Bone Microarchitecture and Volumetric Mineral Density Assessed by HR-pQCT in Patients with 21- and 17α-Hydroxylase Deficiency.

Due to disturbances in hormones and long-term glucocorticoid replacement therapy (GRT), congenital adrenocortical hyperplasia (CAH) patients are at risk of impaired bone structure and metabolism. This cross-sectional, case-control study aims to investigate for the first time bone microarchitecture features in 21-hydroxylase deficiency (21OHD; N = 38) and 17α-hydroxylase deficiency (17OHD; N = 16) patients using high-resolution peripheral quantitative computed tomography (HR-pQCT) by matching the same sex and similar age [21OHD vs. control: 29.5 (24.0-34.3) vs. 29.6 (25.9-35.2) years; 17OHD vs. controls: 29.0 (21.5-35.0) vs. 29.7 (24.6-35.3) years] with healthy controls (1:3). All patients underwent HR-pQCT scans of the nondominant radius and tibia, and had received GRT. Compared with corresponding controls, 17OHD cases had higher height (P < 0.001), weight (P = 0.013) and similar body mass index (BMI), while 21OHD had lower height (P < 0.001), similar weight and higher BMI (P < 0.001). 17OHD and 21OHD patients demonstrated various significant bone differences in most HR-pQCT indices, suggesting abnormalities in bone microarchitectures from healthy people. Further correlation analyses revealed that some characteristics, such as height and hormones, may contribute to the bone differences in HR-pQCT indices between two diseases. However, treatment dosage and time were not correlated, indicating that the current glucocorticoid doses may be within safety limits for bone impairment. Overall, our study for the first time revealed changes of bone microarchitecture in CAH patients and their potential relations with clinical characteristics. Further longitudinal researches are required to confirm these findings.