Newswise — Heavy drinking combined with cadmium exposure — most commonly via smoking — escalates the risk of hypertension, according to a new study. Hypertension (high blood pressure) affects 26 percent of the global population and is the leading cause of cardiovascular disease and mortality. Alcohol consumption and cadmium exposure are known risk factors for hypertension. Exposure to cadmium, a metal that accumulates in body organs, occurs mainly through smoking, which often accompanies heavy drinking. Other cadmium sources include certain foods, air pollution, and wine and beer. Alcohol increases the absorption of cadmium in the body, and evidence suggests that the two substances contribute to hypertension via shared physiological pathways. The new study, in Alcoholism: Clinical & Experimental Research, is the first known epidemiological investigation of the combined effects of alcohol and cadmium on blood pressure.
Researchers analyzed data from 8,403 South Korean adults aged 20–79, a representative sample of the national population, who participated in a series of health evaluations. The participants self-reported the frequency and quantity of their alcohol use. Their blood pressure was measured and their blood tested for cadmium levels. The researchers also tracked and accounted for additional factors that can influence hypertension, including demographic variables, body mass index, smoking status and other health-related behaviors, sodium and calorie intake, and certain diseases. They used statistical analysis to evaluate the associations between alcohol use, blood cadmium levels, and hypertension.
High-risk drinking and higher cadmium levels were each associated with increased risk of hypertension, after accounting for demographic factors and other variables. The more alcohol consumed, or the more cadmium in the blood, the higher the risk of hypertension. Fourteen percent of participants reported high-risk drinking (defined as 7+ drinks for men or 5+ for women in the course of a day at least twice a week). Twenty-five percent of the participants had high blood pressure. Hypertension among the heaviest drinkers (more than 10 drinks a week) was 79% more common than among non-drinkers, and 67% more common than in participants who were not high-risk drinkers. Hypertension in the group with the highest blood calcium levels was 46% more common than in the group with the lowest. When the two exposures were combined, the risk of hypertension was greater than for either heavy drinking or high cadmium exposure alone, and pointed to an interaction that amplified the relative effects of the two substances.
The findings underline the importance of reducing alcohol consumption and cadmium exposure as a matter of public health. Average cadmium exposure appears higher in South Korea than Canada and the US; that said, the study suggests that even low levels of blood cadmium may raise the prevalence of hypertension. The alcohol consumption in this study was self-reported, so may underestimate actual use. The study considered factors using data obtained at the same point in time, preventing researchers from establishing a causal relationship; they recommend follow-up investigation of the long-term effects.
Joint effects of alcohol drinking and environmental cadmium exposure on hypertension in Korean adults: Data analysis of the Korea National Health and Nutrition Examination Survey, 2008–2013. Y.-H. Choi, D.-A. Huh, K. W. Moon (pp xxx).