Dose-Dependent Effect of Rosuvastatin Treatment on Urinary Protein Excretion

Concerns have been raised because of observations of proteinuria associated with rosuvastatin treatment. In this open-label study, a potential dose-dependent effect was investigated of rosuvastatin on urinary protein excretion and renal function parameters in 90 hyperlipidemic patients randomly assigned to rosuvastatin 10 mg/day (n = 45) or 20 mg/day (n = 45). Urinary samples were collected from patients and 40 age- and gender-matched controls to determine electrolyte, uric acid, creatinine, and protein (total, albumin, IgG, and α1-microglobulin) levels at baseline and after 12 weeks. A dose-dependent increase in the excretion of α1-microglobulin (17.6% in rosuvastatin 10 vs 34.9% in rosuvastatin, 20 mg/day; P = .03 for the comparison between groups) was observed. A trend toward an increase in the estimated glomerular filtration rate was noted in only patients receiving 20 mg/day of rosuvastatin. These findings indicate that rosuvastatin treatment increases the urinary excretion of α1-microglobulin urinary excretion in a dose-dependent manner without adversely affecting renal function.

Differential effect of hypolipidemic drugs on lipoprotein-associated phospholipase A2

OBJECTIVE

Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a predictor for incident atherosclerotic disease. We investigated the effect of 3 hypolipidemic drugs that exert their action through different mechanisms on plasma and lipoprotein-associated Lp-PLA2 activity and mass.

METHODS AND RESULTS

In 50 patients with Type IIA dyslipidemia were administered rosuvastatin (10 mg daily), whereas in 50 Type IIA dyslipidemic patients exhibiting intolerance to previous statin therapy were administered ezetimibe as monotherapy (10 mg daily). Fifty patients with Type IV dyslipidemia were given micronised fenofibrate (200 mg daily). Low- and high-density lipoprotein (LDL and HDL, respectively) subclass analysis was performed electrophoretically, whereas lipoprotein subfractions were isolated by ultracentrifugation. Ezetimibe reduced plasma Lp-PLA2 activity and mass attributable to the reduction in plasma levels of all LDL subfractions. Rosuvastatin reduced enzyme activity and mass because of the decrease in plasma levels of all LDL subfractions and especially the Lp-PLA2 on dense LDL subfraction (LDL-5). Fenofibrate preferentially reduced the Lp-PLA2 activity and mass associated with the VLDL+IDL and LDL-5 subfractions. Among studied drugs only fenofibrate increased HDL-associated Lp-PLA2 (HDL-Lp-PLA2) activity and mass attributable to a preferential increase in Lp-PLA2 associated with the HDL-3c subfraction.

CONCLUSIONS

Ezetimibe, rosuvastatin, and fenofibrate reduce Lp-PLA2 activity and mass associated with the atherogenic apoB-lipoproteins. Furthermore, fenofibrate improves the enzyme specific activity on apoB-lipoproteins and induces the HDL-Lp-PLA2. The clinical implications of these effects remain to be established.

The hypertriglyceridemic waist phenotype is a predictor of elevated levels of small, dense LDL cholesterol

The hypertriglyceridemic waist (HTGW) phenotype (hypertriglyceridemia and increased waist circumference) has been proposed as an inexpensive tool to monitor individuals with the atherogenic metabolic triad, hyperinsulinemia, hyperapobetalipoproteinemia, and increased levels of small, dense LDL (sdLDL) particles. We assessed the association of the HTGW phenotype with the metabolic syndrome (MetSyn) and the atherogenic metabolic triad in inhabitants (n = 260) of northwestern Greece attending the Outpatient Lipid Clinic of the University Hospital of Ioannina. The LDL subfractions were assessed using the Lipoprint LDL System. HTGW (+) individuals had a more adverse lipid and lipoprotein profile compared with HTGW (-) individuals. Moreover, HTGW (+) subjects had elevated levels of sdLDL-C, as well as decreased mean and peak LDL particle size compared with HTGW (-) subjects. To our knowledge, this is the first report documenting the sdLDL-C abnormality in HTGW (+) subjects. Among men (n = 105), 52.3% of the MetSyn (+) individuals and 66.7% of the HTGW (+) individuals had the metabolic triad. Among women (n = 155), the corresponding percentages were 42.3% and 50.0%. Only 22.2% and 10.6% of the MetSyn (-) subjects (men and women, respectively) and 19.6% and 15.2% of the HTGW (-) subjects (men and women, respectively) had the atherogenic metabolic triad. In conclusion, the HTGW (+) phenotype is associated with a hostile lipid profile that includes higher levels of sdLDL-C and decreased LDL particle size. The HTGW phenotype, compared with the MetSyn criteria, can provide an easy and inexpensive tool to monitor patients characterized by an adverse lipid and lipoprotein profile.

LDL cholesterol estimation in patients with the metabolic syndrome

BACKGROUND

The Friedewald formula (LDL-F) for the estimation of low-density lipoprotein (LDL) cholesterol concentrations is the most often used formula in clinical trials and clinical practice. However, much concern has been raised as to whether this formula is applicable in all patient populations such as the presence of chylomicronaemia and/or hypertriglyceridaemia. The aim of the present study was to evaluate various LDL cholesterol calculation formulas as well as LDL cholesterol levels provided by the Lipoprint LDL System (LDL-L) in patients with the metabolic syndrome (MetSyn).

RESULTS

LDL-F showed significant differences from other formulas in the total cohort, as well as in MetSyn individuals. This was not the case in nonMetSyn subjects, where LDL-F did not differ with other formulas, with the exception of one formula (LDL by Planella, LDL-P). The bias between LDL-F and other LDL estimation formulas were significantly higher in MetSyn subjects compared to nonMetSyn individuals, except for LDL-L which produced similar bias with LDL-F in both study groups.

CONCLUSION

LDL-F seems to exhibit some limitations as far as the calculation of LDL-C levels in patients with the MetSyn is concerned. LDL-L might be more accurate in MetSyn subjects, but so far its use is limited for the estimation of small, dense LDL (sdLDL) cholesterol levels and mean LDL particle size for research purposes only.