Background: It is unclear whether the association between alcohol consumption and risk of cardiovascular disease is affected by social support.
Methods: The prospective data for 19,356 men aged 40 to 69 years who participated in the Japan Public Health Center-Based Prospective Study. Alcohol consumption was classified into 7 categories: never, past, occasional, 1 to 149, 150 to 299, 300 to 449, or > or =450 g ethanol/wk. Associations between alcohol consumption and risk of cardiovascular disease were stratified by the median level of social support score, which was measured in emotional support score of this cohort study.
Results: During an average follow-up of 9.9 years, 629 total strokes and 207 coronary heart diseases were documented. Light-to-moderate alcohol consumption was associated with reduced risks of coronary heart disease and total cardiovascular disease, while heavy alcohol consumption was associated with increased risk of total stroke, in particular hemorrhagic stroke. When stratified by social support score, the multivariable hazard ratios of total cardiovascular disease associated with light-to-moderate alcohol consumption (1 to 299 g/wk) were 0.99 (0.72 to 1.37) in the low social support group and 0.56 (0.44 to 0.70) in the high social support group (p for interaction = 0.002), while the multivariable hazard ratios of hemorrhagic stroke associated with heavy alcohol consumption (> or =300 g/wk) were 2.09 (1.03 to 4.27) in the low social support group and 1.25 (0.72 to 2.15) in the high social support group (p for interaction = 0.44). There was no interaction between alcohol consumption and social support in relation to risk of coronary heart disease.
Conclusions: Social support may enhance the beneficial effect of light-to-moderate alcohol consumption on risk of cardiovascular disease.