Socioeconomic status and hypertension: a meta-analysis

Background: The relationship between socioeconomic status (SES) and hypertension has been studied in a number of reviews. However, the impact of SES on hypertension has been reported in several studies with conflicting results. Methods: A systematic search was performed in PubMed, Proquest and Cochrane databases for observational studies on hypertension prevalence and SES, published in English, until March 2014. Hypertension was defined as a mean SBP of at least 140mmHg or a DBP of at least 90 mmHg, or use of antihypertensive medication. The inverse variance method with a random-effects model was used to pool the risk estimates from the individual studies. Data abstraction was conducted independently by two authors. Results: Among the 2404 references, 51 studies fulfilled the inclusion criteria. An overall increased risk of hypertension among the lowest SES was found for all three indicators: income [pooled odds ratio (OR) 1.19, 95% confidence interval (CI) 0.96-1.48], occupation (pooled OR 1.31, 95% CI 1.04-1.64) and education (pooled OR 2.02, 95% CI 1.55-2.63). The associations were significant in high-income countries, and the increased risk of hypertension for the lowest categories of all SES indicators was most evident for women, whereas men revealed less consistent associations. Conclusion: Low SES is associated with higher blood pressure, and this association is particularly evident in the level of education. It is important to identify and monitor hypertension to reduce the risk of this disease among the most vulnerable groups in different countries and among different societies.