A Brief Discussion on Diabetic Nephropathy
Update Date：2025/11/04，
Views：122
Nephrology Division, Dr. Chen Jun-Nan, Dr. Wang Han-En
What is Diabetic Nephropathy?
Diabetes not only affects blood sugar but also gradually damages the kidneys. When the kidneys are damaged, it can develop into diabetic nephropathy, which is one of the leading causes of end-stage renal disease (ESRD). This is particularly serious in Taiwan. According to the 2023 U.S. Renal Data System Annual Report, Taiwan had the highest incidence and prevalence rates of ESRD in 2021 globally, with nearly half (47.7%) of new dialysis cases caused by diabetes. Additionally, Taiwan has the highest rate of dialysis treatment worldwide. This means that diabetic nephropathy is not just a personal health issue but also a significant burden on the healthcare system and society.
The kidneys function as filters, removing waste from the blood while retaining necessary proteins. Due to prolonged high blood sugar, diabetes can cause damage to the kidney’s glomeruli, impairing filtration. The earliest warning sign is the appearance of "albumin" in the urine, a condition called "albuminuria." It's important to note that some temporary conditions (such as infection, intense exercise, poor blood sugar control, or worsening heart failure) can also lead to transient albuminuria. Therefore, a diagnosis is confirmed only after three tests over 3-6 months, with at least two positive results.
How is Diabetic Nephropathy Diagnosed?
Diagnosing diabetic nephropathy relies on three main aspects:
1. Medical History: How long has the patient had diabetes? Is the deterioration of kidney function rapid or slow? Generally, diabetic nephropathy progresses slowly and typically occurs after more than 10 years of diabetes.
2. Physical Examination: Is there concurrent diabetic retinopathy? Nearly 95% of type 1 diabetes patients have retinal changes, while about 65-70% of type 2 diabetes patients do.
3. Laboratory Tests: In addition to albuminuria, urine tests should check for hematuria, white blood cells, or urine casts. If present, other kidney diseases should be suspected.
In atypical cases, such as severe kidney damage occurring in less than 5 years of diabetes, the absence of retinopathy with significant proteinuria or hematuria, or rapid deterioration of kidney function, a referral to nephrology or even a kidney biopsy may be recommended. Research has found that only about 37% of diabetic patients with kidney damage have simple diabetic nephropathy, while 36% have non-diabetic kidney disease, and 27% have both. This means that kidney failure in diabetes patients isn't necessarily due to diabetic nephropathy, so careful differential diagnosis is crucial.
Treatment and Control Principles
The focus of treating diabetic nephropathy is to delay kidney function deterioration and reduce complications. Key strategies include blood sugar control (keeping HbA1c below 7%), blood pressure management, use of new glucose-lowering medications (SGLT2 inhibitors and GLP-1 receptor agonists), kidney biopsy for diagnosis, and individualized treatment plans. If a diabetic patient needs to use steroids or immunosuppressants, doctors will be more cautious to avoid worsening blood sugar control.
Introduction to New Glucose-Lowering Medications (SGLT2i, GLP1-RA)
In the treatment strategy for diabetic nephropathy, beyond traditional blood sugar and blood pressure control, SGLT2 inhibitors (commonly known as “sugar-flushing drugs”) and GLP-1 receptor agonists (commonly known as “weight-loss injections”) have become important new drug options.
SGLT2 inhibitors promote the kidneys to excrete glucose via urine, lowering blood sugar, reducing weight, lowering blood pressure, and offering kidney and heart protection. Common drugs include Dapagliflozin and Empagliflozin.
GLP-1 receptor agonists increase insulin secretion, suppress appetite, and delay gastric emptying, effectively lowering blood sugar and reducing weight, while also lowering cardiovascular risk. Common drugs include Liraglutide and Semaglutide.
Health Insurance Coverage Criteria:
1. SGLT2 Inhibitors: Currently approved mainly for type 2 diabetes patients with kidney or cardiovascular high risks, often when HbA1c is poorly controlled or there are signs of kidney dysfunction (such as reduced eGFR or albuminuria).
2. GLP-1 Receptor Agonists: Health insurance coverage is more restrictive, mostly limited to type 2 diabetes patients who have not achieved good blood sugar control despite dual oral medications, and those with weight or cardiovascular risks are considered as well.
Overall, SGLT2 inhibitors and GLP-1 receptor agonists are effective in controlling blood sugar and provide kidney and cardiovascular protection, making them essential treatment options for diabetic nephropathy patients.
How to Protect the Kidneys? Recommendations for Diabetic Patients
1. Regularly check urine albumin levels and kidney function (eGFR).
2. Control blood sugar, blood pressure, and blood lipids, and maintain a healthy lifestyle.
3. Avoid indiscriminate use of painkillers (NSAIDs) or folk remedies to prevent further kidney damage.
4. Seek early medical attention if proteinuria or worsening kidney function is detected, and refer to a nephrologist if necessary.
5. Actively cooperate with doctors in treatment, including adjusting medications and dietary restrictions (low salt, appropriate protein intake).
Conclusion
Diabetic nephropathy is one of the leading causes of end-stage renal disease, particularly a severe issue in Taiwan. Since diabetic patients often have other kidney diseases as well, special attention is needed for differential diagnosis. Early detection of albuminuria, timely referral to nephrology, and kidney biopsy when necessary can help with accurate diagnosis and treatment. Through blood sugar and blood pressure control, appropriate medication use, and a healthy lifestyle, kidney function deterioration can be significantly delayed, improving quality of life and reducing the burden on healthcare and society.