If you live with diabetes (many people simply call it sukari), your doctor probably checks your kidneys regularly. A creatinine result marked high can be worrying. This page explains why diabetes and the kidneys are linked, why a high result does not automatically mean diabetic kidney disease, and why a urine test sits alongside the blood test.
Why diabetes and the kidneys are linked
Over many years, raised blood sugar can damage the small blood vessels in the kidney filters. High blood pressure, which is common in people with diabetes, adds to the strain. This kind of damage is often called diabetic kidney disease, and diabetes is one of the leading causes of chronic kidney disease worldwide.
The early stages usually cause no symptoms. That is why testing matters.
Why urine ACR is often the first sign
In diabetes, one of the earliest signs of kidney damage is often a small amount of albumin in the urine, found with a urine albumin-to-creatinine ratio (ACR) test. This can appear years before creatinine rises. So a normal creatinine does not mean the kidneys are free from diabetes-related changes, and a high creatinine is only part of the picture.
KDIGO guidance for diabetes and CKD advises regular kidney screening with both a urine ACR and an eGFR. Guidelines generally suggest checking at least once a year: from diagnosis for people with type 2 diabetes, and starting about 5 years after diagnosis for people with type 1 diabetes. Your doctor may test more often if results are abnormal. See kidney tests for diabetes.
| Category | ACR in mg/mmol | ACR in mg/g | Plain description |
|---|---|---|---|
| A1 | Below 3 | Below 30 | Normal to mildly increased |
| A2 | 3 to 30 | 30 to 300 | Moderately increased |
| A3 | Above 30 | Above 300 | Severely increased |
Why creatinine may be high in someone with diabetes
A clinician may consider several possibilities, sometimes more than one at once:
- Diabetic kidney disease, particularly if there is albumin in the urine and the change persists.
- High blood pressure affecting the kidneys.
- Dehydration. Very high blood sugar makes you pass more urine, which can dry you out. This can raise creatinine for a time.
- Medicines. Some medicines used in diabetes and blood pressure care cause a small, expected change in creatinine or eGFR when they are started, even though they protect the kidneys in the long term. Doctors often recheck blood tests after starting them. Other medicines, such as anti-inflammatory painkillers, can reduce kidney function.
- Lab factors. With some lab methods, high levels of ketones in the blood can interfere with the creatinine measurement.
- Other kidney conditions. Not every kidney problem in a person with diabetes is caused by diabetes. A clinician may look for other causes, especially if there is blood in the urine, a sudden change, or no albuminuria.
For a full list, see causes of high creatinine.
Why eGFR matters for your diabetes care
eGFR is not only about diagnosing kidney disease. Some diabetes medicines are cleared by the kidneys, and their doses may need to change when eGFR is lower. Some newer medicines are chosen partly because they protect the kidneys and heart. Your eGFR and ACR help your doctor make these decisions. This is one reason not to stop or change any diabetes medicine on your own after seeing a result.
Keep taking your prescribed medicines
If you think a medicine may be affecting your result, discuss it with your doctor or pharmacist. Do not stop blood pressure, diabetes, HIV or other prescribed medicines on your own.
What usually happens next
- A repeat creatinine and eGFR.
- A urine ACR if one has not been done recently, often repeated to confirm.
- A review of blood sugar control, including HbA1c.
- Blood pressure checks.
- A review of all your medicines, including painkillers and herbal remedies.
- Sometimes a urinalysis or kidney ultrasound.
Many people with diabetes and early kidney changes are followed by their usual doctor, diabetes clinic or physician. A nephrologist may become involved when eGFR is low, when there is a lot of albumin in the urine, when kidney function is falling quickly, or when the cause is unclear.
Questions you might ask your doctor
- What is my eGFR, and how does it compare with my last result?
- Have I had a urine ACR test recently? What did it show?
- Do any of my medicines need to change because of my kidney results?
- What blood pressure and blood sugar targets are right for me?
- How often should my kidneys be checked?
More ideas are in questions to ask your doctor.
When to get medical help urgently
Go to the nearest hospital emergency department, or call 999 or 112, if you have very little or no urine, severe breathlessness, chest pain, new confusion or drowsiness, severe swelling with breathlessness, or blood in the urine with fever or severe pain. Also seek care promptly if a lab or doctor has told you your result needs urgent attention.
Sources
- KDIGO 2022 Clinical Practice Guideline for Diabetes Management in Chronic Kidney Disease. kdigo.org
- KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. kdigo.org
- NICE guideline NG203. Chronic kidney disease: assessment and management. nice.org.uk
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Kidney disease health information. niddk.nih.gov
This page explains what a test or condition involves. It is not a diagnosis and does not replace advice from a doctor who knows your history. Your results should be interpreted together with your symptoms, other tests and a clinical assessment. Medical disclaimer.