Date Published: January 2, 2018
Publisher: Public Library of Science
Author(s): Jürgen Rehm, Charlotte Probst
Abstract: In a Perspective, Jürgen Rehm and Charlotte Probst examine the links between socioeconomic status, alcohol use, and cardiovascular mortality and discuss implications for policy.
Partial Text: Income inequalities and associated health consequences—in particular, premature mortality—are a major public health problem in the 21st century . Poorer people die earlier, and they die in part of different causes of death. While the differential distributions of risk factors by socioeconomic status (SES) contribute to the inequality in premature mortality, these distributions alone do not seem to be able to fully explain mortality differences . Thus, a lot of current research focuses on interactions between SES and risk factors and between different risk factors within socioeconomic strata.
In this regard, the paper of Degerud and colleagues in this week’s PLOS Medicine promises to become an important piece of the puzzle given its focus on cardiovascular mortality , globally the leading cause of death. Using a large population-based sample in Norway, they analyzed not only the associations between alcohol use and cardiovascular mortality by SES but also specifically the interaction between SES and alcohol use indicators. They found a significant interaction for drinking frequency and SES, but only a main effect for frequency of heavy drinking occasions with a nonsignificant interaction. Thus, the study observed that while heavy episodic drinking was associated with an elevated risk of cardiovascular mortality irrespective of SES, a moderate frequency of alcohol use was associated with more protective effects in the high compared with low or middle socioeconomic strata, and the protective effect of moderate drinking on cardiovascular mortality was not significant for people of low SES.
Substance use in general and alcohol use in particular have been key to recent reversals of life expectancy  in high- and middle-income countries, and widening mortality inequalities play a key role here. For instance, Case and Deaton  showed that the decreasing life expectancy in middle-aged non-Hispanic whites in the United States was associated with increases in mortality inequalities in key causes of death such as poisoning, suicide, and liver cirrhosis. Life expectancy stagnates for the US as a whole, and again, substance use in lower socioeconomic strata seems to play a key role [10,11]. As in the paper of Degerud and colleagues , the same level of substance use was linked to higher mortality risks in individuals of lower SES compared to those of higher SES.