The results suggest that despite the existence of hegemonic thinking to guide these relationships , BP and physical activity do not always have negative associations , and BP and obesity do not always have positive associations .
In the light of the importance of the impacts that obesity and physical activity may have on  blood pressure ( BP ) among adolescents , and the suggestion that abnormal pressure levels at young ages are maintained into more mature stages of these individuals ' lives , the scope of this study is to conduct a systematic review of the associations between obesity and BP and between physical activity and BP among adolescents .
Blood pressure and associated factors in a North African adolescent population. a national cross-sectional study in Tunisia
Background In southern and eastern Mediterranean countries , changes in lifestyle and the increasing prevalence of excess weight in childhood are risk factors for high blood pressure ( BP ) during adolescence and adulthood . The aim of this study was to evaluate the BP status of Tunisian adolescents and to identify associated factors . Methods A cross-sectional study in 2005 , based on a national , stratified , r and om cluster sample of 1294 boys and 1576 girls aged 15 - 19 surveyed in home visits . The socio-economic and behavioral characteristics of the adolescents were recorded . Overweight/obesity were assessed by Body Mass Index ( BMI ) from measured height and weight ( WHO , 2007 ) , abdominal obesity by waist circumference ( WC ) . BP was measured twice during the same visit  . Elevated BP was systolic ( SBP ) or diastolic blood pressure ( DBP ) ≥ 90th of the international reference or ≥ 120/80 mm Hg for 15 - 17 y. , and SBP/DBP ≥ 120/80 mm Hg for 18 - 19 y. ; hypertension was SBP/DBP ≥ 95th for 15 - 17 y. and ≥ 140/90 mm Hg for 18 - 19 y. Adjusted associations were assessed by logistic regression . Results The prevalence of elevated BP was 35.1%[32.9 - 37.4 ] : higher among boys ( 46.1 % vs. 33.3 % ; P < 0.0001 ) ; 4.7%[3.8 - 5.9 ] of adolescents had hypertension . Associations adjusted for all covariates showed independent relationships with BMI and WC : - obesity vs. no excess weight increased elevated BP ( boys OR = 2.1[1.0 - 4.2 ] , girls OR = 2.3[1.3 - 3.9 ] ) and hypertension ( boys OR = 3.5[1.4 - 8.9 ] , girls OR = 5.4[2.2 - 13.4 ] ) , - abdominal obesity ( WC ) was also associated with elevated BP in both genders ( for boys : 2nd vs. 1st tertile OR = 1.7[1.3 - 2.3 ] , 3rd vs.1st tertile OR = 2.8[1.9 - 4.2 ] ; for girls : 2nd vs. 1st tertile OR = 1.6[1.2 - 2.1 ] , 3rd vs.1st tertile OR = 2.1[1.5 - 3.0 ] ) but only among boys for hypertension . Associations with other covariates were weaker : for boys , hypertension increased somewhat with sedentary lifestyle , while elevated BP was slightly more prevalent among urban girls and those not attending school . Conclusion Within the limits of BP measurement on one visit only , these results suggest that Tunisian adolescents of both genders are likely not spared from early elevated BP . Though further assessment is likely needed , the strong association with overweight/obesity observed suggests that interventions aim ed at changing lifestyles to reduce this main risk factor may also be appropriate for the prevention of elevated BP
The results suggest that despite the existence of hegemonic thinking to guide these relationships , BP and physical activity do not always have negative associations , and BP and obesity do not always have positive associations .
In the light of the importance of the impacts that obesity and physical activity may have on  blood pressure ( BP ) among adolescents , and the suggestion that abnormal pressure levels at young ages are maintained into more mature stages of these individuals ' lives , the scope of this study is to conduct a systematic review of the associations between obesity and BP and between physical activity and BP among adolescents .