature rupture of membranes (OR 2.46, 95%CI 1.2, 5.2, P = 0.015), age ≥35 years (OR 2.28, 95%CI 1.2,4.4, P = 0.011), overweight and obesity (pregnancy BMI≥25 kg/m2) (OR 2.00, 95%CI 1.2,3.2, P = 0.004), pregnancy-induced hypertension (OR 1.89, 95%CI 1.1,3.2, P = 0.019), and Chinese ethnicity (OR 2.36,95%CI 1.01,5.5, P = 0.047). Neonatal predictors included male child (OR 2.10, 95%CI 1.5,3.0, P < 0.0001), presence of meconium-stained liquor during delivery (OR 1.60, 95%CI 1.0,2.5, P = 0.044) and admission to special care nursery (OR 1.51 95%CI 1.0,2.2, P = 0.040). Higher birth lengths reduced OSA odds by 7% for each centimetre (OR 0.93, 95%CI 0.87, 0.99, P = 0.033).

CONCLUSIONS

A range of maternal and neonatal factors predict OSA in young adults, including those related to poor maternal metabolic health, high-risk pregnancy and stressful perinatal events. This information could assist in the early identification and management of at-risk individuals and indicates that better maternal health may reduce the likelihood of young adults developing OSA.

Pediatric Sleep Respiratory Disorders: A Narrative Review of Epidemiology and Risk Factors

Sleep is a fundamental biological necessity, the lack of which has severe repercussions on the mental and physical well-being in individuals of all ages. The phrase "sleep-disordered breathing (SDB)" indicates a wide array of conditions characterized by snoring and/or respiratory distress due to increased upper airway resistance and pharyngeal collapsibility; these range from primary snoring to obstructive sleep apnea (OSA) and occur in all age groups. In the general pediatric population, the prevalence of OSA varies between 2% and 5%, but in some particular clinical conditions, it can be much higher. While adenotonsillar hypertrophy ("classic phenotype") is the main cause of OSA in preschool age (3-5 years), obesity ("adult phenotype") is the most common cause in adolescence. There is also a "congenital-structural" phenotype that is characterized by a high prevalence of OSA, appearing from the earliest ages of life, supported by morpho-structural abnormalities or craniofacial changes and associated with genetic syndromes such as Pierre Robin syndrome, Prader-Willi, achondroplasia, and Down syndrome. Neuromuscular disorders and lysosomal storage disorders are also frequently accompanied by a high prevalence of OSA in all life ages. Early recognition and proper treatment are crucial to avoid major neuro-cognitive, cardiovascular, and metabolic morbidities.

Heart rate surge at respiratory event termination in preterm and term born children with sleep disordered breathing

BACKGROUND

Repetitive surges in heart rate (HR) at respiratory event termination underpin the altered autonomic HR control associated with sleep disordered breathing (SDB). As children born preterm are at greater risk of adverse cardiovascular outcomes, we aimed to determine whether the HR response to obstructive respiratory events was elevated compared to term-born children.

METHODS

Fifty children (3-12 years) born preterm, were matched for SDB severity, age and gender with term born children. Multilevel modelling determined the effect of preterm birth and arousal on HR changes between a 10s baseline to the latter half of respiratory events and 15s post event during NREM and REM.

RESULTS

1203 events were analysed (NREM: term 380; preterm 383; REM: term 207; preterm 233). During NREM fewer events terminated in arousal in the preterm compared with term group (preterm 68%; term 84%; χ² = 27.2, p < 0.001). There were no differences in REM. During NREM, HR was lower in the preterm group at all event phases, with and without associated arousals (P < 0.01 for all). % change in HR from baseline to post event was higher in the preterm compared with term group (preterm: median 23% IQR (12%,34%); term: 18% (10%,29%); p < 0.01) and late event to post event (preterm: 30% (21%, 32%); term 28% (20%,39%); p < 0.01) in events associated with arousals.

CONCLUSION

The greater magnitude of surges in HR following respiratory events terminating with arousal in preterm born children, although small, occur repeatedly throughout the night and may contribute to adverse cardiovascular outcomes, although further studies are required.

The Association between Asthma and OSA in Children

Obstructive sleep apnea (OSA) and asthma are two of the most prevalent and commonly co-existing respiratory conditions seen in the pediatric population. Studies linking asthma and OSA in children are limited but indicate that there is a bi-directional relationship between them with significant overlap in the symptoms, risk factors, pathophysiology, comorbidities, and management. It is suggested that there is a reciprocal association between asthma predisposing to OSA, and OSA worsening symptom control and outcomes from asthma. It stands to reason that inflammation in the upper and/or lower airways can influence each other. Most of the pediatric literature that is available evaluates each aspect of this relationship independently such as risk factors, mechanisms, and treatment indications. This article highlights the relationship between OSA and asthma in the context of shared risk factors, pathophysiology, and available management recommendations in the pediatric population. Early recognition of the co-existence and association between OSA and asthma could ideally improve the treatment outcomes for these two conditions. Gaining a better understanding of the mechanism of this relationship can help identify nuances for medical management, optimize treatment and protect this population at risk from associated morbidity.

Obstructive Sleep Apnea in Neonates

Neonates have distinctive anatomic and physiologic features that predispose them to obstructive sleep apnea (OSA). The overall prevalence of neonatal OSA is unknown, although an increase in prevalence has been reported in neonates with craniofacial malformations, neurological disorders, and airway malformations. If remained unrecognized and untreated, neonatal OSA can lead to impaired growth and development, cardiovascular morbidity, and can even be life threatening. Polysomnography and direct visualization of the airway are essential diagnostic modalities in neonatal OSA. Treatment of neonatal OSA is based on the severity of OSA and associated co-morbidities. This may include medical and surgical interventions individualized for the affected neonate. Based on this, it is expected that infants with OSA have more significant healthcare utilization.

The epidemiology of apnoea of prematurity

WHAT IS KNOWN AND OBJECTIVE

Many premature infants less than 37 weeks gestational age (GA), and almost all infants less than 28 weeks GA, will experience apnoea of prematurity (AOP)-a cessation of respiration for 20 or more seconds (or less than 20 s if accompanied by other signs). Because the treatment options for AOP are so limited, we explore its epidemiology, with the ultimate hope of learning how to decrease its incidence.

COMMENT

Although AOP usually resolves with maturation of the respiratory system, many short- and long-term negative effects are correlated statistically with AOP (although direct causality has not been established). The primary risk factor for AOP is preterm birth, but delivery technique, genetics, socioeconomic status, racial disparities and other influences are suspected to be involved. Anaemia, asthma and gastric reflux have also been associated with preterm birth, but the relationship with AOP is unclear. The postulated associations and the strength of the evidence are briefly reviewed and discussed.

WHAT IS NEW AND CONCLUSION

Attempts to elucidate the epidemiology of apnoea of prematurity have been challenging. Studies of AOP are hampered in part by challenges in monitoring the condition, the interplay of multiple comorbidities in preterm neonates and lack of expert consensus definitions. However, since the primary risk factor is preterm birth, efforts to decrease the prevalence of preterm birth would have a positive secondary effect on the prevalence of AOP. Until then, better pharmacotherapeutic options are needed.