Reference values of Serum Osteocalcin in the healthy population: A potential biomarker for bone turnover

Objective: To analyze the serum concentrations of osteocalcin in healthy subjects to establish the reference intervals in the Pakistani population. Material and Methods: This Cross-sectional, observational study was conducted at the Department of Clinical Chemistry and Immunology, Chughtai Lab Lahore from October 2022 to March 2023. Serum samples from 240 healthy subjects (120 males and 120 premenopausal females) were collected according to CLSI recommendations after taking informed consent. The samples were analyzed for the quantitative determination of Osteocalcin by sandwich electrochemiluminescence immunoassay. Shapiro Wilk test was applied to check normality. A P-value of < 0.05 was considered significant. The formulas used for calculating the 2.5th and 97.5th percentiles were 0.025 (n+1) and 0.0975 (n+1) respectively. Results: The histogram revealed a non-parametric distribution of the data. The established reference intervals by the rank-based method for males were 10.16 ng/mL and 43.33 ng/mL and for females were 5.25 ng/mL and 33.25 ng/mL corresponding to 2.5th and 97.5th percentiles respectively. Conclusion: Ethnic and geographic variation affects the trends of reference intervals of every parameter. This is the need of the hour each laboratory should establish its assay and population-specific reference intervals for accurate clinical decisions.