The association of caffeinated beverages with blood pressure in adolescents.
OBJECTIVE
To assess the association between the consumption of caffeinated beverages and blood pressure in African American and white adolescents.


METHODS
This study was part of ongoing research examining stress-induced hemodynamic responses in adolescents. African American and white adolescents (n = 159) selected foods and beverages for a 3-day sodium-controlled diet. Caffeine in these foods was used to stratify participants into 3 categories (0-50 mg/d, >50-100 mg/d, and >100 mg/d). Before menu selection, blood pressure readings were obtained.


METHODS
A general linear model (multiple regression with both categorical and continuous variables) was developed to assess the effects of race, category of caffeine intake, and interaction of race and caffeine intake on systolic and diastolic blood pressure controlling for sex and body mass index (calculated as weight in kilograms divided by height in meters squared).


RESULTS
The association between systolic blood pressure and caffeine category varied by race (P =.001). African Americans consuming more than 100 mg/d of caffeine had higher systolic blood pressure readings than the groups consuming 0 to 50 mg/d (mean difference, 6.0 mm Hg; 95% confidence interval [CI], 2.3 to 9.7) or more than 50 to 100 mg/d (mean difference, 7.1 mm Hg; 95% CI, 3.4 to 10.7). The effect on diastolic blood pressure was less pronounced (P =.08). The diastolic blood pressure of the group consuming more than 100 mg/d was 3.7 mm Hg (95% CI, 0.41 to 7.0) higher than the group consuming more than 50 to 100 mg/d and was not statistically different from the group consuming 0 to 50 mg/d (mean difference, 2.4 mm Hg; 95% CI, -0.9 to 5.8). There was no evidence that the association between diastolic blood pressure and caffeine intake varied by race (P =.80).


CONCLUSIONS
For adolescents, especially African American adolescents, caffeine intake may increase blood pressure and thereby increase the risk of hypertension. Alternatively, caffeinated drink consumption may be a marker for dietary and lifestyle practices that together influence blood pressure. Additional research is needed owing to rising rates of adolescent hypertension and soft drink consumption.
Savoca
Margaret R
MR
Georgia Prevention Institute, Department of Pediatrics, Medical College of Georgia, Augusta 30912-3715, USA. msavoca@mail.mcg.edu
Evans
Conner D
CD
Wilson
Martha E
ME
Harshfield
Gregory A
GA
Ludwig
David A
DA
D000293:Adolescent; D001741:Black or African American; D001794:Blood Pressure / Q000187:drug effects*; D002110:Caffeine / Q000009:adverse effects / Q000494:pharmacology*; D002253:Carbonated Beverages / Q000009:adverse effects*; D003971:Diastole / Q000187:drug effects; D005260:Female; D006801:Humans; D008019:Life Style; D008297:Male; D013599:Systole / Q000187:drug effects
D002110:Caffeine