Association between low density lipoprotein and rheumatoid arthritis genetic factors with low density lipoprotein levels in rheumatoid arthritis and non-rheumatoid arthritis controls.

Abstract

OBJECTIVES:

While genetic determinants of low density lipoprotein (LDL) cholesterol levels are well characterised in the general population, they are understudied in rheumatoid arthritis (RA). Our objective was to determine the association of established LDL and RA genetic alleles with LDL levels in RA cases compared with non-RA controls.

METHODS:

Using data from electronic medical records, we linked validated RA cases and non-RA controls to discarded blood samples. For each individual, we extracted data on: first LDL measurement, age, gender and year of LDL measurement. We genotyped subjects for 11 LDL and 44 non-HLA RA alleles, and calculated RA and LDL genetic risk scores (GRS). We tested the association between each GRS and LDL level using multivariate linear regression models adjusted for age, gender, year of LDL measurement and RA status.

RESULTS:

Among 567 RA cases and 979 controls, 80% were female and mean age at the first LDL measurement was 55 years. RA cases had significantly lower mean LDL levels than controls (117.2 vs 125.6 mg/dl, respectively, p<0.0001). Each unit increase in LDL GRS was associated with 0.8 mg/dl higher LDL levels in both RA cases and controls (p=3.0×10(-7)). Each unit increase in RA GRS was associated with 4.3 mg/dl lower LDL levels in both groups (p=0.01).

CONCLUSIONS:

LDL alleles were associated with higher LDL levels in RA. RA alleles were associated with lower LDL levels in both RA cases and controls. As RA cases carry more RA alleles, these findings suggest a genetic basis for epidemiological observations of lower LDL levels in RA.

• Authors: Katherine P Liao, Dorothée Diogo, Jing Cui, Tianxi Cai, Yukinori Okada, Vivian S Gainer, Shawn N Murphy, Namrata Gupta, Daniel Mirel, Ashwin N Ananthakrishnan, Peter Szolovits, Stanley Y Shaw, Soumya Raychaudhuri, Susanne Churchill, Isaac Kohane, Elizabeth W Karlson, Robert M Plenge
• Journal: Annals of the rheumatic diseases (Ann Rheum Dis) Vol. 73 Issue 6 Pg. 1170-5 (Jun 2014) ISSN: 1468-2060 [Electronic] England
• PMID: 23716066 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Lipoproteins, LDL

Topics

• Adult
• Aged
• Arthritis, Rheumatoid (blood, genetics)
• Case-Control Studies
• Dyslipidemias (blood, genetics)
• Female
• Genetic Predisposition to Disease
• Genotype
• Humans
• Lipoproteins, LDL (blood)
• Male
• Middle Aged
• Polymorphism, Single Nucleotide