GLP-1 Evidence

Not medical advice. A record of published research and our assessments of it. The limits

Effects of Semaglutide on Body Composition and GFR: A Prespecified Analysis of the SMART Trial

Design
Randomized trial · 101 participants · Intermediate outcome
Match to healthy normal-weight adults aged 55–75
Different populationNon-diabetic CKD with overweight/obesity; small. Relevant to the lean-mass question because roughly a quarter of weight lost was lean tissue.
Could weight loss explain it?
Not applicable[Auto] Participants had obesity and/or type 2 diabetes and the abstract does not separate direct drug effects from weight loss or glycaemic improvement.
Study tier
Study tier 3Small prespecified analysis of an RCT with imprecise body-composition estimates.
Assessment
Version 2 · curated · Sep 13, 2026

Study facts come from the paper. Population match, weight-loss explanation and study tier are our judgments, made against the reference group of healthy normal-weight adults aged 55–75.

In 101 people with kidney disease and overweight or obesity (no diabetes), 24 weeks of semaglutide reduced weight by 9 kg, of which about 2.5 kg was lean mass (imprecise estimate). Body-composition change did not distort kidney-function estimates.

01Findings

What the study reported

Drugs
Semaglutide
Dose
2.4 mg weekly
Route
subcutaneous
Treatment duration
24 weeks
Comparator
placebo
Primary outcome
Prespecified: body composition (bioimpedance), measured and estimated GFR, blood pressure
Effect
Weight -9.1 kg; lean body mass -2.5 kg (95% CI -6.6 to 1.6); fat mass -3.9 kg; extracellular water -0.9 L; systolic BP -6.3 mmHg; no correlation between body-composition change and GFR change
95% confidence interval
Not extracted
Follow-up
24 weeks
Adverse events
Not extracted
Limitations
Auto-classified from abstract only; effect estimates, adverse events and limitations not extracted. Requires manual review.

Who was studied

Obesity status
overweight or obesity required
Diabetes status
excluded
Ckd status
CKD required
Sample size
101

Study quality details

Study design
Randomized controlled trial
Sample size
101
Randomization
yes
Blinding
double-blind
Comparator
placebo
Follow up duration
24 weeks
Outcome type
bioimpedance body composition
Replication
not assessed (auto)
Consistency with other evidence
not assessed (auto)
Population applicability
INDIRECT
Statistical precision
n=101; lean-mass CI includes zero
Risk of bias
not assessed (auto)
Funding conflicts
yes
Peer review status
yes
02Funding

Funding and conflicts

Funding
Novo Nordisk (investigator-initiated, per PubMed grant field)
Industry funded
Yes
Manufacturer
Novo Nordisk
Sponsor role
Funder; investigator-initiated (verify).
Author conflicts
Disclosure forms available with the article.
Independent replication
unknown
Notes
Authors declare relationships with the drug's manufacturer: Novo Nordisk

Funding is shown on every study and never used to score it.

03Claims

Claims this study bears on

04Source

The source, as retrieved

Abstract

[KEY POINTS] Treatment with semaglutide compared with placebo for 24 weeks reduced lean body mass and fat mass in adults with CKD and overweight or obesity. Changes in lean body mass or fat mass during semaglutide treatment did not correlate with changes in creatinine or cystatin C‑eGFR or measured GFR. Semaglutide significantly reduced extracellular water and BP, and changes in BP correlated with extracellular water. [BACKGROUND] The glucagon-like peptide-1 receptor agonist semaglutide reduces hemoglobin A1c, body weight, BP, and GFR decline. Semaglutide may influence serum creatinine and cystatin C levels by nonkidney-related mechanisms and thereby affect eGFR. We studied the relationship between changes in body composition, eGFR and measured GFR (mGFR), and BP during semaglutide treatment. [METHODS] We performed a prespecified analysis of a randomized placebo-controlled double-blind clinical trial in 101 adults with CKD with overweight status or obesity and without type 2 diabetes. Participants were randomized to 24 weeks of semaglutide 2.4 mg/wk subcutaneously or matched placebo treatment. We measured GFR with iohexol clearance, estimated GFR with creatinine and cystatin C, and used bioimpedance spectroscopy to determine lean body mass, fat mass, and extracellular water. [RESULTS] After 24 weeks of treatment, semaglutide compared with placebo changed total body weight, lean body mass, and fat mass by -9.1 (95% confidence interval [CI], -11.0 to -7.2), -2.5 (95% CI, -6.6 to 1.6), and -3.9 (95% CI, -7.8 to 0.0) kg, respectively. No correlations were present between changes in total body weight, lean body mass, and fat mass with changes in eGFR (creatinine or cystatin C) or mGFR during semaglutide treatment (all Spearman correlation coefficients <0.23). Similar results were observed in multivariable adjusted analyses. Semaglutide compared with placebo changed extracellular water and systolic BP by -0.9 (95% CI, -1.6 to -0.1) L and -6.3 (95% CI, -10.9 to -1.7) mm Hg, respectively. Systolic BP changes during semaglutide treatment correlated with extracellular water changes (Spearman correlation 0.40; P = 0.005). [CONCLUSIONS] Semaglutide reduced lean body mass and fat mass in patients with CKD with overweight status or obesity. These changes did not correlate with changes in creatinine or cystatin C eGFR or mGFR, suggesting that body weight reductions of 10% with semaglutide do not influence GFR estimates. [CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER] ClinicalTrials.gov, NCT04889183 .

Where this record came from

SourceRetrievedIdentifier
pubmedSep 13, 202642308057
first ingestion