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Biomedical subjects

Federico Schena

Publications and source records attributed to Federico Schena.

9 recordsLinked to original sources

Influence of physical exercise and relationship with biochemical variables of NT-pro-brain natriuretic peptide and ischemia modified albumin.

BACKGROUND: The diagnostic approach and the clinical management of patients presenting with suspected acute coronary syndrome or cardiac dysfunction are as yet challenging. Although ischemia modified albumin (IMA) and natriuretic peptides were recently proposed for detection of myocardial ischemia and cardiac dysfunction, little information is available on preanalytical and metabolic sources of variability of these markers. METHODS: To establish the influence of a regular endurance training and the relationship with conventional biochemical variables, NT-pro-brain natriuretic peptide (NT-proBNP) and IMA were assayed, along with cardiac troponin T (cTnT), lactate dehydrogenase (LDH), creatine kinase (CK), creatinine and albumin, in 35 sedentary healthy individuals and 50 male professional road cyclists, 12-24 h following the last demanding training session. RESULTS: Athletes displayed higher values of both LDH (299+/-61 vs. 257+/-36 U/l, P=0.002) and CK (184+/-123 vs. 115+/-74 U/l, P=0.011), and slightly lower concentrations of creatinine (82+/-12 vs. 87+/-9 micromol/l, P=0.044). No athlete or sedentary control displayed cTnT concentrations exceeding the lower sensitivity limit of the assay. As compared to the sedentary controls, main IMA concentration was increased in athletes (100+/-13 vs. 94+/-6 KU/l, P=0.035), whereas that of NT-proBNP appeared significantly decreased (2.8+/-1.6 vs. 4.3+/-34, P=0.005). The percentage of subjects displaying values exceeding the upper reference limit for the IMA assay was significantly different between athletes and sedentary controls (50% vs. 7%; P<0.001). Pearson correlation analysis revealed an inverse association between IMA and albumin in both athletes (r=-0.640; P<0.001) and sedentary controls (r=-0.583; P=0.001). CONCLUSIONS: Results of our investigation indicate that a demanding and regular aerobic training regimen, though able to trigger skeletal muscle sufferance, is not associated with any biochemical sign of severe and irreversible chronic cardiac involvement. Moreover, we suggest the adoption of specific IMA diagnostic thresholds following patients' stratification according to serum albumin concentration and physical activity.

Adult↗

Fatigue induced by a cross-country skiing KO sprint.

PURPOSE: The aims of the present study were 1) to analyze whether the KO sprint simulation induced a phenomenon of fatigue of upper and lower limbs and 2) if there was any fatigue, to determine its origin. METHODS: Seven elite male skiers were tested before and after a simulation of KO sprints consisting of three 1200-m laps separated by 12 min of recovery. Surface electromyographic activity and force obtained under voluntary and electrically evoked contractions (single twitch) on knee-extensor muscles were analyzed to distinguish neural adaptations from contractile changes. A maximal power output test of the upper limbs was also performed. RESULTS: During the last lap, the final sprint velocity was significantly lower than during the first lap. After the KO sprint, knee-extensor voluntary (-9.8 +/- 9.5%) and evoked (-16.2 +/- 11.9%) isometric force and upper-limb power output (-11.0 +/- 9.3%) and force (-11.3 +/- 8.7%) significantly decreased, whereas the blood lactate concentration increased to 11.6 mM. On the other hand, no changes were seen in RMS measurement during maximal voluntary contractions, RMS normalized by M-wave amplitude, or M-wave characteristics. CONCLUSION: Changes in performance, lactate concentration, knee-extensor strength, and upper-limb power indicated that the KO sprint test led the skiers to a state of fatigue. On lower-limb muscles, the decrease of knee-extensor strength was exclusively caused by peripheral fatigue, which was at least in part attributable to a failure of the excitation-contraction coupling.

Adult↗

Comparison of the lipid profile and lipoprotein(a) between sedentary and highly trained subjects.

BACKGROUND: There is consolidated evidence that physical activity exerts beneficial effects on several chronic conditions and longevity, on the basis of its proposed biological effects, especially on lipid profiles. However, debate continues regarding the intensity of activity required for good health, as vigorous physical activity might overwhelm advantageous changes. In addition, little is known so far on the effect of a vigorous and regular aerobic training regimen on emerging markers of cardiovascular risk, such as lipoprotein(a), total/high-density lipoprotein cholesterol ratio and the atherogenic index of plasma. METHODS: To further investigate this topic, an extensive lipid profile, in accordance with the most recent guidelines issued by the American Heart Association (AHA)/American College of Cardiology (ACC) and the National Cholesterol Education Program (NCEP), was evaluated in 60 healthy male sedentary controls and in a wide population of professional endurance athletes, including 40 male professional cross-country skiers and 102 male professional road cyclists. RESULTS: Total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), triglycerides, TC low-density lipoprotein cholesterol (LDL-C) ratio and the atherogenic index of plasma were significantly lower in both categories of professional athletes, whereas the mean HDL-C concentration was significantly higher. The concentration of lipoprotein(a) did not differ significantly between the groups. When compared to current NCEP or AHA/ACC goals, the percentage of patients with undesirable values was statistically different for all parameters tested, apart from lipoprotein(a). According to multiple stepwise logistic regression analysis, lower TC/HDL-C ratio in professional skiers and lower TC/HDL-C ratio and TC in professional cyclists were significantly associated with increased aerobic physical activity. CONCLUSIONS: Results of this case-control study confirm that elevated aerobic energy expenditure might be associated with a highly favorable stabilization of most traditional and emerging cardiovascular risk predictors. Therefore, a substantial increase in aerobic physical activity within the population might be recommended to reverse adverse lipid abnormalities, especially in subjects with a higher cardiovascular risk.

Adult↗

Serum ferritin as a marker of potential biochemical iron overload in athletes.

OBJECTIVES: Beyond hematological manipulation, iron supplementation therapy is commonplace in athletes to counterbalance physiological or pathologic anemia and to prevent physiologic dysfunction. However, misuse of iron therapy, occasionally resulting in iron overload, is not free from metabolic risks. DESIGN: We planned to measure baseline serum ferritin concentration in sedentary individual and athletes. SETTING: The Institute of Clinical Biochemistry of the Verona University. PARTICIPANTS Serum ferritin was measured in 60 male healthy sedentary controls, 80 amateur road cyclists, 42 male professional cross-country skiers, and 88 professional male road cyclists. ASSESSMENT OF RISK FACTORS: The biochemical iron overload was ascertained by measuring baseline serum ferritin concentration as a reliable approach that mirrors the total body iron content. MAIN OUTCOME MEASUREMENTS: The concentration of serum ferritin in healthy controls was 112 +/- 78 ng/mL, whereas that of amateur cyclists, professional skiers, and professional cyclists was 127 +/- 76 ng/mL (P = 0.185), 183 +/- 130 ng/mL (P = 0.001), and 332 +/- 218 ng/mL (P < 0.001), respectively. RESULTS: Both categories of professional athletes showed significantly increased concentrations of serum ferritin, whereas the concentration of amateur cyclists was comparable to that of healthy sedentary controls. CONCLUSIONS: Professional endurance athletes have serum ferritin concentrations that are 2-fold to 3-fold higher than those of matched sedentary individuals and amateur athletes, exceeding the threshold for the diagnosis of biochemical iron overload and unveiling potential metabolic risks.

Bicycling↗

Quantifying the contribution of arm postural tremor to the outcome of goal-directed pointing task by displacement measures.

A method for quantifying the outcome of goal-directed postural pointing was presented and used for relating the tremor output to the oscillations of single arm landmarks. The displacement of reflective markers placed on shoulder, upper arm, forearm, and hand were measured by an optoelectronic motion capture system in nine subjects holding a laser penlight pointed at a target. The high signal-to-noise ratio of the measured displacement series (from 7:1 for shoulder marker to 30:1 for hand marker) demonstrated the feasibility of the proposed system to carry out tremor analysis. The track of the laser emission on the target, reconstructed from penlight displacements, was studied as the outcome of the pointing task. By measuring the length and the dispersion of the path covered by the target track in 30 s, a significant and comparable tremor amplitude was found in vertical and lateral directions. The correlation between target track and arm tremor was stronger for distal than for proximal markers. Spectral and cross-spectral analyses evidenced the presence of a dominant low frequency oscillation (1.5 Hz), along with a high frequency one (5-7 Hz), in the displacement of the target track. These two components were significantly linked to the oscillations of the hand, the forearm and the upper arm but not to those of the shoulder, suggesting that the oscillations in the overall tremor output during the pointing task are mainly generated by the arm segments.

Adult↗

Comparison of serum creatinine, uric acid, albumin and glucose in male professional endurance athletes compared with healthy controls.

Owing to considerable physical, endocrinological and metabolic adaptations, the analysis of biochemical data in elite and top-class athletes requires caution. With the aim to identify metabolic and biochemical adaptations to particular lifestyle conditions, such as regular and strenuous physical exercise, we measured the concentration of serum albumin, creatinine, uric acid and glucose in 80 male professional cyclists, 37 male members of the Italian national cross-country ski team and 60 male healthy sedentary controls at rest. At variance with earlier investigations, endurance athletes showed significantly decreased concentrations of serum creatinine (controls: 83.1+/-11.0 micromol/l; skiers: 78.0+/-8.4 micromol/l; p<0.05; cyclists: 73.8+/-10.4 micromol/l; p<0.01), uric acid (controls: 362+/-69 micromol/l; skiers: 331 +/-70 micromol/l; p<0.05; cyclists: 312+/-61 micromol/l; p<0.01) and glucose (controls: 5.35+/-0.54 mmol/l; skiers: 4.94+/-0.41 mmol/l; p<0.01; cyclists: 4.94+/-0.42 mmol/l; p<0.01). The concentration of serum albumin was also decreased in athletes, but the difference did not reach statistical significance (controls: 4.76+/-0.26 g/l; skiers: 4.71+/-0.22 g/l; p=0.384; cyclists: 4.68+/-0.22 g/l; p=0.393). Results of the present investigation demonstrate that values of laboratory testing lying outside conventional reference limits calculated on sedentary populations might express physiological adaptations to regular and demanding physical aerobic activity, emphasizing the need for the estimation of reliable reference limits in elite and professional athletes, to avoid equivocal interpretation of results within clinical and anti-doping contests.

Adaptation, Physiological↗

Moderate aerobic training improves autonomic cardiovascular control in older women.

The decline in the cardiovascular autonomic regulation in advanced age is considered a risk factor for several cardiovascular diseases. We tested, on eleven healthy untreated women aged 60-70 years, whether a six-month period of group-based training exerts positive effects on this age-associated decline. Before and after training, ECG and arterial pressure (Finapres) were recorded in supine position. We calculated mean values +/- SEM of R-R period (RR), systolic (SAP) and diastolic (DAP) arterial pressure, as well as, by autoregressive spectral analysis methods, low (approximately 0.1 Hz) and high (respiratory) frequency oscillations of RR (LF(RR), HF(RR)) and SAP (LF(SAP), HF(SAP)), and the baroreflex sensitivity (BRS). Training induced statistically significant changes (p < 0.05 by paired t-test): increase in RR (mean +/- SEM) from 894 +/- 41 to 947 +/- 31 ms and in heart rate variability (HRV) by 25 %, decrease in DAP from 75.8 +/- 3.0 to 70.8 +/- 2.2 mmHg, no change in SAP. LF(RR) and LF(SAP) increased by more than 100%, while BRS by 32%. We suggest that the increase in BRS might be responsible for the observed bradycardia and higher LF(RR). An improved modulation, rather than an increase, in tonic sympathetic activity, is also suggested. A specific program of moderate aerobic training is adequate to increase the BRS and the HRV in older women.

Aged↗