Dr Alvin Ng
Senior Consultant Nephrologist
MBChB (Auckland), FRACP (Aus), FAMS (Renal Medicine)
What Is Diabetic Kidney Disease (DKD)?
Diabetic kidney disease (DKD), also called diabetic nephropathy, is a serious and progressive complication that can develop in people with either type 1 or type 2 diabetes. It is the leading cause of end-stage renal disease (ESRD) worldwide.
When blood sugar levels remain high over time, they can damage the small blood vessels and filtering units in the kidneys, known as glomeruli. These structures are responsible for removing waste and excess fluid from the blood. As they become damaged, the kidneys lose their ability to filter effectively, leading to a buildup of toxins in the body. Without proper management, this gradual decline in kidney function can eventually lead to kidney failure.
How Is Kidney Function Measured?
Screening and monitoring diabetic nephropathy involves tests that assess how well the kidneys are working and whether any damage has occurred. The two key indicators are the estimated glomerular filtration rate (eGFR) and the urine albumin-to-creatinine ratio (UACR).
- Glomerular Filtration Rate (GFR): This blood test measures how efficiently your kidneys filter waste from the blood. A higher eGFR indicates better kidney function. The result is estimated using your creatinine level, age, and sex.
- Urine Albumin-to-Creatinine Ratio (UACR): This urine test checks for albumin, a protein that healthy kidneys normally keep in the bloodstream. Detecting albumin in the urine, known as albuminuria, is an early sign of kidney damage.
Other tests, such as 24-hour urine collection and cystatin C measurement, may be used when more detailed assessment is needed, but most of the time, eGFR and UACR provide enough information to evaluate kidney function and detect diabetic kidney disease early.
The Five Stages of Diabetic Kidney Disease (DKD)
The progression of diabetic kidney disease (DKD) is usually gradual, and symptoms often do not appear until the later stages. Managing blood sugar and blood pressure at every stage is essential to slow or prevent further kidney damage.
● Stage 1: Kidney Damage with Normal or High GFR
In the earliest stage of DKD, the kidneys show signs of damage but can still filter waste effectively, often maintaining a glomerular filtration rate (GFR) of 90 or higher. There are usually no noticeable symptoms, though small amounts of protein (albumin) may be found in the urine. The main goal at this point is to prevent progression through careful control of blood sugar and blood pressure.
● Stage 2: Mild Kidney Damage with Slight Loss of Function
At this stage, there is a mild decline in kidney function, with a GFR between 60 and 89. Like Stage 1, symptoms are uncommon, but albuminuria may still be present. Ongoing monitoring and strict management of blood sugar and blood pressure remain key to slowing disease progression.
● Stage 3: Moderate Kidney Damage
At this stage, there is a moderate loss of kidney function, with a GFR between 30 and 59. As the kidneys’ filtering ability declines, waste and fluid start to build up, leading to symptoms such as fatigue, swelling in the hands and feet, and changes in urination. Treatment often includes blood pressure medications such as ACE inhibitors or ARBs, along with dietary adjustments to reduce strain on the kidneys.
● Stage 4: Severe Kidney Damage
By Stage 4, kidney function is severely reduced, with a GFR between 15 and 29. The kidneys struggle to remove toxins effectively, leading to persistent fatigue, nausea, loss of appetite, vomiting and significant swelling. At this point, a nephrologist will closely monitor your condition and help prepare for potential end-stage treatments, including dialysis or kidney transplantation.
● Stage 5: Kidney Failure (End-Stage Renal Disease)
Stage 5 marks chronic kidney failure, where the GFR drops below 15 and the kidneys can no longer sustain normal body function. Severe symptoms such as shortness of breath, confusion and muscle cramps may develop. Without treatment, this stage is life-threatening. Management typically involves dialysis (haemodialysis or peritoneal dialysis) or a kidney transplant to replace lost kidney function and sustain life.
Can Diabetic Nephropathy Be Prevented or Slowed?
While kidney damage from diabetic kidney disease (DKD) cannot be reversed, its progression can often be prevented or significantly slowed through early diagnosis and proactive care. With proper management and healthy lifestyle changes, diabetic nephropathy can be effectively controlled to preserve kidney function and overall well-being.
Key strategies include:
- Glycaemic Control: Maintaining blood sugar levels within the target range through medication and lifestyle management reduces the risk of developing or worsening diabetic nephropathy.
- Blood Pressure Management: Controlling high blood pressure with medications such as angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) helps protect kidney function and reduce protein in the urine (proteinuria).
- Lifestyle Modifications: Regular physical activity, a balanced diet low in sodium and protein, maintaining a healthy weight and quitting smoking all support kidney health and slow disease progression.
- Medication: In addition to blood sugar and blood pressure control, newer drugs such as sodium-glucose cotransporter 2 (SGLT2) inhibitors and GLP-1 receptor agonists have shown kidney-protective effects.
- Regular Monitoring: Routine kidney function tests and urine albumin checks allow for early detection of changes and timely intervention.
- Avoiding Nephrotoxic Agents: Limiting or avoiding certain pain medications, such as non-steroidal anti-inflammatory drugs (NSAIDs), reduces the risk of further kidney damage.
Taking Charge of Your Kidney Health
Diabetic kidney disease is a serious condition, but it can be managed with the right care and attention. Understanding the five stages and recognising the importance of early detection are key steps toward protecting your kidney health. By monitoring your eGFR and UACR results and keeping your blood sugar and blood pressure within target ranges, you give yourself the best chance of slowing the disease and maintaining kidney function.
If you have diabetes or are concerned about diabetic nephropathy, consider consulting Dr Alvin Ng, a specialist in diabetic kidney care, to develop a plan that fits your specific health needs. For comprehensive evaluation and ongoing support, visit The Kidney Health Care Clinic for access to tailored treatment and monitoring to help preserve your kidney function. Book an appointment at our clinic today and take the next step toward safeguarding your kidney health.