Creatinine values are used to estimate renal function and to correct for urinary dilution in exposure assessment studies. Interindividual variability in urinary creatinine (UCR) is determined positively by protein intake and negatively by age and diabetes. These factors, among others, need to be accounted for, to increase comparability throughout epidemiological studies. Recently, dietary fiber has been shown to improve renal function. This study aims to evaluate dietary fiber intake relationship with UCR and its methodological implications for studies using UCR-corrected measurements. In a cross-sectional study, we analyzed information regarding UCR, dietary fiber, age, and other UCR-related factors in 801 women residing in Northern Mexico during 2007–2009. The median fiber intake in this population was 33.14 g/day, above the adequate intake level for women > 18 years. We estimated an age-adjusted increase of 10.04 mg/dL UCR for a 10 g/day increase in dietary fiber intake. The main dietary sources of fiber in this population were corn tortillas, raw onions, flour tortillas, and beans. Our results suggest that epidemiological studies adjusting analytes by UCR should also consider controlling dietary fiber intake to improve the comparability of creatinine-corrected values and associations across different populations, such as those in Mexico and Latin America, where protein and fiber intake vary significantly.

在接触评估研究中，肌酐值用于估计肾功能并校正尿液稀释度。尿肌酐（UCR）的个体间差异由蛋白质摄入量决定，而年龄和糖尿病则由否定。除其他因素外，还需要考虑这些因素，以提高整个流行病学研究的可比性。最近，膳食纤维已显示可改善肾功能。这项研究旨在评估膳食纤维摄入量与UCR的关系及其对使用UCR校正后的测量方法的研究的方法学意义。在一项横断面研究中，我们分析了2007-2009年间居住在北墨西哥的801名妇女的UCR，膳食纤维，年龄和其他UCR相关因素的信息。该人群的平均纤维摄入量为33.14 g /天，高于18岁以上女性的适当摄入水平。我们估计年龄调整后的膳食纤维摄入量每增加10 g /天，UCR就会增加10.04 mg / dL。该人群的主要膳食纤维来源是玉米饼，生洋葱，面粉玉米饼和豆类。我们的结果表明，通过UCR调整分析物的流行病学研究还应考虑控制膳食纤维的摄入量，以提高肌酐校正值和不同人群之间的可比性，例如墨西哥和拉丁美洲，其中蛋白质和纤维的摄入量差异很大。