Diabetes can affect the kidneys by damaging small blood vessels and through its association with high blood pressure. The difficulty is that kidney damage can progress for a long time without pain, burning or obvious signs. Monitoring is therefore essential.
Two markers often appear in test results: eGFR, which estimates kidney filtration, and albuminuria, meaning an increased amount of albumin in the urine. This article is for information and does not replace medical consultation.
What is eGFR?
eGFR means estimated glomerular filtration rate. It is usually calculated from creatinine and other factors. It is not perfect, but gives an idea of how well the kidneys filter. A low or declining result needs interpretation with the doctor, especially with diabetes, hypertension, older age or treatments that can affect the kidneys.
Do not mechanically compare your eGFR with someone else's. The trend, age, muscle mass, hydration, medicines and clinical context matter.
What is albuminuria?
Albumin is a protein that should normally remain in the blood. When it appears in urine above certain thresholds, it may signal kidney damage. The uACR test compares urine albumin with creatinine and is useful for early detection.
The result can sometimes be affected by urinary infections, recent intense exercise, fever, menstruation or very high blood pressure. An abnormal result therefore needs confirmation and medical interpretation, rather than automatically becoming a final conclusion.
Why does it matter in diabetes?
Diabetes and high blood pressure are two major causes of chronic kidney disease. Controlling glucose, blood pressure and cholesterol, and stopping smoking, can reduce the risk of progression. If you also have abnormal triglycerides or cholesterol, cardiovascular and kidney risk need to be assessed together.
In diabetes, kidney monitoring is not limited to when symptoms appear. Regular tests are part of complication prevention, alongside eye and foot checks. Also see the articles on diabetic retinopathy and diabetic neuropathy.
What can you do in practice?
- keep track of HbA1c and the glucose readings relevant to your treatment;
- measure blood pressure at home if the doctor recommends it;
- have creatinine, eGFR and uACR checked periodically according to your medical plan;
- speak with the doctor before taking anti-inflammatory medicines or potent supplements;
- do not follow high-protein diets without advice if you have kidney damage;
- limit salt if you have high blood pressure or medical advice to do so.
Diet changes should follow test results
Not everyone with diabetes needs kidney-related dietary restrictions. Some need only a cardiometabolic eating pattern: vegetables, appropriate protein, fibre, controlled salt, less sugar and fewer ultra-processed foods. If kidney disease is confirmed, protein, potassium, phosphorus and salt are adjusted individually.
A personalised nutrition plan therefore needs to be based on tests, not general rules taken from the internet.
When should you seek prompt help?
Sudden leg swelling, a substantial decrease in urine, very high blood pressure, shortness of breath, confusion or chest pain require urgent medical assessment. For abnormal tests without acute symptoms, arrange a structured discussion with your doctor.
Useful questions for your doctor
At your next consultation, ask whether you need uACR, how often eGFR should be repeated, which blood pressure target suits you and whether your current treatment protects the kidneys. Also ask which medicines or supplements should be avoided without medical advice. Answers depend on age, duration of diabetes, blood pressure, albuminuria, cardiovascular disease and hypoglycaemia risk.
If readings fluctuate, bring a simple table: glucose, blood pressure, treatments, illnesses, anti-inflammatory medicine use and any urinary symptoms. Short, clear data are more useful than a long list of impressions.
The link with everyday eating
For the kidneys, extremes are usually problematic: too much salt, too many ultra-processed foods, high-protein diets without an indication or severe restrictions without a reason. A good plan considers diabetes, blood pressure, cholesterol, weight and kidney function together.
