How Diabetic Nephropathy Can Lead to Kidney Issues

Diabetic nephropathy, also referred to as diabetic kidney disease, is a severe complication that arises from diabetes mellitus. This condition progressively damages the kidneys due to prolonged exposure to elevated blood sugar levels (1). Understanding the nuances of diabetic nephropathy is essential for individuals living with diabetes to effectively manage their health and reduce the risks associated with this condition.

In this article you will learn:

• What is Diabetic Nephropathy?
• What are the Causes of Diabetic Nephropathy?
• Which one of the following is the earliest warning indicator of Diabetic Nephropathy?
• How is Diabetic Nephropathy Diagnosed?
• What is the Treatment of Diabetic Nephropathy?
• How to Prevent Diabetic Nephropathy?
• How does Diabetic Nephropathy Cause Hypertension?

Diabetic nephropathy is a type of kidney damage caused by diabetes. The kidneys play a critical role in filtering waste products from the blood and maintaining fluid balance in the body. In individuals with diabetes, persistent high blood sugar levels can inflict damage on the small blood vessels and structures within the kidneys, impairing their function over time (1).

Several factors contribute to the development of diabetic nephropathy (1):

• Prolonged high blood sugar levels: Chronically elevated blood glucose levels can lead to the accumulation of toxic by-products in the blood, which can damage the delicate filtering units of the kidneys.
• Hypertension (high blood pressure): High blood pressure further strains the kidneys, exacerbating kidney damage in individuals with diabetes.
• Genetic predisposition: Some individuals may have a genetic susceptibility to diabetic nephropathy, making them more vulnerable to kidney damage.
• Smoking: Tobacco use accelerates the progression of kidney damage in people with diabetes by constricting blood vessels and reducing blood flow to the kidneys.
• Poorly controlled diabetes: Inadequate management of diabetes, including irregular blood sugar monitoring, improper medication adherence, and unhealthy lifestyle habits, increases the risk of developing diabetic nephropathy.

The symptoms of diabetic nephropathy may not manifest in the early stages, but can become apparent as the condition progresses (1):

• Swelling of the ankles, feet, or hands (oedema) due to fluid retention.
• Fatigue and weakness caused by anaemia resulting from decreased production of erythropoietin, a hormone produced by the kidneys.
• Foamy or bubbly urine, indicative of proteinuria, or the presence of excessive protein in the urine.
• Increased need to urinate, especially at night (nocturia), due to impaired kidney function.
• Persistent itching, often attributed to the accumulation of waste products in the blood.
• Loss of appetite and unintentional weight loss, resulting from a decline in kidney function and poor nutrient absorption.

Diagnosing diabetic nephropathy entails a comprehensive evaluation that may include (2):

• Urine tests: Analysis of urine samples to detect the presence of proteinuria, an early sign of kidney damage.
• Blood tests: Measurement of serum creatinine levels and estimation of glomerular filtration rate (eGFR) to assess kidney function.
• Imaging studies: Ultrasound, magnetic resonance imaging (MRI), or computed tomography (CT) scans may be conducted to evaluate the structure and size of the kidneys, as well as detect any abnormalities.

Management of diabetic nephropathy focuses on slowing the progression of kidney damage, alleviating symptoms, and reducing the risk of complications. Treatments may include (2):

• Blood sugar control: Tight glycaemic control through a combination of dietary modifications, regular physical activity, and appropriate medication regimens helps prevent further kidney damage.
• Blood pressure management: Maintaining optimal blood pressure levels through lifestyle changes and antihypertensive medications, is crucial for preserving kidney function.
• Medications: Certain medications, such as erythropoiesis-stimulating agents (ESAs) to manage anaemia or sodium-glucose cotransporter-2 (SGLT2) inhibitors to reduce the risk of kidney complications, may be prescribed based on individual patient needs.
• Dietary modifications: Adopting a low-sodium, low-protein diet and limiting phosphorus intake can help alleviate symptoms and slow the progression of kidney disease.
• Lifestyle interventions: Quitting smoking, limiting alcohol consumption, and maintaining a healthy weight through regular exercise and proper nutrition are essential components of kidney disease management.

Preventing diabetic nephropathy involves proactive measures aimed at managing diabetes effectively and mitigating modifiable risk factors (3):

• Glycaemic control: Regular monitoring of blood glucose levels, adherence to prescribed diabetes medications, and adherence to a healthy lifestyle, including a balanced diet and regular exercise, are crucial for preventing kidney complications.
• Blood pressure regulation: Individuals with diabetes should aim to maintain blood pressure levels within the recommended target range through lifestyle modifications and antihypertensive medications, as advised by their healthcare provider.
• Smoking cessation: Quitting smoking reduces the risk of kidney damage and cardiovascular complications associated with diabetes.
• Healthy lifestyle habits: Engaging in regular physical activity, consuming a nutritious diet rich in fruits, vegetables, wholegrains, and lean proteins, and avoiding excessive alcohol consumption contribute to overall kidney health and well-being.

Diabetic nephropathy can contribute to the development of hypertension through various mechanisms. One key factor is the impact of persistent high blood sugar levels on the kidneys. Over time, elevated glucose levels can damage the small blood vessels (glomeruli) in the kidneys, impairing their ability to effectively filter waste products and regulate blood pressure. As a result, the kidneys may retain excess sodium and fluid, leading to an increase in blood volume and pressure within the blood vessels. Additionally, diabetic nephropathy can disrupt the balance of hormones involved in blood pressure regulation, such as the renin-angiotensin-aldosterone system (RAAS). The kidneys release renin, an enzyme that triggers the production of angiotensin II, a potent vasoconstrictor that narrows blood vessels and raises blood pressure. Furthermore, the presence of proteinuria (protein in the urine) associated with diabetic nephropathy can contribute to inflammation and oxidative stress, further exacerbating hypertension (4). Overall, the interplay between kidney damage, fluid retention, hormonal imbalances, and inflammation contributes to the development and progression of hypertension in individuals with diabetic nephropathy.

Diabetic nephropathy is a serious complication of diabetes that requires diligent management and proactive measures to prevent complications and preserve kidney function. By understanding the causes, symptoms and prevention strategies outlined, individuals with diabetes can take control of their health and reduce the risk of developing diabetic kidney disease. Early detection, timely intervention, and ongoing monitoring are essential for optimising outcomes and improving quality of life for those affected by diabetic nephropathy.