C-reactive protein and cardiac vagal activity following resistance exercise training in young African-American and white men

Abstract

B. C-reactive protein and cardiac vagal activity following resistance exercise training in young African-American and white men. Am J Physiol Regul Integr Comp Physiol 296: R1098-R1105, 2009. First published February 4, 2009 doi:10.1152 doi:10. /ajpregu.90936.2008 Americans have a greater prevalence of hypertension and diabetes compared with white Americans, and both autonomic dysregulation and inflammation have been implicated in the etiology of these disease states. The purpose of this study was to examine the cardiac autonomic and systemic inflammatory response to resistance training in young African-American and white men. Linear (time and frequency domain) and nonlinear (sample entropy) heart rate variability, baroreflex sensitivity, tonic and reflex vagal activity, and postexercise heart rate recovery were used to assess cardiac vagal modulation. C-reactive protein (CRP) and white blood cell count were used as inflammatory markers. Twenty two white and 19 African-American men completed 6 wk of resistance training followed by 4 wk of exercise detraining (Post 2). Sample entropy, tonic and reflex vagal activity, and heart rate recovery were increased in white and African-American men following resistance training (P Ͻ 0.05). Following detraining (Post 2), sample entropy, tonic and reflex vagal activity, and heart rate recovery returned to baseline values in white men but remained above baseline in African-American men. While there were no changes in white blood cell count or CRP in white men, these inflammatory markers decreased in African-American men following resistance training, with reductions being maintained following detraining (P Ͻ 0.05). In conclusion, resistance training improves cardiac autonomic function and reduces inflammation in African-American men, and these adaptations remained after the cessation of training. Resistance training may be an important lifestyle modification for improving cardiac autonomic health and reducing inflammation in young African-American men.heart rate variability; exercise; heart rate recovery; inflammation

Influence of resistance training on cardiac autonomic modulation: literature review

“…Furthermore, there is evidence that the mechanisms involved in cardiovascular regulation interact with each other in a nonlinear way 13 . Heffernan et al 11 also observed that 4 weeks after the end of the training, in the African-American volunteer group, the entropy values of the sample remained above those found before the start of training.…”

“…Of the three articles included, two used an electrocardiogram 10,11 to capture the series of R-R intervals and one used the Suunto T6 Wristop heart rate monitor. 12 …”

“…Heffernan et al 11 observed 39 healthy adult men, divided into 2 groups: African-American group (18 volunteers) and Caucasian group (21 volunteers), and found that 6 weeks of training sessions performed for 60 minutes, three days per week brought improvements in cardiac autonomic function. The protocol used for resistance training was divided into two stages and applied on alternate days: one of the stages worked muscles in the legs, back and biceps, and the other the muscles in the chest, shoulders and triceps.…”

Cardiovascular and autonomic response induced by a 20-week military training programme in young healthy South African males

“…[4] We hypothesised that a 20-week training programme would have improved blood pressure variables when compared with week 1, instead we found that SBP and MAP remained unchanged, and only the decrease in DBP was statistically significant (Table 4). Week 1 measurements of resting blood pressure showed that only one participant had an elevated SBP (152 mmHg).…”

“…[1,2] Black Africans have stiffer large central arteries, impaired dilation of small peripheral arteries and a greater prevalence of hypertension, diabetes and cardiovascular disease. [2][3][4] It is well established that a number of cardiovascular indices, such as arterial stiffness, blood pressure and autonomic regulation, are differentially affected by ageing. [5] The influence of western lifestyle (sedentary behaviour and increased consumption of high-energy processed foods) and rural urbanisation in sub-Saharan Africa has seen a shift in the underlying population distribution of risk factors for cardiovascular disease.…”