Clinical, Hereditary, and Lifestyle Factors Associated with Cardiovascular Disease in Adults with Type 2 Diabetes in Saudi Arabia: A Cross-Sectional Study

Background/Objectives: Diabetes mellitus and cardiovascular disease (CVD) constitute a dual epidemic in Saudi Arabia. This study examined the associations of cardiometabolic conditions, behavioural risk factors, and family history with cardiovascular disease among adults with type 2 diabetes mellitus (T2DM). Methods: An analytical cross-sectional study was conducted on 423 adults with self-reported physician-diagnosed T2DM drawn from a community-based survey in the Jazan region, Saudi Arabia. Sociodemographic, anthropometric, behavioural, dietary, and clinical variables were assessed using a validated WHO STEPwise-based questionnaire. CVD status was determined through self-reported physician diagnosis. Bivariate analyses and multivariable logistic regression with Firth penalisation were used to identify factors associated with CVD, with a reduced model as a sensitivity analysis. Results: Participants had a mean age of 48 ± 15 years; 60% were male, and 98% were Saudi nationals. The prevalence of self-reported CVD was 9.7%. Family history of CVD showed the strongest association (OR = 14.57; 95% CI: 5.88–40.90; p < 0.001), followed by diagnosed dyslipidaemia (OR = 5.19; 95% CI: 1.91–14.22; p = 0.001) and diagnosed hypertension (OR = 4.71; 95% CI: 1.86–13.16; p < 0.001). Regular whole-grain consumption (OR = 0.30; 95% CI: 0.11–0.75; p = 0.010) and a monthly income of 5000–9999 SAR (OR = 0.23; 95% CI: 0.05–0.89; p = 0.032) were associated with lower odds of CVD; all five associations persisted in a reduced model. Body mass index, physical inactivity, and smoking were not significantly associated with CVD after adjustment. Conclusions: In this exploratory analysis of adults with T2DM, CVD was strongly associated with family history of CVD, hypertension, and dyslipidaemia, and inversely associated with whole-grain intake. Given the cross-sectional design, self-reported measures, and wide confidence intervals, these associations do not establish causality and require prospective confirmation; family history of CVD may nonetheless help prioritise patients for cardiovascular risk assessment.