Night/day ratios of ambulatory blood pressure among healthy adolescents: roles of race, socioeconomic status, and psychosocial factors.

Background: Elevated nighttime blood pressure (BP) predicts hypertension and its complications in adulthood.

Purpose: This study aimed to assess the independent effects of race and family income on night/day BP among adolescents and to examine whether negative emotions, low positive resources, and unpleasant interactions during the day are also related.

Methods: Healthy African American and Caucasian high school students (N = 239) wore an ambulatory BP monitor for 48 h, recorded quality of ongoing interpersonal interactions, and completed questionnaires.

Results: African Americans and those with lower family income had higher night/day BP ratios. African Americans reporting greater negative emotions, lower positive resources, and more unpleasant interactions had higher night/day BP ratios.

Conclusions: Racial differences in night BP emerge by adolescence, independent of family income. African Americans, especially those high in negative emotions and low in positive resources, may be at higher relative risk for hypertension later in life in part due to elevated night BP.