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Yohannes Adama Melaku, MPH, PhD, of the Adelaide (Australia) Institute for Sleep Health at Flinders University and coauthors drew data from the 1970 UK Birth Cohort Study. This study followed an initial cohort of 16,571 babies who were born during a single week, with follow-up at ages 5, 10, 16, 26, 30, 38, 42, and 46 years. For the purposes of this study, the investigators looked at participants who, at 42 years of age, were alive and not lost to follow-up and who responded to an invitation to be interviewed; the sample sizes in the analysis were 8,050 participants aged 5 years, 9,090 participants aged 10 years, 9,653 participants aged 16 years, and 9,841 participants aged 42 years.
Behavior was measured at ages 5 years and 16 years using the Rutter Behavioral Scale (RBS) and at age 10 years using a visual analog scale, and insomnia symptoms were assessed through interviewing participants in adulthood about duration of sleep, difficulty initiating sleep, difficulty maintaining sleep, and not feeling rested on waking. Participants were organized into normal behavior (less than or equal to 80th percentile on RBS), moderate behavioral problems (greater than the 80th percentile but less than or equal to the 95th percentile), and severe behavioral problems (above 95th percentile). The investigators then devised two models for their analysis: Model 1 adjusted for sex, parent’s social class and educational level, marital status, educational status, and social class, and model 2 adjusted for physical activity level and body mass index (BMI) trajectory (from 10 to 42 years), perceived health status, and number of noncommunicable diseases, although this latter model yielded fewer statistically significant results in some analyses.
Odds for difficulty initiating or maintaining sleep as an adult was increased among participants with severe behavioral problems at age 5 years in model 1 (adjusted odds ratio, 1.50; 95% confidence interval, 1.14-1.96; P = .004), as well as for those with severe problems at 10 years (aOR, 1.30; 95% CI, 1.14-1.63; P = .001), and at 16 years (aOR, 2.17; 95% CI, 1.59-2.91; P less than .001). The aORs also were higher individually for difficulty initiating sleep and for difficulty maintaining sleep in all age groups.
The association with adulthood insomnia was stronger in participants with externalizing behavioral problems such as lying, bullying, restlessness, and fighting than it was in those with internalizing behavioral problems such as worry, fearfulness, and solitariness.
“Although early sleep problems should be identified, we should additionally identify children with moderate to severe behavioral problems that persist throughout childhood as potential beneficiaries of early intervention with a sleep health focus,” the authors wrote.
One of the study’s limitations was a lack of standardized insomnia measures in the cohort study; however, the researchers suggested that the symptoms included reflect those of standardized measures and diagnostic criteria.
“This study is the first, to our knowledge, to suggest an unfavorable association of early-life behavioral problems with adulthood sleep health, underlining the importance of treating behavioral problems in children and addressing insomnia from a life-course perspective,” they concluded.
No study sponsor was identified. The authors reported no relevant financial disclosures.
SOURCE: Melaku YA et al. JAMA Netw Open. 2019 Sep 6. doi: 10.1001/jamanetworkopen.2019.10861.