# Semaglutide’s heart and kidney results

> Cardiovascular and kidney trials | Real GLP-1 — Real GLP-1 follows SELECT, FLOW and heart-failure research: which people were studied, which outcomes changed, and why these findings matter beyond weight.

**Heart and kidneys**

These studies redirected my attention toward clinical outcomes. Each begins with a particular group of people.

## SELECT: cardiovascular events without diabetes

SELECT studied [17,604 adults with preexisting cardiovascular disease and overweight or obesity, without diabetes](https://pubmed.ncbi.nlm.nih.gov/37952131/). Semaglutide reduced the primary composite of cardiovascular death, nonfatal heart attack or nonfatal stroke versus placebo: hazard ratio 0.80, with a 95% confidence interval of 0.72–0.90. The trial reported a 20% relative risk reduction.

A composite combines several outcomes into one trial measure; here, those outcomes were cardiovascular death, nonfatal heart attack and nonfatal stroke. The actual contents of that measure matter to me. They make this a different kind of result from a lower body weight.

My enthusiasm for SELECT has a specific address: the population it enrolled. SELECT persuaded me to treat the cardiovascular result as a central topic for that population. It cannot supply the same forecast for every person who is interested in weight loss. The word “relative” also matters: the 20% figure compares risks between the study groups. It does not state an individual’s absolute chance of an event.

## Heart-failure symptoms

The [STEP-HFpEF trial](https://pubmed.ncbi.nlm.nih.gov/37622681/) studied people with obesity-related heart failure with preserved ejection fraction. Semaglutide improved heart-failure-related symptoms and physical limitations and produced greater weight loss than placebo. The symptom and physical-limitation score gives this study a place in the story alongside the cardiovascular-event trials.

I am glad that physical limitations were measured. A paper asking about symptoms gets closer to the ordinary activities that a weight measurement alone leaves out. Physical limitations draw my interest toward an ordinary day and the ordinary things someone hopes to be able to do.

![Pedestrians using a broad outdoor stairway and an accessible ramp with blue handrails.](images/outcomes-public-steps.webp)

*An illustrative public courtyard, with steps and a ramp. No person shown represents a study participant or a treatment outcome.*

## FLOW: type 2 diabetes and chronic kidney disease

FLOW enrolled [3,533 people with type 2 diabetes and chronic kidney disease](https://pubmed.ncbi.nlm.nih.gov/38785209/). Its primary kidney composite included kidney failure, a decline of at least 50% in eGFR, or kidney or cardiovascular death. eGFR is an estimate of how well the kidneys filter blood. Semaglutide reduced that composite versus placebo: hazard ratio 0.76, with a 95% confidence interval of 0.66–0.88, described as a 24% lower risk.

The people studied had both type 2 diabetes and chronic kidney disease. The finding is already consequential with its actual population and outcomes left in place.

## The diabetes trial’s eye finding

SUSTAIN-6 adds an uncomfortable piece of the picture. In [people with type 2 diabetes at high cardiovascular risk](https://pubmed.ncbi.nlm.nih.gov/27633186/), semaglutide reduced the composite cardiovascular outcome while diabetic-retinopathy complications were more frequent. Retinopathy is damage to the retina associated with diabetes.

That pairing is a reason for precision, and I think it improves the conversation. An encouraging cardiovascular result can coexist with a finding that needs clinical attention elsewhere. The [safety review](https://pubmed.ncbi.nlm.nih.gov/34305810/) discusses retinopathy monitoring with rapid glycemic correction. The [side-effects essay](/side-effects) returns to that caution without turning an essay into a personal treatment plan.

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On Real GLP-1, my interest in semaglutide’s published results runs from the scale to the less photogenic outcomes, and these essays offer no medical advice or treatment service.