The 30-second summary
- The study: 75,455 adults with type 2 diabetes in the US, published in The BMJ on 16 September 2026, comparing GLP-1 or SGLT-2 medicines with older diabetes tablets.
- With albuminuria (protein in the urine): the five-year risk of serious kidney decline fell from 5.4% to 3.2%, a 40% lower risk.
- Without albuminuria: 2.4% against 2.1%, no clear benefit over the follow-up.
- The practical point: a simple urine test sorts people into the group the protection was seen in. Ask whether you have had one.
Why this question matters
The kidney benefit of GLP-1 medicines is one of the strongest findings outside weight. Our guide to GLP-1s and your kidneys covers the FLOW trial, in which semaglutide cut the risk of major kidney events by 24% in people with type 2 diabetes and chronic kidney disease (Perkovic et al.).
FLOW enrolled people whose kidneys were already damaged. Most people taking a GLP-1 are not in that group. This study asked whether the protection reaches them too.
How was the study done?
The researchers, led from Brigham and Women's Hospital and Harvard, used a method called target trial emulation. They wrote down the trial they would have run, then copied its rules as closely as possible using real-world records: health records and insurance claims from 10 US health systems and two national insurers.
The people in it:
- had type 2 diabetes and moderate heart risk;
- were on metformin alone, then started a second medicine between 2014 and 2022;
- had an eGFR of 45 or more, so their kidneys were working reasonably well.
The comparison was a GLP-1 medicine or an SGLT-2 inhibitor (one group) against a DPP-4 inhibitor or a sulfonylurea. The headline figures compare against DPP-4 inhibitors.
The outcome was serious kidney decline: a doubling of blood creatinine, or an eGFR below 15, the range of kidney failure. The median follow-up was 32 months. Of the 75,455 people, 48% were women, and 61,583 (81.8%) had no albuminuria.
What did it find?
| Group | Five-year risk on GLP-1 or SGLT-2 | Five-year risk on DPP-4 | Risk ratio |
|---|---|---|---|
| With albuminuria | 3.2% | 5.4% | 0.60 (0.42 to 0.82) |
| Without albuminuria | 2.4% | 2.1% | 1.10 (0.90 to 1.38) |
In people with albuminuria, the newer medicines lowered the risk of kidney decline by 40%. In people without it, the authors found little evidence of kidney benefit over the time studied.
What does the new kidney trial add?
On 1 October 2026, Nature Medicine published a small trial of 106 people with type 2 diabetes and chronic kidney disease, who took semaglutide 1 mg weekly or placebo for 52 weeks (Tuttle et al.). It used kidney MRI and, in some, kidney biopsies.
Its main MRI measures of kidney oxygen, blood flow and inflammation did not change. Its secondary measures pointed to lower resistance in the kidney's arteries, signs that scarring had stopped progressing, and healthier cells lining the kidney's filters. It is a clue to how semaglutide helps damaged kidneys, from a group that already had kidney disease.
What this study cannot tell us
- GLP-1s and SGLT-2s were pooled. The headline result is for the two classes together, so it does not isolate the GLP-1 effect.
- Everyone had type 2 diabetes. People taking Wegovy or Zepbound for weight alone were not studied.
- Older drugs, older doses. The medicines were started between 2014 and 2022, before tirzepatide and before high-dose weight-loss prescribing was common.
- 32 months may be too short. Kidney decline in people with healthy kidneys is slow, and a benefit could take longer to appear.
- It is still observational. Target trial emulation reduces bias but cannot remove it the way randomisation does.
What it means if you take a GLP-1
As of October 2026, the clearest kidney benefit of these medicines is in people whose kidneys already show early damage. That makes one test worth knowing about: the urine albumin to creatinine ratio, often called ACR. The study used 30 mg/g or more as its cut-off for albuminuria.
If you have diabetes, ask your GP or diabetes team for your latest ACR and eGFR. If there is protein in your urine, this study adds to the reasons your prescriber may favour a GLP-1 or an SGLT-2. If there is not, the medicine may still be right for you for other reasons, and this study simply cannot promise a kidney benefit on top. Never stop or swap a medicine without talking to your prescriber.
What to do with this
Kidney function changes what you should eat. If yours is reduced, a protein target built for healthy kidneys can be too high. Our calculator lets you say so, and when you do it treats protein as a ceiling of 0.8 g per kg of ideal body weight, the top of the KDOQI guideline range for chronic kidney disease not on dialysis. Take that figure to the clinician who manages your kidneys.
Sources
- Turchin A, Petito LC, Hegermiller E, et al. Renal outcomes in people with type 2 diabetes with and without albuminuria treated with SGLT-2 inhibitors and GLP-1 receptor agonists: target trial emulation. BMJ 2026. PubMed
- Tuttle KR, Bjornstad P, Smith C, et al. Effects of semaglutide on kidney disease in type 2 diabetes: a randomized placebo-controlled trial. Nat Med 2026. PubMed
- Perkovic V, Tuttle KR, Rossing P, et al. Effects of Semaglutide on Chronic Kidney Disease in Patients with Type 2 Diabetes. N Engl J Med 2024. PubMed