Background and aims Systemic lupus erythematosus (SLE) and may associate with several categories of comorbidities. We conducted this population-based study to examine the risk of a comprehensive range of comorbidities in patients with SLE compared with matched controls.

Methods The UK Clinical Practice Research Data-link (CPRD) was used to identify 1605 incident cases of SLE from 1997 to 2005 and matched 1:4 to 6284 controls by birth year, gender, general practice and year of first continuous registration. Odds ratios (ORs) of comorbidities at diagnosis and hazards ratios (HRs) after diagnosis of SLEs were estimated adjusting for age, sex, diagnosis year, body mass index, smoking and alcohol consumption.

Results SLE was associated with a higher risk for pre-existing comorbidities, with adjusted ORs (95% confidence interval [CI]) of 2.25 (1.97–2.56), 3.37 (2.49–4.57) and 3.54 (1.89–6.63) for the Charlson index of 1–2, 3–4 and ≥5, respectively. SLE was associated with an adjusted HR (95% CI) of 1.30 (95% CI, 1.13–1.49) for developing new comorbidity after the SLE diagnosis. SLE was associated with a greater risk for cancer, cardiovascular, renal, liver, rheumatological and neurological diseases as well as hypothyroidism, psychosis and anaemia. The development of comorbidities was most frequent in the first two years of SLE diagnosis. Patients with SLE also had high risk of death compared with the control group, with a HR of 1.91 (95% CI, 1.62–2.26).

Conclusions SLE patients had a burden of pre-existing comorbidities at diagnosis and the risk of development of multiple comorbidities were higher after the diagnosis compared to matched controls.