Effects of simvastatin on blood pressure in hypercholesterolemic patients: An open-label study in patients with hypertension or normotension.

BACKGROUND

Simvastatin has been reported to improve endotheliumdependent vascular relaxation in patients with hypercholesterolemia. The consequent decrease in arterial stiffness might be associated with a decrease in blood pressure (BP).

OBJECTIVE

The aim of this study was to determine whether simvastatin 20 and 40 mg/d have an effect on systolic and diastolic blood pressure (SBP and DBP, respectively) in patients with hypercholesterolemia, and, if so, whether the effect is dose dependent and/or is related to the changes in the serum lipid profile.

METHODS

This 6-month, open-label study was conducted at the Lipid Clinics of the Department of Internal Medicine, University of Milan, Maggiore Hospital IRCCS, and of the Department of Internal Medicine 1, G. Salvini Hospital, Garbagnate Milanese (Milan, Italy). Patients aged 18 to 80 years with primary hypercholesterolemia who were following a low-fat, low-cholesterol diet for >2 months before the study were enrolled. Patients at high risk for cardiovascular disease (CVD), according to the National Cholesterol Education Program Adult Treatment Panel II guidelines, were given simvastatin 20 mg (tablet) QD for 3 months, and those at low risk for CVD continued with diet only for 3 months (controls). Efficacy variables included body weight, SBP, DBP, and serum lipid levels (total cholesterol [TC], low-density lipoprotein cholesterol [LDL-C], high density lipoprotein cholesterol [HDL-C], and triglycerides [TG]). At 3 months, patients in the simvastatin + diet group who reached their therapeutic goal continued to receive simvastatin 20 mg/d for 3 additional months. In simvastatintreated patients who were normotensive at baseline or who became normotensive at 3 months but who did not reach the therapeutic goal, the simvastatin dosage was increased to 40 mg/d. Patients in both groups who remained hypertensive at 3 months were switched to hypotensive therapy. In the diet-only group, patients who were formerly normotensive or who became normotensive at 3 months but who did not reach their therapeutic goal continued with diet only or started lipid-lowering therapy. All other patients in the diet-only group continued to be treated with diet only, for 3 additional months. Efficacy variables were measured again at 6 months. Tolerability of simvastatin was assessed at each visit using patient interview and measurement of serum aminotransferase and creatine phosphokinase levels.

RESULTS

The study population comprised 222 patients (132 women, 90 men; mean [SEM] age, 53.9 [0.95] years [range, 23-76 years]); 115 high-risk patients (57 with untreated stage 1 hypertension) were assigned to the simvastatin + diet group, and 107 low-risk patients (29 with untreated stage 1 hypertension) were assigned to the diet-only group. In the simvastatin group, after 3 months of therapy, mean SBP was decreased by 3.9 (1.49) mm Hg (change, -2.9%), mean DBP decreased by 3.0 (0.87) mm Hg (change, -3.7%), mean TC decreased by 90.6 (3.98) mg/dL (change, -27.0%), mean LDL-C decreased by 88.9 (3.88) mg/dL (change, -35.6%), and mean TG decreased by 26.3 (7.34) mg/dL (change, -15.8%) (all, P < 0.001). Mean HDL-C increased by 3.6 (1.16) mg/dL (change, 6.9%; P < 0.001). The BP-lowering effect was found only in patients with hypertension at baseline (n = 57); in these patients, mean SBP decreased by 7.2 (2.44) mm Hg (change, -4.8%; P < 0.005 vs baseline) and DBP decreased by 4.8 (1.29) mm Hg (change, -5.6%; P < 0.001 vs baseline). Also in the simvastatin group, 26 patients (22.6%) achieved their target SBP/DBP. In patients with normotension at baseline (n = 58), neither SBP nor DBP was changed significantly (changes, -0.8 [1.65] and -1.4 [1.15] mm Hg, respectively [-0.6% and -1.8%, respectively]). The changes in serum lipid levels were similar between hypertensive and normotensive patients in the simvastatin group. Forty-one patients (18 hypertensive and 23 normotensive at baseline) were treated with simvastatin 40 mg/d plus diet between months 3 and 6. At 6 months, no further significant decrease was observed in mean BP. In contrast, the expected dose-dependent response was observed for TC and LDL-C levels. In the diet-only group, no significant changes occurred in BP or serum lipid levels. Changes in BP, TC, LDL-C, TG, and HDL-C were significantly greater in the simvastatin + diet group than in the diet-only group (all, P < 0.001). Body weight did not change significantly in either group.

CONCLUSIONS

In this group of patients with hypercholesterolemia, the starting dosage of simvastatin (20 mg/d) was associated with reductions in SBP and DBP within 3 months of treatment in patients with hypertension, and this effect was independent of the lipid-lowering properties of the drug. Although the decrease in BP was modest, it is likely clinically relevant. Further studies on this topic are advisable.