How does diabetes affect the kidneys?
ARTICLESourced from Apollo 24/7 (10 December 2020)
Kidneys are one of the most vital organs of the body that help in removing waste products, balance body fluids, maintain blood pressure, produce red blood cells and strengthen the bones. Any damage to the kidneys would disrupt all these functions. The two common reasons for kidney damage are uncontrolled diabetes and high blood pressure.
Diabetic kidney disease (DKD), also called diabetic nephropathy and chronic kidney disease (CKD), are the terms used to describe kidney problems caused by high blood sugar levels in the body. A data pooled by the International Diabetes Federation from 54 countries showed that more than 80% of the cases of end-stage renal disease (kidney failure) occur either due to diabetes, hypertension or both.
How do high blood sugar levels damage the kidneys?
Blood enters the kidney through an artery (a large blood vessel) and then passes through clusters of small blood vessels (medically termed glomeruli) that act as filters. The kidneys filter the waste products and other excess fluids from the blood. Then filtered blood goes to the body via a vein and the excess fluid land up in the urine. However, in the case of diabetics:
- Due to high blood sugar levels, the glomeruli get narrow and clogged. This prevents the blood from passing through the blood vessels, thus damaging the kidney. Damaged kidneys allow albumin (a type of protein) to leak into the urine, which originally used to pass through the filters.
- Diabetes also damages the nerves which carry messages between the brain and the urinary bladder. Due to the damaged nerves, the person is unable to feel if their bladder is full, which puts extra pressure on the kidneys.
- When the urine stays in the bladder for a long time, it increases the risk of getting a urinary tract infection. The high sugar levels in the urine, allow infection-causing bacteria to grow in the urine at a rapid rate.
What are the signs of kidney damage?
In the early stages of kidney disease, a person with diabetes may not have visible symptoms. So, it is important to get the kidneys tested every year to detect any problem at an early stage. The doctors may perform a simple urine test called the albumin creatinine ratio (ACR) to determine the presence of protein in urine and glomerular filtration rate (eGFR) test to determine the ability of kidneys to filter out the waste product.
In the later stages, the person may experience:
- Swelling of ankles, feet and hands
- Frothy, bubbly urine (due to the presence of albumin in it)
- Blood in the urine (rare)
- Shortness of breath
- Persistent fatigue
What can be done to manage the kidney damage caused by diabetes?
Diabetic kidney disease takes time to develop. Therefore, the management of the condition is based on slowing down the rate of the disease progression while protecting the residual function of the kidneys. Things that can help manage diabetic nephropathy include:
- Monitor the blood sugar levels: Keeping the blood sugar levels in a healthy range can help in protecting the kidneys from further damage. One must keep checking their blood sugar levels regularly using a blood glucose meter or get an HbA1c test done, which gives an average level of blood sugar over the past 3 months.
- Adopt healthy eating habits: To keep blood sugar levels under control, a diabetic must indulge in healthy eating habits which include adding lots of fruits, vegetables, healthy fats, and lean protein in the diet and reducing the consumption of sugary and highly refined foods such as cookies, crackers, and soda. Diabetics must consume smaller meals at a time, spread through the day. Consume less salt, as the high sodium content of the salt would cause fluid to buildup in the body.
- Quit using tobacco and limit alcohol: Quit smoking or chewing tobacco as they can worsen the kidney damage. Reduce the consumption of alcohol significantly to an occasional indulgence, to avoid any damage to the kidneys.
- Exercise regularly: Being active helps the body to use insulin better, thus keeping blood sugar levels under control. Practising moderate-intensity exercises for at least 30 minutes every day can help a diabetic person attain a healthy weight. Those who do not wish to go to the gym can work out in their houses by taking stairs instead of elevators, going for an after-dinner walk or just walk briskly.
- Control blood pressure: Diabetic people with high blood pressure are at increased risk of getting kidney disease. Hence one must keep their blood pressure under limits by consuming less salt and processed foods. Anti-hypertensive medications are given to some patients who do not respond to lifestyle changes.
- Reduce cholesterol levels: High cholesterol levels in a diabetic person increase their risk of developing kidney disease, heart disease and stroke later in life. Consume healthy fats found in eggs, chia seeds, avocados, fatty fishes, olive oil and other food items.
Kidney damage usually develops several years (10 to 15) after getting diagnosed with diabetes. By maintaining their blood sugar, cholesterol levels and blood pressure, diabetics can slow down and even prevent the development of kidney disease. Diabetic people must practice healthy eating, regular exercising and routine testing to prevent kidney damage in future as the damage caused to the kidneys cannot always be reversed.
For any queries related to diabetes, speak to an endocrinologist or a diabetologist. And for any queries related to the kidney, you can consult a nephrologist.
- https://idf.org/our-activities/care-prevention/diabetes-and-the-kidney.html#:~:text=Based%20on%20data%20from%20the,will%20develop%20chronic%20kidney%20disease.&text=Pooled%20data%20from%2054%20countries,or%20a%20combination%20of%20both. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5297507/