[年龄对尿镁和肌酐水平的影响]

Simecková A, Zamrazil V, Cerovská J

Endokrinologický ústav, Praha.

Cas Lek Cesk. 1998 Dec 14;137(24):753-6.

BACKGROUND

The concentration of magnesium in urine reflects its intake from food resources. The main regulatory mechanism of magnesium homeostasis is the kidney filtration-absorption process. So far the reference values are not known of the magnesium concentration in urine in dependence on age and sex for the normal population. Therefore, we focused on investigating these problems in a randomly selected sample of persons of both sexes, aged 1-93 years. Beside magnesiuria we also assessed creatininuria.

METHODS AND RESULTS

The selection of 2715 persons of both sexes aged from one to ninety three years was made by the random selection method. As we have found no statistically significant difference between men and women as regards concentrations of magnesium and creatinine in urine, the evaluated groups include persons of both sexes. The whole is divided into age groups as follows: children 1 year (n = 24), 2 years (n = 15), 4 years (n = 18), 6 years (n = 378), 10 years (n = 424), 13 years (n = 416), and adults 18-35 years (n = 396), 36-49 years (n = 482), 50-65 years (n = 453), 66-75 years (n = 53), 76-85 years (n = 42), 86-93 years (n = 14). In the morning urine after twelve-hour fasting we determined the concentration of magnesium and creatinine be using Merck Vitalab Eclipse apparatus. The concentration of magnesium in urine rises from 3.37 +/- 0.28 mmol/l at 1 years to the top value 6.64 +/- 0.58 mmol/l (p < 0.001) at 4 years, and since this age it is continuously dwindling to the value 2.35 +/- 0.17 mmol/l (p < 0.001) at the age of 93 years. The creatinine concentration in urine rises from 2.47 +/- 0.30 mmol/l at the age of one year to 15.33 +/- 0.36 mmol/l (p < 0.001) in the age group 18-35 years, and further it goes down with age to the value 6.23 +/- 0.99 mmol/l (p < 0.001) at 93 years. The highest ratio of the urine concentrations of magnesium and creatinine 1.98 +/- 0.32 is at the age of 2 years, and then it is continuously subsiding to 0.41 +/- 0.15 (p < 0.001) at the age range 66-75 years.

CONCLUSIONS

When evaluating the magnesium concentration in urine as the index of a sufficient supply of organism with this ion, and also in various studies of metabolism, it is essential to consider the patient's age. The ratio of cocentrations in urine of magnesium and creatinine does not improve the meaningfulness of magnesium analysis.

背景

尿液中镁的浓度反映了其从食物来源的摄入量。镁稳态的主要调节机制是肾脏的滤过 - 吸收过程。到目前为止，正常人群中尿液镁浓度随年龄和性别的参考值尚不清楚。因此，我们重点对随机抽取的年龄在1 - 93岁的男女样本进行这些问题的研究。除了尿镁，我们还评估了尿肌酐。

方法与结果

通过随机抽样法选取了2715名年龄在1至93岁的男女。由于我们发现男女尿液中镁和肌酐的浓度无统计学显著差异，所以评估组包括男女两性。整体分为以下年龄组：1岁儿童（n = 24）、2岁儿童（n = 15）、4岁儿童（n = 18）、6岁儿童（n = 378）、10岁儿童（n = 424）、13岁儿童（n = 416），以及18 - 35岁成年人（n = 396）、36 - 49岁成年人（n = 482）、50 - 65岁成年人（n = 453）、66 - 75岁成年人（n = 53）、76 - 85岁成年人（n = 42）、86 - 93岁成年人（n = 14）。在禁食12小时后的晨尿中，我们使用默克Vitalab Eclipse仪器测定镁和肌酐的浓度。尿液中镁的浓度从1岁时的3.37±0.28 mmol/l上升至4岁时的最高值6.64±0.58 mmol/l（p < 0.001），此后从这个年龄开始持续下降，至93岁时降至2.35±0.17 mmol/l（p < 0.001）。尿肌酐浓度从1岁时的2.47±0.30 mmol/l上升至18 - 35岁年龄组的15.33±0.36 mmol/l（p < 0.001），并随年龄进一步下降，至93岁时降至6.23±0.99 mmol/l（p < 0.001）。尿镁与尿肌酐浓度的最高比值1.98±0.32出现在2岁时，然后持续下降，至年龄范围在66 - 75岁时降至0.41±0.15（p < 0.001）。