Objectives This study explored the association between biomarkers of type I collagen metabolism and exposure to physical workload.

Methods In a prospective cohort study, serum concentrations of markers of type I collagen synthesis and degradation were assessed monthly for student nurses who worked as nurses for a period of 6 months and compared with those of a reference group. The number of patient-handling activities was estimated from observations at the workplace. Linear generalized estimating equations were used to analyze differences in the serum concentrations of the biomarkers between the exposed group and reference group, as well as to analyze whether the number of patient-handling activities was associated with serum concentrations of the biomarkers.

Results Serum concentrations of the biomarkers were found to differ between the groups. The biomarkers reflected a higher anabolism of type I collagen in the exposed group when compared with that of the reference group. An analysis of the effect of the number of patient-handling activities revealed that a higher exposure was associated with higher effective type I collagen synthesis within the exposed group.

Conclusions These results indicate that serum concentrations of these biomarkers of type I collagen metabolism can reflect differences in exposure between contrasting groups, and also varying levels of exposure between persons within an occupation.

Key terms back disorder; collagen metabolism; connective tissue; patient handling; physical workload; prospective cohort study; serum marker; spine; student nurse