Blood Pressure, Fitness, And Fatness In Children The Arkansas Active Kids Study

Abstract

PURPOSE: The role of cardiorespiratory fitness (CRF) in pediatric health is gaining recognition. However, the quality and quantity of the current evidence are insufficient to inform clinical pediatric guidelines. Objective: to evaluate the association between direct measures of CRF and blood pressure status as determined by the 2017 screening guidelines from the American Academy of Pediatrics in school-age children. METHODS: Children (n=218) 7 to 10 years old participated in a single-study visit. Children were deemed to have high blood pressure (HBP) if blood pressure status was: elevated, stage-1 or stage-2 hypertension. CRF (V02peak) was measured using an incremental cycle ergometer test. Body composition was measured with DXA, and physical activity with accelerometers (7±1 days). Blood was sampled in the fasting state and estimated glomerular filtration rate (eGRF) calculated using the updated Schwartz equation. Children were categorized as having excess weight (EW) or normal weight (NW) if their fat mass index was above or below 1 z-score, respectively. Children were further classified into EW/NW more-fit or EW/NW less-fit using the groups’ median VO2peak. Multiple logistic regression analyses were used to model the probability of high blood pressure against VO2peak. RESULTS: Participants’ average age was 9 years, with 70% of EW children having HBP vs. 24% in the NW group (p<.0001). The probability of HBP decreased with increasing VO2peak in the EW group only (β=0.09, p=0.0095). There was no association between CRF and probability of HBP in NW children. eGFR was lower in the less-fit groups than in more-fit groups regardless of adiposity status, even after adjusting for age and blood pressure status (adjusted mean difference between more-fit and less-fit groups: EW=7.1 ml·min-1·1.73 m-2, p=0.0046 and NW= 2.9 ml·min-1·1.73 m-2p=0.0144). CONCLUSION: The probability of HBP dramatically decreases with increasing CRF in children with EW but not in children with NW. eGFR is lower in children with lower CRF, regardless of obesity status, but the effect of CRF on and kidney function is greater in EW than in NW kids. Funding USDA-ARS Projects 59-6250-4-001 and 6026-51000-012-06S. ECD partially supported by ArCAPT-8UG1OD024945.