No threshold in the association of alcohol consumption with blood pressure in healthy persons
Alcohol Intake and Blood Pressure Levels: A Dose-Response Meta-Analysis of Nonexperimental Cohort StudiesLiterature - Di Federico S, Filippini T, Whelton PK, et al. - Hypertension. 2023 Jul 31. [Online ahead of print]. doi: 10.1161/HYPERTENSIONAHA.123.21224
Alcohol consumption has been associated with blood pressure (BP) levels [1-2], but the relationship between low levels of alcohol consumption and BP levels remains unclear. A new statistical meta-analytic technique has been developed which allows for the comprehensive exploration of dose-response relationships .
Aim of the study
The aim of the study was to investigate the association between alcohol consumption and BP levels, including the association at lower levels of alcohol consumption, in nonexperimental cohort studies.
The authors performed a systematic search of longitudinal studies published in PubMed and Embase databases that reported on the association between alcohol intake and BP in healthy adults before May 9, 2023. Trials were included in the meta-analysis when they met the following criteria: (1) based on a cohort or case-cohort investigation; (2) evaluated the relationship between alcohol consumption and changes in BP during follow-up; (3) included healthy, adult participants; and (4) reported mean BP and the corresponding 95%CIs by baseline alcohol intake categories, or provided the data needed to calculate the corresponding variances. Studies were excluded when they: had a cross-sectional study design; enrolled participants with prior history of CVD, diabetes or cirrhosis; only enrolled alcoholics; or exclusively investigated acute alcohol consumption and binge drinking. Seven reports were included in this meta-analysis, which were conducted in North America (n=3) or Asia (n=4), and these reports included data of 19,548 participants (65% men). The median follow-up period was 5.3 years. Analysis was performed using data of the entire study population, and as subgroup analyses stratified by gender or geographic region.
Outcomes were the differences over time in systolic BP (SBP) and diastolic BP (DBP) plotted according to baseline alcohol intake, by using a dose-response 1 stage meta-analytic methodology.
- Alcohol consumption at baseline was positively associated with the mean change in BP over time, in an almost linear manner. There was no evidence for a threshold.
- Per 12 g/day greater daily consumption of alcohol there was a +1.25 mmHg (95%CI: +0.49 to +2.01) increase in SBP and a +1.14 mmHg (95%CI: +0.60 to +1.68) increase in DBP compared with no alcohol consumption.
- SBP and DBP were increased by 2.48 mmHg (95%CI: 1.49 to 3.56) and 2.03 mmHg (95%CI: 1.19 to 2.86), respectively, per 24 g/day greater daily alcohol consumption with no alcohol consumption.
Subgroup analysis by sex
- The slope of the linear association between alcohol consumption and SBP was steeper in men compared with woman.
- There was a linear association between alcohol consumption and DBP in men, but not in woman, in whom the association had an inverted U-shape pattern. In woman, at a daily intake of ~40 g/day of alcohol, there was a threshold with no further increase in DBP, and even a slightly decrease in DBP.
Subgroup analysis by region
- In Asia, the association between alcohol consumption and DBP and SBP was similar as in the overall analysis.
- In North America, there was a positive, almost linear association between alcohol consumption and SBP. In contrast, there was only a positive association for DBP up to 24 g/day alcohol consumption, after which the association flattened and tended to decrease.
This meta-analysis showed that there is an almost linear relationship between alcohol intake and SBP in healthy persons, with no evidence for a threshold. In contrast, the association between DBP and alcohol consumption was modified by sex and geographic region.