The Chinese Pharmacopoeia 2025 Edition is about to be officially released. Based on multiple meetings and extensive consultations the vaccine products professional committee of the 12th pharmacopoeia commission, has revised and formed the general chapter 0237 for the preparation of national biological reference standards in Chinese Pharmacopoeia 2025 Edition volume Ⅲ. General chapter 0237, integrating the cutting-edge concepts from WHO’s related guidelines and the practical experience of biological reference standards both domestically, has revised the names of this chapter, updated and improved the technical requirements for candidate reference materials, collaborative calibration and value assignment, as well as stability research and monitoring. It also newly proposes the calculation of uncertainty of biological reference materials and emphasizes to pay attention to commutability. The implementation of general chapter 0237 will play a guiding role in improving the research and application level of biological reference materials in China. This article, by interpreting the revised content of general chapter 0237, aims to provide a reference for the researchers of biological reference materials.

Objective:To explore the prevalence and independent associated factors of vascular calcification (VC) in non-dialysis chronic kidney disease (CKD) patients of stage 3-5.Methods:It was a single-center cross-sectional observational study. Non-dialysis stage 3-5 CKD patients ≥18 years old who were admitted to the Department of Nephrology, the First Affiliated Hospital of Sun Yat-sen University from May 1, 2022 to December 31, 2022 with VC evaluation were enrolled. The patients' general information, laboratory examination and imaging data were collected. Coronary artery calcification (CAC), thoracic aorta calcification (TAC), abdominal aorta calcification (AAC), carotid artery calcification and aortic valve calcification (AVC) were evaluated by cardiac-gated electron-beam CT (EBCT) scans, lateral lumbar x-ray, cervical macrovascular ultrasound and echocardiography, respectively. The differences in clinical data and the prevalence of VC at different sites of patients with different CKD stages were compared, and the prevalence of VC at different sites of patients in different age groups [youth group (18-44 years old), middle-aged group (45-64 years old) and elderly group (≥65 years old)] and patients with or without diabetes were compared. Multivariate logistic regression analysis was used to analyse the independent associated factors of VC for different areas.Results:A total of 206 patients aged (51±14) years were included, including 129 (62.6%) males. There were 44 patients with CKD stage 3 (21.4%), 51 patients with CKD stage 4 (24.8%), and 111 patients with CKD stage 5 (53.9%). CKD was caused by chronic glomerulonephritis [104 cases (50.5%)], diabetic kidney damage [35 cases (17.0%)], hypertensive kidney damage [29 cases (14.1%)] and others [38 cases (18.4%)]. Among 206 patients, 131 (63.6%) exhibited cardiovascular calcification, and the prevalence of CAC, TAC, AAC, carotid artery calcification, and AVC was 37.9%, 43.7%, 37.9%, 35.9% and 9.7%, respectively. The overall prevalence of VC in young, middle-aged and elderly patients was 24.6%, 73.6% and 97.4%, respectively. With the increase of age, the prevalence of VC in each site gradually increased, and the increasing trend was statistically significant (all P<0.001). The overall prevalence of VC in CKD patients with diabetes was 92.5% (62/67), and the prevalence of VC at each site in the patients with diabetes was significantly higher than that in the patients without diabetes (all P<0.001). Multivariate logistic regression analysis revealed that age (every 10 years increase, OR=2.51, 95% CI 1.77-3.56, P<0.001), hypertension ( OR=5.88, 95% CI 1.57-22.10, P=0.009), and diabetes ( OR=4.66, 95% CI 2.10-10.35, P<0.001) were independently correlated with CAC; Age (every 10 years increase, OR=6.43, 95% CI 3.64-11.36, P<0.001) and hypertension ( OR=6.09, 95% CI 1.33-27.84, P=0.020) were independently correlated with TAC; Female ( OR=0.23, 95% CI 0.07-0.72, P=0.011), age (every 10 years increase, OR=3.90, 95% CI 2.42-6.29, P<0.001), diabetes ( OR=5.37, 95% CI 2.19-13.19, P<0.001) and serum magnesium ( OR=0.01,95% CI 0-0.35, P=0.014) were independently correlated with AAC. Moreover, age and diabetes were independently correlated with carotid artery calcification, AVC and overall VC Conclusions:The prevalence of VC in non-dialysis CKD patients of stage 3-5 is 63.59%, of which CAC reaches 37.9%, TAC is the most common one (43.7%), while AVC is the least one (9.7%). Age and diabetes are the independent associated factors for VC of all sites except TAC, while hypertension is an independent associated factor for both CAC and TAC.