Correlation between lipid profile and lipoprotein (a) with inflammatory activity of rheumatoid arthritis

The current study aimed to assess the correlation between lipoproteins, in particular lipoprotein a [Lp (a)], and inflammatory activity in rheumatoid arthritis (RA). This retrospective case control study was conducted over a period of 6 months and studied two groups, RA patients (n=70) and healthy control subjects (n=52), who were matched by age and gender (P value<0.005). The modified Health Assessment Questionnaire (MHAQ) was employed by self-administration. Fasting lipid profiles including LDL, HDL, total cholesterol, triglycerides, and Lp (a) were assayed, and the findings for the two studied groups were compared using the Student t test. Thirty-two patients in the RA group (45.71%) and 27 subjects in the control group (51.92%) had abnormally high Lp (a) levels (P value=0.57). Mean serum Lp (a) values between the RA and control groups were significantly different (P value=0.79). Serum Lp (a) had no significant correlation with ESR (r=0.27, P value=0.028). No significant correlation was found between Lp (a) level and MHAQ (r=0.11, P value=0.37). Serum Lp (a) was also found to have no significant relationship with other laboratory parameters (CRP and RF) or clinical indices of RA activity (functional class and morning stiffness duration). No correlation was observed between serum Lp (a) and clinical/laboratory indices of RA activity other than a weak one with ESR. It is not recommended to use routine serum Lp (a) measurements to assess RA severity.