Glomerular Filtration Rate: What You Need to Know - Internal Medicine

Dr. Xiao Yongxun reply Internal Medicine

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According to a study published in The Lancet in 2008, it is estimated that 11.93% of adults in Taiwan have chronic kidney disease (CKD).
The stages of severity are as follows: 1.
Stage 1: Kidney damage with normal or increased GFR, GFR ≥ 90 ml/min/1.73 m².
2.
Stage 2: Kidney damage with mild decrease in GFR, GFR 60-89 ml/min/1.73 m².
3.
Stage 3: Moderate decrease in GFR, GFR 30-59 ml/min/1.73 m².
4.
Stage 4: Severe decrease in GFR, GFR 15-29 ml/min/1.73 m².
5.
Stage 5: Kidney failure, GFR < 15 ml/min/1.73 m².

In healthy individuals, the amount of protein lost in urine daily is approximately 80-150 mg.
Proteinuria is defined as a urine dipstick test showing 1+ (approximately 30 mg/dl) or more, or a total protein loss exceeding 150 mg in a 24-hour urine collection.
The dipstick test primarily measures the amount of albumin in urine, with qualitative results categorized as follows: 1.
Negative: Urine protein concentration less than 10 mg/dl.
2.
Trace: Urine protein concentration 10-20 mg/dl.
3.
+: Urine protein concentration 30 mg/dl, estimated daily protein loss of about 300-400 mg.
4.
++: Urine protein concentration 100 mg/dl.
5.
+++: Urine protein concentration 300 mg/dl.
6.
++++: Urine protein concentration > 1000 mg/dl.
Clinically, there is a desire to detect kidney changes earlier, such as diabetic nephropathy, hypertensive nephropathy, and chronic glomerulonephritis.
Therefore, a 24-hour urine collection is performed to measure the total amount of albuminuria, with a goal of less than 30 mg/24 hr.
If the amount is between 30-299 mg, it is termed microalbuminuria, indicating early kidney damage, which can sometimes be reversible with treatment or dietary adjustments.

In practice, collecting 24-hour urine from outpatient or some hospitalized patients can be inconvenient and challenging.
Research has shown that the urine protein-to-creatinine ratio (UPCR) from a single urine sample correlates well with the total protein amount in a 24-hour collection and is used clinically.

In summary, microalbuminuria is an important indicator of the onset of diabetic nephropathy and is a risk factor positively correlated with cardiovascular disease.
Clinically, a spot urine collection is often used to estimate kidney damage, specifically the Spot urine Albumin/Creatinine ratio (ACR), with a target of <30 mg/g; between 30-300 mg/g indicates microalbuminuria; and >300 mg/g indicates overt proteinuria.
Regarding your situation: Your fasting blood glucose levels have consistently been between 102-112.
Recent tests showed fasting blood glucose at 108, postprandial at 119, HbA1c at 5.6, blood urea nitrogen at 17, creatinine at 0.92, and an estimated GFR of 102.7.
It appears that a GFR above 90 indicates stage 1 CKD with normal kidney function but with proteinuria or hematuria, characterized by eGFR ≥ 90 ml/min/1.73 m² + UPCR ≥ 150 mg/g (or UACR ≥ 30 mg/g for diabetic patients).
However, I do not understand your statement.
UPCR generally refers to the urine/plasma creatinine ratio, which is different from UACR (urine albumin/creatinine ratio).
eGFR refers to estimated GFR, calculated as eGFR (ml/min/1.73 m²) = 186 × Cr (mg/dl)⁻¹.154 × Age⁻⁰.²⁰³ × [1 (male) or 0.742 (female)], which is known as the MDRD formula, primarily based on serum creatinine concentration, age, and sex for regression estimation.
Therefore, it is difficult to answer your question.
However, I suspect it may just be a mild response of proteinuria and hematuria.

I recommend monitoring your blood pressure, blood glucose, and lipid levels; avoid overeating, excessive salt, and fatty foods, aiming for 80% fullness at meals, and increase physical activity.
Avoid smoking, excessive alcohol consumption, processed foods, food additives, and pain medications.
It would be best to discuss this further with your physician.

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Reply Date: 2014/12/12