An Elevated HbA1c Level Is Associated With Short-Term Adverse Outcomes in Patients With Gastrointestinal Cancer and Type 2 Diabetes Mellitus

BACKGROUND: Although an elevated hemoglobin A1c (HbAc1) level is an independent predictor of worse survival in patients with both digestive cancer and diabetes mellitus, its relationship to short-term prognosis in these patients has not been addressed. This study assessed this relationship in gastrointestinal cancer (GIC) patients with type 2 diabetes mellitus (T2DM). METHODS: A retrospective review of patients with GIC with or without T2DM from 2004 to 2014 was performed. Patients with T2DM were grouped according to HbA1c level, either normal (mean < 7.0%) or elevated (mean ≥ 7.0%). Age- and sex-matched GIC patients without T2DM served as controls. RESULTS: One hundred and eighteen patients aged 33 - 81 years with T2DM met the study eligibility criteria; 51 were in the normal HbA1c group, and 67 were in the elevated HbA1c group. The 91 patients in the non-T2DM group were randomly selected and matched to the T2DM group in terms of admittance date, age, and sex. There was a trend toward a higher 180-day mortality rate in the T2DM group compared with the non-T2DM group (15.3% vs. 7.7%, P = 0.095) and in the elevated HbA1c group compared with the normal HbA1c group (19.4% vs. 9.8%, P = 0.151); however, the differences were not significant. The duration of the hospital stay was longer in patients with T2DM than in those without T2DM (13.2 vs. 8.9 days, P < 0.05) and in patients with elevated versus normal HbA1c levels (14.5 vs. 11.4 days, P < 0.05). Diabetic GIC patients with elevated HbA1c levels had significantly more total postoperative complications than those with normal HbA1c levels (25.4% vs. 9.8%, P < 0.05). In multivariate regression analyses, short-term adverse outcomes were strongly associated with elevated HbA1c levels (odds ratio (OR): 5.276; 95% confidence level (CI): 1.73 - 16.095; P < 0.05) and no strict antidiabetic treatment (OR: 7.65; 95% CI: 2.49 - 23.54; P < 0.001). CONCLUSION: An elevated level of HbA1c significantly correlated with and was an independent predictor of short-term adverse outcomes in GIC patients with T2DM.