The diagnosis of frailty is usually subjective, which calls for objective biomarkers in clinical medicine. 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGsn) and 8-oxo-7, 8-dihydroguanosine (8-oxoGsn) in urine are two aging biomarkers that have not been explored deeply in cases of frailty. A total of 508 elderly patients with cardiovascular disease (mean age 75.0 ± 6.5 years, 50.8% males) were enrolled consecutively. Frailty was assessed by the Fried phenotype (robust: 0 score; pre-frail: 1-2 scores; frail: 3-5 scores). The concentrations of 8-oxoGsn and 8-oxodGsn in urine were measured by improved ultra-high-performance liquid chromatography-mass spectrometry (UPLC-MS/MS). Urinary creatinine (Cre) was tested to correct the 8-oxoGsn and 8-oxodGsn levels. According to the Fried phenotype score, the proportions of robust, pre-frail, and frail subjects were 20.5% (104/508), 53.9% (274/508), and 25.6% (130/508), respectively. The urinary 8-oxoGsn/Cre (P < 0.001) differed significantly among these 3 groups, but the urinary 8-oxodGsn/Cre (P = 0.600) showed no marked difference. Univariate and multivariate logistic regression showed that the age (odds ratio [OR] = 1.090, P < 0.001), systolic blood pressure (OR = 0.981, P = 0.008), 8-oxoGsn/Cre (OR = 1.203, P = 0.007), hemoglobin (OR = 0.980, P = 0.007), and sodium (OR = 0.915, P = 0.044) were independently associated with frailty. The sensitivity and specificity to identify frailty were 53.08% and 71.96%, respectively, for 8-oxoGsn/Cre at the optimal cut-off value of 3.879 μmol/mol according to the maximal Youden index. Urinary 8-oxoGsn, as a recognized biomarker of RNA oxidation, is independently associated with frailty in elderly patients with cardiovascular disease. However, the urinary 8-oxodGsn shows no obvious correlation with frailty. To obtain a better diagnostic performance for frailty, more biomarkers from different pathophysiological pathways should be explored in the future.

中文翻译：

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尿液中的8-oxo-7,8-dihydroguanosine作为老年心血管疾病患者虚弱的潜在生物标志物。

身体虚弱的诊断通常是主观的，这需要在临床医学中使用客观的生物标志物。尿液中的8-oxo-7,8-dihydro-2'-deoxyguanosine（8-oxodGsn）和8-oxo-7，8-dihydroguanosine（8-oxoGsn）是两个衰老生物标志物，在衰弱的情况下尚未深入研究。连续登记了508名老年心血管疾病患者（平均年龄75.0±6.5岁，男性为50.8％）。通过Fried表型评估脆弱性（健壮：0分；脆弱前：1-2分；脆弱：3-5分）。通过改进的超高效液相色谱-质谱法（UPLC-MS / MS）测量尿液中的8-oxoGsn和8-oxodGsn浓度。测试了尿肌酐（Cre）以纠正8-oxoGsn和8-oxodGsn水平。根据弗里德表型评分，健壮，虚弱，体弱的受试者分别为20.5％（104/508），53.9％（274/508）和25.6％（130/508）。这三组尿中的8-oxoGsn / Cre（P <0.001）有显着差异，但尿中的8-oxodGsn / Cre（P = 0.600）没有显着差异。单因素和多因素logistic回归显示年龄（比值比[OR] = 1.090，P <0.001），收缩压（OR = 0.981，P = 0.008），8-oxoGsn / Cre（OR = 1.203，P = 0.007） ，血红蛋白（OR = 0.980，P = 0.007）和钠（OR = 0.915，P = 0.044）分别与体弱相关。根据最佳Youden指数，在3.879μmol/ mol的最佳临界值下，对8-oxoGsn / Cre识别脆弱的敏感性和特异性分别为53.08％和71.96％。尿液中的8-oxoGsn作为公认的RNA氧化生物标记，与老年心血管疾病患者的虚弱独立相关。然而，尿中的8-oxodGsn与衰弱无明显相关性。为了获得更好的体弱诊断性能，将来应探索更多来自不同病理生理途径的生物标志物。