概述

肌酐试验可揭示有关肾脏的重要信息。

肌酐是一种化学废物,由肌肉新陈代谢产生,进食的肉类分解也会产生少量的肌酐。健康的肾脏会过滤掉血液中的肌酐和其他废物。过滤的废物通过尿液排出体外。

如果肾脏功能不正常,则血液中的肌酐水平可能会升高。血清肌酐试验可测量血液中的肌酐水平,并评估肾脏的过滤效果(肾小球滤过率)。尿肌酐测定可以测量尿液中的肌酐。

做手术的理由

血清肌酸酐试验用于测量血液中的肌酸酐水平,也可以显示您的肾脏功能是否正常。您需要多久进行一次肌酸酐试验取决于基础病以及肾损害存在的风险。例如:

  • 如果您患有 1 型或 2 型糖尿病,医生可能会建议您每年至少做一次肌酸酐试验。
  • 如果您患有肾病,为了监测您的病情,医生可能会建议您定期做肌酸酐试验。
  • 如果您患有可能影响肾脏的疾病,如高血压或糖尿病,或正在服用可能影响肾脏的药物,医生可能会建议您做肌酸酐试验。

准备怎么做

肌酸酐试验是一种普通血液检测。检测前通常无需任何准备。医生将会为您提供具体的说明。

您所能期望的目标

进行血清肌酐检测时,医疗团队中的一名成员将针头插入您手臂的静脉来采集血液样本。血液样本会被送到化验室进行分析。您可以马上恢复日常活动。

在某些情况下,您的医生可能还会测量您尿液中的肌酐水平。作为肌酐清除检测的一部分,您的医生可能会要求您在一个特殊的容器中收集 24 小时的尿液并提交进行分析。肌酐检测可以帮助您的医生更准确地评估是否有肾功能衰竭或肾功能衰竭程度。

结果

肌酐血检结果以毫克/分升或微摩尔/升为单位。血液中肌酐的正常范围为 0.84 至 1.21 毫克/分升(74.3 至 107微克/升),具体因实验室、性别及年龄的不同而有所差异。由于血液中的肌酐含量会随着肌肉质量的增加而上升,因此男性的肌酐水平通常高于女性。

一般来说,血清肌酐水平居高不下,则意味着肾脏无法正常发挥作用。如出现脱水、血容量低、摄入过多肉类或服用某些药物,肌酐水平可能会暂时性升高。膳食补充剂肌酸也会产生同样的效果。

如血清肌酐水平高于正常水平,医生会要求您再做一次血检或尿检以确认结果。倘若担心出现肾脏损伤,则应合理控制任何可能导致损害的病症,这点至关重要。控制血压尤其重要,通常采取药物治疗。永久性肾脏损伤通常无法逆转,但经过适当的治疗,有望避免进一步的损伤。

Serum creatinine level

Creatinine usually enters your bloodstream and is filtered from the bloodstream at a generally constant rate. The amount of creatinine in your blood should be relatively stable. An increased level of creatinine may be a sign of poor kidney function.

Serum creatinine is reported as milligrams of creatinine to a deciliter of blood (mg/dL) or micromoles of creatinine to a liter of blood (micromoles/L). The typical range for serum creatinine is:

  • For adult men, 0.74 to 1.35 mg/dL (65.4 to 119.3 micromoles/L)
  • For adult women, 0.59 to 1.04 mg/dL (52.2 to 91.9 micromoles/L)

Glomerular filtration rate (GFR)

The measure of serum creatinine may also be used to estimate how quickly the kidneys filter blood (glomerular filtration rate). Because of variability in serum creatinine from one person to another, the GFR may provide a more accurate reading on kidney function.

The formula for calculating GFR takes into account the serum creatinine count and other factors, such as age and sex. A GFR score below 60 suggests kidney disease. The range of scores below 60 may be used to monitor treatment and disease progression.

Creatinine clearance

Creatinine clearance is a measure of how well the kidneys filter creatinine out of the bloodstream for excretion in urine.

Creatinine clearance is usually determined from a measurement of creatinine in a 24-hour urine sample and from a serum sample taken during the same time period. However, shorter time periods for urine samples may be used. Accurate timing and collection of the urine sample is important.

Creatinine clearance is reported as milliliters of creatinine per minute per body surface area (mL/min/BSA). The typical range for men, 19 to 75 years old, is 77 to 160 mL/min/BSA.

The typical range, by age, for creatinine clearance in women is as follows:

  • 18 to 29 years: 78 to 161 mL/min/BSA
  • 30 to 39 years: 72 to 154 mL/min/BSA
  • 40 to 49 years: 67 to 146 mL/min/BSA
  • 50 to 59 years: 62 to 139 mL/min/BSA
  • 60 to 72 years: 56- to 131 mL/min/BSA

Standard measures have not been determined for older adults.

Results lower than the typical range for your age group may be a sign of poor kidney function or conditions that affect blood flow to your kidneys.

Albumin/creatinine ratio

Another interpretation of urine creatinine count is called the albumin/creatinine ratio. Albumin is a protein in blood. Healthy kidneys generally don't filter it out of the blood, so there should be little to no albumin found in the urine.

Albumin/creatinine ratio describes how much albumin is in a urine sample relative to how much creatinine there is. The results are reported as the number of milligrams (mg) of albumin for every gram (g) of creatinine. Results indicating a healthy kidney are:

  • For adult men, less than 17 mg/g
  • For adult women, less than 25 mg/g

A higher than typical result may be a sign of kidney disease. In particular, the result may indicate a complication of diabetes called diabetic nephropathy, or diabetic kidney disease.

Your doctor or other health care provider will discuss the results of a creatinine test with you and help you understand what the information means for a diagnosis or treatment plan.

Jan. 13, 2022
  1. Creatinine. American Association for Clinical Chemistry. https://labtestsonline.org/understanding/analytes/creatinine/tab/glance/. Accessed Dec. 2, 2015.
  2. Inker LA, et al. Assessment of kidney function. http://www.uptodate.com/home. Accessed Dec. 2, 2015.
  3. Kidney disease of diabetes. National Institute of Diabetes and Digestive and Kidney Diseases. http://www.niddk.nih.gov/health-information/health-topics/kidney-disease/kidney-disease-of-diabetes/Pages/facts.aspx. Accessed Dec. 2, 2015.
  4. Rohren CH (expert opinion). Mayo Clinic, Rochester, Minn. Dec. 4, 2015.

肌酸酐试验