Barbhaiya M, et al. - This study is performed to examine the smoking and SLE risk, overall and by anti-double stranded DNA (dsDNA) presence, in two prospective cohort studies. The outcome uncovered that the strong and particular relationship of current smoking and >10 pack-years of smoking with dsDNA+ SLE were seen. This novel finding recommends smoking is involved in dsDNA+ SLE pathogenesis.

Methods

• For this research, they designed a Nurses’ Health Study (NHS).
• In this study, they selected total 121701 US female nurses in 1976; Nurses’ Health Study II (NHSII) enlisted 116430 in 1989.
• Lifestyle, environmental and medical data were collected through biennial questionnaires.
• Incident SLE was affirmed by medical record review.
• Cox regression models estimated HRs of SLE, overall and by dsDNA subtype, in relationship with time-varying smoking status and cumulative smoking pack-years through the 2-year cycle prior to diagnosis, controlling for potential confounders.

Results

• In this study, they identified total 286 SLE cases.
• Among 286 SLE cases, 159 in NHS (1978-2012) and 127 in NHSII (1991-2013)), mean age was 49.2 (10.3) years and 42% were dsDNA+ at SLE diagnosis.
• At baseline, 45% of women had ever smoked, 51% of whom currently smoked.
• Compared with never smokers, current smokers had increased dsDNA+ SLE risk (HR 1.86 (1.14-3.04)), whereas past smokers did not (HR 1.31 (0.85-2.00)).
• They noticed that women who smoked >10 pack-years (vs never) had an raised dsDNA+ SLE risk (HR 1.60(95% CI 1.04 to 2.45)) compared with never smokers.
• There were no associations between smoking status or pack-years and overall SLE or dsDNA- SLE.