Iron deficiency in athletes: Prevalence and impact on VO2 peak.

BACKGROUND: Iron is an important micronutrient in pathways of energy production, adequate nutrient intake and its balance is essential for optimal athletic performance. However, large studies elucidating the impact of iron deficiency on athletes' performance are sparse. METHODS: Competitive athletes of any age who presented for preparticipation screening 04/2020-10/2021 were included in this study and stratified for iron deficiency (defined as ferritin level <20 µg/l with and without mild anemia [hemoglobin levels ≥11 g/dl]). Athletes with and without iron deficiency were compared and the impact of iron deficiency on athletic performance was investigated. RESULTS: Overall, 1190 athletes (mean age 21.9 ± 11.6 years; 34.2% females) were included in this study. Among these, 19.7% had iron deficiency. Patients with iron deficiency were younger (18.1 ± 8.4 vs. 22.8 ± 12.1 years, P < 0.001), more often females (64.5% vs. 26.8%, P < 0.001), had lower VO2 peak value (43.4 [38.5/47.5] vs. 45.6 [39.1/50.6]ml/min/kg, P = 0.022) and lower proportion of athletes reaching VO2 peak of >50 ml/min/kg (8.5% vs. 16.1%, P = 0.003). Female sex (OR 4.35 [95% CI 3.13-5.88], P > 0.001) was independently associated with increased risk for iron deficiency. In contrast, the risk for iron deficiency decreased by every life year (OR 0.97 [95% CI 0.95-0.99], P = 0.003). Iron deficiency was independently associated with reduced VO2 peak (OR 0.94 [0.91-0.97], P < 0.001) and lower probability to reach VO2 peak >50 ml/min/kg (OR 0.42 [95% CI 0.25-0.69], P = 0.001). CONCLUSIONS: Iron deficiency is common in athletes (predominantly in female and in young athletes). Iron deficiency was independently associated with reduced VO2 peak during exercise testing and lower probability to reach a VO2 peak >50 ml/min/kg.

Epicardial fat volume is associated with primary coronary slow-flow phenomenon in patients with severe aortic stenosis undergoing transcatheter valve implantation.

BACKGROUND: Primary coronary slow flow (CSF) is defined as delayed opacification of the distal epicardial vasculature during coronary angiography in the absence of relevant coronary artery stenoses. Microvascular disease is thought to be the underlying cause of this pathology. Epicardial fat tissue (EFT) is an active endocrine organ directly surrounding the coronary arteries that provides pro-inflammatory factors to the adjacent tissue by paracrine and vasocrine mechanisms. The aim of the present study was to investigate a potential association between EFT and primary CSF and whether EFT can predict the presence of primary CSF. METHODS: Between 2016 and 2017, n = 88 patients with high-grade aortic stenosis who were planned for transcatheter aortic valve implantation (TAVI) were included in this retrospective study. EFT volume was measured by pre-TAVI computed tomography (CT) using dedicated software. The presence of primary CSF was defined based on the TIMI frame count from the pre-TAVI coronary angiograms. RESULTS: Thirty-nine of 88 TAVI patients had CSF (44.3%). EFT volume was markedly higher in patients with CSF (142 ml [IQR 107-180] vs. 113 ml [IQR 89-147]; p = 0.009) and was strongly associated with the presence of CSF (OR 1.012 [95%CI 1.002-1.021]; p = 0.014). After adjustment, EFT volume was still an independent predictor of CSF (OR 1.016 [95%CI 1.004-1.026]; p = 0.009). CONCLUSION: Primary CSF was independently associated with increased EFT volume. Further studies are needed to validate this finding and elucidate whether a causal relationship exists.