Objectives To analyze the impact of smoking through time in the clinical characteristics and disease activity in a cohort of rheumatoid arthritis (RA) patients from an Early Arthritis Clinic (EAC).
Methods We studied a cohort of patients from an EAC, followed up between January 1993 and December 2014. All patients gave informed consent. Patients with early arthritis (less than one year of disease duration), who met the 1987 criteria of the American College of Rheumatology (ACR) for rheumatoid arthritis (RA)1 at some time during the disease course were included and followed up for two years. Microcrystalline and infectious arthritis were excluded, as well as patients who previously had been treated with disease modifying antirheumatic drugs. Patients were assessed for clinical and analytical data using standardized protocols every six months, that included:number of tender joints (out of 28) (NTJ), number of swollen joints (out of 28) (NSJ), DAS28, erythrocyte sedimentation rate (ESR), rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA). Disease activity in different periods of time (first from 01/01/1993 to 31/12/2000, second from 01/01/2001 to 31/12/2007, third from 01/01/2008 to 31/12/2014), as well as the influence of smoking were studied. Data was analyzed with the statistical program SPSS 11.5.
Results Out of 1144 patients included in the cohort, 480 patients fulfilling RA classification criteria were included in this study. The age of onset was similar between the 3 periods (52,5±16,3 years in the first period vs. 53,2±17,1 years in the second vs. 51,8±16,4 years in the third; p=NS). In spite of the fact that RA is a predominant women's disease, the frequency of female sex increased significantly in the last periods (66,7% vs. 81,1% vs. 81,4% respectively; p=0,007) and also an increase of smoking habit in women was observed (proportion of smoking or ex-smoking women for periods: 40% vs. 67,4% vs. 68,1% respectively; p=0,003). In the last period, patients were first seen in our EAC with a longer disease duration (15,4±8,3 vs. 16,2±11,5 vs. 25,5±20,5 weeks respectively; p<0,001), but a lower arthritis activity, with lower NTJ (10,7±6 vs. 9,4± 7 vs.7,6±6,8 respectively; p<0,001), lower NSJ (7,9±5,1 vs. 7,7±5,7 vs. 5,7±5,2 respectively; p<0,001), lower ESR (48,2±28,5 vs. 42,6±25,9 vs. 26,6±25,9 mm/h respectively; p<0,001) and lower DAS28 (5,8±1,3 vs. 5,5±1,3 vs. 4,7±1,4 respectively; p<0,001). A significant increase in ACPA-positive patients (67,6% vs. 59,5% vs. 80,9%; p<0,001) and in ACPA titers (603,1±603,4 UI/mL vs. 500,4±626,7 UI/mL vs. 819,8±1269,6 UI/mL; p=0,004) were observed in the last period.
Conclusions In the last years RA patients from our EAC had a lower disease activity, higher proportion of ACPA-positive and ACPA titers, more female sex and higher smoking habit among women. Probably, smoking has an impact in the increase of the seropositive patients, as well as in the increase in the women's proportion in the last years.
Arnett FC et al. Arthritis Rheum 1988;31(3):315-24
Disclosure of Interest None declared