Socioeconomic position and heart rate recovery after maximal exercise in children.

OBJECTIVE

To determine whether socioeconomic (SE) position is associated with first-minute (1-minute) heart rate (HR) recovery in healthy children and adolescents (hereafter referred to as children).

DESIGN

In a cross-sectional study, we compared 1-minute HR recovery in 3 groups of children (low, medium, and high SE) using multivariable analysis. The groups were based on neighborhood SE data extracted from the US 2000 census database.

SETTING

Children's Hospital Boston.

PARTICIPANTS

Four hundred eighty children referred for exercise testing to exclude cardiac disease and discharged as showing normal results.

MAIN EXPOSURES

Socioeconomic position and body mass index (BMI).

MAIN OUTCOME MEASURE

Heart rate recovery after a maximal treadmill exercise test (Bruce protocol) following a consistent 1-minute cool-down period.

RESULTS

The low SE group had a higher proportion of children with a high BMI (> or =85th percentile) (P = .07) and exercised for a shorter duration, controlling for age, sex, and BMI (P < .001). After adjusting for age (P < .001) and sex (P < .001), a significant interaction of SE group with BMI was found (P = .04). There was no difference in HR recovery in the 3 SE groups in children with a normal BMI (<85th percentile). Among children with a high BMI, only those from low and middle SE neighborhoods had impaired 1-minute HR recovery.

CONCLUSION

Children with a high BMI in low and middle SE positions appear to have worse cardiovascular health compared with children with a high BMI in a high SE position.