Low HDL cholesterol is associated with increased atherogenic lipoproteins and insulin resistance in women classified with metabolic syndrome

Both metabolic syndrome (MetS) and elevated LDL cholesterol (LDL-C) increase the risk for cardiovascular disease (CVD). We hypothesized that low HDL cholesterol (HDL-C) would further increase CVD risk in women having both conditions. To assess this, we recruited 89 women with MetS (25-72 y) and LDL-C ${\geq}$ 2.6 mmol/L. To determine whether plasma HDL-C concentrations were associated with dietary components, circulating atherogenic particles, and other risk factors for CVD, we divided the subjects into two groups: high HDL-C (H-HDL) (${\geq}$ 1.3 mmol/L, n=32) and low HDL-C (L-HDL) (< 1.3 mmol/L, n=57). Plasma lipids, insulin, adiponectin, apolipoproteins, oxidized LDL, Lipoprotein(a), and lipoprotein size and subfractions were measured, and 3-d dietary records were used to assess macronutrient intake. Women with L-HDL had higher sugar intake and glycemic load (P< 0.05), higher plasma insulin (P< 0.01), lower adiponectin (P< 0.05), and higher numbers of atherogenic lipoproteins such as large VLDL (P < 0.01) and small LDL (P<0.001) than the H-HDL group. Women with L-HDL also had larger VLDL and both smaller LDL and HDL particle diameters (P<0.001). HDL-C was positively correlated with LDL size (r=0.691, P<0.0001) and HDL size (r=0.606, P<0.001), and inversely correlated with VLDL size (r=-0.327, P<0.01). We concluded that L-HDL could be used as a marker for increased numbers of circulating atherogenic lipoproteins as well as increased insulin resistance in women who are already at risk for CVD.