HDL cholesterol and beta-adrenoceptor blocking agents in a 5 year multifactorial primary prevention trial.

1 Serum HDL cholesterol measured at the end of a 5 year multifactorial primary prevention trial, aimed to reduce risk factor levels and incidence of ischaemic heart disease, revealed quite low values in drug-treated subjects. 2 Analysis of subgroups treated with beta-adrenoceptor blocking agents (mainly pindolol) alone or in different combinations with diuretics showed inconsistent effects of beta-adrenoceptors blockers on serum HDL cholesterol. HDL cholesterol levels in patients treated with pindolol with or without a diuretic were not different from those of the risk-free control group. 3 Subjects on combined beta-adrenoceptor blocker-hypolipidaemic treatments had lower HDL-cholesterol than those on hypolipidaemic agents alone. 4 Withdrawal of pindolol at the end of the trial caused a small but significant increase in serum HDL cholesterol in a small subgroup of mildly hypertensive patients. Thus, pindolol appears to have slightly reduced serum HDL cholesterol but the relevance of this small decrease on the incidence of ischaemic heart disease is questionable.