Sleep habits and risk factors for sleep-disordered breathing in infants and young toddlers in Louisville, Kentucky

Abstract

Introduction

Snoring affects biobehavioral development among preschool and early school-age children. The goals of the present study were to survey the parents of a large community sample of infants and young toddlers to evaluate (a) naturalistic sleep duration and location; (b) snoring prevalence; and (c) demographic measures and sleep behaviors related to the presence of snoring either 2 or ≥3 days/week.

Methods

Questionnaires were completed by parents of children ages 2 weeks to 2 years attending well-baby checkups and were also mailed to the homes of six-month-old infants.

Results

Data from 944 children were available for analyses. No age differences were reported for total sleep duration, co-sleeping, or snoring. Average daily sleep duration was12.5±1.8 h (standard deviation (SD)), with daytime naps accounting for an increased proportion of total sleep duration among younger infants. Co-sleeping was reported by 15% of families. Snoring 2 days/week was reported in 11.8% and >3 days/week in 5.3% of participants. Survey items indicating risk for sleep-disordered breathing (SDB) clustered into factors related to the child, their environment, and their family; restless sleep was exclusively related to snoring 2 days/week and ethnicity, sweating during sleep, and noisy breathing exclusive to snoring ≥3 days/week.

Conclusions

Young infants appear to sleep less than currently recommended. Co-sleeping is relatively common and not age-dependent through the first 2 years of life. Items relating to the child's sleep behaviors, environment, and parents' perceptions were predictive of positive report of snoring, with snoring rates consistent with a significant risk for SDB being similar to those reported for older children.

Introduction

Among school-age children, the prevalence of sleep-disordered breathing (SDB) is estimated at 2–3% [1], [2]. It is now known that SDB in early childhood leads to greater utilization of healthcare resources [3], more frequent cardiovascular morbidity [4], [5] and co-morbid chronic illnesses [6], [7], and imposes deleterious consequences on cognition and school performance [8], [9], [10], [11], [12], [13], [14], [15], [16], as well as greater psychiatric and behavioral co-morbidities [12], [13], [17], [18], [19]. Although recent evidence points to reversibility of many of these morbid consequences of SDB in children [20], [21], [22], [23], data derived from animal models of SDB [24], [25] and one epidemiological study [10] suggest that some degree of long-term damage may occur, thereby highlighting the importance of early detection and timely treatment of pediatric SDB.

Although the presence of a history of snoring is insufficient for establishing the diagnosis of SDB, this symptom is considered a cardinal feature of SDB [26]. Snoring at frequencies consistent with a measurable risk for SDB have been reported in 6–27% of children [2], [6], [9], [14]. Nevertheless, we should caution that even primary snoring appears to be associated with some degree of disruption of sleep microarchitecture that ultimately may affect daytime functioning in children [27]. Furthermore, an emerging body of work among school-age children indicates that mild SDB and primary snoring, exclusive of obstructive sleep apnea (OSA), may impair executive function [28], verbal and global IQ and memory [29], attention [16], [29], and contributes to social problems and anxious/depressive symptoms [16].

Similar to older children, a 5–26% prevalence of snoring has been reported among community infants [2], [30], [31]. More recently, we have also found that higher snore-related arousal indices are associated with more negative indices on an assessment of mental development in eight-month-old infants, even when overnight polysomnographic evaluation fails to reveal the presence of any obstructive apneas or hypopneas [32].

The goals of the present study were to survey a large community sample to evaluate (a) naturalistic sleep duration and locations; (b) snoring prevalence; and (c) whether other demographic, environmental, and parent-reported infant and young toddler sleep behaviors are associated with snoring rates that are either consistent with primary snoring or likely to indicate SDB.