Background Cardiovascular autonomic neuropathy (CAN) with comprised function of the parasympathetic (PNS) and/or the sympathetic nervous system (SNS) occurs frequently (10–90%) in patients with systemic lupus erythematosus (SLE). CAN is a subclinical dysfunction which is reflected by reduced heart rate variability (HRV). Only a few studies have investigated the clinical impacts of CAN in SLE. However, impaired quality of life occurs frequently among SLE patients, and has, in other patient groups and in healthy individuals, been associated to impaired HRV. Consequently, the purpose of this study is to explore if CAN is associated to self-report of low health related quality of life (HRQoL) in SLE patients.

Methods CAN was tested in 87 SLE patients with a 5-minute HRV-test. HRV-measures reflecting PNS function (high frequency power, HFP) and mixed PNS-SNS function (low frequency power, LFP; total power (TP); low- vs high frequency power-ratio, LFP/HFP-ratio and peak LF frequency) were calculated. The patients were further asked to complete a questionnaire on severity of pain, depression and fatigue, adapted from the Systemic Lupus Activity Questionnaire (SLAQ), along with the questionnaire Short Form 12 (SF-12) on physical and mental HRQoL.

Results TP and peak LF were associated to low quality of life based on the physical domain of the SF-12 (TP: β=0.247, p=0.025 and peak LF: β=0.225, p=0.037). However, no associations were observed between AD and pain, depression, fatigue or the mental domain from the SF-12.

Conclusions Cardiovascular autonomic neuropathy of mixed PNS and SNS impairment was associated to self-report of low physical quality of life in SLE, but not to any mental domains of life quality. Further studies are needed to elaborate on causality between of autonomic dysfunction and the physical component of life quality in SLE patients.