PACKED-CELL VOLUME IN ELITE ATHLETES

Non-physiological substances, but also recombinant human erythropoietin
(epoetin, EPO), are forbidden by the International Olympic Committee (IOC).
EPO regulates erythropoiesis, keeping the packed-cell volume within a narrow
range. Too low a packed-cell volume means a decrease of tissue oxygenation
and too high carries the risk of thromboembolic events. Muscles of elite
athletes need a lot of oxygen. A higher packed-cell volume can be achieved
by injecting EPO, which may help athletes to win. Because missuse of EPO
cannot reliably be detected, the Union Cycliste Internationale (UCI) takes
competitors with a packed-cell volume of more than 050 out of the race "for
health reasons".1 But what is a physiological packed-cell volume for elite
athletes, and what should be the policy if an athlete with a low packed-cell
volume uses EPO? In a recent issue of The Lancet it was stressed that
doctors should worry about doping in sport .2

We have analysed the packed-cell volume of elite athletes (participants in
world championships and Olympic games), who did not use, to the best of our
knowledge, any kind of doping (they all attended a sports clinic, and were
well known to, and confided in, the staff). Over 16 months, 18 men and 28
women athletes were monitored, and 245 packed-cell volume values were
obtained (mean 53 per athlete; range 1-15). Blood samples were collected
after an overnight fast and on a day without a race or strenuous training.
Packed-cell volume was measured from blood with EDTA, with a CD4000
haemocytometer (Abbott Laboratories, Abbott Park, IL, USA). Controls were
134 male and 144 female family members of patients with hereditary
haemochromatosis who were negative or heterozygotes for the C282T mutation
of the HFE gene.3 The means of each athlete were compared with single values
of controls.

There was no significant difference between packed-cell volumes of athletes
and of controls, which were normally distributed (table). Packed-cell volume
distribution curves of elite athletes and controls were identical for men
and for women. Distribution of packed-cell volume values from endurance
athletes was not different from those of sprint disciplines. In three
measurements from men athletes (from two individuals) and in four controls,
a packed-cell volume of more than 050 was found. All six would have been
excluded from competition according to UCI rules despite their packed-cell
volumes being part of normally distributed values. In a study of Australian
top cyclists, in which 360 samples were collected over 10 years, 28% of
packed-cell volumes were higher than 050.4

Men

Mean (SD) Range Athletes

044 (003) 038-052

Controls

045 (003) 037-055

Women

Mean (SD) Range Athletes

040 (002) 034-047

Controls

041 (004) 030-051

Table 1: Packed-cell volume in elite athletes and in controls

We conclude from these observations that some athletes may be banned with a
packed-cell volume in the upper section of the normal distribution curve,
and that people with a physiologically lower packed-cell volume may have a
less favourable tissue oxygenation than competitors with a higher
packed-cell volume. Some athletes--considering that iron, vitamins and other
food supplements are allowed--might be tempted to correct a lower
packed-cell volume towards the higher physiological range by using a
non-detectable substance such as EPO, as long as the value remains below 050.

Although everything possible should be done to protect athletes against any
kind of doping that may be harmful and that may falsify competition, in the
case of EPO the IOC and UCI might consider whether taking a non-detectable
substance that is able to correct a physiological inequality among
competitors should be considered as doping.

1 UCI. Sporting safety and conditions regulations. London: UCI, May 16,1997.
2 Birchard K. Why doctors should worry about doping in sport . Lancet 1998;
352: 42.

3 Santos M, Clevers HC, Marx JJM . Mutations of the hereditary
haemochromatosis gene HLA-H in porphyria cutanea tarda. N Engl J Med 1997;
336: 1327-28.

4 Martin DT, Ashenden M, Pansotto R, Pyne D, Hahn AG. Blood testing for
professional cyclists: what's a fair haematocrit limit? Sportscience News
1997 http://www.sportsci.org/news/news 9703/AIS blood. Html.

Departments of Internal Medicine (J J M Marx; e-mail J.Marx@digd.azu.nl),
and Topsport Medicine, University Hospital Utrecht, 3508 GA, Utrecht,
Netherlands

Checked-by: Melodi Cornett