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The effects of labetalol and oxprenolol on blood lipids
Insights
Labetalol and oxprenolol significantly reduced total cholesterol and the total cholesterol to HDL ratio in healthy volunteers. These beta-blockers did not negatively impact blood lipids, countering concerns about accelerated atherosclerosis.
Area of Science:
- Cardiology
- Pharmacology
- Biochemistry
Background:
- High serum total cholesterol and low high-density lipoprotein (HDL) cholesterol increase coronary heart disease risk.
- Adrenergic blocking agents have been suspected of potentially accelerating atherogenesis due to alterations in lipid transport.
Purpose of the Study:
- To investigate the effects of labetalol and oxprenolol on blood lipid profiles in normal volunteers.
- To determine if beta-blockade influences lipid transport in a way that could promote atherosclerosis.
Main Methods:
- A randomized cross-over trial involving eight healthy volunteers.
- Each participant received labetalol and oxprenolol for 3-week periods, separated by a 1-week wash-out period.
Main Results:
- Both labetalol and oxprenolol significantly reduced total serum cholesterol levels.
- No significant effect on high-density lipoprotein (HDL) cholesterol levels was observed.
- The ratio of total cholesterol to HDL cholesterol was significantly decreased.
- Triglyceride level changes were minimal and not statistically significant.
- Labetalol's alpha-blockade did not materially alter the lipid changes induced by its beta-blockade.
Conclusions:
- Labetalol and oxprenolol effectively lower total cholesterol and improve the total cholesterol to HDL ratio.
- These findings do not support previous hypotheses that beta-blockers might accelerate atherogenesis through lipid transport alterations.
Abstract:
Since a high risk of coronary heart disease is associated with high serum total cholesterol levels and low high-density lipoprotein (HDL) cholesterol levels, the effects of labetalol (Trandate; Allen & Hanburys) and oxprenolol (Trasicor; Ciba-Geigy) on blood lipids were studied. Eight normal volunteers, mean age 25,8 years, were involved in a randomized cross-over trial; all received each of the drugs for a 3-week period, separated by a wash-out period of 1 week. Both labetalol and oxprenolol reduced total serum cholesterol levels; these changes are statistically highly significant; Since the drugs had no significant effect on HDL cholesterol levels, the ratio of total cholesterol to HDL cholesterol was significantly decreased. Changes in triglyceride levels after both labetalol and oxprenolol administration were slight and did not reach statistical significance. The alpha-blockade caused by labetalol does no materially affect changes in blood lipid values brought about by beta-blockade. This study does not support previous reports, which have directed attention towards the possibility that, owing to alterations in lipid transport, adrenergic blocking agents might accelerate atherogenesis.