Summary:
In 788 adults with T2D (HbA1c 7.0-10.5%) inadequately controlled on stable metformin, BMI ≥25, once-weekly semaglutide 1.0 mg for 52 weeks achieved greater HbA1c reduction (1.5% vs 1.0%, difference -0.49%, P<0.0001), weight loss (5.3 vs 4.2 kg), and more reaching <7.0% (66.1% vs 45.1%) compared to daily canagliflozin 300 mg, with more GI adverse events (46.9% vs 27.9%) but fewer genitourinary infections (2.6% vs 12.2%).
| PICO | Description |
|---|---|
| Population | 788 adults with T2D (HbA1c 7.0-10.5%) on stable metformin ≥90 days, BMI ≥25. |
| Intervention | Semaglutide 1.0 mg subcutaneous weekly (titrated from 0.25 mg over 8 weeks). |
| Comparison | Canagliflozin 300 mg oral daily (maximum approved dose). |
| Outcome | HbA1c -1.5% vs -1.0%. Weight -5.3 vs -4.2 kg. Target <7%: 66.1% vs 45.1%. |
SUSTAIN 8: Semaglutide vs Canagliflozin
RCT · type 2 diabetes · 52 weeks
Once-weekly semaglutide 1.0 mg gave superior HbA1c lowering and weight loss versus canagliflozin 300 mg. Choice still hinges on comorbidities and tolerability.
Clinical Context
GLP-1 RAs and SGLT2i are preferred second-line agents after metformin, working through different mechanisms.
Clinical Pearls
1. Clear Glycemic Superiority: 0.49% additional HbA1c reduction is clinically meaningful.
2. Weight Loss Favors Semaglutide: 22.3% lost ≥10% body weight vs 8.9%.
3. Different Adverse Effect Profiles: GI symptoms vs genitourinary infections guide selection.
4. Lipid Improvements Favor Semaglutide: Greater reductions in cholesterol and triglycerides.
Practical Application
Choose GLP-1 RA when glycemic control and weight are primary goals. Choose SGLT2i when HF/CKD present. Many benefit from both.
Study Limitations
52-week duration. Canagliflozin 300 mg is max dose; semaglutide 2.0 mg now available. Cost not evaluated.
Bottom Line
Semaglutide provides superior HbA1c and weight loss vs canagliflozin. Selection should consider comorbidities and tolerability.
Source: Lingvay I, et al. “Semaglutide vs Canagliflozin as Add-On to Metformin (SUSTAIN 8).” Lancet Diabetes Endocrinol, 2019. Read article