OP0154 COMORBIDITY CLUSTERS IN ANKYLOSING SPONDYLITIS AND THEIR ASSOCIATION WITH DISEASE ACTIVITY AND FUNCTIONAL IMPAIRMENT: DATA FROM THE PSOAS COHORT

Background

Comorbidities in ankylosing spondylitis (AS) occur more frequently than in the general population and are associated with higher morbidity and mortality. Some comorbidities may occur together, making one more likely in the presence of another, and different combinations of comorbidities may have differential considerations for AS management and outcomes.

Objectives

To examine the association of baseline comorbidities with disease activity and functional status in AS.

Methods

We used baseline data from the Prospective Study Of Ankylosing Spondylitis (PSOAS) cohort, a multicenter, prospective cohort from five centers (4 in the US, 1 in Australia). AS patients ≥ 18 years fulfilling mNY criteria for AS (2002-20) were included. Patient-reported AS comorbidities (N=28) and extra-musculoskeletal manifestations (EMMs, N=2) within 3 years of enrollment (prespecified on the baseline case-report form) and only those occurring in ≥1% were included. Undocumented comorbidities were assumed to be absent if missing in <15% of patients, and those missing in >50% of patients were excluded. Comorbidity clusters were identified using K-median clustering. The optimal number of clusters was determined using scree plot of the sum of squared errors and “elbow” on the graph line. Baseline characteristics of the clusters were compared, and associations of with disease activity and functional status measures (primary outcomes: ASDAS-CRP and BASFI) were examined using linear regression adjusted for age and sex.

Results

There were 1,270 AS patients included with a mean age of 44.6 ±14.3 years, 74.4% males, and 81.2% whites. Mean AS symptom duration was 20.6±5.6 years, 81.6% HLA-B27 positive, and CRP elevated in 27.5% of patients at baseline. Depression was the most prevalent comorbidity (31.4%) followed by hypertension (26.1%); uveitis was the most common EMM (30.4%). The five clusters identified included depression (27%), no comorbidities (22%), hypertension (21%), uveitis (20%), and asthma/low bone mass (10%) (Figure 1). The cluster with no comorbidities was significantly younger, with lower symptom duration (p<0.001). Females had higher odds of being in the depression (OR=2.00, 95% CI 1.38- 2.90) and uveitis (OR=2.09, 95% CI 1.41-3.11) clusters compared to the cluster with no comorbidities. The number of comorbidities and clusters with depression and hypertension were significantly associated with worse disease activity and functional status (Table 1).

Table 1.

Age and sex adjusted associations between comorbidity clusters, compared to cluster 3, and baseline disease activity/ functional status measures in ankylosing spondylitis based on Linear regression models.

Cluster 1 (depression)Cluster 3 (hypertension)Cluster 4 (uveitis)Cluster 5 (asthma, low bone mass)OutcomesCoef (95% CI)Coef (95% CI)Coef (95% CI)Coef (95% CI)ASDAS-CRP0.98 (0.78-1.18)0.43 (0.18-0.68)0.04 (-0.19-0.27)0.16 (-0.12-0.44)BASFI (0-10)1.92 (1.51-2.34)1.00 (0.53-1.48)-0.03 (-0.49-0.42)0.64 (0.076-1.20)Enthesitis count1.17 (0.73-1.61)0.73 (0.19-1.26)0.18 (-0.32-0.68)0.48 (-0.13-1.08)Swollen joint count (0-44)0.27 (-0.08-0.62)0.43 (-0.01-0.86)0.31 (-0.09-0.71)-0.95 (-0.58-0.39)Tender joint count (0-46)1.24 (0.59-1.88)0.44 (-0.34-1.23)0.56 (-0.18-1.29)0.34 (-0.55-1.23)BASDAI (0-10)2.30 (1.88-2.71)0.88 (0.36-1.40)0.30 (-0.17-0.78)0.61 (0.03-1.19)Patient Global (0-10)2.25 (1.82-2.68)0.76 (0.21-1.30)-0.22 (-0.71-0.27)0.29 (-0.31-0.89)Patient Pain (0-10)2.45 (1.95-2.94)1.00 (0.37-1.62)0.19 (-0.38-0.75)0.16 (-0.54-0.85)Spinal pain (0-10)2.40 (1.89-2.91)1.05 (0.41-1.70)0.43 (-0.16-1.01)0.76 (0.04-1.47)Figure 1.

Comorbidity clusters in PSOAS cohort at baseline

Conclusion

Distinct comorbidity clusters were identified in AS patients in the PSOAS cohort. In addition to the number of comorbidities, the type of comorbidity seems to be important. Depression and hypertension clusters seem to be associated with worse disease activity and function.

Disclosure of Interests

Paras Karmacharya: None declared, Cynthia S. Crowson: None declared, Dilli Poudel: None declared, John M Davis III Consultant of: Dr. Davis has received consulting fees and/or honoraria from AbbVie and Sanofi-Genzyme (less than $10,000 each), Grant/research support from: Dr. Davis has received research support from Pfizer., Alexis Ogdie Consultant of: Dr. Ogdie has served as a consultant for AbbVie, Amgen, BMS, Celgene, Corrona, Gilead, Janssen, Lilly, Novartis, Pfizer, and UCB (less than 10,000 each), Grant/research support from: Dr. Ogdie has received grants from Novartis and Pfizer to Penn and from Amgen to Forward (grants more than 10,000)., Jean Liew Grant/research support from: Dr. Liew received grant/research support from Pfizer (> $10,000), Michael Ward: None declared, Mariko Ishimori: None declared, Michael Weisman Consultant of: Dr. Weisman received consulting fees for Novartis, UCB, Gilead, and GSK (< $10,000)., Matthew Brown: None declared, Mohammad Rahbar: None declared, Mark Hwang: None declared, John D Reveille Consultant of: JDR received consulting fees for UCB (< $10,000), Grant/research support from: Dr. Reveille received research support from Lilly and Janssen unrelated to this work., Lianne S. Gensler Consultant of: Dr. Gensler has received consulting fees for AbbVie, Eli Lilly, GSK, Gilead, Pfizer (< $10,000)., Grant/research support from: Dr. Gensler received grant/research support from UCB and Novartis (> $10,000).

The Postural Effects on Electrical Activities of Heart in Apparently Healthy Young Adults

Background The electrical activities of heart recorded as electrocardiogram (ECG) are mostly done in supine postures. The body postural changes have effects in these electrical activities in heart which needs to be properly recognized. Objective To find the variations in electrocardiogram during postural changes from supine to upright i.e. sitting and standing postures among apparently healthy young adults. Method A cross sectional study was carried out in Manipal College of Medical Sciences after the institutional ethical clearance. The apparently healthy 30 Nepalese male medical students between 18-25 years of age were enrolled. The electrocardiography was elicited in supine, sitting and standing postures in the participants after 5 minutes' interval between each procedure in each participant. Result The highest mean amplitudes of Q wave were seen in sitting postures (0.12±0.04 mm), R wave in standing postures (1.46±0.55 mm) and S wave also in standing postures (0.23±0.2 mm). The mean amplitudes of Q and S waves showed statistically significant difference when compared between supine and upright postures. The maximum QRS duration was found while sitting (0.08±0.01 ms)and maximum heart rate in standing posture (82.43±10.59/min). The mean comparison of heart rate was statistically highly significant when compared between supine and standing postures. The mean QRS frontal axis was comparatively increased while standing (64.30±39.29). Conclusion The electrical activities of heart vary during postural changes among apparently healthy young adults. These changes are most prominent when compared between supine and standing postures which urges for careful interpretation of electrocardiogram if it is done in upright postures.

SAT0404 INCIDENCE OF PSORIATIC ARTHRITIS FROM 2000-2017: A POPULATION-BASED STUDY

Background:

Psoriatic arthritis (PsA) is a chronic inflammatory musculoskeletal disease with an estimated prevalence of 0.05% to 0.25% in the population and 6% to 41% in psoriasis patients. There is disparity in the reported incidence patterns in the general population in more recent years, with increasing incidence seen in Denmark, but relatively stable rates seen in Canada. However, no studies in the US have looked at the recent incidence patterns, and it would be important to see how newer therapies for psoriasis have impacted the incidence of PsA. Variability in the estimates of incidence and prevalence across different studies has been attributed to differences in case ascertainment and most studies have used ICD codes to identify PsA patients.

Objectives:

To determine the annual incidence of PsA (2000-17) and compare it to incidence of PsA in previous years (1970-1999)1in the Olmsted County, Minnesota, USA population.

Methods:

A retrospective, population-based cohort of PsA patients ≥18 years of age from Olmsted County, MN meeting ClASsification of Psoriatic ARthritis (CASPAR) criteria for PsA (2000-17) was identified from the Rochester Epidemiology Project (REP). REP ensures virtually complete ascertainment and follow-up of all clinically diagnosed cases of PsA in a geographically-defined area. The date of fulfillment of CASPAR criteria was taken as the PsA incidence date. Age- and sex-specific incidence rates, adjusted to 2010 US white population, were reported. Our previously reported cohort from REP (1970-1999)1also used the same CASPAR criteria, and trends from the current study were compared to the previous years.

Results:

There were 170 incident cases of PsA, with a mean age of 46.7 (SD=12.3) years and 47% females from 2000-17. The overall age and sex adjusted annual incidence of PsA per 100,000 population was 8.8 (95% CI 7.5-10.1), and higher in males (9.7, 95% CI 7.7-11.7) than females (8.0, 95% CI 6.2-9.8). Overall incidence was highest in the age range 40-59 years (Table 1). The incidence rate was relatively stable in the recent years 2000-2017 compared to 1970-19991where a rise in incidence was observed (3.6 to 9.8 per 100,000 persons from 1970-79 to 1990-99, p<0.001) (Figure 1).

Table 1.

Annual incidence rate, IR (per 100,000) of psoriatic arthritis by age and sex between 2000-17 in Olmsted County, MN.

MaleFemaleTotalAge Group, yrsNIRNIRNRate18-2994.141.6132.830-392413.4147.33810.240-492413.92614.05014.050-592113.52816.24914.960-6976.987.1157.070-7935.000.032.280+26.000.022.2Total (95% CI)909.7 (7.7-11.7)†808.0 (6.2-9.8)†1708.8 (7.5-10.1)††

† Age-adjusted to the 2010 US White population. †† Age- and sex-adjusted to the 2010 US White population

Conclusion:

In the Olmsted County population, the increasing PsA incidence seen in previous years 1970-19991seems to have leveled off after 2000. This is in contrast to increasing incidence in recent years reported from Denmark, Taiwan and Israel. However, similar to our study, incidence rates for PsA from 2008-2015 were reported to be stable in Canada.

References:

[1]Wilson FC, Icen M, Crowson CS, McEvoy MT, Gabriel SE, Kremers HM. Time trends in epidemiology and characteristics of psoriatic arthritis over 3 decades: a population-based study.J Rheumatol. 2009;36(2):361-367.

Acknowledgments:

This project was supported by CTSA Grant Number UL1 TR002377 from the National Center for Advancing Translational Science (NCATS).

Disclosure of Interests:

Paras Karmacharya: None declared, Cynthia S. Crowson Grant/research support from: Pfizer research grant, Delamo Bekele: None declared, Sara Achenbach: None declared, John M Davis III Grant/research support from: Research grants from Pfizer, Consultant of: Served on advisory boards for Abbvie and Sanofi-Genzyme, Alexis Ogdie Grant/research support from: Pfizer, Novartis, Consultant of: Abbvie, Amgen, BMS, Celgene, Corrona, Janssen, Lilly, Pfizer, Novartis, Ali Duarte-Garcia: None declared, Hilal Maradit-Kremers: None declared, Megha Tollefson: None declared, Floranne C. Ernste: None declared, Kerry Wright: None declared