title: Does the aging process significantly modify the Mean Heart Rate?
abstract: BACKGROUND
  The Mean Heart Rate (MHR) tends to decrease with age. When adjusted for gender and diseases, the magnitude of this effect is unclear.
  
  
  OBJECTIVE
  To analyze the MHR in a stratified sample of active and functionally independent individuals.
  
  
  METHODS
  A total of 1,172 patients aged > 40 years underwent Holter monitoring and were stratified by age group: 1 = 40-49, 2 = 50-59, 3 = 60-69, 4 = 70-79, 5 = > 80 years. The MHR was evaluated according to age and gender, adjusted for Hypertension (SAH), dyslipidemia and non-insulin dependent diabetes mellitus (NIDDM). Several models of ANOVA, correlation and linear regression were employed. A two-tailed p value <0.05 was considered significant (95% CI).
  
  
  RESULTS
  The MHR tended to decrease with the age range: 1 = 77.20 ± 7.10; 2 = 76.66 ± 7.07; 3 = 74.02 ± 7.46; 4 = 72.93 ± 7.35; 5 = 73.41 ± 7.98 (p < 0.001). Women showed a correlation with higher MHR (p <0.001). In the ANOVA and regression models, age and gender were predictors (p < 0.001). However, R² and ETA² < 0.10, as well as discrete standardized beta coefficients indicated reduced effect. Dyslipidemia, hypertension and DM did not influence the findings.
  
  
  CONCLUSIONS
  The MHR decreased with age. Women had higher values of MHR, regardless of the age group. Correlations between MHR and age or gender, albeit significant, showed the effect magnitude had little statistical relevance. The prevalence of SAH, dyslipidemia and diabetes mellitus did not influence the results.
authors.forename: Marcos Antonio Almeida
authors.initials: MA
authors.lastname: Santos
authors.forename: Antonio Carlos Sobral
authors.initials: AC
authors.lastname: Sousa
authors.forename: Francisco Prado
authors.initials: FP
authors.lastname: Reis
authors.forename: Thayná Ramos
authors.initials: TR
authors.lastname: Santos
authors.forename: Sonia Oliveira
authors.initials: SO
authors.lastname: Lima
authors.forename: José Augusto
authors.initials: JA
authors.lastname: Barreto-Filho
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology; D050171:Dyslipidemias / Q000503:physiopathology; D015716:Electrocardiography, Ambulatory; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D006973:Hypertension / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D015233:Models, Statistical; D015995:Prevalence; D011446:Prospective Studies; D012737:Sex Factors
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