Hypertension is an important preventable risk factor for cardiovascular disease, the leading cause of mortality in the UK. In England, the prevalence of hypertension in 2002 was 37% in men and 34% in women. Despite substantial evidence on the relationship between alcohol and blood pressure, many questions remain, according to the authors. There is considerable variation on the reported nature of the relationship, that is, whether it is linear, J- or U-shaped or if there is a threshold effect; uncertainty whether it is affected by pattern of drinking, type of beverage, gender, age or ethnicity.
The study aimed to describe recent trends in alcohol consumption and blood pressure in England and the association between them and thus provide information relevant to the development of appropriate health education strategies and targeted policies to reduce harmful effects of alcohol on health.
Relationship between alcohol consumption and blood pressure
Average consumption
Mean Systolic Blood Pressure among women was lowest among those drinking 8-28 units of alcohol per week. After adjusting for age and other potential confounders, the group with the lowest SBP was that drinking up to 7 units/wk. Non-drinkers had a significantly higher SBP, raised on average by 1.64 (0.74;2.54) mm Hg, and SBP also rose as weekly alcohol consumption rose above seven units, with an average increase of nearly 5 mmHg in those drinking above 42 units/wk.
For men, mean SBP was lowest amongst non-drinkers. In the adjusted model, SBP was lowest among non-drinkers, ex-drinkers and those drinking up to 7 units per week, after which it rose with alcohol consumption, with an average increment of 4.39 (3.69;5.10) mmHg in those drinking 50 or more units/week.
The risk of hypertension among men drinking 1-7 units/week (the baseline) was not significantly different from the risk among non-drinkers, ex-drinkers or those drinking <1 unit/week, nor among those drinking up to 14 units/week. However, risk rose monotonically with alcohol intake above 7 units per week, with an odds ratio of 1.76 (1.58-1.96) in those drinking over 50 units/week.
Among women, the risk of hypertension was lowest amongst those drinking 1-7 units/week. Non-drinkers, and those drinking above 14 units/week had significantly higher risks, with the odds doubling in those drinking 43-49 units/week.
Pattern of drinking
Risks of hypertension for both men and women were highest in those who exceeded weekly guidelines, especially if they also exceeded daily limits. For men, there was also a raised risk if exceeding daily guidelines only, but for women there was a marginally reduced risk in this group.
The study concluded that there were clear associations between more than moderate drinking and raised blood pressure, with particular risks if exceeding weekly guidelines. For women, a beneficial effect of moderate drinking was seen, but not for men. For both sexes, the risk increased significantly above 14 units per week.
Source: The Influence of Alcohol on Blood Pressure. Kiran Nanchahal, Sam Pattenden, Paola Primatesta, Betsy Thom. Report to the Alcohol Education & Research Council May 2007.
