Long-term weight and HbA1c% changes following metabolic bariatric surgery: a comparative analysis using routine clinical data in Scotland

Beatrice Leyaro; Raymond Carragher; Abdulmajid Ali

doi:10.1016/j.clnesp.2025.07.309

Abstract

Rationale: Bariatric surgery is a key intervention for individuals with severe obesity, providing substantial and sustained weight loss and improvement in comorbidities. However, limited research has examined long-term weight and glycemic changes by comparing outcomes between patients who undergo surgery and those who do not, despite being eligible after referral.

Methods: This retrospective cohort study included adults with type 2 diabetes and obesity referred for metabolic bariatric surgery (MBS) at University Hospital Ayr, Ayrshire & Arran, between 2009 and 2020. The primary outcomes were percentage total weight loss (%TWL) and change in hemoglobin A1c (HbA1c%) from baseline to fiveyears.

Results: A total of 411 patients were included, 225 (54.7%) did not undergo bariatric surgery. The mean (SD) age was 48.3 (8.5) years, with no significant baseline body mass index difference between the surgery and non-surgery groups [mean (SD) 47.4 (7.9) kg/m²]; 63.3% were women. At five years, patients who underwent surgery maintained a 22.0% weight reduction compared to 8.6% in the non-surgery group (P < 0.001). HbA1c% decreased by 1.0% (95% CI, -1.31 to -0.70) in the surgery group but increased by 0.4% (95% CI, 0.09 to 0.71) in the non-surgery group. Adjusted mixed models showed that, surgery group had a -0.13% (95% CI, -0.18 to
-0.07; P < 0.001) change in HbA1c% and a -1.31% (95% CI, -1.73 to -0.88; P < 0.001) %TWL compared to the non-surgery group.

Original language	English
Pages (from-to)	918-918
Number of pages	1
Journal	Clinical Nutrition ESPEN
Volume	69
Early online date	19 Sept 2025
DOIs	https://doi.org/10.1016/j.clnesp.2025.07.309
Publication status	Published - 31 Oct 2025
Event	ESPEN Congress on Clinical Nutrition & Metabolism - Prague Congress Center, Prague, Czech Republic Duration: 13 Sept 2025 → 16 Sept 2025 Conference number: 47 https://espencongress.com/

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This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 3 Good Health and Well-being

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Cite this

@article{0e2d0e6cff5e47208001bcb99b7a3b68,

title = "Long-term weight and HbA1c\% changes following metabolic bariatric surgery: a comparative analysis using routine clinical data in Scotland",

abstract = "Rationale: Bariatric surgery is a key intervention for individuals with severe obesity, providing substantial and sustained weight loss and improvement in comorbidities. However, limited research has examined long-term weight and glycemic changes by comparing outcomes between patients who undergo surgery and those who do not, despite being eligible after referral. Methods: This retrospective cohort study included adults with type 2 diabetes and obesity referred for metabolic bariatric surgery (MBS) at University Hospital Ayr, Ayrshire \& Arran, between 2009 and 2020. The primary outcomes were percentage total weight loss (\%TWL) and change in hemoglobin A1c (HbA1c\%) from baseline to fiveyears. Results: A total of 411 patients were included, 225 (54.7\%) did not undergo bariatric surgery. The mean (SD) age was 48.3 (8.5) years, with no significant baseline body mass index difference between the surgery and non-surgery groups [mean (SD) 47.4 (7.9) kg/m2]; 63.3\% were women. At five years, patients who underwent surgery maintained a 22.0\% weight reduction compared to 8.6\% in the non-surgery group (P < 0.001). HbA1c\% decreased by 1.0\% (95\% CI, -1.31 to -0.70) in the surgery group but increased by 0.4\% (95\% CI, 0.09 to 0.71) in the non-surgery group. Adjusted mixed models showed that, surgery group had a -0.13\% (95\% CI, -0.18 to -0.07; P < 0.001) change in HbA1c\% and a -1.31\% (95\% CI, -1.73 to -0.88; P < 0.001) \%TWL compared to the non-surgery group.",

author = "Beatrice Leyaro and Raymond Carragher and Abdulmajid Ali",

year = "2025",

month = oct,

day = "31",

doi = "10.1016/j.clnesp.2025.07.309",

language = "English",

volume = "69",

pages = "918--918",

journal = "Clinical Nutrition ESPEN",

issn = "2405-4577",

publisher = "Elsevier Limited",

note = "ESPEN Congress on Clinical Nutrition \& Metabolism, ESPEN 2025 ; Conference date: 13-09-2025 Through 16-09-2025",

url = "https://espencongress.com/",

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TY - JOUR

T1 - Long-term weight and HbA1c% changes following metabolic bariatric surgery

T2 - ESPEN Congress on Clinical Nutrition & Metabolism

AU - Leyaro, Beatrice

AU - Carragher, Raymond

AU - Ali, Abdulmajid

N1 - Conference code: 47

PY - 2025/10/31

Y1 - 2025/10/31

N2 - Rationale: Bariatric surgery is a key intervention for individuals with severe obesity, providing substantial and sustained weight loss and improvement in comorbidities. However, limited research has examined long-term weight and glycemic changes by comparing outcomes between patients who undergo surgery and those who do not, despite being eligible after referral. Methods: This retrospective cohort study included adults with type 2 diabetes and obesity referred for metabolic bariatric surgery (MBS) at University Hospital Ayr, Ayrshire & Arran, between 2009 and 2020. The primary outcomes were percentage total weight loss (%TWL) and change in hemoglobin A1c (HbA1c%) from baseline to fiveyears. Results: A total of 411 patients were included, 225 (54.7%) did not undergo bariatric surgery. The mean (SD) age was 48.3 (8.5) years, with no significant baseline body mass index difference between the surgery and non-surgery groups [mean (SD) 47.4 (7.9) kg/m2]; 63.3% were women. At five years, patients who underwent surgery maintained a 22.0% weight reduction compared to 8.6% in the non-surgery group (P < 0.001). HbA1c% decreased by 1.0% (95% CI, -1.31 to -0.70) in the surgery group but increased by 0.4% (95% CI, 0.09 to 0.71) in the non-surgery group. Adjusted mixed models showed that, surgery group had a -0.13% (95% CI, -0.18 to -0.07; P < 0.001) change in HbA1c% and a -1.31% (95% CI, -1.73 to -0.88; P < 0.001) %TWL compared to the non-surgery group.

AB - Rationale: Bariatric surgery is a key intervention for individuals with severe obesity, providing substantial and sustained weight loss and improvement in comorbidities. However, limited research has examined long-term weight and glycemic changes by comparing outcomes between patients who undergo surgery and those who do not, despite being eligible after referral. Methods: This retrospective cohort study included adults with type 2 diabetes and obesity referred for metabolic bariatric surgery (MBS) at University Hospital Ayr, Ayrshire & Arran, between 2009 and 2020. The primary outcomes were percentage total weight loss (%TWL) and change in hemoglobin A1c (HbA1c%) from baseline to fiveyears. Results: A total of 411 patients were included, 225 (54.7%) did not undergo bariatric surgery. The mean (SD) age was 48.3 (8.5) years, with no significant baseline body mass index difference between the surgery and non-surgery groups [mean (SD) 47.4 (7.9) kg/m2]; 63.3% were women. At five years, patients who underwent surgery maintained a 22.0% weight reduction compared to 8.6% in the non-surgery group (P < 0.001). HbA1c% decreased by 1.0% (95% CI, -1.31 to -0.70) in the surgery group but increased by 0.4% (95% CI, 0.09 to 0.71) in the non-surgery group. Adjusted mixed models showed that, surgery group had a -0.13% (95% CI, -0.18 to -0.07; P < 0.001) change in HbA1c% and a -1.31% (95% CI, -1.73 to -0.88; P < 0.001) %TWL compared to the non-surgery group.

U2 - 10.1016/j.clnesp.2025.07.309

DO - 10.1016/j.clnesp.2025.07.309

M3 - Meeting Abstract

SN - 2405-4577

VL - 69

SP - 918

EP - 918

JO - Clinical Nutrition ESPEN

JF - Clinical Nutrition ESPEN

Y2 - 13 September 2025 through 16 September 2025

ER -