Safarinejad Mohammad R
Department of Urology, Military University of Medical Sciences, Tehran, Iran.
Pediatr Nephrol. 2003 Feb;18(2):140-4. doi: 10.1007/s00467-002-1020-1. Epub 2002 Dec 21.
The purpose of this study was to determine normal reference values for urinary calcium/creatinine (Ca/Cr), phosphate/creatinine (P/Cr), magnesium/creatinine (Mg/Cr), sodium/creatinine (Na/Cr), potassium/creatinine (K/Cr), sodium/potassium (Na/K), calcium/sodium (Ca/Na), and uric acid/creatinine ratios in healthy Iranian children. Nine hundred and ninety children (515 boys, 475 girls) aged 1 month to 14 years were studied. Two non-fasting random urine specimens (1 week apart) from each subject and 24-h urine collections from 114 children were analyzed for Ca, P, Mg, uric acid, Na, K, and Cr. Urinary Ca/Cr, P/Cr, Mg/Cr, Na/Cr, K/Cr, Na/K, Ca/Na, and uric acid/creatinine ratios were determined from each sample. Non-fasting Ca/Cr, P/Cr, Na/Cr, K/Cr, Na/K, Ca/Na, and uric acid/creatinine ratios were not significantly different between the sexes (P>0.05). Urinary Mg/Cr ratios were higher in girls than boys (P<0.001). No significant relationships were found between urinary Ca/Cr and urinary Na/Cr, urinary Ca/Cr and urinary Na/K, and urinary Ca/Cr and urinary Ca/Na (P>0.05). The P/Cr values showed a gradual decrease with age (from mean+/-SD 0.962+/-0.172 mg/mg at 1 month of life to 0.318+/-0.124 mg/mg at 14 years) (P<0.05). The Ca/Cr ratio was highest between 6 months and 3 years (mean+/-SD=0.047+/-0.041 mg/mg). Following a moderate decrease it stabilized by the age of 7 years (mean+/-SD=0.038+/-0.044 mg/mg). Urinary ratios of Mg/Cr were significantly higher in children under 10 years (mean+/-SD=0.042+/-0.015 mg/mg) compared with the 11- to 14-year age group (mean+/-SD=0.031+/-0.001 mg/mg) (P<0.05). The uric acid/creatinine ratios decreased from 0.060+/-0.077 mg/mg in those less than 7 years to 0.041+/-0.033 in the 11- to 14-year group. Urinary Na/Cr ratios were significantly lower in younger age groups compared with the older age group (P<0.05). Urinary K/Cr ratio was highest in younger children, and then steadily decreased with age. There was no correlation between 24-h urinary Ca and Na excretion. The mean Ca/Na ratios significantly decreased with advancing age (P<0.05). The solute/creatinine ratios in the non-fasting urine samples correlated well with the 24-h solute excretion. We provide reference values for urinary Ca/Cr, P/Cr, Mg/Cr, Na/K, K/Cr, and uric acid/creatinine ratios in normal Iranian children. A child's age and ethnicity should be taken into consideration when assessing the urinary solute/creatinine ratios.
本研究的目的是确定伊朗健康儿童尿钙/肌酐（Ca/Cr）、磷/肌酐（P/Cr）、镁/肌酐（Mg/Cr）、钠/肌酐（Na/Cr）、钾/肌酐（K/Cr）、钠/钾（Na/K）、钙/钠（Ca/Na）以及尿酸/肌酐比值的正常参考值。对990名年龄在1个月至14岁的儿童（515名男孩，475名女孩）进行了研究。分析了每个受试者的两份非空腹随机尿液标本（间隔1周）以及114名儿童的24小时尿液收集样本中的钙、磷、镁、尿酸、钠、钾和肌酐。计算每个样本的尿Ca/Cr、P/Cr、Mg/Cr、Na/Cr、K/Cr、Na/K、Ca/Na以及尿酸/肌酐比值。非空腹状态下，Ca/Cr、P/Cr、Na/Cr、K/Cr、Na/K、Ca/Na以及尿酸/肌酐比值在性别之间无显著差异（P>0.05）。女孩的尿Mg/Cr比值高于男孩（P<0.001）。未发现尿Ca/Cr与尿Na/Cr、尿Ca/Cr与尿Na/K以及尿Ca/Cr与尿Ca/Na之间存在显著相关性（P>0.05）。P/Cr值随年龄逐渐降低（从1月龄时的平均±标准差0.962±0.172 mg/mg降至14岁时的0.318±0.124 mg/mg）（P<0.05）。Ca/Cr比值在6个月至3岁之间最高（平均±标准差=0.047±0.041 mg/mg）。经过适度下降后，到7岁时趋于稳定（平均±标准差=0.038±0.044 mg/mg）。10岁以下儿童的尿Mg/Cr比值显著高于11至14岁年龄组（平均±标准差=0.042±0.015 mg/mg与平均±标准差=0.031±0.001 mg/mg）（P<0.05）。尿酸/肌酐比值从7岁以下儿童的0.060±0.077 mg/mg降至11至14岁组的0.041±0.033。年龄较小的年龄组尿Na/Cr比值显著低于年龄较大的年龄组（P<0.05）。尿K/Cr比值在幼儿中最高，然后随年龄稳步下降。24小时尿钙和钠排泄之间无相关性。平均Ca/Na比值随年龄增长显著降低（P<0.05）。非空腹尿液样本中的溶质/肌酐比值与24小时溶质排泄相关性良好。我们提供了伊朗正常儿童尿Ca/Cr、P/Cr、Mg/Cr、Na/K、K/Cr以及尿酸/肌酐比值的参考值。在评估尿溶质/肌酐比值时应考虑儿童的年龄和种族。
