Relation between heart rate recovery after exercise testing and body mass index

Abstract

Background: Impaired heart rate (HR) recovery after exercise testing is considered a predictor of cardiovascular mortality as it reflects vagus nerve dysfunction. Objective: To assess the relationship between body mass index (BMI) and HR recovery after exercise. Methods: We analyzed the records of 2443 patients of both sexes, aged between 20 and 59 years, in sinus rhythm, not using negative chronotropic agents and with no myocardial ischemic response to exercise testing carried out at a specialist clinic, between 2005 and 2011. BMI was categorized as normal (18.5---<25 kg/m 2 ), overweight (25---≤30 kg/m 2 ) or obese (>30 kg/m 2 ). The different BMI groups were compared in terms of HR recovery after exercise, which was calculated as the difference between maximum HR during exercise and in the first minute of recovery. Recovery was considered impaired when the difference was ≤12 bpm. Results: Eighty-seven (3.6%) patients presented impaired recovery, which was three times more prevalent in the obese group and twice as prevalent in the overweight group compared with the normal group (p<0.001 and p=0.010, respectively). Obese patients presented higher basal HR and lower maximum HR, as well as reduced chronotropic reserve (p<0.001). In multivariate analysis, impaired HR recovery was associated with overweight (relative risk [RR]=1.8; p=0.035), obesity (RR=2; p=0.016), number of metabolic equivalents (RR=0.82; p<0.001) and resting HR (RR=1.05; p<0.001). The hazard ratio for hypertension was 2 (p=0.083, NS). Conclusion: Impaired HR recovery was associated with higher BMI, demonstrating that obese individuals present vagus nerve dysfunction. Relação entre a frequência cardíaca de recuperação após teste ergométrico e índice de massa corpórea ResumoFundamento: Declínio atenuado da frequência cardíaca após teste ergométrico é considerado preditor de mortalidade cardiovascular, por refletir disfunção autonômica vagal. Objetivo: Avaliar a relação entre índice de massa corpórea (IMC) e recuperação da frequência cardíaca após teste ergométrico. Métodos: Foram incluídos registros de 2.443 pacientes de ambos os sexos, entre 20-59 anos, em ritmo sinusal, sem uso de cronotrópicos negativos e sem resposta isquêmica miocárdica ao teste ergométrico realizado em clínica especializada, entre 2005-2011. O IMC foi categorizado como: normal (18,5 kg/m 2 <IMC ≤25 kg/m 2 ), sobrepeso (25 kg/m 2 <IMC ≤30 kg/m 2 ) e obeso (IMC >30 kg/m 2 ). A recuperação da frequência cardíaca após esforço, obtida pela diferença entre a máxima no esforço e no 1. • minuto da recuperação, foi comparada entre grupos de IMC. Foi considerada atenuada quando ≤12 bpm. Resultados: Oitenta e sete (3,6%) pacientes registraram recuperação atenuada, sendo três vezes maior no grupo de obesos e duas vezes no de sobrepeso, quando comparados ao grupo adequado (p<0,001, p=0,010, respectivamente). Obesos apresentaram maior frequência cardíaca basal e menor máxima, além de menor reserva cronotrópica (p<0,001). Na análise multivariada, identificou-se influência dessa atenuação po...

Relationship between adiposity and heart rate recovery following an exercise stress test in obese older women

“…In this study, after adjusting for covariates using hierarchical multiple regression percentage body fat, MET, and age were negative determinants of 1-minute HRR. The results are in line with three previous studies 10,13 , that a higher percentage body fat and age were associated with an impaired HRR. Moreover, a higher maximal MET level was associated with a better HRR following 1-minute post treadmill exercise testing.…”

“…For non-parametric variables (disease, medications, chronotropic incompetence, and chrono-tropic index), a Chi square for proportions was used and Cramer's V test of association was applied. First, the multiple linear regression utilized the forward step elimination method for independent variables in the model (percent body fat, BMI, MET, WC, WHR, hypertension, diabetes, and age], according to recommendations from literature 13,12,22 .The continuous dependent variable (1 minute HR recovery) was chosen based on previous research 22 . It is noteworthy that the time constant of an earlier phase of the heart rate (e.g.…”

“…Furthermore, a study in obese subjects with low levels of physical fitness revealed an impaired chronotropic index and HRR during and after exercise stress testing 10 . Several studies have shown that parameters of obesity negatively affect HRR following exercise [11][12][13] . Barbosa et al 13 analysed the relationship between body mass index (BMI) and HRR after one minute of exercise and demonstrated that obese subjects (>30 kg/m 2 ) presented higher basal HR and lower maximum HR accompanied by reduced chronotropic reserve.…”

“…Several studies have shown that parameters of obesity negatively affect HRR following exercise [11][12][13] . Barbosa et al 13 analysed the relationship between body mass index (BMI) and HRR after one minute of exercise and demonstrated that obese subjects (>30 kg/m 2 ) presented higher basal HR and lower maximum HR accompanied by reduced chronotropic reserve. Deniz et al 14 reported that HRR was impaired in young adult males with metabolic syndrome as compared with obese subjects without metabolic syndrome.…”

Influence of maternal physical exercise on fetal and maternal heart rate responses

“…Chronic cardiovascular exercise in adults leads to adaptations of the ANS evidenced by lower heart rate (HR) at rest, exercise and recovery (Barbosa, Valente, Sobral, & Barbosa, 2015;Ostojic et al, 2010). Based on Barker's theory, similar adaptations should occur to the fetus in utero in response to chronic maternal exercise.…”