Kugako Sugimoto, NOST Tokyo
Origineel gepubliceerd op de site van Agentschap NL.
Een onderzoekgroep onder leiding van professor Eiji Ishimura van Osaka City University heeft een nauwkeuriger methode ontwikkeld voor het meten van de glomerulaire filtratiesnelheid (GFR). De GFR is een indicator van het functioneren van de nieren en wordt voornamelijk gebruikt bij patiënten voor de vroege detectie en ernst van diabetes.
Accurate Diagnosis of Kidney Function for Diabetic Patients
Summary
A research team led by Associate Professor Eiji Ishimura of Osaka City University developed a new formula to accurately measure the estimated glomerular filtration rate (eGFR)*, an indicator of the function of the kidneys, for diabetic and non-diabetic people. The conventional formula tends to give an apparently better eGFR for diabetic patients, which might lead to overlooking the severeness of the disease and prevent early detection of diabetes. A new formula incorporates the values of Hemoglobin A1c. The new formula is easily usable at the clinical practice.
Details
GFR indicates how much blood can go through the glomeruli in the kidneys per minute. It is difficult to measure the true GFR. Therefore, a clearance method was used by measuring the rate of removal of a particular substance from blood for estimation of GFR. For GFR, creatinine** clearance was usually used. Creatinine is a waste substance in the blood and most creatinine is filtered out in the kidneys when a person is in good health. However, when the function of the kidneys is lowered, creatinine remains in the blood. Simple eGFR can be calculated from the serum creatinine value, age, and, gender. Alternatively inulin clearance rate can be used for a more accurate GFR. However obtaining inulin clearance rate is troublesome in clinical practice.
A research team led by Associate Professor Eiji Ishimura of Osaka City University pointed out the overestimation of GFR in diabetics in using a conventional formula. This might interfere with the early diagnosis of kidney failure and the right medical treatment.
The research team conducted a study to find out the factors associated with overestimation of the renal function in diabetic patients and to create a new formula for obtaining accurate eGFR. The group consisting of 40 diabetics and 40 non-diabetics with an average age of around 56.5 years, 35 males and 45 females, were monitored. eGFR based inulin clearance, serum creatinine and/or serum cystatin C as well as other values that influence on eGFR were obtained.
The inulin clearance between diabetics and control groups was not significantly different. However, the diabetic group showed significantly higher eGFR values than non-diabetic group. These indicate the overestimation of the function of kidneys for diabetic people.
The intra-class correlation coefficients for each GFR values in the diabetic group were weaker than those in the non-diabetic patients and the intercepts of the regression lines between each eGFR and inulin clearance were significantly higher for diabetic group than those of non-diabetic group.
Multiple regression analyses showed that hemoglobin A1*** and glycated albumin**** related to the overestimation of GFR calculated from both creatinine and cystatin C. Therefore, glycemic control is essential for the accurate measurements of the eGFR.
The research group proposed to use the new formula of eGFR corrected by hemoglobin A1c. This practice is feasible at clinics.
Source
- Diabetes Care October 15, 2013, doi: 10.2337/dc13-1899
- Asahi Shimbun Digital (Nov. 27, 2013) (in Japanese)
*glomerular filtration rate (eGFR) (Wikipedia)
****glycated albumin (human serum albumin, Wikipedia)
