| 摘要: | 背景
最近研究指出，在非砷暴露地區尿液總砷濃度與慢性腎臟病危險性增加有關。目前基因易感受性在其中所扮演的角色仍不清楚。過去慢性腎臟病被認為與砷暴露有關，但高血壓和糖尿病對於砷相關慢性腎臟病的修飾作用也未被證實。腎素-血管張力素-醛固酮系統被認為和纖維化、發炎因子和氧化壓力增加有關，但是在台灣調控腎素-血管張力素-醛固酮系統酵素活性的血管張力素第一型轉化酶、血管張力素原、血管張力素第一型接受器和醛固酮合成酶基因的基因多形性與慢性腎臟病的關係尚未瞭解。因此，本研究目的為探討砷、腎素-血管張力素-醛固酮系統酵素基因多形性與慢性腎臟病的關係，並評估高血壓和糖尿病對慢性腎臟病之交互作用影響。
方法
本研究以醫院為基礎的病例對照研究，自2007至2011年招募233位經由估計腎絲球過濾率判斷小於60 mL/min/1.73 m2的慢性腎臟病例來自新光吳火獅紀念醫院、台北醫學大學附設醫院及市立萬芳醫院腎臟科。經性別和年齡配對來自台北醫學大學附設醫院及市立萬芳醫院健康檢查參與者共449人。尿液砷物種包含三價及五價無機砷、單甲基砷酸和雙甲基砷酸濃度以高效液相層析儀連接氫化器串聯原子吸收光譜儀進行分析。ACE(I/D)、AGT(A[-20]C)、(T174M)、(M235T)、 AT1R(A1166C)和CYP11B2(C[-344]T)六個單一核苷酸基因多形性則利用聚合酵素連鎖反應及限制片段長度多形性之方法進行分析。
結果
高教育程度、飲酒、喝茶及喝咖啡對於慢性腎臟病具有保護作用，高血壓、糖尿病和經常服用止痛藥則會增加慢性腎臟病危險對比值，而抽菸、農藥和化學物質的接觸則無關。調整年齡和性別下CYP11B2(C[-344]T)帶TT基因型者相對於帶CC或CT基因型者會增加慢性腎臟病危險對比值，而AGT(A[-20]C)帶CC基因型者則具有保護作用，其他四個基因形則與慢性腎臟病無關。攜帶危險基因型者若同時有高血壓或糖尿病時，會有更高的危險對比值。慢性腎臟病病例比起健康對照組有較高的尿液單甲基砷酸、雙甲基砷酸及總砷濃度，且隨著尿液總砷濃度增加慢性腎臟病危險對比值呈顯著的劑量效應關係。尿液總砷濃度較高者同時有高血壓或糖尿病時，會有更高的危險對比值，尿液總砷與糖尿病間具有相加模式的協同作用。調整各因子下，當AGT(A[-20]C)和CYP11B2(C[-344]T)同時帶有危險基因型且有較高濃度的尿液總砷時，有更高的慢性腎臟病危險對比值，而此相關性經分層分析僅在非高血壓或非糖尿病者中仍存在。
結論
本論文結果顯示AGT (A[-20]C)與CYP11B2 (C[-344]T)基因多形性及尿液總砷濃度與慢性腎臟病有關。當同時有較高濃度的尿液總砷與攜帶AGT (A[-20]C)與CYP11B2 (C[-344]T)的危險基因型下，對於慢性腎臟病將有更高的危險對比值，而此關聯性會受高血壓或糖尿病所修飾。
Background
Recent study demonstrated that increased risk of chronic kidney disease (CKD) is associated with high urinary total arsenic levels in a non-obvious arsenic exposure area. But whether genomic instability is related or not still remains unclear. The modification of hypertension or diabetes on arsenic related CKD have not been confirmed. Renin-angiotensin-Aldosterone System (RAAS) is known as factors related to fibrosis, inflammatory factors and increasing oxidative stress. But the association among the polymorphisms of regulation enzymes such as ACE, AGT, AT1R and CYP11B2 gene and CKD in Taiwan has not been proved. The aim of present study is to investigate the relationship among arsenic, genetic polymorphisms of RAAS enzymes and CKD. In addition, we also explore the modified effects of hypertension or diabetes on arsenic related CKD.
Methods
Two hundred thirty three CKD patients were defined using estimated glomerular filtration rate lower than 60 mL/min/1.73 m2, and recruited from the Department of Internal Medicine/Nephrology of Shin Kong Wu Ho-Su Memorial Hospital, Taipei Medical University Hospital and Taipei Municipal Wan Fang Hospital from 2007 to 2011. Age and gender matched 449 controls were recruited from a hospital-based pool, including those receiving senior citizen health examinations at Taipei Medical University Hospital and those receiving adult health examinations at Taipei Municipal Wan Fang Hospital. Concentrations of urinary arsenic species, including arsenite (As[III]), arsenate (As[V]), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) were determined by a high-performance liquid chromatography-linked hydride generator and atomic absorption spectrometry. Polymorphisms of six SNPs such as ACE(I/D), AGT(A[-20]C), (T174M), (M235T), AT1R(A1166C) and CYP11B2(C[-344]T) were examined by polymerase chain reaction and restriction fragment length polymerase.
Results
Study participants who had high educational levels, or alcohol, coffee or tea consumption had a significantly lower risk of CKD, while those with hypertension, diabetes and analgesic users had a higher risk. Cigarette smokers, pesticide and chemicals users did not affect CKD. After adjustment for age and gender, subjects carrying CYP11B2 T/T genotype had an increasing OR of CKD; while those with AGT (A[-20]C) C/C genotype had a lower OR of CKD. However, there was no association between other four SNPs and CKD. Study subjects carried -20A allele of AGT and CYP11B2 with T/T genotype, concurrent with hypertension or diabetes had a high OR of CKD. CKD cases had a greater urinary MMA, DMA, and total arsenic level than healthy controls. We also found a dose-response relationship between CKD and total arsenic. It suggests that participants with hypertension or diabetes and concurrently had high urinary total arsenic had a higher OR of CKD than those with normaltension or non-diabetes and had lower urinary total arsenic. There is a synergism effect of additive model between urinary total arsenic and diabetes on CKD. After confounders adjusted, participants with AGT-20A allele, or with CYP11B2 with T/T genotype and had high urinary total arsenic had a high OR of CKD, and it presents a significant dose-response relationship. This relationship still exists in participants with normaltension or non-diabetes.
Conclusions
We found that polymorphism of AGT(A[-20]C) and CYP11B2(C[-344]T) and urinary total arsenic levels were associated with increased OR of CKD and this association might be modified by the hypertension or diabetes status. |
