Obesity and Ventilatory Responses During Exercise in the Fitness Registry and the Importance of Exercise National Database (FRIEND).

Adults with obesity had a higher VE/VCO2 slope compared to those without obesity, but the effect size was negligible.

• VE/VCO2 slope was 25.0 [IQR 3.5] in adults with obesity versus 24.7 [IQR 3.6] in adults without obesity (BMI cutoff of 30 kg/m2).
• The linear regression model adjusted for age, sex, and race/ethnicity yielded R2 = 0.132, adjusted R2 = 0.131, F4,3529 = 134, p < 0.001.
• Despite statistical significance, the effect size was described as negligible.
• All participants completed a cardiopulmonary exercise test on a cycle ergometer.

VE/VCO2 slope was weakly but statistically significantly associated with BMI across the entire cohort after adjustment for covariates.

• Partial correlation adjusted for age, sex, race/ethnicity, and cardiorespiratory fitness yielded ρ = 0.079, p < 0.001.
• The association was described as 'weak' by the authors.
• The analysis included n = 3534 apparently healthy adults from the FRIEND Registry.

The FRIEND Registry sample used in this study was predominantly male, middle-aged, and had a median BMI in the overweight range.

• Sample size was n = 3534.
• Median age was 40 [IQR 17] years.
• 20% of participants were female.
• Median BMI was 26.1 [IQR 5.0] kg/m2.
• Cardiorespiratory fitness was 27.8 [IQR 10.8] mL O2·kg-1·min-1 and 2.3 [IQR 0.9] L O2·min-1.

A high VE/VCO2 slope during exercise is prognostic for cardiovascular mortality among clinical populations, providing context for studying its relationship with obesity.

• Obesity is described as a major modifiable risk factor for cardiovascular disease.
• The VE/VCO2 slope represents minute ventilation relative to rate of carbon dioxide production during exercise.
• Prior to this study, it was unclear whether BMI is associated with VE/VCO2 slope among apparently healthy adults.