FAST HEART RATE AS PREDICTOR OF OVERWEIGHT IN SUBJECTS SCREENED FOR STAGE 1 HYPERTENSION: PP.34.354

Abstract

Objective: Increased sympathetic activity has been found to predict body weight (BW) gain. We did a prospective study to investigate whether clinic heart rate (HR) and 24 h ambulatory HR assessed at baseline and changes in heart rate during follow-up were independent predictors of subsequent increase in BW. Design and Methods: The study was conducted in a cohort of 1008 white stage 1 hypertensive subjects from the HARVEST never treated for hypertension and followed-up for an average of 7 years. Clinic heart rate was the average of 6 readings. Ambulatory heart rate was obtained in 701 subjects. Data were adjusted for baseline body mass index, blood pressure, age, gender, physical activity habits, parental hypertension, cigarette smoking, and alcohol consumption. Results: At the baseline, clinic heart rate was 74.7 ± 9.7 bpm and body mass index was 25.4 ± 3.4 Kg/m2. During the follow-up BW increased by 2.1 ± 7.2 Kg. Both clinic HR (p = 0.005) and 24h HR (p = 0.02) were significant predictors of BW gain. Also changes in HR measured in the clinic (p = 0.005) or with 24h recording (p = 0.004) during the follow-up were independent associates of BW gain. In multivariable Cox regression, baseline body mass index (p < 0.001), male gender (p < 0.001), systolic blood pressure (p = 0.01), baseline clinic HR (p = 0.02) and follow-up changes in clinic HR (p < 0.001) were independent predictors of overweight at the end of the follow-up. Subjects with persistent tachycardia (heart rate > = 80 bpm) but not transient tachycardia had a 40% increase in the adjusted risk of overweight in comparison with subjects with normal heart rate (p = 0.02). In the subgroup of subjects with ambulatory HR data, clinic HR remained a significant predictor of subsequent BW gain (p = 0.008) whereas 24h HR was excluded from the model. Conclusions: Baseline clinic HR and HR changes during the follow-up are independent predictors of BW gain in young persons screened for stage 1 hypertension suggesting that sympathetic nervous system activity may play a role in the development of obesity in hypertension.