Abstract
Abstract
Background
Serum creatinine is widely used to assess kidney function, but its interpretation depends on population characteristics and analytical methodology. Locally applicable reference intervals remain poorly characterized in Mauritania. This study aimed to derive a candidate serum creatinine reference interval in apparently healthy Mauritanian adult male blood donors and to assess discordance with the manufacturer-supplied reference limits.
Methods
This single-centre cross-sectional study included 288 adult blood donors recruited at the National Blood Transfusion Centre in Nouakchott between May and November 2024. Serum creatinine was measured using an IDMS-traceable compensated Jaffé assay on a BioSystems A15 analyser. The central 95% reference interval was estimated non-parametrically according to CLSI EP28-A3c, with 90% confidence intervals for the reference limits obtained by bootstrap resampling. Because only 16 participants were women, the primary reference-interval analysis was restricted to men (n = 272). Discordance with the manufacturer-supplied male interval of 7.0–12.0 mg/L was quantified, and associations with age and body mass index were explored.
Results
Among men, the candidate serum creatinine reference interval was 6.50–15.10 mg/L (0.65–1.51 mg/dL; 57–134 µmol/L). The 90% confidence intervals were 5.55–7.25 mg/L for the lower reference limit and 14.20–15.55 mg/L for the upper reference limit. Sixty-one men (22.4%) had creatinine concentrations outside the manufacturer-supplied interval, including 52 (19.1%) above its upper limit. Increasing body mass index was associated with a higher prevalence of discordance with the manufacturer interval (adjusted prevalence ratio 1.58 per 5 kg/m², 95% CI 1.09–2.31), whereas age was not independently associated with discordance.
Conclusions
The serum creatinine reference interval observed in apparently healthy Mauritanian adult male blood donors was wider than the manufacturer-supplied interval, and more than one in five men were classified outside the latter. These findings support local verification of manufacturer-supplied creatinine reference limits. The proposed interval should be considered method-specific and requires independent validation before routine clinical implementation.