Metabolic effects of fluvastatin extended release 80 mg and atorvastatin 20 mg in patients with type 2 diabetes mellitus and low serum high-density lipoprotein cholesterol levels: a 4-month, prospective, open-label, randomized, blinded-end point (probe) trial

Abstract

Background: Diabetic dyslipidemia is characterized by greater triglyceridation of all lipoproteins and low levels of plasma high-density lipoprotein cholesterol (HDL-C). In this condition, the serum level of low-density lipoprotein cholesterol (LDL-C) is only slightly elevated. The central role of decreased serum HDL-C level in diabetic cardiovascular disease has prompted the establishment of a target of ≥50 mg/dL in patients with diabetes mellitus (DM).

Objective: The aim of the study was to assess the effects of once-daily administration of fluvastatin extended release (XL) 80 mg or atorvastatin 20 mg on serum HDL-C levels in patients with type 2 DM and low levels of serum HDL-C.

Methods: This 4-month, prospective, open-label, randomized, blinded-end point (PROBE) trial was conducted at Endocrinology and Diabetology Service, L. Sacco-Polo University Hospital (Milan, Italy). Patients aged 45 to 71 years with type 2 DM receiving standard oral antidiabetic therapy, with serum HDL-C levels <50 mg/dL, and with moderately high serum levels of LDL-C and triglycerides (TG) were enrolled. After 1 month of lifestyle modification and dietary intervention, patients who were still showing a decreased HDL-C level were randomized, using a 1:1 ratio, to receive fluvastatin XL 80-mg tablets or atorvastatin 20-mg tablets, for 3 months. Lipoprotein metabolism was assessed by measuring serum levels of LDL-C, HDL-C, TG, apolipoprotein (apo) A-I (the lipoprotein that carries HDL), and apo B (the lipoprotein that binds very low-density lipoprotein cholesterol, intermediate-density lipoprotein, and LDL on a molar basis). Patients were assessed every 2 weeks for treatment compliance and subjective adverse events. Serum creatine phosphokinase and liver enzymes were assessed before the run-in period, at the start of the trial, and at 1 and 3 months during the study.

Results: One hundred patients were enrolled (50 patients per treatment group; fluvastatin XL group: 33 men, 17 women; mean [SD] age, 58 [12] years; atorvastatin group: 39 men, 11 women; mean [SD] age, 59 [11] years). In the fluvastatin group after 3 months of treatment, mean (SD) LDL-C decreased from 149 (33) to 95 (25) mg/dL (36%; P < 0.01), TG decreased from 437 (287) to 261 (164) mg/dL (40%; P < 0.01), and HDL-C increased from 41 (7) to 46 (10) mg/dL (12%; P < 0.05). In addition, apo A-I increased from 118 (18) to 124 (15) mg/dL (5%; P < 0.05) and apo B decreased from 139 (27) to 97 (19) mg/dL (30%; P < 0.05). In the atorvastatin group, LDL-C decreased from 141 (25) to 84 (23) mg/dL (40%; P < 0.01) and TG decreased from 411 (271) to 221 (87) mg/dL (46%; P < 0.01). Neither HDL-C (41 [7] vs 40 [6] mg/dL; 2%) nor apo A-I (117 [19] vs 114 [19] mg/dL; 3%) changed significantly. However, apo B decreased significantly, from 131 (20) to 92 (17) mg/dL (30%; P < 0.05). Mean changes in HDL-C (+5 [8] vs -1 [2] mg/dL; P < 0.01) and apo A-I (+6 [18] mg/dL vs -3 [21] mg/dL; P < 0.01) were significantly greater in the fluvastatin group than in the atorvastatin group, respectively. However, the decreases in LDL-C (54 [31] vs 57 [32] mg/ dL), TG (177 [219] vs 190 [65] mg/dL), and apo B (42 [26] vs 39 [14] mg/dL) were not significantly different between the fluvastatin and atorvastatin groups, respectively. No severe adverse events were reported.

Conclusions: Fluvastatin XL 80 mg and atorvastatin 20 mg achieved mean serum LDL-C (≤ 100 mg/dL) and apo B target levels (≤ 100 mg/dL) in the majority of this population of patients with type 2 DM, but mean serum HDL-C level was increased significantly only with fluvastatin-16 patients (32%) in the fluvastatin group compared with none in the atorvastatin group achieved HDL-C levels ≥50 mg/dL. The increase in HDL-C in the fluvastatin-treated patients was associated with an increase in apo A-I, suggesting a potential pleiotropic and selective effect in patients with low HDL-C levels.

Keywords: HDL; LDL; apo A-I; apo B; atorvastatin; fluvastatin XL; triglycerides; type 2 DM.