Cardiovascular risk beyond dietary adherence and antipsychotic metabolic liability in severe mental illness

Abstract Background Individuals with severe mental illness (SMI) experience increased cardiovascular disease (CVD) morbidity and mortality, yet CVD risk factors and preventive treatment remain insufficiently addressed in psychiatric care. Data integrating dietary habits, psychopharmacological treatment, and CVD risk assessment across treatment settings are limited and may contribute to understanding mechanisms underlying increased cardiovascular morbidity in this patient group. Methods We conducted a cross-sectional study to assess cardiovascular risk and dietary habits in Norwegians with SMI. Adults with schizophrenia spectrum disorder or bipolar disorder type 1 were recruited from inpatient and outpatient psychiatric services in south-eastern Norway. Anthropometric measures, biochemical markers, smoking exposure, medication use, and estimated 10-year CVD risk using QRISK3 were assessed. A comprehensive dietary assessment was performed. Cardiometabolic and dietary outcomes were compared with population-based reference data. Antipsychotic treatment was categorised according to established metabolic liability profiles described in previous literature. Group comparisons were performed using chi-square tests, t-tests or non-parametric tests as appropriate, and associations with estimated CVD risk were explored using regression analyses. Results Eighty-six participants with SMI were included. QRISK3 was markedly increased compared to reference population estimates, with a relative risk of 1.9, and 26% meeting criteria for initiation of active primary CVD treatment. Prevalence of hypertension and type 2 diabetes mellitus did not differ from the general population. Further, the adherence to dietary recommendations was broadly comparable to that of the general population. Dietary adherence differed across antipsychotic metabolic risk categories, but not across psychiatric treatment settings. Smoking contributed to elevated CVD risk, but QRISK3-derived relative risk remained elevated after excluding smoking. Few participants were receiving lipid-lowering therapy despite high CVD-risk. Conclusions Adults with SMI displayed substantial CVD risk and limited use of preventive treatment. Elevated CVD risk was not explained by dietary quality or smoking alone. Dietary quality was nonetheless associated with estimated CVD risk in exploratory analyses, and patients treated with antipsychotics with high metabolic liability had poorer dietary habits than those receiving low-risk agents. These findings highlight the complexity of CVD risk in SMI and support systematic risk assessment and preventive interventions in psychiatric care.