3.4 Overall results of studies
All 12 studies were included in the pooled analysis. This included 2415
cases and 2545 controls. The pooled results (Figure 3) suggest that
patients with DELC have an increased likelihood of having coronary
artery disease. (OR= 4.61, 95% CI: 3.17 to 9.60). There was significant
heterogeneity among studies (I2=83%,
P<0.00001) whilst test for overall effect, Z, was 8.01
(p<0.00001). Ten of the 12 studies found a significant
association between DELC and CAD. The two studies that found no
significance association (14, 15) were poorer quality
studies which both attributed their findings to age without any
statistical analysis.