Diabetic nephropathy is a type of kidney disease caused by diabetes. This disease can occur in people with type 1 diabetes and type 2 diabetes. The longer a person has diabetes, or the presence of other risk factors such as hypertension, the higher the risk of developing diabetic nephropathy.
Symptoms of Diabetic Nephropathy
In the early stages of its development, diabetic nephropathy often does not show any symptoms. However, if kidney damage continues, a number of symptoms will occur, such as:
- Increased frequency of urination or vice versa.
- Itchy rash.
- Loss of appetite.
- Insomnia.
- Weak.
- Swollen eyes.
- Nausea and vomiting.
- Swelling in the arms and legs.
- It's hard to concentrate.
- There is protein in the urine and foamy urine.
Causes of Diabetic Nephropathy
Diabetic nephropathy occurs when diabetes causes damage and scar tissue to form in the nephrons. Nephron is the part of the kidney that functions to filter waste from the blood, and remove excess fluid from the body. In addition to causing impaired function, the damage also makes a protein called albumin wasted into the urine and not reabsorbed.
It is not known why the above conditions occur in people with diabetes, but it is thought to be associated with high levels of sugar and blood pressure, two conditions that can interfere with kidney function. One of the risk factors for this disease is the habit of consuming foods that cause kidney failure, such as foods that are too sweet.
In addition to high blood sugar levels (hyperglycemia) and uncontrolled high blood pressure (hypertension), other factors that can increase the risk of diabetic nephropathy are:
- Smoke.
- Had type 1 diabetes before the age of 20.
- Suffer from high cholesterol.
- Have excess weight.
- Have a family history of diabetes and kidney disease.
- Have other complications of diabetes, such as diabetic neuropathy.
Diabetic Nephropathy Diagnosis
Doctors can suspect a patient has diabetic nephropathy if a person with diabetes experiences a number of the symptoms described previously. But to be sure, the doctor can perform further tests to check kidney function, such as:
- BUN test (blood urea nitrogen) or urea. This test aims to measure the level of urea nitrogen in the blood. Urea nitrogen is a metabolic waste substance that is normally filtered by the kidneys and excreted in the urine. A high BUN can indicate abnormalities in the kidneys. Normal BUN levels depend on age and sex, namely 8-24 mg/dL in adult men, 6-21 mg/dL in adult women, and 7-20 mg/dL in children aged 1-17 years.
- Creatinine test. This test is done to measure the level of creatinine in the blood. Just like urea nitrogen, creatinine is also a waste product of metabolism, which is normally excreted in the urine. Generally, normal creatinine in individuals aged 18-60 years ranges from 0.9-1.3 mg/dL for men, and 0.6-1.1 mg/dL for women.
- GFR (glomerular filtration rate) test. The GFR test is a type of blood test that is done to measure kidney function. The lower the GFR value, the worse the kidney function in filtering waste, as will be explained below:
- Stage 1 (GFR 90 and above): the kidneys are functioning properly.
- Stage 2 (GFR 60-89): mild impairment of renal function.
- Stage 3 (GFR 30-59): intermediate stage renal function impairment.
- Stage 4 (GFR 15-29): severe impairment of renal function.
- Stage 5 (GFR 15 and below): kidney failure.
- Microalbuminuria urine test. Patients can be suspected of having diabetic nephropathy if the urine contains a protein called albumin. The test can be done by taking a sample of the patient's urine at random in the morning or collected for 24 hours. Albumin levels in the urine are still fairly normal if they are below 30 mg. Meanwhile, albumin levels in the range of 30-300 mg (microalbuminuria), indicate an early stage of kidney disease. If more than 300 mg (macroalbuminuria), this condition indicates kidney disease that has progressed more severe.
- Imaging test. Doctors can do kidney ultrasound or X-rays, to see the structure and size of the patient's kidneys. CT scans and MRIs can also be done to assess the condition of blood circulation in the kidneys.
- Kidney biopsy. If needed, the doctor can take a small sample of tissue from the patient's kidney. The sample will be taken with a fine needle and examined using a microscope.
Diabetic Nephropathy Treatment
Diabetic nephropathy cannot be treated, but its development can be prevented from getting worse. Treatment aims to control blood sugar levels and high blood pressure. Treatment methods include the administration of drugs, such as:
- Angiotensin converting enzyme inhibitors (ACE inhibitor) or ARBs (angiotensin II receptor blocker), to lower high blood pressure while preventing albumin from leaking into the urine.
- Cholesterol-lowering drugs, such as statins, to treat high cholesterol, a risk factor for diabetic nephropathy.
- Insulin, to lower blood sugar levels.
In addition to giving drugs, doctors will also recommend patients undergo a stricter diet. These include limiting protein intake, reducing sodium or salt intake to less than 1500-2000 mg/dL, limiting consumption of high-potassium foods such as bananas and avocados, and limiting consumption of high-phosphorus foods such as yogurt, milk, and processed meats.
If a patient with diabetic nephropathy has end-stage renal failure, the doctor may advise the patient to undergo renal replacement therapy. This procedure aims to clean the blood of metabolic waste. The form of kidney replacement therapy can be in the form of dialysis using a machine (hemodialysis) 2-3 times a week, dialysis through the stomach or dialysis peritoneal dialysis (CAPD), or a kidney transplant.
Prevention of Diabetic Nephropathy
Diabetic nephropathy can be avoided by improving your lifestyle through simple steps, such as:
- Treat diabetes properly. Proper diabetes management can delay or even prevent diabetic nephropathy.
- Maintain blood pressure and general health. Individuals with risk factors for diabetic nephropathy are advised to visit their doctor regularly to watch for signs of kidney damage.
- Follow the instructions for using the drug. Use medication properly, especially if patients with diabetic nephropathy are taking pain relievers from the non-steroidal anti-inflammatory drug class. The use of drugs that are not in accordance with the instructions can trigger kidney damage.
- Maintain ideal body weight. Do regular exercise several days a week so that your ideal body weight is maintained. For people with obesity, consult with your doctor about the right way to lose weight.
- Quit smoking. Smoking can damage the kidneys and worsen the condition of already damaged kidneys.
Complications of Diabetic Nephropathy
Diabetic nephropathy is the most common cause of chronic kidney disease or end-stage chronic kidney failure in Indonesia and in the world. In Indonesia alone, 52 percent of patients undergoing dialysis are caused by diabetic nephropathy.
Other complications from diabetic nephropathy that can develop gradually over months or years include:
- Open wound on the leg.
- Anemia or lack of red blood cells.
- A sudden increase in potassium levels in the blood (hyperkalemia).
- Fluid retention which can lead to swelling in the hands, feet, or lungs (pulmonary oedema).