Reference intervals of routine clinical chemistry parameters among apparently healthy young adults in Amhara National Regional State, Ethiopia

BACKGROUND: Clinical laboratory reference intervals (RIs) are essential for clinical diagnosis, treatment and therapeutic monitoring. Locally established RIs are required to correctly interpret clinical laboratory results. In Ethiopia, clinical laboratory test results are interpreted based on RIs derived from a western population. METHODS: A multicenter cross-sectional study was conducted among blood donors in Amhara National Regional State, Ethiopia from March 2016 to May 2017. A total of 1,175 apparently healthy study participants were included in the study from four blood banks in the region. All clinical chemistry parameters were analyzed using Mindray BS-200E full automated clinical chemistry analyzer. The 95% RIs were estimated using reference limits at 2.5th percentile for the lower reference limit and 97.5th percentile for the upper reference limit. Kolmogorov-Sminorv and Wilcoxon rank-sum tests were used to check data distribution normality and whether partitions were needed between variables, respectively. RESULTS: RIs established include: ALT 5.13-42.88 U/L for males and 4.3-37 U/L for females; AST 12.13-46.88 for males and 10-43.8 U/L for females; ALP 77.2-475.8 U/L for males and 89-381 U/L for females; amylase 29-309.8 U/L for males and 29-287.9 U/L for females; GGT 7-69.8 U/L for males and 6-39.1 U/L for females; total bilirubin 0.11-1.18 mg/dl for males and 0.08-0.91 mg/dl for females; creatinine 0.48-1.13 mg/dl for males and 0.47-1.09 mg/dl for females; total cholesterol 78.13-211.75 mg/dl for males and 83.6-202.7 mg/dl for females; total protein 5.7-9.7 g/dl for males and 5.6-9.47 for females; triglycerides 36-221.9 mg/dl for males and 35.3-201.5 mg/dl for females; urea 12-43 mg/dl for males and 10-38.7 mg/dl for females; and uric acid 2.7-6.9 mg/dl for males and 2.1-5.9 mg/dl for females. CONCLUSION: This study has established RIs for routine clinical chemistry parameters. These RIs are important as they support the interpretation of clinical laboratory results for medical decision making and other health-related activities.