17-Hydroxyprogesterone Response to Standard Dose Synacthen Stimulation Test in CYP21A2 Heterozygous Carriers and Non-carriers in Symptomatic and Asymptomatic Groups: Meta-analyses

Abstract

Objective: Standard dose synacthen stimulation test (SDSST) is a gold standard screening test for evaluating adrenal gland function. Despite studies using SDSST to identify heterozygosity in CYP21A2 , the reliability of the test for this purpose is still controversial. Therefore, the meta-analyses were performed to determine the differences in 17-hydroxyprogesterone (17-OHP) responses to standard dose (0.25 mg) SDSST in the diagnosis of CYP21A2 heterozygous individuals, with or without clinical signs of androgen excess disorders. Methods: PubMed and MEDLINE databases were searched. A total of 1215 subjects (heterozygous carriers n=669, mutation-free controls n=546) were included in the meta-analyses. Results: Basal 17-OHP median/mean levels were 4.156 (3.05-10.5)/5.241 (±2.59) nmol/L and 3.90 (2.20-9.74)/4.67 (±2.62) nmol/L in symptomatic heterozygous carriers and symptomatic mutation-free controls, respectively. Stimulated 17-OHP median/mean levels were 17.29 (14.22-37.2)/19.51 (±7.63) nmol/L and 9.27 (7.32-15.9)/10.77 (±3.48) nmol/L in symptomatic heterozygous carriers and symptomatic mutation-free controls, respectively. Basal 17-OHP median/mean levels were 3.21 (2.64-4.78)/3.33 (±0.84) nmol/L and 3.12 (1.82-3.6)/2.83 (±0.71) nmol/L in asymptomatic heterozygous carriers and asymptomatic mutation-free healthy controls, respectively. Stimulated 17-OHP median/mean levels were 14.16 (12.73-16.37)/14.16 (±1.37) nmol/L and 6.26 (4.9-8.23)/6.48 (±1.2) nmol/L in asymptomatic heterozygous carriers and asymptomatic mutation-free healthy controls, respectively. The cut-off levels for stimulated 17-OHP were 10.48 nmol/L and 13.48 nmol/L for asymptomatic heterozygous and symptomatic heterozygous, respectively. Conclusion: The meta-analyses support the idea that stimulated 17-OHP level has potential for use in identifying CYP21A2 carriers. Besides, considering differences in the basal and stimulated 17-OHP levels in symptomatic heterozygous individuals compared to those who were asymptomatic heterozygous could increase the accuracy of the test.