Biochemical markers after the Norseman Extreme Triathlon

Blood Profiling of Athletes after COVID-19: Differences in Blood Profiles of Post-COVID-19 Athletes Compared to Uninfected Athletic Individuals-An Exploratory Analysis

Blood profiling data in athletic populations and their respective responses to SARS-CoV-2 infection are lacking. Thus, this exploratory pilot study aimed to analyze and compare clinical blood markers in previously infected trained athletes (ATH; 30 m/29 f) and a not previously infected healthy athletic control group (HC; 12 m/19 f). The ATH group undertook a sports medical examination which included extended blood analyses. Blood profiles with a total of 74 variables were assessed (blood counts, pro-/inflammatory and immunological markers, and micronutrients), and the ATH group was compared to the age-matched, vaccinated HC group with comparable athletic back grounds, though without previous SARS-CoV-2-infections. The ATH group showed lower IgG, Troponin-T levels, and they had a lower complement/acute-phase protein activation. Furthermore, Vitamin D levels were lower and electrolyte/micronutrient concentrations were higher in ATH. Soluble transferrin receptor as a marker of erythrocyte turnover was decreased whereas PTT as a coagulation marker was increased. Subgroup analyses according to sex revealed more differences between the women of the ATH and HC groups (for 25 different variables) than between the men (for 5 different variables), especially for immunological and metabolic variables. In particular, the immune system and electrolyte/micronutrient status should be observed frequently and sex-specifically in this athletic cohort.

The ratio of cardiac troponin T to troponin I may indicate non-necrotic troponin release among COVID-19 patients

BACKGROUND

Although cardiac troponin T (cTnT) and troponin I(cTnI) are expressed to similar amount in cardiac tissue, cTnI often reach ten-times higher peak levels compared to cTnT in patients with myocardial necrosis such as in acute myocardial infarction (MI). In contrast, similar levels of cTnT and cTnI are observed in other situations such as stable atrial fibrillation and after strenuous exercise.

OBJECTIVE

Examine cTnT and cTnI levels in relation to COVID-19 disease and MI.

METHODS

Clinical and laboratory data from the local hospital from an observational cohort study of 27 patients admitted with COVID-19 and 15 patients with myocardial infarction (MI) that were analyzed with paired cTnT and cTnI measurement during hospital care.

RESULTS

Levels of cTnI were lower than cTnT in COVID-19 patients (TnI/TnT ratio 0.3, IQR: 0.1-0.6). In contrast, levels of cTnI were 11 times higher compared to cTnT in 15 patients with MI (TnI/TnT ratio 11, IQR: 7-14). The peak cTnI/cTnT ratio among the patients with MI following successful percutaneous intervention were 14 (TnI/TnT ratio 14, IQR: 12-23). The 5 COVID-19 patient samples collected under possible necrotic events had a cTnI/cTnT ratio of 5,5 (IQR: 1,9-8,3).

CONCLUSIONS

In patients with COVID-19, cTnT is often elevated to higher levels than cTnI in sharp contrast to patients with MI, indicating that the release of cardiac troponin has a different cause in COVID-19 patients.

Natriuretic Peptides and Risk of Type 2 Diabetes: Results From the Biomarkers for Cardiovascular Risk Assessment in Europe (BiomarCaRE) Consortium

OBJECTIVE

Natriuretic peptide (NP) concentrations are increased in cardiovascular diseases (CVDs) but are associated with a lower diabetes risk. We investigated associations of N-terminal pro-B-type NP (NT-proBNP) and midregional proatrial NP (MR-proANP) with incident type 2 diabetes stratified by the presence of CVD.

RESEARCH DESIGN AND METHODS

Based on the Biomarkers for Cardiovascular Risk Assessment in Europe (BiomarCaRE) Consortium, we included 45,477 participants with NT-proBNP measurements (1,707 developed type 2 diabetes over 6.5 years of median follow-up; among these, 209 had CVD at baseline) and 11,537 participants with MR-proANP measurements (857 developed type 2 diabetes over 13.8 years of median follow-up; among these, 106 had CVD at baseline). The associations were estimated using multivariable Cox regression models.

RESULTS

Both NPs were inversely associated with incident type 2 diabetes (hazard ratios [95% CI] per 1-SD increase of log NP: 0.84 [0.79; 0.89] for NT-proBNP and 0.77 [0.71; 0.83] for MR-proANP). The inverse association between NT-proBNP and type 2 diabetes was significant in individuals without CVD but not in individuals with CVD (0.81 [0.76; 0.86] vs. 1.04 [0.90; 1.19]; P multiplicative interaction = 0.001). There was no significant difference in the association of MR-proANP with type 2 diabetes between individuals without and with CVD (0.75 [0.69; 0.82] vs. 0.81 [0.66; 0.99]; P multiplicative interaction = 0.236).

CONCLUSIONS

NT-proBNP and MR-proANP are inversely associated with incident type 2 diabetes. However, the inverse association of NT-proBNP seems to be modified by the presence of CVD. Further investigations are warranted to confirm our findings and to investigate the underlying mechanisms.

Reduced L-Arginine and L-Arginine-ADMA-Ratio, and Increased SDMA after Norseman Xtreme Triathlon

Endothelial vasodilatory function is dependent on the NO synthesis from L-arginine by endothelial NO-synthetase (eNOS). eNOS can be inhibited by asymmetric dimethylarginine (ADMA) by competitive inhibition on the binding site, and symmetric dimethylarginine (SDMA) can reduce the L-arginine availability intracellularly through competing for transport over the cellular membrane. To study the NO synthesis after prolonged exercise, we assessed circulatory L-arginine, the L-arginine/ADMA ratio, and SDMA before, after, and on the day after the Norseman Xtreme triathlon, an Ironman distance triathlon. We found significantly reduced levels of L-arginine and the L-arginine/ADMA ratio and increased levels of SDMA after the race (all p < 0.05). L-arginine rose toward baseline levels the day after the race, but ADMA increased beyond baseline levels, and SDMA remained above baseline the day after the race. The reduced levels of L-arginine and the L-arginine/ADMA ratio, and increased SDMA, after the race indicate a state of reduced capability of NO production. Increased levels of ADMA and SDMA, and reduced L-arginine/ADMA ratio, as seen the day after the race, are known risk markers of atherosclerosis and warrant further studies.

Transient Reduction of FMD-Response and L-Arginine Accompanied by Increased Levels of E-Selectin, VCAM, and ICAM after Prolonged Strenuous Exercise

We assessed endothelial function by flow-mediated dilatation (FMD), levels of the NO-precursor L-arginine, and markers of endothelial inflammation before, at the finish line, and one week after the Norseman Xtreme triathlon. The race is an Ironman distance triathlon with a total elevation of 5200 m. Nine male participants were included. They completed the race in 14.5 (13.4–15.3) h. FMD was significantly reduced to 3.1 (2.1–5.0)% dilatation compared to 8.7 (8.2–9.3)% dilatation before the race (p < 0.05) and was normalized one week after the race. L-arginine showed significantly reduced levels at the finish line (p < 0.05) but was normalized one week after the race. Markers of endothelial inflammation E-Selectin, VCAM-1, and ICAM-1 all showed a pattern with increased values at the finish line compared to before the race (all p < 0.05), with normalization one week after the race. In conclusion, we found acutely reduced FMD with reduced L-arginine levels and increased E-Selectin, VCAM-1, and ICAM-1 immediately after the Norseman Xtreme triathlon. Our findings indicate a transient reduced endothelial function, measured by the FMD-response, after prolonged strenuous exercise that could be explained by reduced NO-precursor L-arginine levels and increased endothelial inflammation.