University of Belgrade, Faculty of Pharmacy, Department of Medical Biochemistry, Belgrade, Serbia.
Clin Biochem. 2013 Mar;46(4-5):321-6. doi: 10.1016/j.clinbiochem.2012.12.008. Epub 2012 Dec 19.
Although there are many nucleobase modifications, 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) is one of the dominant form of oxidative modifications of DNA. Urinary 8-oxodG is potentially the best non-invasive biomarker of oxidative stress. Defining reference interval for urinary 8-oxodG is a prerequisite for its clinical use as biomarker.
Reference population included 229 healthy Serbian adults (130 males and 99 females). The spot urinary 8-oxodG was determined using high performance liquid chromatography and tandem mass spectrometry (HPLC-MS/MS). Urinary creatinine was measured by the kinetic Jaffé method.
Analytical performances of the HPLC-MS/MS: CVs within and between-run variations were 5.6% and 2.6%; LOD and LOQ were 1.65 nmol/L and 3.30 nmol/L; mean recovery and relative accuracy were 96% and 97%. Creatinine level was higher in males than in females, but no gender difference in 8-oxodG level was observed. Upon the adjustment of 8-oxodG to creatinine (8-oxodG/creatinine), higher values were obtained in females (1.38 ± 0.65 nmol/mmol) than in males (1.05 ± 0.48 nmol/mmol). Distribution of 8-oxodG/creatinine in spot urine sample was log-normal and gender-related reference intervals (estimated as the 2.5th-97.5th percentiles) were 0.45-2.22 nmol/mmol for males, and 0.54-3.11 nmol/mmol for females. Body mass index (BMI) affects excretion of the 8-oxodG in males, independently of urinary creatinine, while in females it does not. Therefore, BMI might contribute to the gender-related differences of 8-oxodG/creatinine in spot urine samples.
This is the first established gender-related reference intervals of spot urinary 8-oxodG/creatinine. Our results contribute to the full validation of 8-oxodG as biomarker of oxidative stress.
尽管存在许多碱基修饰,但 8-氧代-7,8-二氢-2'-脱氧鸟苷(8-oxodG)是 DNA 氧化修饰的主要形式之一。尿液 8-oxodG 可能是氧化应激的最佳非侵入性生物标志物。定义尿液 8-oxodG 的参考区间是将其作为生物标志物临床应用的前提。
参考人群包括 229 名健康的塞尔维亚成年人(130 名男性和 99 名女性)。使用高效液相色谱和串联质谱法(HPLC-MS/MS)测定尿液中的 8-oxodG。尿液肌酐采用动力学 Jaffé 法测定。
HPLC-MS/MS 的分析性能:批内和批间变异的 CV 值分别为 5.6%和 2.6%;LOD 和 LOQ 分别为 1.65 nmol/L 和 3.30 nmol/L;平均回收率和相对准确度分别为 96%和 97%。男性的肌酐水平高于女性,但尿液 8-oxodG 水平无性别差异。在将 8-oxodG 校正为肌酐(8-oxodG/肌酐)后,女性(1.38±0.65 nmol/mmol)的 8-oxodG 值高于男性(1.05±0.48 nmol/mmol)。尿液中 8-oxodG/肌酐的分布呈对数正态分布,男女参考区间(估计为第 2.5 至 97.5 百分位数)分别为男性 0.45-2.22 nmol/mmol,女性 0.54-3.11 nmol/mmol。体重指数(BMI)独立于尿肌酐影响男性 8-oxodG 的排泄,但在女性中则不然。因此,BMI 可能导致尿液中 8-oxodG/肌酐的性别相关差异。
这是首次建立尿液中 8-oxodG/肌酐的性别相关参考区间。我们的结果有助于将 8-oxodG 完全验证为氧化应激的生物标志物。