Supplementary Material for: The Association of Combined Total Kidney and Liver Volume with Pain and Gastrointestinal Symptoms in Patients with Later Stage Autosomal Dominant Polycystic Kidney Disease

Background: There is an ongoing debate if and how kidney and liver volume are associated with pain and gastrointestinal (GI) symptoms in autosomal dominant polycystic kidney disease (ADPKD) patients. Since both kidney and liver volume could interact, we investigated whether combined total kidney and liver volume had stronger associations with ADPKD-related pain and GI symptoms than the volumes of the organs separately. Methods: We used baseline data from the DIPAK-1 study, which included ADPKD patients with an estimated glomerular filtration rate (eGFR) between 30 and 60 mL/min/1.73 m2. MR imaging was performed to measure height-adjusted total kidney volume (hTKV), height-adjusted total liver volume (hTLV) and the combination of both (height-adjusted total kidney liver volume [hTKLV]). Results: Three hundred nine ADPKD patients were included with a mean age of 48 ± 7 years, 53% female, eGFR 50 ± 11 mL/min/1.73 m2 and median hTKV, hTLV and hTKLV of 1,095 (758-1,669), 1,173 (994-1,523) and 2,496 (1,972-3,352) mL/m, respectively. ADPKD-related pain and GI symptoms were present in, respectively, 27.5 and 61.2% of patients. Gender was no effect modifier in the association between kidney and/or liver volume, and symptom burden, indicating that all models could be tested in the overall study population. hTKLV and hTLV were significantly associated with pain and GI symptoms, whereas hTKV was not. Model testing revealed that the associations of pain and GI symptoms with hTKLV were significantly stronger than with hTKV (p = 0.04 and p = 0.04, respectively) but not when compared to hTLV (p = 0.2 and p = 0.5, respectively). Conclusions: This study indicates that combined kidney and liver volume was associated with the presence and severity of pain and GI symptoms in ADPKD, with a more prominent role for hTLV than for hTKV.研究背景：目前针对常染色体显性遗传性多囊肾病（autosomal dominant polycystic kidney disease, ADPKD）患者的肾、肝体积是否与疼痛及胃肠道（gastrointestinal, GI）症状相关，以及二者的关联模式如何，仍存在学术争议。鉴于肾体积与肝体积可能存在交互作用，本研究旨在探讨相较于单独测量单个器官体积，联合计算总肾与总肝体积是否与ADPKD相关疼痛及GI症状存在更强的关联。 研究方法：本研究采用DIPAK-1研究的基线数据集，纳入对象为估算肾小球滤过率（estimated glomerular filtration rate, eGFR）介于30~60 mL/min/1.73 m²之间的ADPKD患者。通过磁共振成像（MR imaging）测量身高校正后总肾体积（height-adjusted total kidney volume, hTKV）、身高校正后总肝体积（height-adjusted total liver volume, hTLV）以及二者的联合指标——身高校正后总肝肾体积（height-adjusted total kidney liver volume, hTKLV）。 研究结果：本研究共纳入309例ADPKD患者，患者平均年龄为48±7岁，女性占比53%，平均eGFR为50±11 mL/min/1.73 m²；中位身高校正后总肾体积、中位身高校正后总肝体积及中位身高校正后总肝肾体积分别为1095（四分位距758~1669）、1173（994~1523）及2496（1972~3352）mL/m。分别有27.5%和61.2%的患者存在ADPKD相关疼痛与GI症状。性别未对肾/肝体积与症状负荷之间的关联产生效应修饰作用，提示所有分析模型均可在全部研究人群中开展检验。数据分析显示，身高校正后总肝肾体积（hTKLV）与总肝体积（hTLV）均与疼痛及GI症状存在显著关联，而身高校正后总肾体积（hTKV）则未观察到此类关联。模型对比检验结果表明，hTKLV与疼痛及GI症状的关联强度均显著高于hTKV（分别对应p=0.04与p=0.04），但与hTLV相比差异无统计学意义（分别对应p=0.2与p=0.5）。 研究结论：本研究结果提示，联合计算的肾与肝体积与ADPKD患者疼痛及GI症状的发生与严重程度存在显著关联，其中身高校正后总肝体积（hTLV）相较于身高校正后总肾体积（hTKV）发挥了更为突出的作用。