Effect of dietary versus pharmacological correction of hypertriglyceridemia on red blood cell membrane sodium/lithium countertransport activity.

An elevated red blood cell Na/Li countertransport (Na/Li CT) is often associated with high blood pressure and metabolic abnormalities. Recent studies suggested that a reduction in serum TG levels is associated with a decrease in Na/Li CT activity. However, it is still unclear if this phenomenon could be originated from systemic metabolic alterations or from modifications of the membrane dynamic properties. Aim of the present study was to investigate whether dietary or pharmacological TG lowering therapy might have a different effect on Na/Li CT activity and related metabolic parameters. Twenty normotensive hyper-TG patients were recruited from the Lipid outpatient Clinic: they had a baseline Na/Li CT activity significantly higher compared with age- and BMI-matched normolipidemic controls (386+/-33 vs 274+/-39 umol/l RBC/h, p<0.05). The patients were randomly prescribed one of the following two-months treatment: Group 1)-triglyceride lowering diet; Group 2)-lipid lowering drug (Gemfibrozil 600 mg b.i.d.). Na/Li CT and metabolic and anthropometric variables were measured at baseline and after 1 and 2 months of treatment. At the end of intervention, there was in both groups a significant and comparable fall in plasma triglyceride (group 1: -2.61+/-0.73 mmol/l p<0.01; group 2: -4.29+/-1.20 mmol/l p<0.01). In the diet-treated group there were, in addition small but significant reductions in body weight (-3.7+/-0.8 kg p<0.01), fasting glucose (-0.36+/-0.14 mmol/l p<0.05) and insulin levels (-2.1+/-0.5 mU/l, p<0.01), while no such changes were observed in the fibrate treated patients. Na/Li CT activity was significantly and comparably reduced at the end of treatment in both groups (group 1: -97+/-28 umol/l cell/h, p<0.01; group 2: -89+/-30 umol/l cell/h, p<0.01). In conclusion, these results indicate that the decrease in Na/Li CT associated with both dietary and drug treatment of hypertriglyceridemia is to be traced to a direct effect of plasma TG concentration on this transport system (probably as a result of modification in the membrane lipid environment) rather than to changes in plasma insulin levels or insulin resistance

Efficacy of diltiazem in elderly patients with stable effort angina

The antianginal effects of 360 mg/day of diltiazem were evaluated, using intrapatient comparisons, in a double/blind, randomized, placebo/controlled trial in 24 young patients (50 +/- 7 years) and in 16 elderly patients (67 +/- 3 years) with stable effort angina. All patients had angiographic documentation of significant coronary artery disease. An open-labelled, randomized, crossover design was employed. For 1 week prior to beginning the study, the patient was on no medication except sublingual nitrates. The study consisted of an initial 2-week single-blind placebo run-in period followed by a 4-week randomized double-blind crossover between diltiazem, 120 mg t.i.d., and placebo. A diary of chest pain and nitroglycerin usage was kept during this period and run-in. Exercise tests were carried out during the run-in period (2 tests) and at the end of the 4-week treatment. After diltiazem 12 of the 24 young patients stopped the exercise test because of angina. A similar number (9/16) of elderly patients stopped the exercise test because of angina. During diltiazem treatment, weekly angina frequency was significantly reduced in the young patients (1.25 +/- 0.67 vs 3.87 +/- 1.19-run-in, 4.08 +/- 1.24-placebo; p less than 0.01) and in the elderly patients (0.87 +/- 0.71 vs 4.06 +/- 1.48-run-in, 4.12 +/- 1.5-placebo; p less than 0.01). Weekly TNT consumption significantly decreased in both groups of patients