3 AC&R Study Summaries: Lupus Fog, SSc Variance By Ethnicity & Tuberculosis Screening in New DMARD Users

Lupus Fog?

By Laura C. Plantinga, PhD, Patricia P. Katz, PhD, S. Sam Lim, MD, MPH, C. Barrett Bowling, MD, MSPH, & Jinoos Yazdany, MD, MPH

Why was this study done? Perceived cognitive impairment (i.e., lupus fog) is common in systemic lupus erythematosus (SLE). However, comprehensive, multidomain assessments of objective cognitive function are rarely performed. Particularly, little is known about SLE and fluid cognition (i.e., the capacity to reason and solve problems in novel situations), which is largely independent of acquired knowledge and acculturation.

What were the study methods? Participants from a population-based SLE cohort completed the NIH Toolbox Fluid Cognition Battery—with assessments of episodic memory (i.e., remembering objects, people or events experienced at particular times and places); working memory (i.e., remembering and seeing connections between items or ideas); attention and inhibitory control (i.e., focusing on relevant stimuli in the presence of irrelevant stimuli); processing speed (i.e., taking in and using information); and cognitive flexibility (i.e., shifting thoughts and adapting behavior to new conditions). Age-corrected standard scores (mean score of individuals of the same age from the general U.S. population=100; SD=15) were calculated. Potential impairment was defined as a standard score >1.5 SD below the mean. Descriptive statistics were calculated, and associations of various participant characteristics with potential fluid cognition impairment were assessed with multivariable logistic regression.

What were the key findings? The mean overall fluid cognition score of participants (N=199; mean age, 46; 87% female, 86% Black, 5% Hispanic) was 87.2 (episodic memory, 96.2; working memory, 91.4; attention and inhibitory control, 82.0; processing speed, 93.4; and cognitive flexibility, 94.7). Working status (OR=0.30 [95% CI, 0.14–0.64]) and higher self-reported physical functioning (OR=0.46 [95% CI, 0.28–0.75]) and physical performance (OR=0.72 [95% CI 0.59–0.87]) were associated with lower odds of potential impairment; lower educational attainment was associated with higher odds (OR=3.82 [95% CI, 1.67–8.75]). Self-reported forgetfulness, neuropsychiatric damage and depressive symptoms were not statistically significantly associated with potential impairment.

What were the main conclusions? Scores for fluid cognition were ~1 SD lower than those in the similarly aged general U.S. population. Potential impairment was less frequent among those who were working, had higher physical functioning and performance, and had higher educational attainment.

What are the implications for patients and clinicians? Impairment in fluid cognition may be common in SLE and has implications for self-management. Future work is needed to track fluid cognition among those with SLE to develop and implement interventions that can support fluid cognition and, hopefully, establish treatments that prevent impairment.