Maristella Lucchini, Shambhavi Thakur, Thomas Anders, Natalie Barnett
Presented at World Sleep, Rio de Janeiro, 2023
Currently, most US states adopt a biannual time change between Standard Time (ST) and Daylight Saving Time (DST). In the past several years abolishing the time change has been the subject of public debate. The AASM has issued a statement in favor of abolishing the time change, recommending permanent ST, because of the negative impact of time change on sleep and overall health, and the knowledge that ST better matches the body’s internal clock. In spite of extensive research and heated discussions on this subject, there has been a paucity of work focusing on the impact of time change in infancy. Only one study has examined the effect of the start of DST on infants’ sleep, reporting a shift in sleep midpoint (SMP) and a decrease in total sleep time (TST). However, this study relied on parental reports of infant sleep, which are subject to recall bias. In this study we report on the effect of the start of DST on infants’ sleep utilizing objective sleep metrics.
Materials and Methods
Participants were 389 children ages 4-24 months (0.1±5.1), who regularly used the Nanit camera monitor. TST, SMP, and number of night-wakings were collected for 5 nights preceding the time change (March 6-10, 2023) and 5 nights during the following week (March 12-17, 2023). Wilcoxon rank sum tests were used to compare sleep metrics before and after the time change.
After the time change, there was a significant increase in TST (+10.5 min Monday, p<0.001; +5.5 min Tuesday, p<0.001; +4.3 min Friday, p<0.01). When stratified by age, the 4-6 and 7-12 month groups had an average increase of 10 min for Monday, Tuesday and Friday, while the 13-24 months group had a 6 min increase on Monday, followed by a 7.5 min decrease on Tuesday and a 15 min decrease on Friday. Furthermore, there was a significant shift to a later SMP for the entire week after the time change (+10.2 min Sunday, p<0.001; +9.9 min Monday, p<0.001; +5.0 min Tuesday, p<0.001; +8.04 min Wednesday, p<0.001; +9.4 min Thursday, p<0.001; +12.1 min Friday, p<0.001). When stratified by age, the 4-6 months infants had the biggest shift on Sunday (+11.7min) followed by a gradual decrease, reachinga +3.2 min difference on Thursday. In contrast, children aged 7-24 months maintained a consistent shift of about +12 mins in SMP throughout the duration of the week following the time change.
These preliminary results suggest that infants’ response to sudden time changes might be moderated by infants’ age, with an increase in TST for younger infants and a decrease for older infants. In addition, research has found a negative impact of habitual late sleep midpoint in childhood. More research is needed to determine the magnitude, developmental trajectories and potential consequences of these changes.
About the researchers
The authors include Maristella Lucchini, Shambhavi Thakur, Thomas Anders, and Natalie Barnett.
- Dr. Maristella Lucchini serves as Senior Clinical Researcher at Nanit. In her role, Maristella works to secure grant funding in collaboration with Nanit’s university research partners and supports the development of the company’s research collaborations around the world. Previously, Maristella served as an Assistant Research Scientist in the Division of Developmental Neuroscience, Department of Psychiatry at Columbia University Irving Medical Center where she led projects across several cohorts focusing on sleep health for pregnant and postpartum women and their children. Maristella’s research focused on underserved communities and sleep health disparities in the perinatal period. During her years as a postdoctoral researcher at Columbia University Irving Medical Center in the Department of Psychiatry, Maristella was selected to participate in the American Academy of Sleep Medicine Young Investigator Research Forum. She holds a Ph.D. in Biomedical Engineering from Politecnico di Milano.
- Shambhavi Thakur serves as Clinical Research Data Analyst at Nanit. She holds a Masters degree in Health Informatics and Life Sciences. She oversees the research collaborations with various universities and analyzes sleep data for internal as well as external studies.
- Dr. Thomas Anders graduated from Stanford University (1956) and Stanford University School of Medicine (1960). He completed psychiatry and psychoanalytic training at Columbia Presbyterian Medical Center, NY. A two-year post-doctoral research fellowship preceded his appointment as Director of the Division of Child Psychiatry at SUNY/Buffalo. He also has headed Divisions of Child and Adolescent Psychiatry at Stanford (1974-1984) and Brown University (1985-1992). At UC Davis, he served as Department of Psychiatry Chair (1992-1998) and then as Executive Associate Dean (1998-2002). His long standing clinical and research interests are in the areas of maturation of infant sleep-wake states and pediatric sleep disorders in children with ASD. He has been an NIH funded investigator and served as President of the American Academy of Child and Adolescent Psychiatry (2005-2007).
Dr. Natalie Barnett serves as VP of Clinical Research at Nanit. Natalie initiated sleep research collaborations at Nanit and in her current role, Natalie oversees collaborations with researchers at hospitals and universities around the world who use the Nanit camera to better understand pediatric sleep and leads the internal sleep and development research programs at Nanit. Natalie holds a Ph.D. in Genetics from the University of New England in Australia and a Postgraduate Certificate in Pediatric Sleep Science from the University of Western Australia. Natalie was an Assistant Professor in the Neurogenetics Unit at NYU School of Medicine prior to joining Nanit. Natalie is also the voice of Nanit's science-backed, personalized sleep tips delivered to users throughout their baby's first few years.