Diabetic Nephropathy – Diabetes and Kidney

Early detection and therapy play an essential role in diabetic nephropathy. If the kidney disorder is recognized too late, it can become chronic. It is possible to prevent or treat kidney damage in people with diabetes if control measures (reasonable blood sugar control, optimal blood pressure, control of microalbumin) and adequate treatment are carried out. However, if kidney damage is noticed too late, it can no longer be reversed and inevitably leads to kidney failure.

Diabetic nephropathy is one of the most common complications of diabetes. Type 1 diabetes and type 2 diabetes patients are equally affected, with a frequency of 20 to 40 per cent. Kidney disease is now the most common cause of permanent kidney failure in Germany, accounting for around 35%.

What is the job of the kidneys?

The kidneys perform essential functions in our body. They detoxify the body from the waste products produced during metabolism and control the fluid and electrolyte balance, the amount and composition of the blood and blood pressure. The kidneys also ensure that there are always enough red blood cells.

However, the kidneys filter in two steps: First, the blood is filtered in the so-called kidney corpuscles. However, in addition to waste, many other substances the body needs also pass through the delicate pores of the kidney corpuscles. Therefore, a second step follows, namely the recovery of valuable and vital substances for the body.

 

Causes of diabetic nephropathy

In people with diabetes – both type 1 and type 2 – persistently high blood sugar levels or genetic predisposition can lead to changes in the small vessels of the kidneys. The filter performance of the kidneys decreases more and more, and with it, the detoxification capacity. This is what is known as diabetic nephropathy.

But what favours diabetic nephropathy? The following factors increase the risk of developing such kidney damage:

• high blood pressure (hypertension)
• poor blood sugar control
• long duration of diabetes, genetic predisposition
• high protein intake, increased blood fat levels
• To smoke cigarettes

Diabetic Nephropathy: Symptoms

People with diabetes don’t even notice if their kidneys are damaged over time because they don’t feel any pain, and the urine doesn’t change visibly. Only at an advanced stage, after a few years, can noticeable symptoms appear. This includes:

• anemia _
• Tiredness, exhaustion and poor performance
• headache
• itching
• weight gain
• Water retention (oedema), especially in the legs
• foaming urine
• nausea or vomiting
• high blood pressure
• increased blood fat levels
• Discoloration of the skin (coffee au lait)
• Disturbances in the water-salt balance
• susceptibility to infection

 

Diagnosis of diabetic nephropathy

The earlier the disease is detected, the more effectively a deterioration can be counteracted. Every person with diabetes should, therefore, also pay attention to their kidneys. If diabetes is present, two values ​​are checked regularly to diagnose diabetic nephropathy as early as possible: the albumin value in the urine and the creatinine value.

Control of urinary albumin secretion

The first sign of an incipient nephropathy is the slightest traces of protein in the urine. This is known as microalbuminuria (20-200 mg albumin/litre morning urine). It is, therefore, the most critical factor in the early detection of diabetic kidney disease.

Therefore, urine albumin release should be checked once a year in people with diabetes. In people with type 1 diabetes from five years after the onset of diabetes, but in type 2 diabetics from the time of diagnosis. Even if there are no signs of diabetic nephropathy.

It can be detected early and quickly using unique test strips. The first-morning urine test is done on three days within several weeks. To diagnose nephropathy, at least two of the three morning urine samples must have a concentration of > 20 mg albumin/litre.

A more significant amount of protein characterizes the next stage in the urine, the so-called macroalbuminuria (micros: small, low; macros: large, many). Once there is persistent macroalbuminuria (> 300 mg/l albumin/24 h urine), the progression of the kidney disease can, in most cases, only be contained by appropriate medication, i.e. it is no longer reversible.

Elevated creatinine may indicate nephropathy.

To diagnose kidney disease as early as possible, the filter performance of the kidneys should also be checked at regular intervals, ideally once a year. If there is a functional disorder of the kidneys, this is shown by increased creatinine levels in the blood plasma and urine. Creatinine is a product of muscle metabolism.

The more the detoxification capacity of the kidneys is restricted, the higher the creatinine. The filter performance of the kidneys is determined together with the creatinine level, body weight, age and gender.

 

Always check the kidneys when diagnosing diabetes.

Especially in older people, elevated blood sugar levels often go undetected for a very long time, and diabetes is usually diagnosed years later. Therefore, when diabetes becomes known, whether the kidney function is already impaired should always be clarified.

Consequences of diabetic nephropathy

The disease progresses in five stages, the last of which is chronic renal failure. Almost every third of diabetic patients develop a kidney dysfunction with varying degrees of severity during the disease. If left untreated, diabetic nephropathy can result in kidney failure in about a third of those affected.

In Germany, several thousand diabetic patients come to dialysis every year. Diabetes mellitus is the most common cause of chronic kidney failure.

Therapy and treatment of diabetic nephropathy

Appropriate therapeutic measures are already required at the stage of microalbuminuria to prevent the transition to the chronic, i.e. irreversible, form of kidney damage. This includes the following measures:

• If diabetic nephropathy is present, microalbuminuria is monitored and documented more closely than in prophylactic examinations for early diagnosis, approximately every three to six months.
• For people with diabetes with kidney disease, the lowest possible blood pressure (120/80 mmHg) should be aimed for. Because The lower the blood pressure, the better the kidneys work. The so-called ACE inhibitors and the angiotensin II antagonists have proven themselves here. Those affected benefit from lower blood pressure not only by slowing the progression of kidney disease but also by reducing the frequency of strokes and heart attacks. The reason: High blood pressure is one of the most critical risk factors for heart and brain diseases and death.
• The SGLT-2 inhibitor empagliflozin can also slow the progression of diabetic nephropathy. This drug is considered very important for the treatment of diabetic kidney disease. SGLT-2 inhibitors reduce the absorption of carbohydrates in the blood, meaning less glucose is available for energy. When no more glucose is metabolized, the body switches metabolism and uses fat for energy. In this state of ketosis, the concentration of sodium and chloride ions is increased, reducing the back pressure in the kidney corpuscles. This also minimizes the hyperfiltration of the kidneys. Doctors assume that this effect of empagliflozin alone slows the progression of diabetic nephropathy.
• Adjust blood sugar optimally and check the long-term adjustment based on the HbA1c value (below 7.0 per cent or 53 mmol/mo).
• Reduce the risk of urinary tract infection and pay attention to frequent ophthalmological checks.
• Smoking and drinking alcohol should be avoided.
• Losing excess weight is an essential therapeutic measure. Even a slight weight loss can bring about a significant improvement in blood pressure and metabolic control. You can also help with weight loss:
  • An active lifestyle with plenty of exercise can help maintain blood pressure and reduce excess body weight.
  • High-fiber, balanced diet with lots of vegetables.

 

Nutrition in diabetic nephropathy

A change in diet can be of great benefit not only for the course of the underlying diabetes disease itself but also for diabetic nephropathy. The first step is to aim for a low blood sugar level and counteract obesity and its complications.

A low-salt diet and avoiding nicotine are also recommended in any case. Likewise, generally applicable recommendations that can positively influence the course of the disease must be observed. In addition, those affected should avoid ready meals, and instead of animal fat sources, it is better to rely on wholesome, high-quality vegetable oils, nuts and seeds.

Increased protein intake: advisable or not?

In the case of diabetic nephropathy, there are conflicting recommendations regarding protein intake. People with diabetes often follow the recommendation of increased protein intake, which can be helpful for weight loss.

However, an increased protein intake is also considered a risk factor for the progression of diabetic nephropathy since this also requires an increased filter capacity of the kidneys. Therefore, it makes sense for some patients to exchange high-protein, animal-based foods for low-protein, predominantly plant-based foods.

What should sufferers eat?

For most patients, a kidney-friendly diet contains a lot of vegetables and plant-based foods in general, as these have a beneficial effect on blood sugar levels, counteract inflammation and reduce the acid load in the body.

Dialysis patients often benefit from a high-fat diet since fats contain more energy and less potassium than carbohydrates.

Since the recommendations for optimal nutrition can vary highly depending on the stage and course of the disease in diabetic nephropathy, advice from a trained nutritionist or doctor is usually helpful. If, for example, nephropathy requiring dialysis is already present, the focus is often more on counteracting malnutrition.