1. β-Adrenoceptor blocker therapy is known to cause disturbances of the lipoprotein profile. The long-term effects of β-adrenoceptor blockers and the influence of intrinsic sympathomimetic activity (ISA) has not been clearly defined. We measured serum lipoproteins during chronic β-adrenoceptor blockade in patients with stable angina pectoris treated with propranolol (without ISA) (n = 21) or pindolol (with ISA) (n = 19).
2. No significant changes occurred in the lipoprotein profile of the patients taking pindolol. In those taking propranolol, very low density lipoprotein (VLDL) increased at 52 weeks (P < 0.05) and total high density lipoprotein (HDL) decreased at 26 weeks (P < 0.01) and at 52 weeks (P < 0.05). However, HDL2 rose significantly at 52 weeks (P < 0.05). There was a corresponding increase in HDL2/HDL3 ratio.
3. We conclude that pindolol is less likely to exert a harmful effect on plasma lipoproteins than β-adrenoceptor blockers without ISA.