Biochemical mechanisms involved in the β-blocker-induced changes in serum lipoproteins

Beta-blocker effects on plasma lipids during prolonged treatment of hypertensive patients with hypercholesterolemia

The aim of this study was to compare the effects of long-term monotherapy with four different beta-blockers on plasma lipids in hypercholesterolemic hypertensive patients. We studied 152 subjects with essential hypertension [diastolic blood pressure (DBP) >90 mm Hg], total cholesterol (TC) >240 and <330 mg/dl, and triglycerides (TGs) <300 mg/dl. After a 4-week washout period with placebo, patients were randomized to receive propranolol, 160 mg/day (n = 37), atenolol, 100 mg/day (n = 38), bisoprolol, 10 mg/day (n = 39), or celiprolol, 400 mg/day (n = 38), for 18 months. No cholesterol-reducing drug was allowed. Blood samples for evaluation of TC, low-density lipoprotein cholesterol (LDL-C), HDL cholesterol (HDL-C), and TGs were taken before and after the placebo period and subsequently every 6 months. No beta-blocker worsened TC or LDL-C. Nonselective propranolol caused the most pronounced changes in HDL-C and TGs. Beta1-Selective atenolol produced the same qualitative effects, but to a lesser extent. The more beta1-selective bisoprolol did not affect HDL-C and TGs. Celiprolol significantly improved the lipid profile by significantly decreasing TC, LDL-C, and TGs, and increasing HDL-C. These findings suggest that in hypercholesterolemic hypertensive patients, (a) beta1-selective beta-blockers are likely to adversely affect plasma lipids to a lesser extent than nonselective ones; and (b) celiprolol is able to improve the lipid pattern, which could be because of its peculiar ancillary properties.

Insulin sensitivity in a long-term crossover trial with celiprolol and other antihypertensive agents

The effects of a vasodilating beta-blocker, celiprolol, on insulin sensitivity and cardiovascular risk factors were compared with those of another beta1-selective adrenoceptor blocker, calcium channel blockers, and angiotensin-converting enzyme (ACE) inhibitors. A randomized 21-month crossover trial was carried out with 25 patients with dyslipidemia receiving antihypertensive monotherapy. The study consisted of a 3-month active run-in period and two treatment periods, during which the patients received celiprolol (200-400 mg daily) or the control drug for 12 and 6 months in a crossover manner. A hyperinsulinemic euglycemic clamp and an oral glucose tolerance test (OGTT) were performed every 6 months. According to the clamp tests, the insulin-sensitivity index increased on average by 32% (p < 0.0001) during celiprolol treatment compared with that with the other antihypertensive agents, including ACE inhibitors. In OGTT, area under the incremental glucose curve decreased by 36% (p = 0.002) during celiprolol treatment, whereas insulin secretion diminished on average by 26% (p = 0.006). The mean decrease in fasting serum triglycerides was 11% (NS), whereas the high-density lipoprotein to low-density lipoprotein (HDL/LDL) ratio increased by 15% (p = 0.012). The results suggest that celiprolol improves insulin sensitivity of hypertensive patients with dyslipidemia in long-term therapy.

Metabolic manifestations of low-dose diuretics

Hypertension has been defined and treated as a disease of abnormal systolic and diastolic blood pressure. Recent data have, however, demonstrated that effective blood-pressure control has not resulted in the expected decrease in coronary artery disease. These findings are probably a result of hypertension being a complex inherited syndrome of cardiovascular risk factors, all of which are genetically linked and all of which contribute to the development of cardiovascular disease in these patients. Included in the hypertension syndrome are abnormalities of lipid profile, insulin resistance, changes in renal function, left ventricular hypertrophy and reduced arterial compliance. In many patients, high blood pressure is a late manifestation of this disease process. Since all cardiovascular risk factors contribute to heart disease in these patients, they should all be considered in the management of this disease process. Diuretics and beta blockers, when used at high doses, negatively impact lipid metabolism and insulin sensitivity, while angiotensin converting enzyme (ACE) inhibitors and calcium antagonists tend to have a neutral effect on these metabolic risk factors. These findings have resulted in decreased use of diuretics and beta blockers in favor of newer agents such as ACE inhibitors and calcium antagonists. However, recent data have demonstrated that when used at low doses (6.25 or 12.5 mg of hydrochlorothiazide), diuretics lack significant metabolic side effects while bringing about significant reductions in blood pressure. Thus, at these doses, hydrochlorothiazide is a useful drug in the treatment of hypertension, both as monotherapy and in combination therapy.

Effects of celiprolol vs. nifedipine on serum lipoproteins in patients with mild to moderate hypertension

During a double-blind, randomized study in hypertensive patients, changes in plasma lipid and lipoprotein levels during treatment with celiprolol were compared with those occurring during nifedipine treatment. Fifty-three patients (28 men and 25 women) with mild-to-moderate hypertension, aged 20-64 years, were studied. After a 1-month placebo run-in period, patients were randomly assigned to receive either nifedipine (40 mg daily) or celiprolol (200 mg daily), each time using a double-dummy technique. After 6 weeks, dosages of each drug could be doubled. After 6 weeks, there were no differences in plasma lipids between the two treatment groups. However, the changes after 12 weeks of treatment were different (p < 0.05) between the groups, leading to lower levels of plasma esterified cholesterol, low-density lipoprotein (LDL) cholesterol, and apoprotein AI, AII, and B in the celiprolol group. Plasma lecithin cholesterol acyltransferase activity (LCAT) was not modified. The present study showed that celiprolol was at least equivalent to nifedipine in terms of secondary effects on plasma lipids and lipoprotein.