POS0686 EFFECTIVENESS OF UPADACITINIB IN THE TREATMENT OF RHEUMATOID ARTHRITIS: ANALYSIS OF 6-MONTH REAL-WORLD DATA FROM THE UNITED RHEUMATOLOGY NORMALIZED INTEGRATED COMMUNITY EVIDENCE (UR-NICETM) DATABASE

Background

The efficacy of upadacitinib (UPA), an oral Janus kinase inhibitor (JAKi), in the treatment of rheumatoid arthritis (RA) has been demonstrated in the phase 3 SELECT clinical trial program.1–6 However, few real-world data have been reported to date.

Objectives

To assess the 6-month effectiveness of UPA in patients (pts) with RA initiating UPA treatment in clinical practice.

Methods

This observational study included US-based pts from the United Rheumatology Normalized Integrated Community Evidence (UR-NICE) database who initiated UPA 15 mg once daily from Aug 2019 to the data cut-off in Nov 2021. Pts with ≥6 months of baseline (BL) data before UPA initiation, and with Clinical Disease Activity Index (CDAI) score recorded at BL and 6 months (±45 days) after initiation, were included in the analysis. Effectiveness measures included CDAI score, Routine Assessment of Patient Index Data 3 (RAPID3), and Disease Activity Score in 28 joints based on C-reactive protein (DAS28-CRP); patient-reported outcomes (PROs) including Health Assessment Questionnaire-Disability Index (HAQ-DI), Pain, and Patient’s Global Assessment of Disease Activity (PtGA); and Physician’s Global Assessment of Disease Activity (PhGA). Subgroup analyses were conducted by prior tumor necrosis factor inhibitor (TNFi) and tofacitinib (TOFA) treatment history.

Results

363 pts were included in the analysis and most were female (80.2%) (Table 1). 140 (39%) received UPA monotherapy and 223 (61%) received UPA plus conventional synthetic (cs) disease-modifying antirheumatic drugs (DMARDs). 83% of pts received prior csDMARDs, 72% prior biologics (TNFi 55%), and 41% JAKis (TOFA 39%). Overall, 46% (166/363), 23% (57/245), and 55% (95/173) of pts achieved LDA by CDAI, RAPID3, and DAS28-CRP, respectively, and 14% (51/363), 16% (39/245), and 36% (62/173) of pts achieved remission (REM) by CDAI, RAPID3, and DAS28-CRP, respectively. Results were similar regardless of prior TNFi or TOFA exposure (Figure 1). Improvements from BL were seen in PhGA and all PROs in the total population and all subgroups.

Table 1.

Demographic and baseline characteristics

Parameter, n (%)Full analysis setPrior TNFiPrior TOFA(N=363)(n=199)(n=143)Female291 (80.2)156 (78.4)119 (83.2)Age, years<4022 (6.1)11 (5.5)8 (5.6)40–<65240 (66.1)132 (66.3)94 (65.7)≥65101 (27.8)56 (28.1)41 (28.7)Oral steroid use185 (51.0)103 (51.8)83 (58.0)Parameter, mean (SD)NMean (SD)nMean (SD)nMean (SD)Duration of RA, years2764.5 (3.1)1625.1 (3.0)1135.1 (2.9)Body mass index, kg/m232130.0 (6.9)17529.9 (6.6)12529.2 (6.7)Oral steroid dose (prednisone equivalent), mg/day1547.9 (6.9)877.8 (6.5)707.6 (6.1)Methotrexate dose, mg/week11918.3 (4.9)7417.8 (5.2)3718.2 (4.7)C-reactive protein, mg/L2289.6 (16.2)1329.4 (15.0)9011.3 (17.9)CDAI36321.2 (12.8)19922.1 (13.0)14321.7 (13.3)RAPID32684.7 (2.1)1414.7 (2.2)1004.9 (2.1)DAS28-CRP2283.9 (1.3)1324.0 (1.4)904.2 (1.3)HAQ-DIa2732.6 (2.1)1482.8 (2.2)1063.0 (2.2)Painb33859.6 (26.6)18658.4 (27.2)13161.3 (25.1)PtGAb36354.1 (25.6)19954.7 (26.9)14355.9 (25.2)PhGAb36341.3 (26.0)19941.2 (24.8)14340.7 (26.8)

a0–10 visual analog scale. b0–100 visual analog scale. SD, standard deviation.

Conclusion

In this study, almost half (46%) of pts treated with UPA achieved CDAI LDA at 6 months and 14% achieved CDAI REM. Improvements in all PROs and PhGA were observed. Effectiveness of UPA was not impacted by prior TNFi or TOFA exposure, supporting UPA as an effective treatment option in clinical practice, including in pts with prior exposure to advanced therapy.

References

[1]Burmester GR, et al. Lancet 2018;391:2503–12.

[2]Smolen JS, et al. Lancet 2019;393:2303–11.

[3]Fleischmann R, et al. Arthritis Rheumatol 2019;71:1788–800.

[4]Genovese MC, et al. Lancet 2018;391:2513–24.

[5]van Vollenhoven R, et al. Arthritis Rheumatol 2020;72:1607–20.

[6]Rubbert-Roth A, et al. N Engl J Med 2020;383:1511–21.

Acknowledgements

AbbVie funded this study; contributed to its design; participated in data collection, analysis, and interpretation of the data; and participated in the writing, review, and approval of the abstract. AbbVie and the authors thank all study investigators for their contributions and the patients who participated in this study. No honoraria or payments were made for authorship. Medical writing support was provided by Laura Chalmers, PhD, of 2 the Nth (Cheshire, UK), and was funded by AbbVie.

Disclosure of Interests

Allan Gibofsky Shareholder of: AbbVie, Amgen, Johnson & Johnson, and Pfizer (stocks), Consultant of: AbbVie, Celgene, Eli Lilly, Flexion, Pfizer, Relburn Pharma, and Samumed (consulting fees); and Gerson Lehrman Group (paid consultant with investment analysts), Mark E. Pearson Shareholder of: AbbVie (may own stock or options), Andrew Concoff Speakers bureau: Flexion Therapeutics and Exagen, Consultant of: Flexion Therapeutics and Exagen, Anna Shmagel Shareholder of: AbbVie (may own stock or options), Employee of: AbbVie, Patrick Zueger Shareholder of: AbbVie (may own stock or options), Employee of: AbbVie, Yanna Song Shareholder of: AbbVie (may own stock or options), Employee of: AbbVie, Lauren Smith Shareholder of: AbbVie (may own stock or options), Employee of: AbbVie, Grace C. Wright Speakers bureau: AbbVie, Amgen, Bristol-Myers Squibb, Eli Lilly, Exagen, Myriad Autoimmune, Novartis, Sanofi/Regeneron, UCB, and Vindico, Consultant of: AbbVie, Amgen, Bristol-Myers Squibb, Eli Lilly, Exagen, Gilead, Janssen, Myriad Autoimmune, Novartis, Pfizer, Sanofi/Regeneron, and UCB, Employee of: Association of Women in Rheumatology (President and Founder)

POS0693 IMPACT OF UPADACITINIB VERSUS ABATACEPT ON INDIVIDUAL DISEASE OUTCOMES IN PATIENTS WITH RHEUMATOID ARTHRITIS AND INADEQUATE RESPONSES TO BIOLOGIC DMARDS

Background

The phase 3 SELECT-CHOICE trial of patients with rheumatoid arthritis (RA) and prior inadequate response to biologic DMARD(s) (bDMARD-IR) demonstrated superiority of the JAK inhibitor upadacitinib (UPA) vs abatacept (ABA) in the mean change from baseline (BL) in DAS28(CRP) and in the proportion achieving DAS28(CRP) <2.6 at week (wk) 12, with higher incidence of serious adverse events reported in the UPA treatment group.

Objectives

To evaluate the impact of UPA vs ABA on individual components of composite measures of disease activity in SELECT-CHOICE.

Methods

In SELECT-CHOICE, a double-blind phase 3 trial, bDMARD-IR patients were randomly assigned to UPA 15 mg once daily or ABA, each with background conventional synthetic DMARDs, for 24 wks. For this post hoc analysis, the proportions of patients achieving improvement from BL through wk 24 in ACR core variables (including SJC, TJC, Patient Global Assessment [PtGA], Physician Global Assessment [PhGA], pain, HAQ-DI, and hsCRP) and Boolean remission criteria were evaluated. Differences in the cumulative distributions of CDAI, DAS28(hsCRP), SDAI, and ACR-n (the lowest of percent change in TJC, percent change in SJC, or median of the other 5 ACR components) were determined using the Kolmogorov-Smirnov test and are reported as observed. For all other variables, non-responder imputation was applied for missing data. Nominal P values are provided throughout.

Results

A total of 616 bDMARD-IR patients with moderate to severe RA were randomized in SELECT-CHOICE (UPA 15 mg, n=303; ABA, n=309). BL demographic and disease characteristics were generally comparable between treatment groups, with a mean disease duration of approximately 12 years and mean CDAI of 39.6. At wk 12, more patients receiving UPA vs ABA achieved ≥50% improvements from BL in TJC68, PtGA, and hsCRP, with comparable proportions observed between UPA and ABA for the remaining ACR components (Figure 1). At wk 24, similar proportions of patients receiving UPA and ABA achieved ≥50% improvements in all but the hsCRP component. Overall, 15% and 26% of patients on UPA compared with 6% and 15% on ABA demonstrated ≥50% improvements across all ACR components at wks 12 and 24, respectively. At wks 12 and 24, Boolean remission was achieved by 6% and 14% of patients on UPA vs 2% and 10% of patients on ABA, respectively; the proportion of patients in both treatment groups achieving the individual Boolean components were also reported (Table 1). While comparable at BL, cumulative distributions of CDAI, SDAI, DAS28(hsCRP), and ACR-n were improved on UPA vs ABA at wk 12 (all nominal P <0.05); differences persisted for most measures at wk 24.

Table 1.

Proportions of Patients Achieving Boolean Remission and Its Components at Week 12 and 24 (NRI)

Week 12Week 24n (%)UPA 15 mgABAUPA 15 mgABA(N=303)(N=309)(N=303)(N=309)Boolean Remission19 (6)***5 (2)42 (14)*30 (10) PtGA ≤1054 (18)***29 (9)80 (26)*66 (21) TJC ≤189 (29)***64 (21)134 (44)*115 (37) SJC ≤1127 (42)**106 (34)169 (56)*152 (49) hsCRP ≤1 mg/dL257 (85)***209 (68)244 (81)***199 (64)

Nominal ***P <.001, **P <.01, *P <.05 for UPA vs ABA. ABA, abatacept; PtGA, Patient’s Global Assessment of disease severity; UPA, upadacitinib.

Conclusion

In this post hoc analysis of bDMARD-IR RA patients, improvements in components of disease measures were reported for both UPA and ABA through 24 weeks, with numeric differences noted for several components. Nominally higher attainment of Boolean remission and its components were observed for UPA over ABA.

References

[1]Rubbert-Roth A, et al. N Engl J Med 2020; 383:1511-21.

Acknowledgements

AbbVie and the authors thank the patients, study sites, and investigators who participated in these clinical trials. AbbVie funded these studies and participated in the study design, research, analysis, data collection, interpretation of data, reviewing, and approval of the publication. All authors had access to relevant data and participated in the drafting, review, and approval of this publication. No honoraria or payments were made for authorship. Medical writing support was provided by Matthew Eckwahl, PhD, of AbbVie.

Disclosure of Interests

Ronald van Vollenhoven Speakers bureau: AbbVie, Galapagos, GSK, Janssen, Pfizer, R-Pharma, UCB, Consultant of: AbbVie, AstraZeneca, Biogen, BMS, Galapagos, Janssen, Miltenyi, Pfizer, UCB, Grant/research support from: Research: BMS, GSK, UCB; Educational programs: MSD, Pfizer, Roche, Andrea Rubbert-Roth Speakers bureau: AbbVie, Pfizer, Sanofi, UCB, BMS, Lilly, Gilead, Roche, Consultant of: AbbVie, Gilead, Lilly, BMS, Sanofi, R-Pharm, Stephen Hall Consultant of: AbbVie, BMS, Lilly, Janssen, Pfizer, UCB, Novartis, Grant/research support from: AbbVie, BMS, Lilly, Janssen, Pfizer, UCB, Novartis, Ricardo Xavier Consultant of: AbbVie, Amgen, BMS, Lilly, Janssen, Novartis, Pfizer, UCB, Anna Shmagel Shareholder of: AbbVie, Employee of: AbbVie, Yanna Song Shareholder of: AbbVie, Employee of: AbbVie, Samuel Anyanwu Shareholder of: AbbVie, Employee of: AbbVie, Vibeke Strand Consultant of: AbbVie, Amgen, Arena, AstraZeneca, Bayer, BMS, Boehringer Ingelheim, Chemocentryx, BMS, Celltrion, Lilly, Genentech/Roche, Gilead, GlaxoSmithKline, Ichnos, Inmedix, Janssen, Kiniksa, Lilly, Merck, Myriad Genetics, Novartis, Pfizer, Regeneron Pharmaceuticals, Rheos, R-Pharma, Samsung, Sandoz, Sanofi, Scipher, Setpoint, Sorrento, Spherix, UCB

POS0540 CLINICAL OUTCOMES ASSOCIATED WITH GLUCOCORTICOID DISCONTINUATION AMONG PATIENTS WITH RHEUMATOID ARTHRITIS RECEIVING UPADACITINIB OR ADALIMUMAB

Background

Patients (pts) with rheumatoid arthritis (RA) are often administered glucocorticoids (GCs) as bridging therapy when initiating or adjusting disease-modifying antirheumatic drugs (DMARDs). Due to their systemic effects, short-term use of GCs at the lowest possible dose is recommended with rapid tapering.1

Objectives

We describe GC discontinuation patterns and the associated clinical outcomes in pts with RA receiving upadacitinib (UPA) or adalimumab (ADA).

Methods

SELECT-COMPARE is a randomized phase 3 trial of UPA vs placebo and ADA with a 48-week (wk) double-blind treatment period and a 10-year long-term extension in pts with RA receiving concomitant methotrexate (MTX) who had an inadequate response to MTX.2 Background GCs (≤10 mg/day prednisone or equivalent) were permitted and could be tapered or discontinued starting at wk 26 per physician discretion. This post hoc analysis included pts who received ≥1 dose of UPA 15 mg once daily or ADA 40 mg every other wk while on concomitant GCs at baseline. The proportion of pts with disease worsening (Clinical Disease Activity Index [CDAI] >2 and Disease Activity Score 28-joint count C-reactive protein [DAS28-CRP] >0.6) following GC discontinuation through follow-up is described. Maintenance of clinical response, including remission and low disease activity based on CDAI ≤2.8 and ≤10, respectively, as well as DAS28-CRP <2.6 and ≤3.2, were assessed among pts who discontinued GCs. Adverse events (AEs) were assessed before and after GC discontinuation through follow-up. Data were analyzed descriptively.

Results

Of 1,629 pts randomized, 978 (60%) used GCs at baseline; 128 (13%) discontinued use at/after wk 26 (UPA, n=97; ADA, n=31). Baseline demographics and clinical characteristics were broadly similar between pts who continued or discontinued GCs. Median follow-up time after GC discontinuation was 60 wks for UPA and 84 wks for ADA. At the time of GC discontinuation, a numerically higher proportion of pts treated with UPA vs ADA were in disease control (CDAI ≤2.8: 55% vs 32%; CDAI ≤10: 85% vs 68%; DAS28-CRP <2.6: 71% vs 48%; DAS28-CRP ≤3.2: 87% vs 62%) (Table 1). Few pts receiving UPA experienced disease worsening following GC discontinuation (1% CDAI increase >2; 7% DAS28-CRP increase >0.6) and none on ADA (Table 1). At 6 months follow-up after GC discontinuation, most pts treated with UPA and ADA maintained CDAI ≤2.8 (74% vs 88%) and ≤10 (92% vs 95%) and DAS28-CRP <2.6 (89% vs 85%) and ≤3.2 (91% vs 94%), respectively (Table 1). GCs were reintroduced (albeit usually temporarily) in 14% of pts on UPA and 19% on ADA (Figure 1). AEs were generally similar across treatment groups. Rates of serious infection before and after GC discontinuation were 0.8 (95% CI 0.0–4.2) and 1.5 (0.2–5.4) events per 100 patient-years (E/100 PY) for UPA and 7.7 (1.6–22.4) and 0 E/100 PY for ADA, respectively. Interpretation of results is limited by small pt numbers and different exposure times.

Table 1.

Clinical outcomes of pts who discontinued GCs at/after wk 26

n/N (%)Pts who discontinued GCs N=128UPAn=97ADAn=31CDAI≤10 at discontinuation79/93 (85%)21/31 (68%) Maintained at 6 months post discontinuationa61/66 (92%)18/19 (95%)≤2.8 at withdrawal51/93 (55%)10/31 (32%) Maintained at 6 months post discontinuationa32/43 (74%)7/8 (88%)Increase >2 any visit after withdrawal1/93 (1%)0DAS28-CRP≤3.2 at withdrawal78/90 (87%)18/29 (62%) Maintained at 6 months post discontinuationa58/64 (91%)15/16 (94%)<2.6 at withdrawal64/90 (71%)14/29 (48%) Maintained at 6 months post discontinuationa47/53 (89%)11/13 (85%)Increase >0.6 any visit after withdrawal6/92 (7%)0

aAs a proportion of pts achieving outcome at GC discontinuation and with observed data 6 months post GC discontinuation.

Conclusion

In pts who achieved disease control and discontinued GCs, disease control was maintained in almost all without worsening disease activity over time following GC discontinuation.

Conclusion

In pts who achieved disease control and discontinued GCs, disease control was maintained in almost all without worsening disease activity over time following GC discontinuation.

References

[1]Smolen JS, et al. Ann Rheum Dis. 2020;79:685–99.

[2]Fleischmann R, et al. Ann Rheum Dis. 2019;78:1454–62.

Acknowledgements

AbbVie funded this study and participated in the study design, research, analysis, data collection, interpretation of data, review, and approval of the publication. All authors had access to relevant data and participated in the drafting, review, and approval of this publication. No honoraria or payments were made for authorship. Medical writing assistance was provided by Julia Zolotarjova, MSc, MWC of AbbVie Inc.

Disclosure of Interests

Roy M. Fleischmann Consultant of: AbbVie, Amgen, BMS, Galvani, Gilead, GSK, Janssen, Eli Lilly, Novartis, Pfizer, and UCB, Grant/research support from: AbbVie, Amgen, Astra-Zeneca, BMS, Flexion, Galvani, Gilead, GSK, Janssen, Eli Lilly, Novartis, Noven, Pfizer, Samumed, Selecta, Teva, UCB, Viela, and Vorso., Bernard Combe Speakers bureau: AbbVie, BMS, Celltrion, Eli Lilly, Gilead-Galapagos, Janssen, Merck Sharp & Dohme, Novartis, Pfizer, and Roche-Chugai, Consultant of: AbbVie, BMS, Celltrion, Eli Lilly, Gilead-Galapagos, Janssen, Merck Sharp & Dohme, Novartis, Pfizer, and Roche-Chugai, Grant/research support from: Pfizer and Roche-Chugai, Andrew Ostor Consultant of: AbbVie, BMS, Eli Lilly, Gilead, Janssen, Novartis, Paradigm, Pfizer, Roche, and UCB., Cesar Francisco Pacheco Tena Consultant of: AbbVie, Astra-Zeneca, Eli Lilly, Gilead, Janssen, Pfizer, Roche, R-Pharm, Sanofi Regeneron, and UCB., Grant/research support from: AbbVie, Astra-Zeneca, Eli Lilly, Gilead, Janssen, Pfizer, Roche, R-Pharm, Sanofi Regeneron, and UCB., Nasser Khan Shareholder of: May own AbbVie stock or stock options, Employee of: AbbVie, Jessica Suboticki Shareholder of: May own AbbVie stock or stock options, Employee of: AbbVie, Anna Shmagel Shareholder of: May own AbbVie stock or stock options, Employee of: AbbVie, Yanna Song Shareholder of: May own AbbVie stock or stock options, Employee of: AbbVie, Ivan Lagunes-Galindo Shareholder of: May own AbbVie stock or stock options, Employee of: AbbVie, Gerd Rüdiger Burmester Speakers bureau: AbbVie, Eli Lilly, Galapagos, Gilead, Janssen, MSD, Pfizer, Roche, Sanofi, and UCB., Consultant of: AbbVie, Eli Lilly, Galapagos, Gilead, Janssen, MSD, Pfizer, Roche, Sanofi, and UCB.

Vitamin D and bisphosphonate therapy in systemic lupus erythematosus patients who receive glucocorticoids: are we offering the best care?

OBJECTIVE

This study aimed to evaluate management practices for glucocorticoid (GC)-induced osteoporosis (GIOP) in systemic lupus erythematosus (SLE) patients using 2017 American College of Rheumatology guidelines as a gold standard.

METHODS

We conducted a retrospective cohort study using a clinical database from the years 2011 to 2016. SLE cases with >90 days continuous prednisone use at doses of ≥7.51 mg daily were identified. Osteoporosis risk factors were assessed via chart review. The Fracture Risk Assessment (FRAX) score was estimated for patients > 40 years of age. Vitamin D, bisphosphonate prescriptions, and osteoporotic (OP) fractures were ascertained through chart review. A classification tree was used to identify the key patient-related predictors of bisphosphonate prescription.

RESULTS

A total of 203 SLE patients met the inclusion criteria. The recommended dose of vitamin D supplement was prescribed to 58.9% of patients < 40 years of age and 61.5% of patients ≥ 40 years of age. Among patients aged ≥ 40 years, 25% were prescribed bisphosphonates compared to 36% who met indications for bisphosphonates per the ACR guidelines. Another 10% were prescribed a bisphosphonate, despite not having indication per the ACR guidelines, which was considered as overtreatment. Among patients aged ≥ 40 years, older age and a higher FRAX score for major OP fracture and hip fracture predicted bisphosphonate prescription. In a classification tree analysis, patients with FRAX scores (for major OP fracture) of ≥ 23.5% predicted bisphosphonate prescription in this SLE population. Among patients who had OP fractures in the follow-up period, nine (6.50%) were inpatients receiving appropriate GIOP care versus 12 (13.6%) who were inpatients not receiving ACR-appropriate care (p = 0.098).

CONCLUSIONS

In clinical practice, fewer SLE patients with or at risk for GIOP are prescribed vitamin D and bisphosphonates than recommended by the 2017 ACR guidelines. Also, in this study, another 10% were prescribed a bisphosphonate, despite not having an indication per the ACR guidelines. Patients were most likely to receive a bisphosphonate prescription if they had a major OP FRAX score of > 23.5%.

The Association between Objectively Measured Physical Activity and the Gut Microbiome among Older Community Dwelling Men

OBJECTIVES

To determine the relationship between objectively measured physical activity (PA) and the gut microbiome among community-dwelling older men.

DESIGN

Cross-sectional study.

SETTING

Osteoporotic Fractures in Men (MrOS) cohort participants at Visit 4 (2014-16).

PARTICIPANTS

Eligible men (n=373, mean age 84 y) included participants with 5-day activity assessment with at least 90% wear time and analyzed stool samples.

MEASUREMENTS

PA was measured with the SenseWear Pro3 Armband and stool samples analyzed for 16S v4 rRNA marker genes using Illumina MiSeq technology. Armband data together with sex, height, and weight were used to estimate total steps, total energy expenditure, and level of activity. 16S data was analyzed using standard UPARSE workflow. Shannon and Inverse Simpson indices were measures of (within-participant) α-diversity. Weighted and unweighted Unifrac were measures of (between-participant) β-diversity. We used linear regression analysis, principal coordinate analysis, zero-inflated Gaussian models to assess association between PA and α-diversity, β-diversity, and specific taxa, respectively, with adjustments for age, race, BMI, clinical center, library size, and number of chronic conditions.

RESULTS

PA was not associated with α-diversity. There was a slight association between PA and β-diversity (in particular the second principal coordinate). Compared to those who were less active, those who had higher step counts had higher relative abundance of Cetobacterium and lower relative abundance of taxa from the genera Coprobacillus, Adlercreutzia, Erysipelotrichaceae CC-115 after multivariable adjustment including age, BMI, and chronic conditions. There was no consistent pattern by phylum.

CONCLUSION

There was a modest association between levels of PA and specific gut microbes among community-dwelling older men. The observed associations are consistent with the hypothesis that underlying health status and composition of the host microbiome are related.

Low magnesium intake is associated with increased knee pain in subjects with radiographic knee osteoarthritis: data from the Osteoarthritis Initiative

OBJECTIVE

As magnesium mediates bone and muscle metabolism, inflammation, and pain signaling, we aimed to evaluate whether magnesium intake is associated with knee pain and function in radiographic knee osteoarthritis (OA).

METHODS

We investigated the associations between knee pain/function metrics and magnesium intake from food and supplements in 2548 Osteoarthritis Initiative cohort participants with prevalent radiographic knee OA (Kellgren-Lawrence score ≥2). Magnesium intake was assessed by Food Frequency Questionnaire (FFQ) at baseline. WOMAC and Knee Injury and Osteoarthritis Outcome Score (KOOS) scores were reported annually with total follow up of 48 months. Analyses used linear mixed models.

RESULTS

Among participants with baseline radiographic knee OA the mean total magnesium intake was 309.9 mg/day (SD 132.6) for men, and 287.9 mg/day (SD 118.1) for women, with 68% of men and 44% of women below the estimated average requirement. Subjects with lower magnesium intake had worse knee OA pain and function scores, throughout the 48 months (P < 0.001). After adjustment for age, sex, race, body mass index (BMI), calorie intake, fiber intake, pain medication use, physical activity, renal insufficiency, smoking, and alcohol use, lower magnesium intake remained associated with worse pain and function outcomes (1.4 points higher WOMAC and 1.5 points lower KOOS scores for every 50 mg of daily magnesium intake, P < 0.05). Fiber intake was an effect modifier (P for interaction <0.05). The association between magnesium intake and knee pain and function scores was strongest among subjects with low fiber intake.

CONCLUSION

Lower magnesium intake was associated with worse pain and function in knee OA, especially among individuals with low fiber intake.