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 ≥ 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) (≥ 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.