Suwazono Y, Akesson A, Alfvén T, Järup L, Vahter M
Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
Biomarkers. 2005 Mar-Jun;10(2-3):117-26. doi: 10.1080/13547500500159001.
The aim was to assess how urinary creatinine is affected by age, gender, body size and meat intake, and to determine to what extent such factors might affect the creatinine adjustment of urinary cadmium. The study was based on three Swedish studies: (1) 67 non-smoking women aged 20-50 years (24-h urine samples); (2) 289 men and 434 women aged 16-81 years (spot urine samples); and (3) 98 men and 105 women aged 19-72 years (spot urine samples). The effects of age, body surface area (as an indicator of muscle mass), and meat intake on urinary creatinine and cadmium were analysed using multiple regression analyses. Gender- and age-related variations in urinary creatinine and cadmium adjusted for creatinine or specific gravity were compared by ANOVA or ANCOVA. In the multiple regression analyses, body surface area, gender, age and meat intake were the major determinants of urinary creatinine. Urinary cadmium adjusted for creatinine and specific gravity were also dependent on body size, gender and age. Urinary cadmium adjusted for creatinine was 15-92% higher in women or older individuals than in men or younger individuals. Women or older individuals had -3 to 79% higher urinary cadmium adjusted for specific gravity than men or younger individuals had, and such a difference between gender or age group was less obvious in specific gravity adjustment than in creatinine adjustment. Thus, urinary cadmium adjusted for creatinine is more affected by age, gender, body size and meat intake than is specific gravity adjustment. When comparing individuals or populations with large differences in muscle mass or meat intake, such effects can be especially important. In such studies, specific gravity adjustment seems to be more appropriate.
本研究旨在评估年龄、性别、体型和肉类摄入量对尿肌酐的影响，并确定这些因素在多大程度上可能影响尿镉的肌酐校正值。该研究基于三项瑞典的研究：（1）67名年龄在20 - 50岁的非吸烟女性（24小时尿液样本）；（2）289名男性和434名年龄在16 - 81岁的女性（随机尿液样本）；以及（3）98名男性和105名年龄在19 - 72岁的女性（随机尿液样本）。使用多元回归分析来分析年龄、体表面积（作为肌肉量的指标）和肉类摄入量对尿肌酐和尿镉的影响。通过方差分析（ANOVA）或协方差分析（ANCOVA）比较经肌酐或比重校正后的尿肌酐和尿镉的性别及年龄相关差异。在多元回归分析中，体表面积、性别、年龄和肉类摄入量是尿肌酐的主要决定因素。经肌酐和比重校正后的尿镉也取决于体型、性别和年龄。经肌酐校正后的尿镉在女性或年龄较大个体中比男性或年龄较小个体高15% - 92%。经比重校正后，女性或年龄较大个体的尿镉比男性或年龄较小个体高 - 3%至79%，并且这种性别或年龄组之间的差异在比重校正中比在肌酐校正中不太明显。因此，经肌酐校正的尿镉比比重校正受年龄、性别、体型和肉类摄入量的影响更大。在比较肌肉量或肉类摄入量差异较大的个体或人群时，这种影响可能尤为重要。在这类研究中，比重校正似乎更合适。
