OBJECTIVE -The oral antidiabetic agent pioglitazone improves insulin sensitivity and glycemic control and appears to lower atherogenic dense LDL in type 2 diabetes. Insulin resistance may occur frequently in nondiabetic patients with hypertension. This study is the first to report the effect of pioglitazone on LDL subfractions in normolipidemic, nondiabetic patients with arterial hypertension.RESEARCH DESIGN AND METHODS -We performed a monocentric, double-blind, randomized, parallel-group comparison of 45 mg pioglitazone (n ϭ 26) and a placebo (n ϭ 28), each given once daily for 16 weeks. Fifty-four moderately hypertensive patients (LDL cholesterol, 2.8 Ϯ 0.8 mmol/l; HDL cholesterol, 1.1 Ϯ 0.3 mmol/l; triglycerides, 1.4 mmol/l (median; range 0.5-7.1) were studied at baseline and on treatment.RESULTS -At baseline, dense LDLs were elevated (apolipoprotein [apo]B in LDL-5 plus LDL-6 Ͼ250 mg/l) in 63% of all patients. Sixteen weeks of treatment with pioglitazone did not significantly change triglycerides, total, LDL, and HDL cholesterol. However, pioglitazone reduced dense LDLs by 22% (P ϭ 0.024). The mean diameter of LDL particles increased from 19.83 Ϯ 0.30 to 20.13 Ϯ 0.33 nm (P Ͻ 0.001 vs. placebo), whereas the mean LDL density decreased from 1.0384 Ϯ 0.0024 to 1.0371 Ϯ 0.0024 kg/l (P ϭ 0.005 vs. placebo). The effect of pioglitazone on LDL size and density was independent of fasting triglycerides and HDL cholesterol at baseline and of changes in fasting triglycerides and HDL cholesterol.CONCLUSIONS -The prevalence of atherogenic dense LDL in nondiabetic, hypertensive patients is similar to patients with type 2 diabetes. Pioglitazone significantly reduces dense LDL independent from fasting triglycerides and HDL cholesterol. The antiatherogenic potential of pioglitazone may thus be greater than that expected from its effects on triglycerides, LDL, and HDL cholesterol alone.

Disorders of the lipoprotein metabolism are a major cause of endothelial dysfunction that may result in hypertension and proteinuria, clinical hallmarks of preeclampsia (PE). Lipoproteins and low-density lipoprotein (LDL) subfractions were investigated in 15 women with severe PE and compared with 23 women with a normal course of pregnancy. Compared with normal pregnancy, in PE apolipoprotein (apo)B in very low-density lipoprotein was increased by 76% (P = 0.008), and the triglyceride content of intermediate dense lipoproteins (IDL) was increased by 51% (P < 0.001); cholesterol and apoB in LDL were decreased by 26% (P = 0.005) and 23% (P = 0.016), respectively. Although not significant, the LDL profile was dominated by the most buoyant LDL-1. ApoB in the most dense LDL (dLDL), namely LDL-5 and LDL-6, was significantly decreased by 49% (P < 0.001) and 55% (P < 0.001), respectively. Diastolic blood pressure was positively correlated with the triglyceride content of IDL (r = 6.31; P < 0.001 and r = 0.352; P = 0.033 by partial correlation controlling for the presence or absence of PE) and negatively correlated with the concentration of apoB in dLDL (r = -0.500; P = 0.002). In addition, IDL triglycerides correlated negatively with infant birth weight percentile (r = -0.373; P = 0.027) and positively with proteinuria (r = 0.430; P = 0.014). Low birth weight was associated with high IDL triglycerides and low rather than high concentrations of dLDL. Triglyceride-rich remnants are known to cause endothelial dysfunction. Because the triglyceride content of IDL was positively correlated with elevated blood pressure and proteinuria, triglyceride-rich remnant lipoproteins might contribute to the pathophysiology of PE.

Pregnancy is accompanied by changes in the maternal lipoprotein metabolism that may serve to satisfy the nutritional demands of the fetus. In this study lipoprotein metabolism was investigated in 23 women during normal pregnancy in the first, second, and third trimesters and in 15 healthy nonpregnant women with regular menstrual cycles. Lipid and apolipoprotein concentrations were measured in total plasma, very low density, intermediate density, low density (LDL), and high density lipoproteins, and in each of six LDL subfractions. During early pregnancy, triglycerides, and dense LDL were higher than in the nonpregnant state. With advancing gestation, triglycerides increased and the distribution of apolipoprotein B-100-containing lipoproteins became increasingly dominated by the accumulation of very low density and intermediate density lipoproteins and buoyant, triglyceride-rich LDL. This is the first study that investigates LDL subfractions in pregnancy using a method that strictly separates LDL subfractions by virtue of density. The accumulation of buoyant, triglyceride-rich lipoproteins may be related to the down-regulation of maternal lipase activities by placental hormones. As a consequence, the metabolic changes of late pregnancy may result in an increased flux of lipoprotein-derived lipids to the placenta, which, with advancing gestation, increasingly expresses receptors with a high affinity for triglyceride-rich lipoproteins.

Fluvastatin reduces atherogenic dense low-density lipoprotein (dLDL) in patients with type 2 diabetes mellitus (T2DM). dLDLs are associated with platelet-activating factor acetyl hydrolase (PAF-AH), an enzyme involved in inflammation and related to coronary artery disease (CAD). The association of preexisting CAD and PAF-AH and the effect of fluvastatin on enzyme activity is investigated in a placebo-controlled trial in patients with T2DM. A multicenter, double-blind, randomized comparison of fluvastatin XL (80 mg) (n = 42) and placebo (n = 47), each given once-daily for 8 wk, in 89 patients with T2DM, was conducted. At baseline and on treatment, lipoproteins, including lipoprotein (a) [Lp(a)] and LDL subfractions, and the activity of PAF-AH were measured. Increasing PAF-AH activity was significantly associated with a positive history of CAD (+0.7% per IU/liter PAH-AH; P = 0.010), the odds ratio estimate adjusted for age, gender, and body mass index of the highest quartile being 10.6 (P = 0.036). At baseline and at study end, PAF-AH activity was associated with the apolipoprotein B (apoB) content in dLDL (LDL-5 and LDL-6) (r = 0.447; P < 0.001 and r = 0.651; P < 0.001, respectively) and with non-HDL cholesterol at baseline (r = 0.485; P < 0.001). However, after additional adjustment for apoB in dLDL and non-HDL cholesterol at baseline, the odds ratio increment for CAD across PAF-AH quartiles was 2.09 (95% confidence interval, 1.02-4.29; P = 0.043). Fluvastatin treatment decreased the activity of PAF-AH by 22.8% compared with an increase of 0.4% in the placebo group (P < 0.001). This effect was independent of changes of Lp(a) concentrations. In patients with T2DM, PAF-AH activity is associated with a positive history of CAD. Fluvastatin not only decreases atherogenic dLDL but also PAF-AH activity, emphasizing the significance of fluvastatin treatment in T2DM. The antiatherogenic potential of fluvastatin in T2DM may thus be greater than expected from its effects on LDL-C and triglycerides alone.

The objective of this study was to determine the effect of slow-release (XL) fluvastatin on low density lipoprotein (LDL) subfractions in type 2 diabetes. A multicenter, double-blind, randomized, parallel-group comparison of fluvastatin XL 80 mg (n = 42) and placebo (n = 47), each given once-daily for 8 wk, in 89 patients with type 2 diabetes (HbA1c: 7.2 +/- 1.0%, LDL cholesterol (LDL-C): 3.4 +/- 0.7 mmol/liter, high density lipoprotein cholesterol: 1.1 +/- 0.3 mmol/liter, and triglycerides (TG): 2.4 +/- 1.4 mmol/liter). At baseline and on treatment, plasma lipoproteins were isolated and quantified. Eight weeks of fluvastatin treatment decreased total cholesterol (-23.0%, P < 0.001), LDL-C (-29%, P < 0.001) and TG (-18%, P < 0.001), compared with placebo. At baseline, there was a preponderance of dense LDL (dLDL) (apolipoprotein B in LDL-5 plus LDL-6 > 25 mg/dl) in 79% of patients, among whom fluvastatin decreased all LDL subfractions, reductions in dLDL being greatest (-28%, P = 0.001; cholesterol in dLDL -29%). In patients with low baseline dLDL (apolipoprotein B in LDL-5 plus LDL-6