Acute autonomic effects of vitamins and fats in male smokers

Abstract

Background/Objectives: Vitamins can help improve cardiovascular control. In contrast, smoking works in the opposite fashion, reducing the baroreflex control of heart rate (HR) possibly via oxidative stress. High-fat challenges also impair cardiovascular regulation. Whether vitamins have acute beneficial effects on the baroreflex control of HR in smokers is unclear. Subjects/Methods: A randomized, placebo-controlled crossover study in 30 male smokers (34.276.9 years). Interventions were: (1) moderate (vitamin C (300 mg) and E (75 IU) and folic acid (1 mg)); (2) high doses of vitamins (vitamin C (2 g) and E (800 IU), and folic acid (5 mg)); or, (3) placebo. Vitamins were ingested with cream (a high-fat challenge) or milk (low-fat control). Four hours later, blood was withdrawn and radial pulse wave forms recorded via tonometry. Spontaneous beat-to-beat variations in HR and systolic blood pressure (SBP) were analysed by spectral analysis techniques and sympathovagal control of HR and baroreflex sensitivity (BRS) were assessed. Results: High doses of vitamins increased plasma vitamin C, E and folic acid levels (Po0.05) with no change in SBP, HR or BRS (P40.05, analysis of variance). Plasma vitamin levels did not correlate with any cardiovascular parameters. Moderate vitamins increased the vagal control of HR ( þ 23%; Po0.05) and cream led to small increases (Po0.05) in SBP ( þ 2 mm Hg) and HR ( þ 2 beats min À1 ) with no change in BRS. Conclusions: In male smokers, circulating antioxidants had no effect on BRS and minor effects on the cardiovascular system were seen following acute fat and vitamin ingestion.

Catalase Inhibition Into the Fourth Cerebral Ventricle Affects Bradycardic Parasympathetic Response to Increase in Arterial Pressure Without Changing the Baroreflex

“…Monahan et al [29] supported the hypothesis that oxidative stress contributes to age-associated decreases in cardiovagal baroreflex sensitivity in healthy men. On the other hand, Wright et al [30] indicated that in male smokers, circulating antioxidants had no effect on baroceptor reflex function and minor effects on the cardiovascular system were seen following acute fat and vitamin ingestion. To the best of our knowledge, no previous study investigated the effects of ATZ into the 4 th V on baroreflex function.…”

“…Therefore, we believe that our investigation provides honest and useful information regarding the effects of the catalase inhibitor ATZ into the 4 th V on baroreflex components in conscious Wistar rats. These data present relevant information since currently, baroceptor reflex is largely studied in different models and strain of rats [14,15] aiming to prevent hypertension development in human [29,30], due to the fact that impaired autonomic regulation of cardiovascular system is indicative of cardiovascular disease [32][33][34][35].…”

ATZ (3-amino-1,2,4-triazole) injected into the fourth cerebral ventricle influences the Bezold–Jarisch reflex in conscious rats

“…Monahan et al23 supported the hypothesis that oxidative stress contributes to age‐associated decreases in cardiovagal baroreflex sensitivity in healthy men. On the other hand, Wright et al24 indicated that in male smokers, circulating antioxidants had no effect on baroceptor reflex function, and minor effects on the cardiovascular system were seen following acute fat and vitamin ingestion. To the best of our knowledge, no previous has study investigated the effects of ATZ injected into the V4 on cardiopulmonary reflex.…”

Reactive Oxygen Species and Cardiovascular Diseases

“…Monahan et al (2007) supported the hypothesis that oxidative stress collaborates to ageassociated decreases in cardiovagal baroreflex sensitivity in healthy men. On the other hand, Wright et al (2009) indicated that in male smokers, circulating antioxidants had no effect on baroceptor reflex function and minor effects on the cardiovascular system were seen following acute fat and vitamin ingestion.…”