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Athletes undergoing a strenuous training schedule can develop a
significant decrease in performance associated with systemic symptoms or
signs: the fatigue and overtraining syndromes. A more critical issue in
sport medicine is as yet to establish whether laboratory abnormalities may
be useful or not in guiding evaluation and treatment of the fatigue
syndrome and related disorders.
In the rece...
In the recent article of Fallon, it was
concluded that the use of a wide panel of blood tests at the initial
consultation with an athlete with short term fatigue has very little
effect on the diagnosis (1). The major drawback of this conclusion is that
laboratory test results laying outside the conventional reference ranges
of a clinical laboratory are not necessarily “pathological” in elite and
professional athletes. Strenuous and regular physical exercise commonly
induces a wide series of metabolic and biochemical adaptations that
substantially modify the biochemical profile of an elite athlete. We have
earlier demonstrated that most conventional laboratory reference ranges,
as deducted on healthy and presumably low to null physically active
individuals, would be rarely applicable or clinically informative in
athletes (2). Most laboratory test results in top class athletes,
especially when interpreted on the basis of the respective conventional
reference ranges, would be considered either increased (i.e. ischemia
modified albumin, creatine kinase, aminotransferase) (3) or decreased
(i.e. triglycerides, cholesterol, NT pro-Brain Natriuretic Peptide) (4,5),
reflecting normal adaptations to a regular and demanding aerobic training
instead of the presence of underlying pathologies or fatigue syndromes.
Therefore, the estimation of accurate and reliable reference ranges and
decision limits in elite and top-class athletes is a necessary
prerequisite to prevent misleading interpretation of laboratory data, that
would finally produce clinically meaningful “false positive” or “false
negative” results for identifying pathologies or fatigue syndromes.
Laboratory abnormalities are frequently detected in a large number of
athletes, though they are not clinically significant. Therefore, the
crucial issue raised by the article of Fallon “to test or not to test?”
would remain mostly unresolved until the pitfall of appropriate reference
ranges for test results in athletes would be settled. However, there may
be an alternative approach to solve this question. Strategies based on the
use of arbitrary thresholds of hemoglobin or hematocrit to detect blood
doping in endurance athletes have essentially failed to deter this
malpractice. To overcome this tangible problem, the “hematologic passport”
based on proper sequential determinations of hematologic variables has
been recently proposed, with the aim to identify subject-specific
reference ranges that would allow to identify reliably non-physiologic
variations of the hematologic profile (6). Beside identification of unfair
practices, longitudinal laboratory testing in athletes would produce
valuable information on the athlete’s health and fitness, allowing early
recognition of subject-specific laboratory changes that may underlie
clinically meaningful alterations of the athletes’ state of health.
1. Fallon KE, Gerrard DF. Clinical utility of blood tests in elite
athletes with short term fatigue. Br J Sports Med 2006;40:541-544.
2. Lippi G, Brocco G, Franchini M, Schena F, Guidi G. Comparison of
serum creatinine, uric acid, albumin and glucose in male professional
endurance athletes compared with healthy controls. Clin Chem Lab Med
3. Lippi G, Brocco G, Salvagno GL, Montagnana M, Dima F, Guidi GC.
High-workload endurance training may increase serum ischemia-modified
albumin concentrations. Clin Chem Lab Med 2005;43:741-4.
4. Lippi G, Schena F, Salvagno GL, Montagnana M, Ballestrieri F,
Guidi GC. Comparison of the lipid profile and lipoprotein(a) between
sedentary and highly trained subjects. Clin Chem Lab Med 2006;44:322-6.
5. Lippi G, Salvagno GL, Montagnana M, Schena F, Ballestrieri F,
Guidi GC. Influence of physical exercise and relationship with biochemical
variables of NT-pro-brain natriuretic peptide and ischemia modified
albumin. Clin Chim Acta 2006;367:175-80.
6.Malcovati L, Pascutto C, Cazzola M. Hematologic passport for
athletes competing in endurance sports: a feasibility study. Haematologica