Metabolic effects of beta-adrenoreceptor blockers.

The effects of beta-blockade on glucose metabolism are complex. Some patients with impaired glucose tolerance while taking a non-selective beta-blocker, showed some improvement in glucose tolerance when therapy was changed to a beta1-blocker (metoprolol). Serum K+ values tend to rise slightly on beta-blocking therapy; small increases in serum urea and creatinine also occur. A rise in plasma triglycerides was noted in patients starting beta-blocking therapy; this effect seemed to be more marked on metoprolol than on non-selective beta-blockers.