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Use this page to prepare questions for your care team. It does not replace their advice. Your own targets and doses come from your nephrologist, diabetes team and renal dietitian.

Type 1 diabetes and your kidneys

No doses on this page

This handbook never gives insulin or medicine doses and never tells you to change one. Your prescriber sets every dose and every change, and writes down when to pause a medicine and when to restart it. A low blood glucose is always treated straight away: see Treating a low and Get help now.

In short

Over many years, high glucose damages the tiny blood vessels that filter your blood, and albumin starts to leak into the urine. That leak is the earliest sign, long before your eGFR falls or you feel anything (NIDDK; ADA 2026 §11). In type 1 diabetes, kidney disease usually appears after about 10 years, most often 5 to 15 years after diagnosis (ADA 2026 §11). About 1 in 3 adults with diabetes has kidney disease, but most never reach kidney failure (NIDDK). The things that slow it are well proven: glucose in range, lower blood pressure, an ACE inhibitor or ARB when albumin is present, not smoking and staying active. Since September 2026, finerenone is also FDA-approved for kidney disease with type 1 diabetes (Kerendia label).

Your numbers

Starting points, not your prescription

These numbers are typical starting points from guidelines. Your nephrologist, diabetes team and renal dietitian set your own numbers from your blood tests, urine output and medicines, and change them as your labs change. If your lab report or your team says something different, they win.

What helps Typical goal Source
Yearly kidney tests UACR and eGFR every year, starting 5 years after diagnosis ADA 2026 §11, rec. 11.1a
A1c (not on dialysis) your own goal, somewhere from under 6.5 % to under 8.0 % KDIGO 2022, rec. 2.2.1
CGM time in range (70–180 mg/dL) more than 70 % of the day, with less than 4 % under 70 mg/dL. If lows are a risk for you, as they often are with kidney disease, your team may set more than 50 % with less than 1 % under 70 mg/dL ADA 2026 §6; time in range consensus
Blood pressure KDIGO: top number under 120 if you tolerate it, measured the standard way at the clinic. ADA: under 130/80 if safe, with under 120 encouraged KDIGO 2024, rec. 3.4.1; ADA 2026 §11, rec. 11.5
Albumin in the urine an ACE inhibitor or ARB once UACR is 30 mg/g or more KDIGO 2024, rec. 3.6.3
Sodium under 2,000 mg a day KDIGO 2022, rec. 3.1.2
Protein (not on dialysis) about 0.8 g per kg of body weight a day KDIGO 2022, rec. 3.1.1
Activity at least 150 minutes a week of moderate activity, or what your heart and body allow KDIGO 2022, rec. 3.2.1
Tobacco none KDIGO 2022, rec. 1.5.1
What helps Typical goal Source
Yearly kidney tests UACR and eGFR every year, starting 5 years after diagnosis ADA 2026 §11, rec. 11.1a
A1c (not on dialysis) your own goal, somewhere from under 48 to under 64 mmol/mol KDIGO 2022, rec. 2.2.1
CGM time in range (3.9–10.0 mmol/L) more than 70 % of the day, with less than 4 % under 3.9 mmol/L. If lows are a risk for you, as they often are with kidney disease, your team may set more than 50 % with less than 1 % under 3.9 mmol/L ADA 2026 §6; time in range consensus
Blood pressure KDIGO: top number under 120 if you tolerate it, measured the standard way at the clinic. ADA: under 130/80 if safe, with under 120 encouraged KDIGO 2024, rec. 3.4.1; ADA 2026 §11, rec. 11.5
Albumin in the urine an ACE inhibitor or ARB once UACR is 3 mg/mmol or more KDIGO 2024, rec. 3.6.3
Sodium under 2 g a day (about 5 g of salt) KDIGO 2022, rec. 3.1.2
Protein (not on dialysis) about 0.8 g per kg of body weight a day KDIGO 2022, rec. 3.1.1
Activity at least 150 minutes a week of moderate activity, or what your heart and body allow KDIGO 2022, rec. 3.2.1
Tobacco none KDIGO 2022, rec. 1.5.1

At stage 4–5 and on dialysis, A1c becomes less reliable, so your team may judge glucose by your CGM report instead (KDIGO 2022, practice point 2.1.2; A1c; CGM metrics).

Medicines that protect the kidneys

ACE inhibitors and ARBs lower the pressure inside the kidney filters and cut the albumin leak. KDIGO recommends one for people with diabetes and a UACR of 30 mg/g (3 mg/mmol) or more (KDIGO 2024, recommendation 3.6.3; KDIGO 2022, recommendation 1.2.1). What to expect:

  • Blood pressure, creatinine and potassium are checked 2–4 weeks after starting or after a dose change (KDIGO 2024, practice point 3.6.2).
  • A small early drop in eGFR is expected and is not a reason to stop. KDIGO says to keep going unless creatinine rises by more than 30 % within 4 weeks (practice point 3.6.4).
  • A higher potassium can often be managed without stopping the medicine (practice point 3.6.3), and the medicine is usually continued even when eGFR falls below 30 (practice point 3.6.7).
  • If you could become pregnant, ask about pregnancy safety and birth control before you start. KDIGO asks clinicians to check every medicine for this (KDIGO 2024, practice point 4.1.4; Sex, fertility and pregnancy).

Finerenone (Kerendia) was approved by the FDA in September 2026 "to reduce urinary albumin-to-creatinine ratio (UACR)" in adults with CKD and type 1 diabetes (Kerendia label).

  • In the FINE-ONE trial, 242 adults who were already taking an ACE inhibitor or ARB took finerenone or a dummy pill for 6 months. UACR fell 34 % with finerenone and 12 % with the dummy pill, a 25 % greater fall (FINE-ONE).
  • High potassium was the most common side effect: 10.1 % of people on finerenone and 3.3 % on the dummy pill. eGFR dipped a little more with finerenone and came back toward its starting level after the medicine was stopped (FINE-ONE).
  • Potassium and eGFR are checked before starting, and it is not started if potassium is above 5.0 mmol/L. Avoid grapefruit and grapefruit juice. Some other medicines, such as certain antifungal pills, must not be taken with it, so tell every prescriber and pharmacist (Kerendia label).

SGLT2 inhibitors (for example empagliflozin or dapagliflozin) protect the kidneys in type 2 diabetes, but their safety and benefit have not been established in type 1 diabetes, and the FDA has not approved them for it (KDIGO 2022, chapter 1). In Europe, dapagliflozin was approved for some adults with type 1 diabetes in 2019, and its maker withdrew that use in 2021. The UK regulator said this was not because of a new safety problem, but diabetic ketoacidosis (DKA) was common in the type 1 diabetes trials, affecting up to 1 in 10 people (MHRA). KDIGO still lists people with type 1 diabetes as not well studied (KDIGO 2024, research recommendations). In trials in type 1 diabetes, a fasting ketone level of 0.8 mmol/L or more meant a 3.2 times higher chance of DKA in the next month (ADA 2026 §6). DKA can happen even when glucose is not very high (2024 consensus). If a specialist prescribes one off-label, you need a blood ketone meter, a written sick-day plan, and ketone checks whenever you feel unwell, whatever your glucose. See Kidney-protecting medicines and Sick days.

Statins (cholesterol medicines) protect the heart, the biggest risk in CKD. KDIGO recommends one for adults aged 50 or over with CKD who are not on dialysis, whatever their eGFR, and suggests one for adults aged 18–49 with diabetes and CKD who are not on dialysis (KDIGO 2024, recommendations 3.15.1.1–3.15.1.3).

When to suspect another cause

Not every kidney problem in someone with diabetes comes from diabetes. ADA lists these signs that something else may be going on (ADA 2026 §11):

  • blood cells or "casts" in the urine (an active urine sediment);
  • albumin or protein in the urine that rises fast, or very heavy protein loss (nephrotic syndrome);
  • an eGFR that falls fast;
  • no diabetic eye disease (retinopathy), which points away from diabetes, especially in type 1.

Kidney disease that shows up in the first few years after diagnosis is also unusual, because it typically takes about 10 years (ADA 2026 §11). If any of these apply, ask whether you need a nephrologist to look for another cause. ADA also advises a nephrology referral when eGFR is under 30, when the cause is unclear, or when albumin rises or eGFR falls quickly (recommendations 11.12a–11.12b).

What to do

  • Get your UACR and eGFR at least once a year (ADA 2026 §11, recommendation 11.1a).
  • Know your blood pressure goal, and check at home if your team asks you to.
  • Ask whether you should be on an ACE inhibitor or ARB, and whether finerenone fits you.
  • Keep your yearly eye exam: the result helps your team judge whether diabetes is the cause.
  • Use a CGM if you can, and share the report at visits (CGM metrics).
  • Stop smoking; ask for help to quit (KDIGO 2022, recommendation 1.5.1).
  • Aim for 150 minutes of activity a week (Exercise).
  • Keep sodium under 2,000 mg a day (Sodium) and protein near your goal (Protein).
  • Avoid ibuprofen, naproxen and other NSAIDs unless your team says otherwise (Medicines to avoid).
  • Have a written sick-day plan (Sick days).

Examples

  • Sam, 34, type 1 diabetes for 18 years. UACR 85 mg/g (10 mg/mmol) on two tests, eGFR 78, mild retinopathy. He has CKD G2 A2 from diabetes. His team starts an ARB, sets a blood pressure goal and rechecks potassium and creatinine in 3 weeks. Six months later his UACR is 40 mg/g.
  • Rosa, 29, type 1 diabetes for 4 years. UACR 900 mg/g, blood in the urine and no retinopathy. The short time since diagnosis, the blood and the clear eyes all point away from diabetes, so she is referred to a nephrologist to look for another cause.
  • Dev, 52, type 1 diabetes, CKD G3b A3, on an ACE inhibitor. His potassium is 4.6 mmol/L. His nephrologist adds finerenone, tells him to stop drinking grapefruit juice, and checks potassium again after starting.

Ask your care team

  1. Is my kidney disease from diabetes, or could there be another cause?
  2. What blood pressure goal is right for me, and should I check it at home?
  3. Should I be on an ACE inhibitor or ARB? If I am, is it at the dose that protects my kidneys?
  4. Is finerenone right for me? How often would you check my potassium?
  5. What A1c or time-in-range goal is safe for me at this stage?
  6. Should I take a statin?

Get help now if…

  • You have a low you cannot treat yourself, ketones of 1.6 mmol/L or more, or a lab potassium of 6.0 mmol/L or more: see Get help now.
  • On finerenone or an ACE inhibitor or ARB: new weakness, a slow or irregular pulse or fainting can mean high potassium. Call 911.

What CKD is · CKD stages · UACR · Kidney-protecting medicines · Type 1 diabetes and CKD · in the app: Targets and warnings.

Sources

Not yet reviewed by a clinician. Facts and sources last checked 2026-10-06.