Increase in clinically recorded type 2 diabetes after colectomy
Figures

Study design.
The chart illustrates the number of eligible patients, number of patients excluded and reasons for exclusions, and the final number of patients included. For each colectomy patient, 15 non-colectomy patients were selected among (1) patients who had undergone orthopedic surgery, (2) patients who had undergone abdominal surgery leaving the gastrointestinal tract intact, and (3) patients who had undergone other surgery, unrelated to the gastrointestinal tract. Five non-colectomy patients were selected from each surgery group resulting in inclusion of a total of 694,110 non-colectomy patients matched on age, sex, and year of surgery. Non-colectomy patients were selected using sampling with replacement wherefore the total number of matches are slightly lower than the total number of colectomy patients times 15. Total colectomy includes colectomy and proctocolectomy. T2D: clinically recorded type 2 diabetes.

Cumulative hazards of clinically recorded type 2 diabetes.
Cumulative hazards are presented for patients with total colectomy, right hemicolectomy, resection of colon transversum, left hemicolectomy, sigmoidectomy, and proctectomy and for non-colectomy patients. Total colectomy includes colectomy and proctocolectomy. The cumulative hazard was estimated using the Nelson-Aalen estimator. The slopes of the curves equalize the hazard ratios: a slope of 1.00 corresponds to a hazard ratio of 1.00, whereas a slope >1 implies that colectomy patients have a higher risk of type 2 diabetes compared with non-colectomy patients. The linearity attests to the fulfillment of the assumption of proportional hazards in the Cox regression models.

Hazard ratio of clinically recorded type 2 diabetes after colectomy.
Hazard ratios are presented for total colectomy, right hemicolectomy, resection of colon transversum, left hemicolectomy, sigmoidectomy, and proctectomy. Total colectomy includes colectomy and proctocolectomy. Hazard ratios are adjusted for age, sex, and year of surgery. T2D: clinically recorded type 2 diabetes.
Tables
Characteristics of the study population.
https://doi.org/10.7554/eLife.37420.004Patients with colectomy or proctectomy | Non-colectomy patients | |||||||||
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All | Orthopedic surgery | Abdominal surgery leaving the GI tract intact | Other surgery unrelated to the GI tract | |||||||
No. (% women) | Age, years | No. (% women) | Age, years | No. (% women) | Age, years | No. (% women) | Age, years | No. (% women) | Age, years | |
Total colectomy | 3793 (50) | 54.6 (15) | 56,895 (50) | 54.6 (15) | 18,965 (50) | 54.6 (15) | 18,965 (50) | 54.6 (15) | 18,965 (50) | 54.6 (15) |
Right hemicolectomy | 10,989 (61) | 68.1 (13) | 164,815 (60) | 68.0 (13) | 54,940 (60) | 68.0 (13) | 54,940 (60) | 68.0 (13) | 54,935 (60) | 67.9 (13) |
Resection of colon transversum | 673 (61) | 66.6 (14) | 10,085 (60) | 66.5 (14) | 3365 (61) | 66.5 (14) | 3360 (60) | 66.5 (13) | 3360 (60) | 66.5 (14) |
Left hemicolectomy | 2513 (53) | 66.4 (12) | 37,685 (53) | 66.3 (12) | 12,560 (53) | 66.3 (12) | 12,560 (53) | 66.3 (12) | 12,565 (53) | 66.2 (12) |
Sigmoidectomy | 13,927 (53) | 65.0 (13) | 208,880 (53) | 64.9 (13) | 69,635 (53) | 65.0 (13) | 69,620 (53) | 64.9 (13) | 69,625 (53) | 64.9 (13) |
Proctectomy | 14,384 (48) | 65.7 (12) | 215,750 (48) | 65.6 (12) | 71,920 (48) | 65.6 (12) | 71,915 (48) | 65.6 (12) | 71,915 (48) | 65.6 (12) |
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Total colectomy includes colectomy and proctocolectomy. Age is mean (SD). GI: Gastrointestinal tract
Hazard ratio of clinically recorded type 2 diabetes after total colectomy, left hemicolctomy, and sigmoidectomy for patients with co-occurring colon cancer and patients with other colorectal diseases.
https://doi.org/10.7554/eLife.37420.007Patients with colectomy (T2D/total) | Non-colectomy patients (T2D/total) | Hazard ratio (95% CI) | P-value | |
---|---|---|---|---|
Total colectomy | 201/3793 | 2323/56,895 | 1.40 (1.21–1.62) | <0.001 |
Colorectal cancer | 56/993 | 620/14,895 | 1.61 (1.22–2.11) | <0.001 |
Other colorectal diseases | 145/2800 | 1703/42,000 | 1.34 (1.13–1.59) | <0.001 |
Left hemicolectomy | 145/2513 | 1754/37,685 | 1.41 (1.19–1.67) | <0.001 |
Colorectal cancer | 93/1804 | 1271/27,050 | 1.24 (1.01–1.53) | 0.04 |
Other colorectal diseases | 52/709 | 483/10,635 | 1.88 (1.41–2.50) | <0.001 |
Sigmoidectomy | 829/13,927 | 10,504/208,880 | 1.30 (1.21–1.40) | <0.001 |
Colorectal cancer | 334/6903 | 5071/103,520 | 1.11 (0.997–1.24) | 0.06 |
Other colorectal diseases | 495/7024 | 5433/105,360 | 1.47 (1.34–1.62) | <0.001 |
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Total colectomy includes colectomy and proctocolectomy. T2D: clinically recorded type 2 diabetes.
Additional files
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Supplementary file 1
Diagnoses for patients with colectomy who did not have colorectal cancer.
- https://doi.org/10.7554/eLife.37420.008
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Supplementary file 2
Hazard ratio of clinically recorded type 2 diabetes after colectomy according to start of follow-up time.
- https://doi.org/10.7554/eLife.37420.009
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Supplementary file 3
Procedure codes for colectomies and proctectomies used to identify patients in the Danish National Patient Register.
- https://doi.org/10.7554/eLife.37420.010
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Supplementary file 4
Procedure codes used to identify non-colectomy patients in the Danish National Patient Register.
- https://doi.org/10.7554/eLife.37420.011
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Supplementary file 5
Cumulative hazards plots of survival for patients with total colectomy, right hemicolectomy, resection of colon transversum, left hemicolctomy, sigmoidectomy, proctectomy, and non-colectomy patients.
- https://doi.org/10.7554/eLife.37420.012
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Transparent reporting form
- https://doi.org/10.7554/eLife.37420.013