Poster #94 - Cortisol, Sleep Timing, and Sleep Duration: Risk Factors for Overweight Status in Midwestern Latino Youth

• In Event: 2-002 - Special Poster Session 05 with Continental Breakfast Reception
  In Poster Session: PS 05 - Interdisciplinary Section

Integrative Statement

Introduction. Researchers have linked physiological stress to poor sleep (Charles et al., 2015), and, in turn, both stress and sleep problems have been associated with obesity (Chen et al., 2008). These associations are concerning because obesity increases the risk for chronic health conditions such as obstructive sleep apnea, hypertension, osteoarthritis, and type II diabetes mellitus, among many others (Bose et al., 2009; Finkelstein et al., 2009). Researchers have identified some of the processes that connect stress and distinct sleep factors, such as duration and sleep timing, to increased obesity risk (Olds et al., 2011). Chronic stress can over-activate the hypothalamic-pituitary-adrenal (HPA) axis, leading to increases in stress hormones (glucocorticoids), inflammatory proteins, and glucose in the blood. This response can in turn make sleep more difficult, and contributes to increased obesity risk. Much of this previous research has been conducted on adults and Non-Hispanic White children. The purpose of this study was to cross-sectionally examine the links between salivary cortisol awakening response (sCAR), sleep timing and duration, and body mass index (BMI) in Midwestern Latino children.

Participants. Participants included 119 Latino 5th and 6th grade children (Mage=11.53 years; 59% female; mean family income $27,500; 85.6% two-parent homes). The majority of the children (96%) were born in the U.S., and the majority of the parents were born outside the U.S. (91%, mostly in Mexico).

Measures. Children and parents completed surveys (in English or Spanish) regarding children’s daily sleep patterns. Adolescents were placed into one of four categories for both weekdays and weekends: early-to-bed/early-to-rise (EE); early-to-bed/late-to-rise (EL); late-to-bed/early-to-rise (LE); or late-to-bed/late-to-rise (LL). sCAR was calculated from saliva samples which were self-collected for two consecutive days (wake up, 30 minutes after wake up, and before bedtime). BMI was calculated using height and weight measurements taken by two trained researchers, following standard CDC protocols.

Results. sCAR was highest among children in the EE weekday group (65.29 ± 76.47 nmol/L) and lowest among children in the LL weekday group (9.42 ± 76.64 nmol/L). This finding suggests that poor sleep timing habits may lead to an unhealthy pattern of a blunted sCAR.
LL weekday children were much more likely to be overweight compared to EE weekday children (OR=4.67; 95% CI: 1.12-19.44). Compared to EE weekend children, LE and LL weekend children were more likely to be overweight (OR=4.02; CI: 1.09-14.87 and OR=3.64; CI: 0.99-13.44, respectively). For every additional hour delay in weekday bedtime, children were almost three times as likely to be overweight (OR=2.72; CI: 1.39-5.31). Overall, multivariate-adjusted sleep duration was associated with a decreased risk for obesity (OR=0.47, CI: 0.26-0.84). Sleep timing patterns were significantly associated with sCAR levels and risk for being overweight. This is especially concerning considering overweight status and chronic stress often carry into adulthood, and Latino youth are particularly at risk for obesity. Our findings support a need for more research in Latino youth using biomarkers, and they confirm the benefits of maintaining earlier bedtimes for children. Finally, pediatricians should consider discussing sleep routines with children and parents during routine healthcare visits.

Authors

• Blake Lee Jones, Brigham Young University
  Presenting Author

• Jaime Escobedo, Purdue University
  Non-Presenting Author

• Leilah Miller, Purdue University
  Non-Presenting Author

• Sarah Null, Purdue University
  Non-Presenting Author

• Zoe Ellen Taylor, Purdue University
  Non-Presenting Author