Effect of glucagon-like peptide-1 agonists on DIEP flap breast reconstruction outcomes in obese patients

Authors: Sidhu AS, Chopra AA, Ahmed S, Corpuz GS, Towfighi PN, Danforth RM, Lester ME, Hassanein AH

Affiliation: Indiana University School of Medicine; Penn State College of Medicine

Journal: Journal of Plastic, Reconstructive & Aesthetic Surgery, February 2026

PMID: 41308379

Key takeaways

• Analysis of the TriNetX multicenter EMR network showed that Class III obesity patients (BMI >40) had significantly higher 90-day wound debridement rates than Class I/II patients (BMI 30–40).

• GLP-1 agonist use (within 1 year before surgery) in BMI 30–40 kg/m² patients (class I and II obesity) was not associated with higher 90-day dehiscence, debridement, or revision rates.

• Patients with BMI 30–40 kg/m² who used GLP-1 agonists had lower 90-day revision surgery rates than both BMI 30–40 nonusers and BMI >40 nonusers.

• The study supports preoperative GLP-1–assisted weight loss for BMI >40 patients pursuing DIEP, but only as an association.

• Major missing data: actual weight loss, diabetes control, GLP-1 agent/dose/duration adherence, smoking, mastectomy timing, and flap-specific complications.

Background

Obesity increases wound morbidity after DIEP flap breast reconstruction, and BMI >40 kg/m² is often treated as a high-risk threshold for autologous reconstruction. GLP-1 agonists are increasingly used for obesity and diabetes, but their effect on DIEP-specific outcomes has not been well defined.

Objective

To evaluate whether GLP-1 agonist use is associated with improved 90-day outcomes in obese patients undergoing DIEP-based breast reconstruction, and to inform preoperative weight-loss counseling for patients with class III obesity.

Methods

• Design/database: Retrospective cohort study using TriNetX, a global network of federated EMRs, that aggregates de-identified records from participating health care organizations.

• Study period: 2005–2025.

• Population: Adults ≥18 years undergoing DIEP-based autologous breast reconstruction.

• Procedure codes: CPT 19364; HCPCS S2066, S2067, S2068.

• Initial sample: 5,618 patients with 90-day follow-up.

Groups: Propensity score matching was performed for age, race, and prior radiation.

• Group 1: GLP-1 agonist use within 1 year before surgery; BMI 30–40 kg/m²

• Group 2: No GLP-1 agonist; BMI 30–40 kg/m²

• Group 3: No GLP-1 agonist; BMI >40 kg/m²

• Outcomes: 90-day wound dehiscence, wound debridement, and revision surgery.

• Statistics: Chi-square testing for categorical variables; independent t-tests for continuous variables; 95% confidence intervals; significance set at P<0.05.

• Level of evidence: Retrospective database cohort; therapeutic level III.

Results

Baseline characteristics

• After matching, groups were similar for age, race, ethnicity, and prior radiation.

• Mean ages in the matched comparisons were approximately:

  • Group 1 vs Group 2: 51.6 vs 51.7 years.

  • Group 1 vs Group 3: 51.6 vs 51.3 years.

  • Group 2 vs Group 3: 48.3 vs 48.2 years.

90-day wound dehiscence

• Group 1 vs Group 2: 16.6% vs 14.2%; RD −2.4%; 95% CI −9.3 to 4.5; P=0.500.

• Group 1 vs Group 3: 16.3% vs 19.2%; RD 3.0%; 95% CI −4.5 to 10.4; P=0.436.

• Group 2 vs Group 3: 13.8% vs 17.3%; RD 3.5%; 95% CI 0.5 to 8.0; P=0.087.

• No statistically significant dehiscence differences were observed.

90-day wound debridement

Group 1 (GLP-1) had significantly lower rates (6.9%) than Group 3 (13.3%; $P=0.032$). Note: For the Group 2 vs. 3 comparison, an internal discrepancy exists between the text (4.6% vs 7.8%) and Table 2 (8.1% vs 11.8%), though both show a statistically significant increase in Group 3 (P=0.019).

90-day revision surgery

• Group 1 vs Group 2: 5.7% vs 11.4%; RD 5.7%; 95% CI 0.4 to 11.0; P=0.037.

• Group 1 vs Group 3: 5.4% vs 10.8%; reported as “OR: 5.4%” in the table, likely intended as risk difference; 95% CI 0.1 to 10.7; P=0.046.

• Group 2 vs Group 3: 10.0% vs 10.5%; RD 0.5%; 95% CI −3.8 to 2.9; P=0.780.

Conclusion

The authors conclude that patients with BMI >40 kg/m² seeking DIEP flap reconstruction should be counseled that weight loss with GLP-1 agonist therapy to a lower obesity class may decrease wound complications. In this dataset, GLP-1 agonist use in class I/II obesity was not associated with increased short-term wound morbidity.

Strengths

• Large cohort of 5,618 DIEP reconstruction patients.

• Clinically relevant BMI/GLP-1 comparison groups.

Limitations

• Key inference is indirect: the authors imply GLP-1 therapy could help BMI >40 patients lose weight into a lower-risk BMI class, but the study does not show that Group 1 was formerly BMI >40 or document actual weight loss.

• Retrospective database study; coding-dependent and cannot establish causation.

• Limited matching: age, race, and prior radiation only.

• No granular data on GLP-1 agent, dose, adherence, weight loss, diabetes control, smoking, or reconstruction details.

• Outcomes were broad administrative endpoints, not DIEP-specific complications.

Editorial Notes

• The comparator structure is the central weakness. The clinically interesting cohort is BMI >40 patients treated with GLP-1 therapy who successfully lose weight before DIEP. That group is not directly studied. Instead, Group 1 is already BMI 30–40 while using GLP-1 agonists. Therefore, the conclusion about class III obesity patients “weight losing into” a lower obesity class is plausible but not directly proven.

• Residual confounding is substantial. GLP-1 users may differ systematically from nonusers: endocrine engagement, diabetes control, socioeconomic access, nutrition counseling, health literacy, and institutional optimization pathways. Those factors could reduce complications independent of the medication.

• The study does not separate weight loss from drug exposure. GLP-1 agonists could improve glycemic control, reduce inflammation, improve endothelial function, or simply select for patients who achieved meaningful preoperative weight loss. Without pre-GLP-1 BMI, day-of-surgery BMI trajectory, HbA1c, albumin/prealbumin, and diabetes status, mechanism cannot be assigned.

• The 90-day revision endpoint is difficult to interpret. Revision surgery within 90 days after DIEP may reflect a wound healing or flap complication, but may also represent a revision to improve cosmesis.