Supplementary Material for: Long-Term Progression of Coronary Artery Calcification Is Independent of Classical Risk Factors, C-Reactive Protein, and Parathyroid Hormone in Renal Transplant Patients

Aims: Compared to the general population, mortality is
significantly increased in renal transplant recipients. In the general
population, coronary artery calcification (CAC) and its evolution over
time are associated with cardiovascular and all-cause mortality, and the
study of this biomarker could provide useful information for describing
the long-term progression of coronary heart disease in renal transplant
recipients. Methods: We followed up a cohort of 113 renal
transplant patients by performing three multi-detector computed
tomography studies over 83.6 ± 6.8 months. Data analysis was performed
by logistic regression analysis and by mixed linear modelling. Results:
Progression was observed in 34.5% of patients. Baseline CAC and
time-to-transplantation were the sole variables that predicted CAC
evolution over time. Neither classical nor nontraditional risk factors,
biomarkers of renal function (GFR) and kidney damage (albuminuria) or
biomarkers of bone mineral disorder (BMD), such as serum phosphorus,
calcium, and PTH, were associated with the long-term progression of
coronary calcification. Serum triglycerides predicted CAC progression
only in logistic regression analysis, while in addition to baseline CAC,
time to transplantation was the sole variable predicting CAC
progression when the data were analyzed by mixed linear modelling. These
data suggested that, in addition to the background calcification
burden, other unmeasured factors play major roles in promoting the
evolution of coronary calcification in the transplant population. Conclusion:
CAC progression continued over the long-term follow-up of renal
transplant patients. This phenomenon was unaccounted for by classical
and nontraditional risk factors, as well as by biomarkers of renal
dysfunction and renal damage.

研究目的：与普通人群相比，肾移植受者的死亡率显著升高。在普通人群中，冠状动脉钙化（coronary artery calcification, CAC）及其随时间的进展与心血管疾病及全因死亡率相关，对该生物标志物的研究可为阐明肾移植受者的冠心病长期进展情况提供有价值的信息。
方法：本研究对113名肾移植患者组成的队列进行了长期随访，在83.6±6.8个月的随访周期内共完成三次多层探测器计算机断层扫描（multi-detector computed tomography）检查。数据分析采用logistic回归分析与混合线性建模方法开展。
结果：34.5%的患者出现了冠状动脉钙化进展。基线CAC水平与移植后时长是唯一可预测冠状动脉钙化随时间进展的变量。无论是传统还是非传统心血管危险因素、肾功能生物标志物（肾小球滤过率（glomerular filtration rate, GFR））与肾损伤生物标志物（蛋白尿（albuminuria）），还是骨矿物质代谢紊乱相关生物标志物（如血清磷、钙与甲状旁腺激素（parathyroid hormone, PTH）），均与冠状动脉钙化的长期进展无显著关联。血清甘油三酯仅在logistic回归分析中可预测冠状动脉钙化进展；而在混合线性模型分析中，除基线CAC水平外，移植后时长是唯一可预测冠状动脉钙化进展的变量。上述结果提示，除了基础钙化负荷外，其他未被测量的因素在移植人群冠状动脉钙化的进展中发挥主要作用。
结论：在肾移植患者的长期随访过程中，冠状动脉钙化仍持续进展。这一现象无法通过传统与非传统心血管危险因素、肾功能不全与肾损伤相关生物标志物来解释。