Polymyalgia rheumatica and risk of coronary artery disease: a systematic review and meta-analysis of observational studies.

Several chronic inflammatory disorders, such as rheumatoid arthritis and systemic lupus erythematosus, are associated with an increased risk of coronary artery disease (CAD) as a result of accelerated atherosclerosis. However, the data on CAD risk of polymyalgia rheumatica (PMR), one of the most common chronic inflammatory disorders in older adults, remain unclear due to limited number of epidemiological studies. To further investigate this possible association, this systematic review and meta-analysis of observational studies was performed to compare the risk of CAD in patients with PMR versus subjects without it. Published studies indexed in MEDLINE and EMBASE were searched from inception to April 2016 using the terms "polymyalgia rheumatica" combined with the terms for CAD. The inclusion criteria were: (1) observational studies published as original studies to evaluate the risk of CAD among patients with PMR; (2) published odds ratios, relative risk or hazard ratio or standardized incidence ratio with 95 % confidence intervals (CI) in the studies; and (3) subjects without PMR were used as comparators in cohort studies and cross-sectional studies, while subjects without CAD were used as comparators in case-control studies. Point estimates and standard errors were extracted from individual studies and were combined by the generic inverse variance method of DerSimonian and Laird. Four studies with 34,569 patients with PMR were identified and included in this meta-analysis. The pooled risk ratio of CAD in patients with PMR was 1.72 (95 % CI 1.21-2.45). The statistical heterogeneity of this meta-analysis was high with an I 2 of 97 %.