Prevalence and persistence of sleep disordered breathing symptoms in young children: a 6-year population-based cohort study

Pediatric sleep disorders and special educational need at 8 years: a population-based cohort study

OBJECTIVES

To examine associations between sleep-disordered breathing (SDB) and behavioral sleep problems (BSPs) through 5 years of age and special educational need (SEN) at 8 years.

METHODS

Parents in the Avon Longitudinal Study of Parents and Children reported on children's snoring, witnessed apnea, and mouth-breathing at 6, 18, 30, 42, and 57 months, from which SDB symptom trajectories, or clusters, were derived. BSPs were based on report of ≥ 5 of 7 sleep behaviors at each of the 18-, 30-, 42-, and 57-month questionnaires. Parent report of SEN (yes/no) at 8 years was available for 11049 children with SDB data and 11467 children with BSP data. Multivariable logistic regression models were used to predict SEN outcome by SDB cluster and by cumulative report of SEN.

RESULTS

Controlling for 16 putative confounders, previous history of SDB and BSPs was significantly associated with an SEN. BSPs were associated with a 7% increased odds of SEN (95% confidence interval [CI] 1.01-1.15), for each ∼1-year interval at which a BSP was reported. SDB, overall, was associated with a near 40% increased odds of SEN (95% CI 1.18-1.62). Children in the worst symptom cluster were 60% more likely to have an SEN (95% CI 1.23-2.08).

CONCLUSIONS

In this population-based longitudinal study, history of either SDB or BSPs in the first 5 years of life was associated with increased likelihood of SEN at 8 years of age. Findings highlight the need for pediatric sleep disorder screening by early interventionists, early childhood educators, and health professionals.

Persistent snoring in preschool children: predictors and behavioral and developmental correlates

OBJECTIVE

To clarify whether persistent snoring in 2- to 3-year-olds is associated with behavioral and cognitive development, and to identify predictors of transient and persistent snoring.

METHODS

Two hundred forty-nine mother/child pairs participated in a prospective birth cohort study. Based upon parental report of loud snoring ≥ 2 times weekly at 2 and 3 years of age, children were designated as nonsnorers, transient snorers (snored at 2 or 3 years of age, but not both), or persistent snorers (snored at both ages). We compared groups by using validated measures of behavioral and cognitive functioning. Potential predictors of snoring included child race and gender, socioeconomic status (parent education and income), birth weight, prenatal tobacco exposure (maternal serum cotinine), childhood tobacco exposure (serum cotinine), history and duration of breast milk feeding, and body mass relative to norms.

RESULTS

In multivariable analyses, persistent snorers had significantly higher reported overall behavior problems, particularly hyperactivity, depression, and inattention. Nonsnorers had significantly stronger cognitive development than transient and persistent snorers in unadjusted analyses, but not after demographic adjustment. The strongest predictors of the presence and persistence of snoring were lower socioeconomic status and the absence or shorter duration of breast milk feeding. Secondary analyses suggested that race may modify the association of childhood tobacco smoke exposure and snoring.

CONCLUSIONS

Persistent, loud snoring was associated with higher rates of problem behaviors. These results support routine screening and tracking of snoring, especially in children from low socioeconomic backgrounds; referral for follow-up care of persistent snoring in young children; and encouragement and facilitation of infant breastfeeding.

Time course of EEG slow-wave activity in pre-school children with sleep disordered breathing: a possible mechanism for daytime deficits?

BACKGROUND

Daytime deficits in children with sleep disordered breathing (SDB) are theorized to result from hypoxic insult to the developing brain or fragmented sleep. Yet, these do not explain why deficits occur in primary snorers (PS). The time course of slow wave EEG activity (SWA), a proxy of homeostatic regulation and cortical maturation, may provide insight.

METHODS

Clinical and control subjects (N=175: mean age 4.3±0.9 y: 61% male) participated in overnight polysomnography (PSG). Standard sleep scoring and power spectral analyses were conducted on EEG (C4/A1; 0.5-<3.9Hz). Univariate ANOVA's evaluated group differences in sleep stages and respiratory parameters. Repeated-measures ANCOVA evaluated group differences in the time course of SWA.

RESULTS

Four groups were classified: controls (OAHI ≤ 1 event/h; no clinical history); PS (OAHI ≤ 1 event/h; clinical history); mild OSA (OAHI=1-5 events/h); and moderate to severe OSA (MS OSA: OAHI>5 events/h). Group differences were found in the percentage of time spent in NREM Stages 1 and 4 (p<0.001) and in the time course of SWA. PS and Mild OSA children had higher SWA in the first NREM period than controls (p<0.05). All SDB groups had higher SWA in the fourth NREM period (p<0.01).

CONCLUSIONS

These results suggest enhanced sleep pressure but impaired restorative sleep function in pre-school children with SDB, providing new insights into the possible mechanism for daytime deficits observed in all severities of SDB.

Sleep-disordered breathing in a population-based cohort: behavioral outcomes at 4 and 7 years

OBJECTIVES

Examine statistical effects of sleep-disordered breathing (SDB) symptom trajectories from 6 months to 7 years on subsequent behavior.

METHODS

Parents in the Avon Longitudinal Study of Parents and Children reported on children's snoring, mouth breathing, and witnessed apnea at ≥2 surveys at 6, 18, 30, 42, 57, and 69 months, and completed the Strengths and Difficulties Questionnaire at 4 (n = 9140) and 7 (n = 8098) years. Cluster analysis produced 5 "Early" (6-42 months) and "Later" (6-69 months) symptom trajectories ("clusters"). Adverse behavioral outcomes were defined by top 10th percentiles on Strengths and Difficulties Questionnaire total and subscales, at 4 and 7 years, in multivariable logistic regression models.

RESULTS

The SDB clusters predicted ≈20% to 100% increased odds of problematic behavior, controlling for 15 potential confounders. Early trajectories predicted problematic behavior at 7 years equally well as at 4 years. In Later trajectories, the "Worst Case" cluster, with peak symptoms at 30 months that abated thereafter, nonetheless at 7 years predicted hyperactivity (1.85 [1.30-2.63]), and conduct (1.60 [1.18-2.16]) and peer difficulties (1.37 [1.04-1.80]), whereas a "Later Symptom" cluster predicted emotional difficulties (1.65 [1.21-2.07]) and hyperactivity (1.88 [1.42-2.49]) . The 2 clusters with peak symptoms before 18 months that resolve thereafter still predicted 40% to 50% increased odds of behavior problems at 7 years.

CONCLUSIONS

In this large, population-based, longitudinal study, early-life SDB symptoms had strong, persistent statistical effects on subsequent behavior in childhood. Findings suggest that SDB symptoms may require attention as early as the first year of life.

Snoring, mouth-breathing, and apnea trajectories in a population-based cohort followed from infancy to 81 months: a cluster analysis

OBJECTIVE

The objective of this study was to characterize phenotypes of sleep disordered breathing (SDB) in early childhood that clinicians may find useful while monitoring symptom progression and associated SDB morbidity.

METHODS

We performed a cluster analysis of SDB's primary symptoms: snoring, mouth-breathing, and apnea. Parents in the Avon Longitudinal Study of Parents and Children (ALSPAC) reported SDB symptoms by questionnaire for their child at 6, 18, 30, 42, 57, 69, and 81 months of age. Participants were those from the original cohort exclusive of children with congental or other medical conditions predisposing growth aberrations or respiratory problems (i.e. cleft palate, heart surgery and associated conditions, genetic syndromes-primarily Down's, cancer or kidney conditions, celiac disease, congenital adrenal hyperplasia), missing SDB measures for ≥ 2 timepoints, or missing birth length plus 2 subsequent height measures.

RESULTS

Five clusters emerged from 10,441 children and were characterized according to patterns of mean severity of SDB symptoms over time. "Normals" (50%) were asymptomatic throughout. The "late snores and mouth-breathing" cluster (20%) remained asymptomatic until 4 years old. The "early snores" (10%) and "early apnea" (10%) clusters had peak symptoms at 6 and 18 months, respectively. In "all SDB after infancy" (10%), symptoms peaked from 30 to 42 months and remained elevated. Exploratory analyses found that "early snores" were significantly shorter than "normals." Associations with tonsillectomies and wheezing frequency supported external validation.

CONCLUSIONS

Cluster analysis has elucidated the dynamic multi-symptom expression of SDB. The utility of cluster analysis will be evaluated in future analyses to predict growth, cognition and behavior outcomes.