Significant differences in the microarchitecture and volumetric mineral density of bone assessed by HR-PQCT in patients with 21- and 17α-hydroxylase deficiency

Abstract Purpose Due to disturbances in hormones and long-term glucocorticoid replacement therapy, congenital adrenocortical hyperplasia (CAH) patients are at risk of impaired bone structure and metabolism. The current study investigats bone microarchitecture in 21-hydroxylase deficiency (21OHD) and 17α-hydroxylase deficiency (17OHD) patients using high-resolution peripheral quantitative computed tomography (HR-pQCT). Methods A total of thirty-eight 21OHD and sixteen 17OHD patients were recruited with controls matched for age and sex at a ratio of 1:3. All underwent HR-pQCT scans of the nondominant radius and tibia. Comparisons of HR-pQCT indices between each cohort and the matched controls or between the two cohorts were conducted. Spearman analyses and multiple linear regression were performed to reveal the relations between clinical characteristics and HR-pQCT indices. Results Compared with the 17OHD group, the 21OHD group predominated in Tt.vBMD (P < 0.001), Ct.vBMD (P < 0.001), and Tb.vBMD (P < 0.001) at the radius. Comparisons of clinical characteristics between the two cohorts showed that 17OHD patients were taller, weighed more, and had higher levels of fasting blood glucose with shorter treatment course. Further correlation analyses revealed that some characteristics, such as height and FSH, contributed significantly to bone differences in HR-pQCT indices. However, treatment dosage and time were not correlated, indicating that the current glucocorticoid doses were within safety limits for bone impairment. Conclusions 21OHD and 17OHD patients had different bone characteristics in BMD, the cortex and the trabecula, as assessed by HR-pQCT. Clinical manifestations, especially sex hormones and height, may contribute to these differences.