Renal osteodystrophy and clinical outcomes: data from the Brazilian Registry of Bone Biopsies - REBRABO

ABSTRACT Introduction: Mineral and bone disorders (MBD) are major complications of chronic kidney disease (CKD)-related adverse outcomes. The Brazilian Registry of Bone Biopsy (REBRABO) is an electronic database that includes renal osteodystrophy (RO) data. We aimed to describe the epidemiological profile of RO in a sample of CKD-MBD Brazilian patients and understand its relationship with outcomes. Methods: Between August 2015 and March 2018, 260 CKD-MBD stage 3-5D patients who underwent bone biopsy were followed for 12 to 30 months. Clinical-demographic, laboratory, and histological data were analyzed. Bone fractures, hospitalizations, and death were considered the primary outcomes. Results: Osteitis fibrosa, mixed uremic osteodystrophy, adynamic bone disease, osteomalacia, osteoporosis, and aluminum (Al) accumulation were detected in 85, 43, 27, 10, 77, and 65 patients, respectively. The logistic regression showed that dialysis vintage was an independent predictor of osteoporosis (OR: 1.005; CI: 1.001-1.010; p = 0.01). The multivariate logistic regression revealed that hemodialysis treatment (OR: 11.24; CI: 1.227-100; p = 0.03), previous parathyroidectomy (OR: 4.97; CI: 1.422-17.241; p = 0.01), and female gender (OR: 2.88; CI: 1.080-7.679; p = 0.03) were independent predictors of Al accumulation; 115 patients were followed for 21 ± 5 months. There were 56 hospitalizations, 14 deaths, and 7 fractures during follow-up. The COX regression revealed that none of the variable related to the RO/turnover, mineralization and volume (TMV) classification was an independent predictor of the outcomes. Conclusion: Hospitalization or death was not influenced by the type of RO, Al accumulation, or TMV classification. An elevated prevalence of osteoporosis and Al accumulation was detected.

摘要
引言：矿物质与骨病（mineral and bone disorders, MBD）是慢性肾脏病（chronic kidney disease, CKD）相关不良结局的主要并发症。巴西骨活检注册库（Brazilian Registry of Bone Biopsy, REBRABO）是收录肾性骨营养不良（renal osteodystrophy, RO）数据的电子数据库。本研究旨在描述巴西CKD-MBD患者队列中肾性骨营养不良的流行病学特征，并阐明其与临床结局的关联。
方法：2015年8月至2018年3月期间，共纳入260例接受骨活检的CKD-MBD 3~5D期患者，随访时长12~30个月。对患者的临床人口学资料、实验室检查结果及组织病理学数据进行分析，以骨骨折、住院及死亡作为主要研究结局。
结果：纤维性骨炎、混合性尿毒症性骨营养不良、动力缺失性骨病、骨软化症、骨质疏松症及铝（Al）蓄积分别在85例、43例、27例、10例、77例及65例患者中被检出。Logistic回归分析显示，透析时长是骨质疏松症的独立预测因素（比值比OR=1.005；95%置信区间CI=1.001~1.010；P=0.01）。多因素Logistic回归分析显示，血液透析治疗（OR=11.24；CI=1.227~100；P=0.03）、既往甲状旁腺切除术史（OR=4.97；CI=1.422~17.241；P=0.01）及女性性别（OR=2.88；CI=1.080~7.679；P=0.03）是铝蓄积的独立预测因素。本研究中共115例患者的随访时长为21±5个月。随访期间共发生56例次住院、14例死亡及7例骨折。COX回归分析显示，与肾性骨营养不良/转换、矿化及容积（TMV）分类相关的所有变量均未成为主要结局的独立预测因素。
结论：肾性骨营养不良类型、铝蓄积及TMV分类均未对住院或死亡结局产生影响。本研究检出骨质疏松症及铝蓄积的患病率均较高。