Limited diagnostic value of questionnaire-based pre-participation screening algorithms: A "risk-exposed" approach to sports activity

Background: Several pre-participation screening algorithms (PPSAs) have been proposed to assess sports eligibility in different populations. They are usually based on self-administered questionnaires, without further medical assessment if no risk factors are documented. The Med-Ex "Formula Benessere"worksite program includes a complete cardiovascular (CV) screening for all participants. The purpose of this study was to assess PPSAs accuracy in detecting medical and/or CV abnormalities in the general population, comparing the results with the date derived from Med-Ex program. Methods: The Med-Ex medical evaluation, consisting of medical history, physical examination (including body composition), resting electrocardiogram (ECG) and exercise stress test in 464 male subjects (38.4 aged) was analyzed and matched to several PPSAs - Physical Activity Readiness Questionnaire (PAR-Q) (2002-2020), American Heart Association (AHA)/American College of Sport Medicine (ACSM) (1998-2009-2014-2015), European Association of Cardiovascular Prevention and Rehabilitation (EACPR) (2011) - retrospectively simulated. Results: Five-hundred and 67 abnormalities were detected though Med-Ex medical evaluation, and one-fourth (24%) would have been undetected applying PPSA alone. In particular 28% of high blood pressure, 21% of impaired fasting glycaemia, 21% of high Body Mass Index (BMI) values and 19% of ECG abnormalities would have been missed, on average, by all PPSAs. Conclusions: The simulation analysis model performed in this study allowed to highlight the limits of PPSAs in granting sport eligibility, compared to a medical-guided CV screening. These findings emphasize the importance of a more balanced approach to pre-participation screening that includes a thorough evaluation of the cost/benefit ratio

How can storage time and temperature affect enzymic activities in urines?

We measured a tubular brush-border enzyme (alanine aminopeptidase, AAP) and a lysosomal hydrolase (N-acetyl-beta-D-glucosaminidase, NAG) in morning urines from 15 healthy normal subjects to check if different storage times and temperatures could modify enzyme concentrations. Short-term (24 h) storage time at room temperature or 4 degrees C does not affect AAP and NAG activities. Both enzymes are well preserved at -70 degrees C. AAP dramatically falls after 1 month at -20 degrees C, lowering to about 8% of the initial value after only 4 days of storage. On the contrary, NAG is well preserved at these storage conditions. Centrifugation has revealed not critical for measurement of these two enzymes

Measurement of ATPases in red cells: setting up and validation of a highly reproducible method.

Our aim was to set up and validate a reproducible method to study ATPase family on erythrocyte membranes. We compared several methods for erythrocyte washing and hemolysis and succeeded in preparing completely hemoglobin-free membrane ghosts still bearing intact ATPases. We compared the conventional incubation procedure with the coupled enzyme assay to measure Na-K-Mg, Ca-Mg and Mg ATPase on the membranes. A significant difference was constantly observed between the results by these methods, the values by the incubation procedure being 28, 57 and 58% of the respective values obtained by the linked enzyme assay. By adopting this last one, we obtained uniform and reproducible results in 31 healthy subjects. The following activities of the measured pumps resulted: Na-K-Mg ATPase 0.026 +/- 0.007, mean +/- SD; Ca-Mg ATPase 0.030 +/- 0.010, and Mg ATPase 0.017 +/- 0.003 U/mg protein, respectively. Finally, we investigated the effect of membrane storage time and temperature on ATPase results

Effects of storage time and temperature on urinary enzymes.

We measured three renal tubular brush-border enzymes (lactate dehydrogenase, LDH, EC 1.1.1.27; gamma-glutamyltransferase, GGT, EC 2.3.2.2; and alkaline phosphatase, AP, EC 3.1.3.1) in morning urine samples from 48 healthy subjects to check whether different storage times and temperatures could modify enzyme concentrations. Short-term (24 h) storage time at room temperature or 4 degree C does not affect urinary enzyme activity. A few days of freezing, at -20 or -70 degrees C, dramatically lowers LDH and AP values; GGT is partially preserved only at -70 degrees C, if the sample has been previously centrifuged. Urinary enzymes investigated in this study are extremely labile at low temperatures