Helicobacter pylori in sedentary men is linked to higher heart rate, sympathetic activity, and insulin resistance but not inflammation or oxidative stress.

Helicobacter pylori (H.pylori) is a widely spread infection causing major gastroenterological diseases like chronic gastritis, peptic ulcer, gastric adenocarcinoma, and mucosa-associated lymphoid tissue lymphoma (1). In addition, several extragastric diseases and pathological conditions have been linked to this microorganism (2). Since H.pylori is able to cause local tissue damage through reactive oxygen species generation, local oxidative stress is currently considered as a triggering mechanism for inflammatory processes in the stomach (3). Local oxidative stress associated with low grade inflammation is suggested to be responsible for numerous systemic changes, including metabolic deteriorations like nonalcoholic fatty liver disease, insulin resistance, metabolic syndrome, and diabetes type 2 (2-7). It was previously demonstrated that H.pylori induced excessive lipid peroxidation and accumulation of 4-hydroxynonenal (HNE)-histidine adducts in the gastric mucosa of patients with duodenal peptic ulcer (8). Interestingly, shortly after H.pylori eradication in four weeks period, manifestations of oxidative stress in these patients persisted (9). The other important finding of these two studies is that in a significant number of the control group participants, consisting of both H.pylori positive and negative participants without the history of peptic ulcer disease, mild accumulation of HNE-histidine adducts was observed. It is also possible that, to some extent, HNE production may be a physiological process, and that this molecule may be exploited by mucosal cells as a local regulatory mechanism (10). 1,4-dihydroxynonane mercapturic acid (DHN-MA) in urine, a water soluble metabolite of HNE, is a potential noninvasive biomarker of oxidative stress (11). Insulin resistance, metabolic syndrome, atherosclerosis, and type 2 diabetes develop gradually and have a long latency period. Until recently, most of the studies have focused on already established pathologic conditions, and relatively little attention has been paid to early stages of these diseases in participants without any clinical manifestations. Early shifts, hence difficult to diagnose, are extremely attractive from the clinical point of view, since their detection allows early interventions, enabling the reversal of the pathological process. Conventional clinical parameters, however, cannot detect these changes. Recently, we have suggested that heart rate variability (HRV) may be one of the methods allowing determination of early metabolic changes (12). Importantly, HRV allows noninvasive examinations, which is important for screening programs. Following this hypothesis we found that in apparently healthy sedentary participants HRV reduction correlated with age, subclinical deteriorations of carbohydrate metabolism, and excessive fat accumulation (13). A significant reduction of HRV reflecting autonomic imbalance was also observed in a number of other diseases and conditions, for example ventricular arrhythmia, heart failure, myocardial infarction, and type 2 diabetes, even without evidence of autonomic neuropathy, liver damage, hypertension, all-cause mortality (14), Marfan syndrome (15), and many other problems. Early interventions may reverse initial metabolic shifts and improve HRV, which was shown in particular in the treatment of H.pylori-associated duodenal peptic ulcer (16). Correlations of HRV and metabolic parameters were also shown in athletes, and amaranth seed oil (Amaranthus cruenthus, L.) was used as a remedy to enhance recovery and to improve HRV (17). Since H.pylori positivity is associated with metabolic syndrome and insulin resistance (5,6), and early metabolic deteriorations cause HRV reduction in sedentary apparently healthy young participants (13), we hypothesize that contamination by this microorganism may cause low grade systemic oxidative stress, inflammation, and HRV reduction in sedentary participants. Therefore the aim of our study was to compare anthropometric parameters, body composition, HRV, carbohydrate metabolism, hormonal and inflammatory profiles, and DHN-MA in H.pylori positive and negative healthy sedentary male participants.