Table 1. Characterization and methodological quality score of the studies with evidence of the association between short sleep duration and high blood pressure.

Author (year)	Design Location	Sample Age group	Measurement method	Sleep duration	Adjustment variables	Association between sleep duration and BP in adolescents	Score*
Kuciene et al. 20 (2014)	Cross-sectional Lithuania	n=6,940 12-15 years old	Sleep: self-reported BP: oscillometric	<7 h 7-8 h ≥8 h	Age, sex, BMI, physical activity and smoking	Sleep duration <7 h and hypertension: aOR=2.28; sleep duration 7-8 h and hypertension: ORa=1.99; both sexes; for all p <0.001.	9
Javaheri et al. 21 (2008)	Cross-sectional United States	(n=238) 13-16 years old	Sleep: PSG and actigraphy BP: PSG and auscultatory	≤6.5 h > 6.5 h	Age, sex, race, BMI, preterm status, and socioeconomic status	Sleep duration <6.5 h and pre-hypertension: OR=2.79, p=0.0366. Sleep duration and SBP: β = -1.74, p = 0.0012. Unadjusted analyzes	7
Wells et al. 24 (2008)	Cross-sectional Brazil	n=4,452 10-12 years old	Sleep: self-reported BP: oscillometric	≤8, 8-10, 9, ≥11 h	Maternal education, sex, alcohol, birth weight, smoking during pregnancy, physical activity, socioeconomic status, maternal BMI	Sleep duration and SBP: β =0.31, p=0.03.	5
Au et al. 26 (2014)	Cross-sectional China	n=143 10-17 years old	Sleep: PSG and sleep diary for 7 days BP: 24 hours	≤7, 7.01-8, 8.01-9, 9.0-10,> 10 h	Age, sex, BMI, hypertensive parents, hypopnea index (index <5)	Sleep diary: sleep duration and SBP (β = -2.0, p<0.001) and DBP (β = -1.1, p <0.02). PSG: sleep duration and SBP (β =-1.6, p<0.07)	6
Meininger et al. 27 (2014)	Cross-sectional United States	n=366 11-16 years old	Sleep: actigraphy BP: 24 hours	Continuous in hours	Age, sex, race, mother’s education, sexual maturation, physical activity, BMI, position during BP measurement	Duration of nighttime sleep and SBP: β =-0.57, p<0.0001. Duration of daytime sleep and SBP: β =-0.73, p <0.001 e PAD β=-0.50, p<0.001	6
Lee and Park 29 (2014)	Cross-sectional South Korea	n=1,187 12-18 years old	Sleep: self-reported BP: auscultatory	≤5, 6-7, 8-9, ≥10 h	Age, sex, family, income, caloric intake and physical activity	Sleep duration ≤5 h and high BP: aOR = 2.11 (95%CI 1.22-3.65)	8
Mezick et al. 30 (2012)	Cross-sectional United States	n=246 14-19 years old	Sleep: actigraphy BP: 24 hours	Continuous in hours	Age, sex, race and BMI	Sleep duration and SBP and DBP: (both β=-0.17 p=0.01). 1 h increase in sleep duration, 24 h prehypertension and elevated daytime BP (aOR = 0.66, 95%CI 0.46-0.97; aOR=0.65, 95%CI 0.42-0.98), respectively	6
Guo et al. 31 (2011)	Cross-sectional China	n=4,902 5-18 years old	Sleep: reported by parents. BP: auscultatory	11-14 years old: <9, 9-10, ≥ 10 h	Age, BMI, physical activity and waist circumference	Sleep duration <9 h and hypertension (boys 11-14 years old): aOR=1.5, p <0.05. Sleep duration and BP (boys 11-14 years old), SBP β = -1.04, p = 0.001, DBP β = -0.55, p=0.030	7
Peach et al. 32 (2015)	Longitudinal United States	n=541 10-13 years old	Sleep: self-reported BP: auscultatory	Continuous in hours	Age, sex, race, income, physical activity, eating habits, sexual maturation, attention or behavior problems, depression	Sleep duration on weekdays and weekends and hypertension in boys: β = -0.13, β = -0.05, respectively, for both p <0.01	6

*Methodological quality score of the studies: low quality=0 to 3; moderate quality= 4 to 7 and high quality= 8 to 11; PSG: polysomnography; BMI: body mass index; aOR: adjusted Odds Ratio; OR: Odds Ratio; β: beta coefficient; 95%CI: 95% confidence interval; SBP: systolic blood pressure; DBP: diastolic blood pressure.