Sex stratified differences in comorbidity patterns among early- and late-onset dementia patients: original research article

Dementia is a clinical syndrome characterized by cognitive decline that interferes with daily functioning; however, sex-specific differences in early-onset dementia (EOD) and late-onset dementia (LOD) remain underexplored in Middle Eastern populations. Thus, this study aimed to examine sex-stratified differences in comorbidity patterns among EOD and LOD patients in Saudi Arabia. A retrospective cohort study of 4,445 dementia cases from the Saudi National Guard Health System (2016–2025) was conducted. Patients were classified as EOD (< 65 years) or LOD (≥ 65 years) based on the age at their first recorded dementia diagnosis during the study period. Logistic regression was used to identify comorbidities associated with EOD while adjusting for sex interactions. Analysis of 4,445 dementia cases revealed distinct comorbidity profiles between EOD (9.74%, n = 433) and LOD (90.26%, n = 4,012). LOD showed higher prevalence of hypertension (67.0% vs. 47.6%), heart disease (29.5% vs. 18.7%), and chronic kidney disease (12.5% vs. 7.4%; all p < 0.01). EOD demonstrated elevated rates of mood disorders (OR = 2.16, 95%CI:1.26–3.70) and documented amnesia/memory-loss diagnoses (OR = 1.60, 95%CI:1.25–2.05). Sex-stratified analyses identified significant interactions in ischemic stroke associated more with EOD in males ( p = 0.04). Distinct age- and sex-specific comorbidity patterns were identified among dementia patients in Saudi Arabia. These findings highlight clinically relevant differences in comorbidity profiles between early- and late-onset dementia and may inform age- and sex-sensitive assessment within dementia care.