Comparative Study of Multimorbidity of Diabetic Patients Living in Ardabil and Tehran Publisher



Abdollahi M ; Pourfarzi F ; Poustchi H ; Sadeghipour P ; Hashemi Madani N ; Matin S ; Malekzadeh R
Source: Journal of Diabetes and Metabolic Disorders Published:2026

Abstract

Background : Multimorbidity is highly prevalent among individuals with diabetes mellitus and substantially worsens clinical outcomes. This study compared the prevalence and patterns of multimorbidity among diabetic patients living in Ardabil and Tehran. Method : In this retrospective comparative study, data were obtained from diabetic patients enrolled in the PERSIAN cohort in Ardabil and the Institute of Diabetes and Metabolism in Tehran. Multimorbidity was defined as the coexistence of two or more chronic conditions, including hypertension, coronary artery disease, cerebrovascular disease, chronic kidney disease, dyslipidemia, obesity, asthma/COPD, and malignancy. Comparisons between two cities were conducted using the Chi-square (χ²) test and were also visually assessed using bar plots with 95%CI. Poisson regression models with robust standard errors (SE) were used to estimate prevalence ratios (PRs) for comorbidity according to city of residence. Results : A total of 921 diabetic patients were included. Multimorbidity was significantly more prevalent in Tehran than in Ardabil (97.8% vs. 92.4%, P < 0.001), with a higher proportion of patients having three or more comorbidities (44.7% vs. 30.2%). Hypertension, coronary artery disease, chronic kidney disease, dyslipidemia, and cancer were more common in Tehran, whereas obesity was more prevalent in Ardabil. In the fully adjusted model, residence in Tehran was associated with a 5.2% higher comorbidity prevalence (PR = 1.052, 95% CI: 1.017–1.087). Conclusion : Diabetic patients in Tehran exhibit a significantly greater multimorbidity burden than those in Ardabil, possibly driven by longer diabetes duration. These findings highlight the need for region-specific strategies for multimorbidity management in Iran. Clinical trial number: Not applicable. © The Author(s), under exclusive licence to Tehran University of Medical Sciences 2026.