Visceral fat, cardiovascular risk factors and quality of life in lupus activity categorised via complement C3

Abstract

Background: Patients with lupus face increased cardiovascular risk linked to their autoimmune status. This study assesses the relationships between cardiovascular risk factors, lifestyle and health-related quality of life (HRQoL) concerning SLE activity categorised by complement C3.

Methods: 74 patients with SLE were recruited and stratified as active (C3 <90 mg/dL) or inactive (C3 >90 mg/dL), alongside 74 controls with obesity-related low-grade inflammation, at Hospital Universitario Puerta de Hierro Majadahonda. Anthropometric measurements, clinical and demographic data were recorded, and participants completed validated questionnaires on physical activity, dietary intake and HRQoL. Fasting blood samples were collected for metabolic determinations. Comparative analyses between SLE groups and controls, along with regression models adjusted for variables associated with disease activity, were performed.

Results: The inactive SLE group exhibited a less healthy adiposity profile compared with the active group (36.7% vs 33.2% total fat mass; 8.5 AU vs 6.5 AU visceral fat mass) and showed a higher prevalence of cardiovascular risk factors, including markers of obesity, hypertension, dyslipidaemia and increased waist circumference, along with worse HRQoL outcomes. Notably, age, body mass index and insulin resistance were associated with SLE inactivity, while fibrinogen correlated with disease activity as assessed by complement C3 levels. Interestingly, household composition as a sociodemographic variable (alone, couple/children/elderly or other) also showed an independent association with SLE activity.

Conclusions: Inactive patients with SLE exhibited more adverse cardiovascular risk markers compared with active patients categorised by complement C3, even when glucocorticoid administration was accounted for. Additionally, this research highlights the potential influence of fibrinogen as well as metabolic and sociodemographic factors on disease activity. These findings emphasise the need for personalised precision management strategies such as measurement of fibrinogen levels and insulin resistance and sociodemographic considerations that address both cardiovascular risk and overall lifestyle plus exposome in patients with SLE and may partly explain SLE activity evolution.