Inter- and intra-individual variation of carbon monoxide production in young healthy males

Abstract

Duplicate studies of endogenous CO production (V_co) were performed in three groups of young healthy males. In group A (eleven subjects) V_co studies were performed with an interval of approximately 1 week. In group B (ten subjects) duplicate studies were done on the same day and in group C (ten subjects) duplicate studies were also done on the same day but with the subjects strictly resting between determinations. The error of the single determination estimated from duplicate measurements (±√[∑d²/2n]) was ±4.3μmol/mmol TBH day (TBH=total body haem) in group A and ±3.7 and ±1.0 in group B and C, respectively. Thus the intra-individual variation in V_co was considerably diminished when the duplicate determinations were performed with the subjects strictly resting between determinations. A possible explanation for this might be less variation in blood flow or metabolic processes in tissues engaged in haem breakdown in the resting group compared with the other groups.

Key Words:

• haem turnover
• haemoglobin breakdown
• infrared method
• rebreathing technique