Hypertension: Looking beyond the classic risk factors
A recent study examines the relationship between where people live and the risk of developing hypertension and metabolic syndrome. The authors conclude that the location and type of home could play a significant role.
According to the Centers for Disease Control and Prevention (CDC), hypertension, or high blood pressure, affects almost 1 in 3 adults in the United States.
Hypertension forms part of metabolic syndrome, which is a cluster of conditions that also includes excess body fat around the waist, high blood sugar levels, and abnormal levels of cholesterol or triglyceride in the blood.
Risk factors for metabolic syndrome include obesity, increasing age, genetics, and diabetes.
The above are also risk factors for hypertension, as are smoking, dietary factors, such as high salt intake, drinking too much alcohol, and stress.
Because both hypertension and metabolic syndrome affect a growing number of people, understanding the range of factors that leads to these conditions is vital.
Some researchers are investigating the potential impact of where we live. In this vein, scientists from the Lithuanian University of Health Sciences and Vytautas Magnus University, also in Lithuania, recently published new findings in the Journal of Public Health.
Air pollution and hypertension
Earlier studies investigating exposure to air pollution and its relationship with hypertension produced conflicting results. However, a meta-analysis of 17 studies published in the journal Hypertension in 2016 concluded:
"Our results suggest that short-term or long-term exposure to some air pollutants may increase the risk of hypertension."
The authors of the latest study, which uses data from Kaunas, in Lithuania, paid particular attention to average exposure to ambient air pollution and the distance to green spaces and major roads. They also examined differences between living in multifamily homes, such as blocks of flats, and private single-family homes.
Specifically, they looked for links between these factors and the risk of developing arterial hypertension and certain measures of metabolic syndrome: reduced levels of high-density lipoprotein cholesterol (HDL, or "good," cholesterol), high triglyceride levels, obesity, and elevated blood sugar.
The study utilized data from three questionnaires taken by a total of 1,354 individuals; all of these participants had lived at the same location throughout the 10-year duration of the study.
The questions covered factors such as education level, alcohol consumption, smoking status, level of physical activity, blood pressure medication, and lipid-lowering treatment.
By using each participant's address, the scientists could predict their exposure to pollution. They also calculated the distance to the nearest green space, which they defined as a park larger than 1 hectare (10,000 square meters), and proximity to major roads.
The researchers also controlled for a number of variables, including body mass index, salt consumption, and education level.
All things considered, they found that long-term exposure to air pollution levels that were above the median increased the risk of having lower HDL. Higher than average exposure to pollution also increased the risk of having higher levels of triglycerides.
They also concluded that living closer than 200 meters to a major road increased the risk of hypertension.
