Determination of high-sensitivity C-reactive protein reference intervals for apparently healthy children in Addis Ababa, Ethiopia

Objective: Since then, the reference intervals of serum hsCRP in apparently healthy Ethiopian children are unknown. Therefore, this study aimed to determine the reference intervals of serum hsCRP for apparently healthy children. Methods: In this cross-sectional study, a total of 492 apparently healthy children aged 5-17 years were recruited from residents of Addis Ababa. Well-trained professionals took anthropometric measurements. The biochemical analysis was performed with the automatic biochemical analyzer Cobas Integra 400 Plus from Roche. The 2.5th and 97.5th percentile limits were calculated using a non-parametric method as per the Clinical Laboratory Standard Institute (CLSI) guide. A box plot was used to show the distribution of hsCRP by age and gender. Furthermore, bivariate and multivariable logistic regression analyses were carried out to evaluate factors associated with elevated hsCRP levels. Percentiles were displayed by age subgroup and sex. p-values <0.05 were considered statistically significant. Results: The study included 245 boys and 247 girls. For the age group of 5-11 years, the combined 2.5th and 97.5th percentiles, which can be used as a reference interval for children in Addis Ababa, were 0.15-6.78 mg/L, while for the older age group (12-17 years), the determined percentile was 0.14-4.40 mg/L. Likewise, the current study shows that never or occasionally eating vegetables and/or fruits (AOR = 2.28, 95% CI, 0.84-4.97), and being obese (AOR = 3.63, 95% CI, 1.14-11.53) were independent risk factors for elevated serum hsCRP concentrations. Conclusion: This study is the first to determine the reference intervals of hsCRP concentrations among apparently healthy Ethiopian children. Notable differences were observed in the established percentiles of hsCRP in comparison with published literature.