IMPACT OF DIABETES MELLITUS ON MORTALITY AMONG ADMITTED INTERNAL MEDICINE PATIENTS

Background: Diabetes mellitus (DM) represents one of the most prevalent chronic non-communicable diseases globally and constitutes a major comorbidity among hospitalized patients. The impact of DM on in-hospital mortality and adverse clinical outcomes remains a significant concern. At King Hussein Medical Center, a substantial proportion of admitted internal medicine patients carry a diagnosis of DM, yet comprehensive local data on its prognostic significance are limited.
Objective: To determine the effect of pre-existing diabetes mellitus on all-cause in-hospital mortality in patients admitted to the internal medicine department of King Hussein Medical Center.
Methods: A retrospective cohort study was performed using electronic medical records of all adult patients (≥18 years) admitted to the department of internal medicine between January 2023 and August 2026. Patients were divided into DM and non-DM groups The data collected included demographics, clinical parameters, comorbidity profile and admission diagnosis. Primary outcome was all-cause in-hospital mortality. Multivariate logistic regression analysis adjusted for potential confounders.
Results: Among 847 patients (mean age 68.4±14.2 years, 54.6% male), DM was present in 42.8% (n=362). DM patients were younger (66.2±12.8 vs 70.2±14.8 years, p=0.001) but had higher BMI (29.8±4.6 vs 27.4±4.2 kg/m2, p<0.001), higher prevalence of hypertension (78.2% vs 61.4%), chronic kidney disease (34.8% vs 16.5%) and cardiovascular disease (46.4% vs 28.2%). The DM group had a significantly higher in-hospital mortality (11.3% vs. 6.6%, p=0.012). On multivariate analysis, DM was independently associated with increased mortality (OR=1.78, 95% CI: 1.18–2.68, p=0.006). Patients with poorly controlled DM (HbA1c ≥9%) had the highest mortality (16.1%, OR=2.84, 95% CI: 1.62–4.98). DM patients also had longer hospital stays (median 12 vs. 9 days, p<0.001) and higher ICU admission rates (22.4% vs. 13.2%, p<0.001).
Conclusion: Diabetes mellitus is independently associated with increased in-hospital mortality among admitted internal medicine patients. Poor glycemic control (HbA1c ≥9%) identifies a particularly high-risk subgroup. Such findings underscore the importance of optimal diabetes management during hospitalization.