Premature birth and circadian preference in young adulthood: evidence from two birth cohorts

Abstract

A preference for eveningness (being a "night owl") and preterm birth (<37 weeks of gestation) are associated with similar adversities, such as elevated blood pressure, impaired glucose regulation, poorer physical fitness, and lower mood. Yet, it remains unclear if and how preterm birth is associated with circadian preference. The aim of this study was to assess this association across the whole gestation range, using both objective and subjective measurements of circadian preference. Circadian preference was measured among 594 young adults (mean age 24.3 years, SD 1.3) from two cohorts: the ESTER study and the Arvo Ylppö Longitudinal Study. We compared 83 participants born early preterm (<34 weeks) and 165 late preterm (34 to <37 weeks) with those born at term (≥37 weeks, n = 346). We also compared very low birth weight (VLBW, <1500 g) participants with term-born controls. We obtained objective sleep data with actigraphs that were worn for a mean period of 6.8 (SD 1.4) nights. Our primary outcome was sleep midpoint during weekdays and weekend. The sleep midpoint is the half-way time between falling asleep and waking up, and it represents sleep timing. We also investigated subjective chronotype with the Morningness-Eveningness Questionnaire (MEQ) in 688 (n = 138/221/329) ESTER participants. The MEQ consists of 19 questions, which estimates the respondent to be of a "morning", "evening," or "intermediate" chronotype, based on the Morningness-Eveningness Score (MES). We analyzed the data from the actigraphs and the MES with three linear regression models, and analyzed distribution of the chronotype class with Pearson χ2. There were no consistent differences across the study groups in sleep midpoint. As compared with those born at term, the mean differences in minutes:seconds and 95% confidence intervals for the sleep midpoint were: early preterm weekdays 11:47 (-8:34 to 32:08), early preterm weekend 4:14 (-19:45 to 28:13), late preterm weekdays -10:28 (-26:16 to 5:21), and late preterm weekend -1:29 (-20:36 to 17:37). There was no difference in sleep timing between VLBW-participants and controls either. The distribution of chronotype in the MEQ among all participants was 12.4% morningness, 65.4% intermediate, and 22.2% eveningness. The distribution of the subjective chronotype class did not differ between the three gestational age groups (p = 0.98). The linear regression models did not show any influence of gestational age group or VLBW status on the MES (all p > 0.5). We found no consistent differences between adults born early or late preterm and those born at term in circadian preference. The earlier circadian preference previously observed in those born smallest is unlikely to extend across the whole range of preterm birth.

Perinatal Physiological and Psychological Risk Factors and Childhood Sleep Outcomes: A Systematic Review and Meta-analysis

“…Two studies found no differences in most macrosleep architecture variables including bedtime, get up time, total sleep duration, nocturnal wakefulness, sleep midpoint, and circadian preference between preterm and full-term children at age 2 years 42 and in early adulthood. 34 However, in another study of 5- to 12-year-olds that used polysomnography to measure and compare sleep in preterm children with fetal growth restrictions, preterm children with appropriate birth weight for gestational age, and full-term children, the preterm children with appropriate birth weight for their gestational age had a significant decrease in total sleep duration, sleep efficiency, and nonrapid eye movement sleep and a significant increase in wake after sleep onset compared with the other 2 groups. 31 This study also investigated microsleep architecture and found that preterm children had altered microarchitecture compared with full-term children.…”

“…Nine studies explicitly reported a population-based participant recruitment. 16,[32][33][34][35][36][37][38][39] The follow-up frequency ranged from 1 to 6 times, with the earliest postnatal follow-up started from 10 days after birth 40 and the longest follow-up happened at 24 years of the children's age. 34 Regarding study quality appraisal, 96.67% of included studies (29/ 30) had the Newcastle-Ottawa Scale score ranging from 6 to 8, indicating moderate to high quality.…”

Musculoskeletal pain in adults born preterm: Evidence from two birth cohort studies

“…Of the 2,193 individuals in the AYLS cohort, 1,913 were invited and 1,136 (51.8% of original cohort) took part in a clinical examination between 2009 and 2012. As in previous ESTER‐AYLS publications (Bjorkqvist et al., ; Matinolli et al., ), we included as term controls only individuals from the group not admitted to neonatal ward (see Study design above), because the admitted group represents a range of prenatal and neonatal adversities not representative of those born at term. Length of gestation was confirmed from medical records for 489 individuals who gave their permission; 46 were born early preterm, 129 late preterm and 314 were born at term.…”

Fetal and infant growth patterns, sleep, and 24‐h activity rhythms: a population‐based prospective cohort study in school‐age children

“…Studies of fetal or infant determinants of 24-h activity rhythms in childhood are scarce. Findings from two Finnish actigraphy studies among young adults born preterm and full-term suggest that very low birth weight children might show an earlier chronotype in adult life (Björkqvist et al, 2018(Björkqvist et al, , 2020. Possible mechanisms include a longer period of melatonin deficiency after birth and adverse effects on circadian rhythm programming by prenatal hypoxia, and protein malnutrition and environmental factors in the early postnatal period (Björkqvist et al, 2018).…”

“…Findings from two Finnish actigraphy studies among young adults born preterm and full-term suggest that very low birth weight children might show an earlier chronotype in adult life (Björkqvist et al, 2018(Björkqvist et al, , 2020. Possible mechanisms include a longer period of melatonin deficiency after birth and adverse effects on circadian rhythm programming by prenatal hypoxia, and protein malnutrition and environmental factors in the early postnatal period (Björkqvist et al, 2018). The age of onset of developing the suggested earlier chronotype, as well as its relationship with cardiometabolic health, require further investigation.…”