Heart rate recovery does not predict endothelial function in obese women

The purpose of the present study was to examine the relationship between heart rate recovery (HR(REC)) and endothelial function in obese women with the metabolic syndrome. The metabolic syndrome has been associated with increased cardiometabolic risk including endothelial dysfunction. However, measurement of endothelial function via flow-mediated dilation (FMD) requires expensive equipment and qualified medical personnel, and therefore may be impractical in some healthcare settings. Heart rate recovery (HR(REC)) has predictive utility with respect to endothelial function in individuals with suspected coronary artery disease and individuals with the metabolic syndrome also have elevated risk for developing coronary artery disease. Thirty-one obese, sedentary women (age: 47.7±11.2 yr, mean±SD) who met the International Diabetes Federation criteria for the metabolic syndrome underwent a brachial artery ultrasound to determine FMD and nitroglycerine-mediated dilation (NTG). HR(REC) was assessed during 5 min of active recovery following a standardized VO(2 Peak) treadmill protocol. Results revealed that the %FMD was not correlated to HR(REC) when examined across all participants (r= 0.067, p=0.72). However, this relationship was significant in participants with impaired FMD (n=16, %FMD<6%) (r=0.71, p=0.002). Although HR(REC) may be a significant correlate of FMD in women with the metabolic syndrome and with prevalent endothelial dysfunction, it was not a significant correlate across all women with the metabolic syndrome. The present data do not support the use of HR(REC) as a possible screening tool for endothelial dysfunction in obese women with the metabolic syndrome.