Getting Out of the Car Best for Blood Pressure, Weight Control, Studies Say

New research supports the idea that adding steps to your day can help control blood pressure, prevent weight gain, and perhaps prevent diabetes.

Two studies that looked at using a car less—by moving to walkable neighborhoods or by using public transportation—were presented early Sunday at the 2015 Scientific Sessions of the American Heart Association (AHA), meeting in Orlando, Florida. Both showed that walking for routine errands and commuting is healthier than using the car.

The first study, from the Institute for Clinical Evaluative Services in Toronto, Canada,¹ comes from a team that has produced other studies on the health effect of “walkable neighborhoods.” This one found that those who moved to a walkable neighborhood had a 54% lower risk of high blood pressure after at least 4 years than those who moved to a place that still required use of a car.

The second study, from the Moriguchi City Health Examination Center in Osaka, Japan,² examined health status based on how commuters got to work. Compared with drivers, those who used public transportation were 44% less likely to be overweight, 27% less likely to have high blood pressure, and 34% less likely to have diabetes.

In September, US Surgeon General Vivek H. Murthy issued a “Call to Action” on walking—he said that adding just 22 minutes of exercise a day could make a difference in lowering high blood pressure and preventing chronic conditions like diabetes and obesity. Walking is especially helpful for those who haven’t been exercising at all and need a place to start, Murthy said.

Walking helps control blood pressure, the main risk factor in heart disease, which is the leading cause of death in the United States. High blood pressure is also the leading indicator for stroke, which is the fifth leading cause of death, according to the AHA.

Walkable neighborhoods matter. In this study, researchers compared 1057 pairs of adults from the Canadian Community Health Survey for the years 2001 to 2010. Pairs moved from a low-walkability neighborhood to a high-walkability one, or from one low-walkability neighborhood to another.

To gauge “walkability,” researchers used WalkScore, a tool that rates neighborhoods from 1 to 100 based on accessibility on foot to destinations such as stores, parks, and schools. Places that scored 90 had “high walkability.” The matched groups were balanced on 16 factors such as age, income, marital status and body mass index. Researchers used electronic health records to obtain their hypertension measures. Researchers noted they did not have detailed dietary information on the pairs.

Lead author Maria Chiu, MSc, PhD, said the pairs were followed for a total of 11 years and a median of 4 years. Pairs were remarkably well-matched, including for factors such as alcohol use and vegetable consumption. Chiu said the study used the propensity score method to control for confounders such as education, income, and marital status. At a press conference Sunday, she said she was surprised at the magnitude of difference in the rate of hypertension: incident rate of hypertension was 8.6 per 1000 person years among those who moved from low walkability to high walkability neighborhoods, while it was 14.9 per 1000 per years among those who moved between low walkability neighborhoods in the same period.¹

“The low to high movers survived longer hypertension free than the low to low movers,” Chiu said.

As they have in other work, the study’s authors said their findings are a call on planners and elected officials to talk walkability into account when approving neighborhood design.

“We need to set people up for success by making walking instead of driving the more convenient and enjoyable choice,” Chiu said.

The bus beats the car. Researchers from Moriguchi, Osaka, Japan studied 5908 commuters who were identified from a larger group of 16,397 commuters during their annual health checkup in 2012. The subjects were asked about both the level activity at their workplace and how they got to work.

Controlling for work activity, age, gender, and smoking status, the researchers found that those who took public transportation had better health measures than those who drove to work, either by car or motorbike. The analysis showed that those taking public transportation were much less likely to be overweight, (OR=0.56, 95% CI=0.45 to 0.69, P<0.0001); had lower prevalence of hypertension (OR=0.73, 95% CI=0.59 to 0.90, P=0.0035); and lower prevalence of diabetes (OR=0.66, 95% CI=0.44 to 0.99, P=0.0427), after adjusting for covariates.²

To their surprise, researchers found that those taking the bus or the train had better measures for diabetes, high blood pressure and weight control than even commuters who walked or biked to work. The researchers speculated that the bus and train commuters were actually walking more steps to get to work than those with shorter commutes.

“If it takes longer than 20 minutes one-way to commute by walking or cycling, many people seem to take public transportation or a car in urban areas of Japan,” said lead author Hisako Tsuji, MD, director of the Moriguchi City Health Examination Center. She said physicians should ask their patients how they get to work.

The team noted the limits of its study: most who used public transportation were women, and most drivers were men. They did not know if their findings would apply in the United States, where more commuters are already overweight. The average age of the study participants was 49 to 54 years old.

References

1. Chiu M, Rezai MR, Maclagan L, et al. Moving to a highly walkable neighborhood and incidence of hypertension: a propensity-score matched cohort study. Presented at the American Heart Association Scientific Sessions; Orlando, Florida; November 8, 2015. Abstract 134.

2. Tsuji H, Shiojima I. Taking public transportation instead of driving linked with better health. Presented at the American Heart Association Scientific Sessions; Orlando, Florida; November 8, 2015. Abstract 15214.