Abstract 1070: Fatness, Fitness, and Systolic Blood Pressure
Modifying risk factors to delay or prevent hypertension is critical for subsequent cardiovascular risk reduction. Understanding the independent and joint association between cardiorespiratory fitness and obesity on systolic blood pressure (SBP) is therefore of major significance. In this study we assessed the relative contribution of body mass index (BMI) and cardiorespiratory fitness to SBP in a large, healthy population.
Methods: Blood pressure, BMI, and cardiovascular fitness were measured in 38,502 patients seen for a preventive health exam (1990 to present). BMI was treated both as a continuous variable and categorized into sex-specific quartiles. Cardiorespiratory fitness was determined by maximal exercise testing and categorized into age and sex-adjusted quintiles. Generalized linear models were used to determine the independent association between BMI and SBP after accounting for fitness.
Results: The study group was predominately men (69%) with an average age of 46 years. BMI explained 11% of the variance of SBP while fitness explained 1% of the variance. BMI was independently associated with SBP after adjusting for age, gender, diabetes, smoking history, cholesterol level, and fitness quintile (P<0.0001). BMI quartile was more strongly associated with SBP compared to fitness level (figure⇓). Lean individuals with modest levels of fitness (>Q1) had the lowest SBP (p-interaction <0.001).
Conclusion: The major finding of this study is that obesity is pivotal in predicting SBP, independent of fitness. These data suggest weight loss is the best intervention to optimize blood pressure, while cardiorespiratory fitness may be of modest importance after weight loss.