Aims: This critical review aimed to summarize: (1) the variability and determinants of testosterone (T) measurements; and (2) reference values for the variability and determinants of T measurements in children.
Background: As T is a representative androgen, it has been widely used to explain male vulnerability to child health and developmental problems. T measurements in children, however, have been challenging because of low levels, diurnal and episodic secretion patterns, limited quantity and quality of the samples, and inconsistent study findings.
Methods: The search strategy used PubMed, CINAHL, Cochrane Library, Embase, Scopus, and Google Scholar. Studies published between 2008 through 2020 that examined factors influencing T measurement were included. The final 30 studies were selected using two appraisal forms. We extracted five categories of data from the reports.
Findings: Variability and determinants of T measurement included assay methods, the source of samples, and child demographic and environmental characteristics. T levels were higher 1-3 months after birth and in males up to 1 year; fewer sex differences were found up to 10-12 years. Serum T levels measured by using liquid chromatography-mass spectrometry were most reliable because immunoassays overestimated the levels, especially in neonates. T levels were stable at different temperatures and durations of storage, although sample collection remained an ongoing challenge for researchers.
Conclusion: Depending on the study aims and feasibility, mass-spectrometry, multi-methods, and multi-materials are the recent trends in T measurement. Immunoassays may be an option if the study aims for relative rather than absolute comparisons.
Keywords: children; determinants; reference values; testosterone measurement; variability.