The adherence by women to four or more healthy lifestyle factors appears to halve of the risk of developing systemic lupus erythematosus.
Lupus is a condition which causes skin rashes, joint pains and fatigue and systemic lupus erythematosus (SLE) is the most common form of lupus, accounting for around 70% of cases. SLE is a chronic, autoimmune disease with a significant disease burden and has been ranked as among the top 20 causes of death in women aged between 5 and 64 years of age. The cause of SLE remains unclear although external factors such as exposure to UV radiation, obesity and cigarette smoking, have all been implicated in worsening of the disease, potentially due to increased oxidative stress and systemic inflammation.
The adoption of a healthy lifestyle, e.g., increased exercise, maintaining a healthy weight, stopping smoking etc, reduces the risk of many chronic conditions such as cardiovascular disease, risk of stroke etc and a recent study has shown that nearly a third of cases of the autoimmune disease, rheumatoid arthritis could be attributed to unhealthy lifestyle factors, e.g., obesity and smoking. With the possibility that lifestyle measures could impact on autoimmune diseases, a team from the Division of Rheumatology, University of Calgary, Canada, decided to prospectively evaluate the effect of healthy lifestyle measures on the development of SLE. The researchers turned to the two Nurses’ Health Studies which were in 1976 and 1989 respectively and are long-term prospective studies, following the health of women. Participants in these two studies, are required to self-complete lifestyle questionnaires every four years. The team identified participants who did not have SLE or any other connective tissue disorder at the start of the study but subsequently identified incident cases from their follow-up questionnaires and cross-referenced with medical records. The team used the healthy living index score (HLIS) which assesses physical activity, cigarette smoking, body mass index and dietary habits and ranges from 0 (least healthy) to 5 (most healthy). The score was calculated at baseline and every 2 years and the researchers used multivariate analysis to determine the relationship between HLIS scores and the risk of systemic lupus erythematosus.
A total of 185,962 women with mean age of 52.1 years included in the analysis. There were 203 incident cases of systemic lupus erythematosus were diagnosed a median of 10.8 years after enrolment in the study. Overall, the researchers calculated that adoption of each additional healthy lifestyle behaviour was associated with a 19% lower risk of developing SLE (hazard ratio, HR = 0.81, 95% CI 0.71 – 0.94). Among women within the highest HLIS category who had at least four healthy lifestyle behaviours, the risk of developing SLE was more than halved (HR = 0.42, 95% CI 0.25–0.70) compared with women who had less than or equal to one healthy behaviour.
Commenting on their findings, the authors suggested that it was likely that the combination of healthy lifestyle behaviours acted synergistically to mitigate the biological processes involved in the development of systemic lupus erythematosus. They concluded that healthy lifestyle measures should be adopted to help reduce the risk of developing SLE.
Choi MY et al. A combination of Healthy Lifestyle Behaviours Reduces Risk of Incident Systemic Lupus Erythematosus. Arthritis Rheumatol 2021