Routine alcohol consumption, even in small amounts, was linked to an increased risk of high blood pressure in findings from an international meta-analysis that comprised more than 19 500 participants.
To sharpen an already fine point, researchers found that even adults who consumed just 1 standard alcoholic drink a day tended to have higher blood pressure compared to nondrinkers over time.
Further, the investigators say their results suggest that there is a linear, direct association between alcohol consumption and systolic blood pressure “with no evidence of threshold for the association.”1
According to senior investigator Marco Vinceti, MD, PhD, a professor of epidemiology and public health at the Medical School of the University of Modena and Reggio Emilia University in Italy and an adjunct professor in the department of epidemiology at Boston University’s School of Public Health, he and his colleagues were “somewhat surprised” to see that even low levels of alcohol consumption were associated with detectable increases in BP that could over time lead to greater risk of cardiovascular (CV) events.2
The evidence for a link between alcohol consumption and level of BP is robust, the authors wrote, but much less is clear about that link when consumption is ≤2 standard drinks per day. Also unknown is whether low statistical power in studies of low consumption may be to blame for uncertainty or if biological differences between light and heavy drinkers may intervene to cloud results.1
To help begin building the research base in this area, Vinceti and colleagues sought to assess how limited levels of alcohol consumption might influence risk of hypertension among healthy adults. They explain the study was an opportunity to apply a new statistical meta-analytic technique that allows “comprehensive exploration of dose-response relationships for aggregated data.” The study was designed as a dose-response meta-analysis of nonexperimental cohort studies.1
The research team searched Pubmed and Embase for studies that reported on an association between usual alcohol intake and blood pressure levels, published in English or Italian before May 9, 2023. Studies were required to be based on a cohort or case-cohort investigation; evaluate the relationship between alcohol consumption and change in blood pressure during follow-up; include healthy, adult participants; and report mean blood pressure and the corresponding 95% confidence intervals by baseline alcohol intake categories.1
The investigators were primarily interested in mean differences over time in systolic and diastolic blood pressure and plotted those according to baseline alcohol intake using the 1-stage meta-analytic methodology mentioned.
Overall, the team found 7256 studies that met inclusion criteria of which 7 were evaluated as eligible for the final analysis. These studies were published between 1997 and 2021, were conducted in North America or Asia, and included 19 548 participants, 65% of whom were men. The researchers point out that 3 of the studies included only men, 2 included both men and women, and 2 stratified the analysis by sex. The studies ranged in duration from 4 to 12 years, with a median follow-up of 5.3 years.1
Vinceti et al reported “a substantially linear positive association between baseline alcohol intake and changes over time” for both systolic and diastolic blood pressure and stressed there was no exposure-effect threshold observed. When they compared the highest with the lowest category of alcohol intake, they found an increased mean difference of +4.30 mm Hg for systolic blood pressure (95% CI, −2.76 to +5.85) ] and of+2.42 mm Hg for diastolic blood pressure (95% CI, +1.13 to +3.71).1
Compared with no alcohol consumption, the investigators found that usual systolic blood pressure was 1.25 mm Hg higher (95% CI, +0.49 to +2.01) for a 12 g/day greater consumption of alcohol and diastolic pressure 1.14 mm Hg higher (95% CI, +0.60 to +1.68). The corresponding differences in systolic and diastolic blood pressure for a daily alcohol consumption of 24 g/day were 2.48 (95% CI, +1.40 to +3.56) and 2.03 (95% CI, 1.19 to +2.86) mm Hg, respectively.1
Findings from subgroups analyses showed that by sex there was a near-linear association between baseline alcohol intake and systolic blood pressure changes for both men and women. For diastolic blood pressure the same dose-response association held for men but for women the team observed an inverted U-shaped association. Further subgroup analysis revealed alcohol consumption was positively associated with blood pressure changes in both Asian- and North American-based cohorts, with the exception of diastolic blood pressure among North Americans.1
“Alcohol is certainly not the sole driver of increases in blood pressure; however, our findings confirm it contributes in a meaningful way. Limiting alcohol intake is advised, and avoiding it is even better,” Vinceti said.2