DOI: 10.15154/1523142
title: Physical Activity as a Protective Factor Against Sleep Health Disparities for Gender-Diverse Youth

description: Introduction/Background: Gender-diverse youth are more likely than non-gender diverse peers to report shorter nighttime sleep duration (Levenson et al., 2021). Even in non-clinical samples, consequences of short sleep in adolescence are broad, including increased risk for depressive symptoms and diminished academic performance (Short et al., 2013). Physical activity, however, is associated with longer sleep duration among adolescents (Philbrook & El-Sheikh, 2016), and has been shown to decrease disparities in sleep duration for historically minoritized individuals (Gillis et al., 2020). 

Specific Aim: To examine physical activity as a protective factor that reduces disparities in sleep duration for gender-diverse youth.

Materials and Method: A community sample of 2,978 gender-diverse (n = 89) and non-gender-diverse (n = 2,889) youth were drawn from the National Institutes of Health’s Adolescent Brain and Cognitive Development Study. Participants ranged in age from 10.08 to 13.58 years (M = 11.96 years, SD = 7.73 months) with an average Tanner stage of 2.62 (SD = 0.95). Youth were coded as being gender diverse if they answered “yes” or “maybe” to the question, “Are you transgender?;” if they responded “not at all,” “a little,” or “somewhat” to the question, “How much do you feel like [your sex assigned at birth]?;” or if they responded “totally,” “mostly,” or “somewhat” to the question, “How much do you feel like [the dichotomous sex opposite to your sex assigned at birth]?” Youth wore a Fitbit Charge HR at home continuously for 21 days to provide objective assessments of physical activity and sleep. Physical activity was operationalized by average metabolic equivalents of task (METs) per minute (METs/minute), an established indicator of physical activity intensity (Maher & Olds, 2011). Sleep duration was indexed in raw hours of sleep per night on average (excluding wake minutes during the night). 

Results: An independent-samples t-test demonstrated that gender-diverse youth (M = 7.29 hours, SD = 43.86 minutes) slept 13.88 fewer minutes per night on average than non-gender-diverse peers (M = 7.52 hours, SD = 37.22 minutes), t(2,976) = 3.45, p = .001. Path analyses controlling for sex assigned at birth, pubertal status, and socioeconomic status revealed that physical activity moderated the association between gender diversity and sleep duration, B = 0.56, SE = 0.26, p = .03 (see Figure 1). At lower levels of physical activity, the relationship between gender diversity and shorter sleep duration remained, B = –0.29, SE = 0.07, p < .001. At higher levels of physical activity, sleep duration did not vary by gender diversity, B = 0.003, SE = 0.12, p = .98, suggestive of a protective effect of physical activity. 

Conclusion: Disparities in sleep duration for gender-diverse youth might be mitigated at higher levels of physical activity. Clinicians and other practitioners could utilize this information to encourage physical activity as an intervention that may lessen the downstream consequences of sleep health disparities among gender-diverse youth.