Physical activity in relation to the risk of systemic lupus erythematosus: a prospective study including 401 745 individuals

Abstract Objective Physical activity (PA) or exercise, an essential health behaviour, may impart beneficial biological effects. Association of PA with the incidence of SLE has not been explored to date. This study aimed to evaluate the association of PA with the incidence of SLE via a prospective study. Methods Among the 502 492 participants originally enrolled in the UK Biobank Study between 2006 and 2010, a total of 401 745 participants with PA data but no SLE at baseline were included. Main outcome was the occurrence of SLE. Results During a median follow-up of 12.46 years, a total of 222 incident SLE patients were identified. Individuals with moderate (3.9/100 000 person-years) or high (4.3/100 000 person-years) PA levels exhibited a lower incidence of SLE than did those with low PA levels at baseline (6.4/100 000 person-years) (log-rank test: P = 0.010). Compared with those with a low level of PA, those with a moderate level of PA had a 40% lower risk of incident SLE (95% CI 0.43–0.85, P = 0.004), while a high level was associated with a 31% lower risk of incident SLE (95% CI 0.49–0.97, P = 0.033). The results revealed variations concerning age and sex. A high level of PA was proven to be more effective at preventing early-onset (<50 years old) SLE, whereas a moderate level of PA demonstrated more significant benefits at preventing late-onset (≥50 years old) SLE. Conclusions Participants with moderate or high PA levels had a lower risk of incident SLE than those with low PA levels, independent of sociodemographic and lifestyle factors and environmental triggers. PA shows promising health benefits in regard to reducing the risk of SLE in mid-age and elder people.