Elevated Lipoprotein(a) Is Highly Prevalent in Autoimmune or Inflammatory Disease: A Multisite Study.

BACKGROUND: There is a complex interplay between inflammation and lipoprotein(a) [Lp(a)]. OBJECTIVES: Examine whether individuals with autoimmune or inflammatory diseases (AIIDs) are more likely to have elevated Lp(a). METHODS: Cross-sectional study assessing the relationship between Lp(a) and 6 AIIDs using data from electronic health records from 5 University of California Health Systems between January 1, 2012 and December 31, 2024. Included patients had at least 1 Lp(a) measurement and were stratified by the presence of one or more AIID diagnosis vs individuals with atherosclerotic cardiovascular disease (ASCVD) vs controls (without AIIDs or ASCVD). RESULTS: A total of 49,431 patients with at least 1 Lp(a) measurement were included (7,995 with AIID, 8,633 with ASCVD, 34,741 controls). Those with AIIDs had a mean (SD) age of 61.1 (13.7) years, 45.7% were women, and 66.9% were White individuals. Among those with AIIDs, 28.3% (n = 2,259) had Lp(a) >50 mg/dL vs 24.6% (n = 8,560) of controls (P < 0.001) and 21.3% had Lp(a) >70 mg/dL vs 17.2% of controls (P < 0.001). The adjusted odds (95% CI) of Lp(a) >50 mg/dL was 1.22 (1.15-1.29) in those with AIIDs vs controls and was especially high in those with gout (1.33 [1.23-1.44]), inflammatory bowel disease (1.26 [1.06-1.49]), and ankylosing spondylitis (1.21 [1.09-1.34]). The prevalence of Lp(a) >50 mg/dL for AIIDs was between that of controls and those with ASCVD. CONCLUSIONS: Individuals with AIIDs are more likely to have elevated Lp(a) (>50 mg/dL and >70 mg/dL). Further study of the relationship between inflammation and Lp(a) in this population is needed.