Exercise heart rate kinetics in individuals with and without a family history of hypertension

Background Young adults with a family history of hypertension (+FHH) are genetically predisposed to hypertension development and share similar cardiovascular characteristics of adults with established hypertension. Exercise heart rate (HR) kinetics is primarily controlled by the autonomic nervous system and is likely altered in +FHH compared to adults without a family history of hypertension (-FHH). This observational research aimed to study HR kinetics in +FHH during physical activity modalities that relate to activities of daily living (i.e., walking and stair climbing/stepping). Methods Participants completed a maximal treadmill test and submaximal stepping test with continuously monitored HR. Exercise onset HR responses from rest through the first 10, 20, and 30 s of treadmill (3.2 km/h 1% grade) and stepping (30.5 cm 24 steps/min) exercise were analyzed. Postexercise HR recovery (HRR) was analyzed using peak HR vs. 15 s postexercise HR for both modalities. Results Thirty-seven young healthy adults participated (-FHH=22, age: 23±4 years, resting blood pressure 111±9/74±8, resting HR 76±14; +FHH=15, age: 23±3 years P=0.854, resting blood pressure 115±12/73±7 P=0.341/0.914, resting HR 68±12 P=0.116). Treadmill exercise onset HR was greater in the +FHH group (10 s 30.9±11.7, 20 s 36.6±11.4, 30 s 39.1±10.8 ∆BPM) compared to the -FHH group (10 s 23.6±9.6, 20 s 28.0±10.1, 30 s 31.2±12.0 ∆BPM; group P=0.028) with no group effect for HRR. There were no group differences for exercise onset HR or HRR during stepping exercise. Conclusions +FHH experience exaggerated heart rate responses at the onset of low intensity walking suggesting altered autonomic function and likely greater parasympathetic withdrawal. This may impact clinical outcomes and hypertension development.