Elevated plasma hydroxyproline

Abstract

Basal plasma hydroxyproline was measured in 104 male Navy Seal candidates 1 week into their intense physical training program, which lasted 7 weeks, and correlated to the incidence of connective tissue injuries incurred later in the training program. Eleven subjects (10.6%) were diagnosed as having connective tissue injuries. Those subjects with connective tissue injuries had a significantly higher (P < 0.05) mean plasma hydroxyproline value (4.02 μg/ml) than subjects without injury (3.10 μg/ml). The majority of graduates (75%) had plasma hydroxyproline values less than 3.3 μg/ml. These graduates represented the strongest and most enduring injury-free subjects. Of the subject pool who incurred connective tissue injuries, only 27% had plasma hydroxyproline values less than 3.3 μg/mi. The majority of the injured subjects (73%) had plasma hy droxyproline values greater than or equal to 3.3 μg/ml. In conclusion, there is a relationship between initial training basal plasma hydroxyproline levels and con nective tissue injuries later incurred in an intense phys ical training program. These data suggest that elevated plasma hydroxyproline levels may represent a risk fac tor associated with connective tissue injuries.