Only rheumatoid factor-positive subset of anti-citrullinated peptide/protein antibody-negative rheumatoid arthritis may seroconvert to anti-citrullinated peptide/protein antibody-positive

The Clinical Course of Rheumatoid Arthritis in Kazakhstani Patients

BACKGROUND: Rheumatoid arthritis (RA) prevalence according to the worldwide epidemiological data varies from 0.4% to 1.3%. The disability and mortality rate in RA is high. RA clinic is various, and compiles from articular and systemic manifestations. AIM: The aim of our study was to investigate the clinical course of RA in Kazakhstani patients living in North region of our country. METHODS: The 81 women at the age of 30–55 years with a verified diagnosis of RA who have lived in Kazakhstan for at least 10 years were recruited to the study. All participants were examined by the rheumatologist and a standard laboratory examination was carried out. Statistical analysis was conducted in IBM SPSS Statistics 26 software (IBM.USA;1). RESULTS: The statistically significant higher frequency of erosive radiological stages, bone ankylosis (χ2 = 18.070 df = 6 p = 0.005) was found in seropositive (rheumatoid factor [RF]+) anti-citrullinated protein/peptide antibody positive (ACPA+) subgroup. The correlation analysis showed strong association between certain RA form activity and inflammatory markers, as well as disease triggers. The discriminant model which predicts the stage of radiological damage was obtained. The sensitivity of model in predicting X-ray Stage I-71.6%, Stage II-29.4%, Stage III-37.5%, and Stage IV-63.6%. CONCLUSION: The debut of the RA on average occurred in the third decade of the patients’ life. The joint syndrome had a more unfavorable character RF+ACPA+ patients’ subgroup; however, RF+ACPA-negative (ACPA-) subgroup also showed a predisposition to poorer prognosis. The obtained discriminant model may be useful for RA patients’ management.

Abdominal Obesity in Comparison with General Obesity and Risk of Developing Rheumatoid Arthritis in Women

OBJECTIVE

Being overweight or obese increases rheumatoid arthritis (RA) risk among women, particularly among those diagnosed at a younger age. Abdominal obesity may contribute to systemic inflammation more than general obesity; thus, we investigated whether abdominal obesity, compared to general obesity, predicted RA risk in 2 prospective cohorts: the Nurses' Health Study (NHS) and NHS II.

METHODS

We followed 50,682 women (1986-2014) in NHS and 47,597 women (1993-2015) in NHS II, without RA at baseline. Waist circumference (WC), BMI, health outcomes, and covariate data were collected through biennial questionnaires. Incident RA cases and serologic status were identified by chart review. We examined the associations of WC and BMI with RA risk using time-varying Cox proportional hazards models. We repeated analyses restricted to age ≤ 55 years.

RESULTS

During 28 years of follow-up, we identified 844 incident RA cases (527 NHS, 317 NHS II). Women with WC > 88 cm (35 in) had increased RA risk (HR 1.22, 95% CI 1.06-1.41). A similar association was observed for seropositive RA, which was stronger among young and middle-aged women. Further adjustment for BMI attenuated the association to null. In contrast, BMI was associated with RA (HR_{BMI ≥ 30 vs < 25} 1.33, 95% CI 1.05-1.68) and seropositive RA, even after adjusting for WC, and, as in WC analyses, this association was stronger among young and middle-aged women.

CONCLUSION

Abdominal obesity was associated with increased RA risk, particularly for seropositive RA, among young and middle-aged women; however, it did not independently contribute to RA risk beyond general obesity.