Association of salivary lysozyme and C‐reactive protein with metabolic syndrome

Qvarnstrom M, Janket S‐J, Jones JA, Jethwani K, Nuutinen P, Garcia RI, Baird AE, Van Dyke TE and Meurman JH. Association of salivary lysozyme and C‐reactive protein with metabolic syndrome. J Clin Periodontol 2010; 37: 805–811. doi: 10.1111/j.1600‐051X.2010.01605.x. Abstract Introduction: Salivary lysozyme (SLZ) is a proteolytic enzyme secreted by oral leucocytes and contains a domain that has an affinity to advanced glycation end products (AGE). Thus, we hypothesized that SLZ would be associated with metabolic syndrome (metS), a pro‐inflammatory state. Methods: Utilizing cross‐sectional data from 250 coronary artery disease (CAD) and 250 non‐CAD patients, the association of SLZ with metS was tested by logistic regression analyses controlling for age, sex, smoking, total cholesterol and C‐reactive protein (CRP) levels. The analyses were stratified by CAD status to control for the possible effects of CAD. Results: MetS was found in 122 persons. The adjusted odds ratio (OR) for metS associated with the highest quartile of SLZ was 1.95 with 95% confidence interval (CI) 1.20–3.12, p ‐value=0.007, compared with the lower three quartiles combined. Among the 40 subjects with metS but without CAD, the OR was 1.63 (CI: 0.64–4.15, p =0.31), whereas in the CAD group, SLZ was significantly associated with metS [OR=1.96 (1.09–3.52), p =0.02]. In both subgroups, CRP was not significantly associated with metS. Conclusion: SLZ was significantly associated with metS (OR=1.95) independent of CRP level. Future longitudinal research is warranted.