Abstract : BACKGROUND We hypothesized that patients with high HDL-cholesterol (HDL-C) and ischemic heart disea
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Abstract : BACKGROUND We hypothesized that patients with high HDL-cholesterol (HDL-C) and ischemic heart disease (IHD) may have dysfunctional HDL or unrecognized nonconventional risk factors.|METHODS Individuals with IHD (Copenhagen University Hospital) and either high HDL-C (n = 53 women gtor=735 mg/L men gtor=619 mg/L) or low HDL-C (n = 42 women ltor=387 mg/L men ltor=341 mg/L) were compared with individuals without IHD (Copenhagen City Heart Study) matched by age sex and HDL-C concentrations (n = 110). All participants had concentrations within reference intervals for LDL-C (lt1600 mg/L) and triglyceride (lt1500 mg/L) and none were treated with lipid-lowering medications. Pre-beta(1) HDL and phospholipid transfer protein concentrations were measured by using commercial kits and lecithincholesterol acyltransferase (LCAT) activity by using a proteoliposome cholesterol esterification assay.|RESULTS Pre-beta(1) HDL concentrations were 2-fold higher in individuals with IHD vs no IHD in both the high 63 (5.7) vs 35 (2.3) mg/L P lt 0.0001 and low HDL-C 49 (5.0) vs 27 (1.5) mg/L P = 0.001 groups. Low LCAT activity was also associated with IHD in the high 95.2 (6.7) vs 123.0 (5.3) micromol x L(-1) x h(-1) P = 0.002 and low 93.4 (8.3) vs 113.5 (4.9) micromol x L(-1) . h(-1) P = 0.03 HDL-C groups. ROC curves for pre-beta(1) HDL in the high-HDL-C groups yielded an area under the curve of 0.71 (95 CI 0.61-0.81) for predicting IHD which increased to 0.92 (0.87-0.97) when LCAT was included. Similar results were obtained for low HDL-C groups. An inverse correlation between LCAT activity and pre-beta(1) HDL was observed (r(2) = 0.30 P lt 0.0001) in IHD participants which was stronger in the low HDL-C group (r(2) = 0.56 P lt 0.0001).|CONCLUSIONS: IHD was associated with high pre-beta(1) HDL concentrations and low LCAT levels, yielding correct classification in more than 90% of the IHD cases for which both were measured, thus making pre-beta(1) HDL concentration and LCAT activity level potentially useful diagnostic markers for cardiovascular disease.|
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