Obesity Modifies the Effect of Fitness on  Heart Rate Indices during Exercise Stress  Testing in Asymptomatic Individuals.
OBJECTIVE
To assess the impact of aerobic fitness on exercise heart rate (HR) indices in an asymptomatic cohort across different body mass index (BMI) categories.


METHODS
We performed a cross-sectional analysis of 506 working-class Brazilian subjects, free of known clinical cardiovascular disease(e.g. ischemic heart disease and stroke) who underwent an exercise stress test.


RESULTS
There was a significant trend towards decreased HR at peak exercise, HR recovery and chronotropic index (CI) measures as BMI increased, but resting HR increased significantly across BMI categories. In multivariate analysis, the change in CI per unit change in metabolic equivalents of task was greater among the obese subjects than the normal-weight (2.7 vs. –0.07; p interaction = 0.029)and overweight (2.7 vs. 0.7; p interaction = 0.044) subjects. A similar pattern was seen with peak HR and HR recovery, although the formal tests of interaction did not achieve statistical significance.


CONCLUSIONS
Our findings strongly suggest that fitness is associated with a favorable HR profile and is modified by BMI. Intervention programs should place emphasis on fitness and not only on weight loss.
Ehimen C
EC
Aneni
Ebenezer T
ET
Oni
Chukwuemeka U
CU
Osondu
Seth S
SS
Martin
Michael J
MJ
Blaha
Emir
E
Veledar
Arthur S
AS
Agatston
Theodore
T
Feldman
Jose A M
JA
Carvalho
Raquel D
RD
Conceição
Raul D
RD
Santos
Khurram
K
Nasir
D000328:Adult; D015992:Body Mass Index; D001938:Brazil; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000453:epidemiology*; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009765:Obesity / Q000150:complications*; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology*