The effects of alcohol on ambulatory blood pressure and other cardiovascular risk factors in type 2 diabetes: a randomized intervention.

Objective: Although prospective studies suggest light-to-moderate chronic alcohol intake protects against coronary artery disease in type 2 diabetic patients, the balance of effects on individual cardiovascular risk factors needs further assessment. We examined the effects of alcohol consumption on 24-h ambulatory blood pressure (BP) and heart rate (HR), high-density lipoprotein cholesterol, fibrinogen, C-reactive protein, homocysteine, and glycaemic control in well controlled type 2 diabetes.

Methods: Twenty-four participants aged 49-66 year were randomized to a three-period crossover study with women drinking red wine 230  ml/day (∼24  g alcohol/day) and men drinking red wine 300  ml/day (∼31  g alcohol/day), or equivalent volumes of dealcoholized red wine (DRW) or water, each for 4 weeks. Ambulatory BP and HR were monitored every 30  min for 24  h at the end of each period. Home blood glucose monitoring was carried out twice weekly throughout.

Results: Red wine increased awake SBP and DBP relative to water by 2.5 ± 1.2 /1.9 ± 0.7  mmHg (P = 0.033, P = 0.008, respectively), with a similar nonsignificant trend relative to DRW. Asleep DBP fell with red wine relative to DRW (2.0 ± 0.8  mmHg, P = 0.016) with a similar nonsignificant trend relative to water. Red wine increased 24-h, awake and asleep HR relative to water and DRW. Relative to DRW, red wine did not affect glycaemic control or any other cardiovascular risk factor.

Conclusion: In well controlled type 2 diabetic individuals 24-31  g alcohol/day (∼2-3 standard drinks) raises awake BP and 24-h HR and lowers asleep BP but does not otherwise favourably or adversely modify cardiovascular risk factors.