A316 SLEEP, Volume 41, Abstract Supplement, 2018 (p=<.0001 and p=.0003 respectively), but was greater during the short week (mean drop of 20.3 vs. 14.7 L/min). No significant differences between study weeks were found for weekly spirometry or eNO. Self- reported asthma symptoms and asthma impact were worse during the short week vs. the long week (p=.07). Conclusion: Objective and subjective changes in asthma were found during a week of deficient sleep, with worse lung function meas- ured by daily peak flow and increased subjective asthma symptoms/ asthma impact. However, no differences were found for spirometry or eNO performed in a clinical setting. Because objective lung func- tion measures are effort dependent, sleep deprived adolescents may perform worse at home than when trained professionals are coaching them. That said, subjective asthma symptoms in combination with daily peak flow are often used to make treatment decisions; thus a better understanding of the relationship between sleep duration and asthma is needed. Support (If Any): NIH-R01HL119441. 0852 STRESS AND OBJECTIVE SHORT SLEEP DURATION PREDICT HIGHER BLOOD PRESSURE IN ADOLESCENTS Gaines J 1 , Vgontzas AN 1 , Fernandez-Mendoza J 1 , He F 2 , Liao D 2 , Calhoun S 1 , Basta M 1 , Bixler EO 1 1 Sleep Research & Treatment Center, Hershey, PA, 2 Department of Public Health Sciences, Hershey, PA Introduction: In adults, emotional and physiological stress is asso- ciated with elevated risk for hypertension, particularly in those with objective short sleep duration. The goal of this study was to exam- ine whether cortisol levels (an index of physiological stress) combined with objective short sleep duration are associated with higher blood pressure as young as adolescence. Methods: Participants were 416 children (5-12y) in the Penn State Child Cohort who were followed up as adolescents (12-23y) 8 years later. All participants underwent 9-hour polysomnography, a physical examination including a measure of seated blood pressure (BP), and provided a saliva sample at 7pm for the assessment of cortisol (via ELISA). High cortisol (≥2.5ng/mL in childhood, ≥6.7ng/mL in adoles- cence) and short sleep duration (<467min in childhood, <460.6min in adolescence) were defined based on median cut-offs at both lab visits. All data were adjusted for age at follow-up, sex, ethnic minority status, and BMI percentile. Results: Cross-sectionally, in adolescence, cortisol was signifi- cantly associated with systolic (SBP), diastolic (DBP), and mean arterial pressure (MAP; all p<0.01). The subgroup of adolescents with high cortisol/short sleep duration (n=118) had significantly higher SBP (117.4 ± 1.0 mmHg) and DBP (69.3 ± 0.8 mmHg) com- pared to those with normal cortisol/normal sleep duration (n=117, 110.5 ± 1.0 mmHg and 63.9 ± 0.8 mmHg, respectively; both p<0.001). Longitudinally, baseline cortisol predicted follow-up DBP and MAP (both p<0.01). There was a trend for increased SBP (114.8 ± 1.4m mmHg) in adolescents who had high cortisol/short sleep duration at baseline compared to the subgroup who had nor- mal cortisol/normal sleep duration at baseline (111.6 ± 1.3 mmHg, p=0.092). Conclusion: Children and adolescents who are physiologically stressed with short sleep duration are at risk for higher blood pressure. Reducing stress and improving night time sleep in this young popula- tion should be included as therapeutic strategies to protect from early development of hypertension. Support (If Any): NIH grants R01 HL63772, R01 HL97165, UL1 RR033184, and C06 RR16499. 0853 ADIPOSITY IN MEXICO CITY ADOLESCENTS: THE INTERPLAY OF SLEEP DURATION AND SLEEP VARIABILITY Jansen E 1 , Dunietz G 1 , Chervin R 1 , Baylin A 1 , Baek J 2 , Banker M 1 , Song P 1 , Cantoral A 3 , Tellez Rojo M 4 , Peterson K 1 1 University of Michigan, Ann Arbor, MI, 2 University of Massachusetts Medical School, Worcester, MA, 3 National Council of Science and Technology, National Institute of Public Health, MEXICO, 4 Center for Nutrition and Health Research, National Institute of Public Health, MEXICO Introduction: Insufficient sleep predicts adolescent obesity prospec- tively. Sleep variability has also been associated with adiposity among adolescents, although studies are scarce and findings inconsistent. Furthermore, previous studies examined independent associations of sleep duration and sleep variability rather than sleep duration and sleep variability in combination. Methods: In a cohort of 528 Mexico City adolescents aged 9 to 17 years, actigraphy was used to assess sleep. Sleep duration was averaged across the wear time (5–7 days), and categorized into sufficient or insufficient for age (American Academy of Sleep Medicine recommendations). Sleep variability was calculated as the standard deviation of the sleep duration, and split at the me- dian into stable versus variable. Adiposity measures -- body mass index, triceps skinfolds, waist circumference, and percent body fat-- were collected by trained assistants. We conducted linear re- gression analyses with adiposity measures as the outcome (each in separate models) and combinations of sleep duration and sleep variability as the exposure (insufficient-stable, insufficient-varia- ble, sufficient-stable (reference), and sufficient-variable). Log bi- nomial models were used to estimate prevalence ratios (PR) and 95% confidence interval (CI) for obesity, by joint sleep duration and sleep variability categories. Adjusted models included sex, age, and maternal education. Results: Approximately 40% of the adolescents had insufficient sleep, and 13% were obese. Relative to sufficient-stable sleepers, adolescents with insufficient-stable sleep had higher adiposity across all four meas- ures (e.g. adjusted difference in BMI-for-age z scores was 0.68, 95% CI 0.35, 1.00); and had a greater than twofold higher obesity preva- lence (PR=2.54 95% CI 1.36, 4.75). Insufficient-variable sleepers had slightly higher adiposity than sufficient-stable sleepers, although not across all measures. Conclusion: Adolescents with insufficient sleep on a regular basis may be at particular risk of obesity. The fact that insufficient-varia- ble sleepers had only slightly higher adiposity than sufficient-stable sleepers suggests that “catch-up sleep” may play a protective role in adiposity gain. Support (If Any): Dr. Jansen was supported by a T32 grant from the National Institute of Diabetes and Digestive and Kidney Diseases (5T32DK071212-12). 0854 ASSOCIATION BETWEEN THE SLEEP HABITS, SLEEP PROBLEMS AND SCHOOL START TIMES OF SCHOOL-AGE CHILDREN IN SOUTH-WESTERN NIGERIA. Olorunmoteni OE 1 , Komolafe MA 2 , Seun-Fadipe C 3 1 Paediatric Neurology Unit, Department of Paediatrics and Child Health, Obafemi Awolowo University, Ile-Ife, Ile-Ife, NIGERIA, 2 Adult Neurology Unit, Department of Internal Medicine,Obafemi Awolowo University, Ile-Ife, NIGERIA, 3 Department of Mental B. Clinical Sleep Science and Practice VII. Pediatrics Downloaded from https://academic.oup.com/sleep/article-abstract/41/suppl_1/A316/4988902 by guest on 05 July 2020