Abstract Background Upper-airway and respiratory conditions impose a large and growing global burden, yet there is no standardized way to assess whether a nasal microbiome is “healthy”. Currently, monitoring remains reactive, beginning only after symptoms manifest. The nasal cavity is well suited to proactive monitoring: it shapes respiratory health and pathogen colonization resistance, and can be sampled non-invasively and repeatedly. To address this gap, we introduce the Nasal Microbiome Wellness Index (NMWI), a disease-agnostic, continuous score of nasal microbiome health derived from LASSO-penalized logistic regression. Rather than counting taxa, it learns which taxa (and in what balance) characterize a healthy nose and returns the predicted log-odds that a profile resembles a healthy state. The index was trained on 1654 nasal 16S rRNA gene amplicon sequencing samples (589 healthy, 1065 non-healthy) pooled from 27 publicly available studies, uniformly reprocessed through a single computational pipeline. Results The NMWI comprises an interpretable signature of 24 taxa whose combined relative abundances determine the health-associated log-odds. Health-associated genera such as Corynebacterium and Cutibacterium raised the score, while dysbiosis-associated genera such as Pseudomonas and Escherichia – Shigella lowered it. The NMWI substantially outperformed the Shannon, Simpson, and Chao1 diversity indices, which showed negligible, directionally inconsistent separation between healthy and non-healthy samples (|Cliff’s δ | = 0.01–0.20), whereas the NMWI produced large, consistent separation ( δ = 0.65). It achieved a balanced accuracy of 74.37% on the training data (resubstitution estimate), and 73.43% under repeated 10-times 10-fold cross-validation. Performance remained stable at mean balanced accuracy of 73.82% under a leave-one-study-out framework, reflecting cross-study generalizability. In independent external cohorts, the balanced accuracy was 71.49%, and leave-one-disease-out analysis (in which each disease condition was withheld from training) showed a mean balanced accuracy of 63.92% across unseen conditions, consistent with a disease-agnostic design. The index also generalized across heterogeneous datasets spanning multiple 16S rRNA gene hypervariable regions—to our knowledge the first demonstration of such cross-study, cross-region transferability for the nasal cavity. Conclusions The NMWI distills a complex nasal microbial profile into a single interpretable score computed directly from the 16S rRNA gene data that dominate existing nasal research, making it immediately applicable to published and future datasets without re-sequencing. By replacing descriptive, diversity-based comparison with a quantitative standard, it offers a reproducible, open-source foundation for cross-study benchmarking, individual-level phenotyping, and longitudinal respiratory wellness monitoring.
Association of Diet, Supplements, and Physical Activity With Risk of Incident Spondyloarthritis
Background/Objective: Dietary, supplement, and activity exposures have only been studied in spondyloarthritis (SpA) with retrospective studies. We aimed to determine the association of diet, supplements, and physical activity with incident SpA. Patients and Methods: We performed a case-control study in the Mayo Clinic Biobank from 2009 through 2015, matching criteria-confirmed incident SpA cases to controls 1:5 on age, sex, recruitment year, and location. Questionnaires assessed 16 dietary, 29 supplement, and leisure-time/work activity exposures. Logistic regression models calculated adjusted odds ratios (aOR) with 95% CIs of SpA for each exposure, adjusting for covariates. Sensitivity analyses were conducted within HLA-B27-positive patients, and those with baseline questionnaires completed 5+ years before index. Results: We identified 73 cases of incident SpA matched with 365 controls (mean age: 60, 70% females). No dietary or activity exposures were associated with SpA overall. However, among HLA-B27-positive individuals, non-diet soft drink consumption was associated with increased risk of SpA (aOR: 4.82, 95% CI: 1.29-18.1), whereas caffeinated coffee was associated with decreased risk (aOR: 0.20, 95% CI: 0.04-0.89). Zinc was associated with increased risk of SpA (aOR: 4.16, 95% CI: 1.19-14.6), as were B vitamins in the HLA-B27-positive subgroup (aOR: 4.21, 95% CI: 1.04-17.1). In the 5-year sensitivity analysis, low leisure-time physical activity plus high work physical activity was associated with increased risk of SpA (relative excess risk due to interaction: 0.50, 95% CI: 0.03-0.98). Conclusions: Due to small sample size and multiple comparisons, the risk factors we identified (non-diet soft drinks, B vitamins, and zinc) should be considered hypothesis-generating and warrant further investigation.
Impact of Dual Rheumatoid Factor and Anticitrullinated Protein Antibody Seropositive, Single Seropositive, and Seronegative Rheumatoid Arthritis on Outcomes
Objective The objective of this study was to investigate the association between dual seropositive, single seropositive, and seronegative rheumatoid arthritis (RA) with radiographic erosions, disease flares, and death. Methods We performed a retrospective, population‐based study of residents in Southern Minnesota with incident RA who fulfilled criteria for RA in 2003 to 2019. Radiographic erosions and flares were evaluated within one year of incident RA. All‐cause mortality was obtained from medical records and death certificates. Cox models adjusted for age, sex, smoking status, year of incident RA, and comorbidities were used. Results The study included 1,373 patients with RA. At RA incidence, 37% were dual seropositive, 13% seropositive for anti–cyclic citrullinated protein (anti‐CCP) only, 12% seropositive for rheumatoid factor (RF) only, and 38% seronegative. The highest proportion of radiographic erosions before or within one year of RA incidence was in the dual seropositive (31%) and lowest in those seropositive for anti‐CCP only (13%). Flares occurred in 69% of the dual seropositive and 51% of the seropositive for anti‐CCP only within the first year of RA incidence. Those seropositive for RF only had over a two‐fold increase in mortality rates compared with the seronegatives (adjusted hazard ratio [aHR] 2.18, 95% confidence interval [CI] 1.47–3.24). In contrast, the dual seropositives had only a >50% increase in mortality rates (aHR 1.66, 95% CI 1.21–2.28), and those seropositive only for anti‐CCP had a >30% increase in mortality rates (aHR 1.32, 95% CI 0.83–2.11). Conclusion Patients with RA seropositive for RF only have an increase in mortality rates compared with patients who are dual seronegative. RF positivity could be an indicator of inflammation that requires pharmacologic treatment to decrease mortality rates.
Long‐Term Outcomes in Seronegative Rheumatoid Arthritis
Objective The purpose of this study was to determine the cumulative incidence of diagnosis switching, drug‐free remission, and initiation of a biologic or targeted synthetic disease‐modifying antirheumatic drug (b/tsDMARD) in individuals with seronegative rheumatoid arthritis (RA). Methods Adult residents of Olmsted County, Minnesota, with incident seronegative (rheumatoid factor negative/anti–cyclic citrullinated peptide antibody negative) RA meeting the 1987 and/or 2010 American College of Rheumatology classification criteria were included. Data were collected from January 1, 2005, to December 31, 2023, through manual chart review. Drug‐free remission was defined as a period of at least six months where the individual was no longer taking treatment for RA and did not have evidence of active inflammatory arthritis upon evaluation by a rheumatologist. We calculated the 10‐year cumulative incidence of a change in diagnosis, adjusting for the competing risk of death, and of drug‐free remission and initiation of a b/tsDMARD, adjusting for the competing risks of death or change in diagnosis. Results A total of 176 individuals with seronegative RA (68% women) were included. The 10‐year cumulative incidence of a change in diagnosis was 12.8% (95% confidence interval [CI] 8.7%–18.9%). The most common change in diagnosis was to spondyloarthritis (4%). The 10‐year cumulative incidence of drug‐free remission and initiation of a b/tsDMARD was 26.6% (95% CI 20.7%–34.2%) and 19.9% (95% CI 14.7%–26.9%), respectively. Over a median follow‐up of 11.8 years, 49 individuals entered drug‐free remission. Conclusion After initial diagnosis of seronegative RA, about 13% of individuals had a change in diagnosis and a quarter experienced drug‐free remission within 10 years.
Multimorbidity burden predicts lower likelihood of remission and higher likelihood of disease flare in patients with rheumatoid arthritis
Objectives To examine associations between multimorbidity, the social determinants of health (SDoHs) and rheumatoid arthritis (RA) flare and remission. Methods All patients aged ≥18 years in Olmsted County, Minnesota, with incident RA in 1999–2014 were identified. Using a list of 55 chronic medical conditions, multimorbidity was defined as the presence of ≥2 conditions and substantial multimorbidity as ≥5 conditions. The Area Deprivation Index and Social Vulnerability Index (SVI) were used as proxies for adverse SDoH burden. Flare and remission were defined using Outcome Measures in Rheumatoid Arthritis Clinical Trials definitions. Mixed effects models were used to assess associations between flare/remission and multimorbidity, adverse SDoH burden and other patient characteristics. Results This study included 659 patients with incident RA. Multimorbidity and substantial multimorbidity predicted 29% (OR:1.29, 95% CI:1.04 to 1.59) and 26% (OR:1.26, 95% CI:1.03 to 1.53) higher odds of flare, respectively. Both were associated with 34% (OR:0.66, 95% CI:0.49 to 0.90) and 33% (OR:0.67, 95% CI:0.51 to 0.90) lower odds of remission, respectively. SVI predicted 8% lower odds of remission for every 0.1 increase above 0.3 (OR:0.92, 95% CI:0.85 to 0.99). Flare was also associated with female sex, smoking, younger age and shorter disease duration, but not seropositivity. Remission was also associated with male sex, never smoking, older age and longer disease duration, but not seropositivity. Conclusions Multimorbidity predicts higher odds of RA flare and lower odds of remission. Adverse SDoH burden predicts lower odds of remission. These findings have the potential to inform disease prognostication and clinician interventions.
Carpal Tunnel Syndrome as an Early Underrecognized Feature of Rheumatoid Arthritis: A Population‐Based Study of Carpal Tunnel Syndrome Occurrence Before and After Rheumatoid Arthritis Incidence
Objective We aimed to assess the occurrence of carpal tunnel syndrome (CTS) before and after rheumatoid arthritis (RA) incidence and by serologic status. Methods This population‐based study included residents of a geographically defined area meeting the 1987 American College of Rheumatology classification criteria for RA in 1980 to 2019 matched 1:1 with individuals without RA. At least two diagnosis codes ≥30 days apart were used to identify CTS. Cumulative incidence of CTS adjusting for competing risk of death was assessed. Logistic regression and Cox proportional hazard models were used, adjusting for age, sex, calendar year, smoking, obesity, diabetes mellitus, and hypothyroidism. Results We included 1,335 patients with RA and 1,331 individuals without RA. The overall prevalence of CTS before or on RA incidence or index was 179 patients with RA (13%) and 85 individuals without RA (6%), respectively (odds ratio [OR] 2.23; 95% confidence interval [CI] 1.69–2.94). Most previous incidences of CTS occurred ≥2 years before the index date (112 events in patients with RA and 75 events in individuals without RA, respectively). Following RA incidence or index, individuals with RA (vs those without RA) had ~80%‐higher risk of CTS (hazard ratio [HR] 1.78; 95% CI 1.38–2.30). The risk estimates of CTS in patients with seronegative (vs seropositive) RA were OR 1.33 (95% CI 0.96–1.84) before RA incidence and HR 1.37 (95% CI 0.99–1.88) after RA incidence. In RA, obesity (HR 1.42, 95% CI 1.02–1.99) and seronegative cyclic citrullinated peptide antibody status (HR 1.79, 95% CI 1.07–2.99), but not other risk factors, were associated with increased CTS risk. Conclusion We found a more than two‐fold increase in risk of CTS in the years preceding RA and a 1.8‐fold increased risk of incident CTS following RA onset. image
Objective The aim of this study was to determine whether pollutants such as fire smoke–related particulate matter <2.5 μm (PM 2.5 ) are associated with incident rheumatoid arthritis (RA) and RA‐associated interstitial lung disease (RA‐ILD). Methods This patient–control study used Veterans Affairs (VA) data from October 1, 2009, to December 31, 2018. We identified patients with incident RA and RA‐ILD using validated algorithms, matching each patient to ≤10 controls on age, sex, and VA enrollment year. We obtained pollutants including fire smoke PM 2.5 , carbon monoxide, nitrogen oxides (NOx), ozone, overall PM 2.5 , PM 10 , and sulfur dioxide (SO 2 ) at least one year before the index date. We fit conditional logistic regression models to estimate adjusted odds ratios (aORs) with 95% confidence intervals (CIs) for incident RA and RA‐ILD, adjusted for confounders. Results We identified 9,701 patients with incident RA (mean age 65 years, 86% male), including 531 patients with RA‐ILD (mean age 69 years, 91% male), and 68,852 matched controls. Fire smoke PM 2.5 was not associated with RA (aOR 1.07, 95% CI 0.92–1.23) but was associated with RA‐ILD (aOR 1.98, 95% CI 1.08–3.62, per 1 μg/m 3 ). Increased levels of NOx were associated with RA (aOR 1.16, 95% CI 1.06–1.27, highest vs lowest quartile). The highest quartiles of ozone (aOR 1.19, 95% CI 1.06–1.34) and PM 10 (aOR 1.25, 95% CI 1.10–1.43) were associated with seronegative RA. Carbon monoxide, overall PM 2.5 , and SO 2 were not, or negatively, associated with RA and RA‐ILD. Conclusion Increased fire smoke PM 2.5 was associated with RA‐ILD, whereas NOx, ozone, and PM 10 were associated with RA risk. Thus, air pollution may increase the risk of RA and RA‐ILD. image
Disparities in multimorbidity and comorbidities in rheumatoid arthritis by sex across the lifespan
Abstract Objectives Multimorbidity is burdensome for people with RA. We investigated differences in multimorbidity and comorbidities by sex and age in the RA population. Methods This cross-sectional analysis used national administrative claims (OptumLabs® Data Warehouse) from people with RA and non-RA comparators (matched on age, sex, race, census region, index year and length of baseline insurance coverage) from 2010–2019. RA was determined using a validated algorithm. Multimorbidity was defined as ≥2 (MM2+) or ≥5 (MM5+) comorbidities from a validated set of 44 chronic conditions. We used logistic regression to assess associations between characteristics and multimorbidity. Results The sample included 154 391 RA patients and 154 391 non-RA comparators. For people aged 18–50 years, RA women (vs RA men) had 7.5 and 4.4 (vs 3.2 and 0.9 in non-RA women vs non-RA men) percentage point increases for MM2+ and MM5+, respectively. For people aged 51+ years, RA women (vs RA men) had 2.1 and 2.5 (vs 1.2 and 0.3 in non-RA women vs non-RA men) percentage point increases for MM2+ and MM5+, respectively. Interactions revealed that differences in multimorbidity between women and men were exacerbated by RA (vs non-RA) (P < 0.05), with more pronounced effects in people aged 18–50. Men had more cardiovascular-related conditions, whereas RA women had more psychological, neurological and general musculoskeletal conditions. Other comorbidities varied by sex and age. Conclusion Multimorbidity disproportionately impacts women with RA. Research, clinical and policy agendas for rheumatic diseases should acknowledge and support the variation in care needs by sex and gender across the lifespan.
Racial Differences in Multimorbidity and Comorbidities in Rheumatoid Arthritis
ObjectiveTo identify differences in multimorbidity and individual comorbidities among individuals with rheumatoid arthritis (RA), separated by race and ethnicity.MethodsThis case–control study within OptumLabs Data Warehouse from 2010 to 2019 matched RA cases (defined by 2 codes plus prescription of an RA drug) to non‐RA controls 1:1 on age, sex, race and ethnicity, region, index date of RA, and insurance coverage duration. We defined multimorbidity as the presence of ≥2 or ≥5 validated comorbidities. Logistic regression models calculated adjusted odds of multimorbidity with 95% confidence intervals (95% CIs) within each race and ethnicity.ResultsWe identified 154,391 RA cases and 154,391 controls (mean age 59.6, 76% female). Black enrollees had the most multimorbidity ≥2/≥5 (73.1%, 34.3%); Asian enrollees had the least (52.4%, 17.3%). Adjusted odds of multimorbidity ≥2 and ≥5 in RA cases versus controls was 2.19 (95% CI 2.16–2.23) and 2.06 (95% CI 2.02–2.09), respectively. This increase was similar across race and ethnicity. However, we observed elevated occurrence of certain comorbidities by race and ethnicity versus controls (P < 0.001), including renal disease in White enrollees (4.7% versus 3.2%) and valvular heart disease in Black and White enrollees (3.2% and 2.8% versus 2.6% and 2.2%).ConclusionMultimorbidity is a problem for all RA patients. Targeted identification of certain comorbidities by race and ethnicity may be a helpful approach to mitigate multimorbidity.