Type 2 Diabetes Risk Up in Highly Deprived Neighborhoods

Risk for type 2 diabetes may be increased for people living in highly deprived areas, according to data from a study of refugee immigrants in Sweden.¹

“We found that living in a high-deprivation neighborhood led to an increased risk of type 2 diabetes, compared to living in the least deprived areas. Although the increased risk was small, we found that the effect accumulated over time,” study author Justin S. White, PhD, from the University of California, San Francisco, said in a press release.

Earlier studies have demonstrated an association between risk for chronic diseases such as type 2 diabetes and heart disease and living in a highly deprived area. Without randomized trials, though, researchers have been unable to observe more than a statistical association, as they were unable to account for certain limitations like selection bias.

In the present study, published in The Lancet Diabetes & Endocrinology, the researchers analyzed data from 61 386 refugee immigrants aged 25 to 50 who arrived in Sweden from 1987 to 1991 — a period during which Sweden saw a large influx of refugees, primarily from the Middle East and North Africa. Government policy during the time sought to distribute the refugees across the country to improve integration and avoid putting a strain on local job markets by inundating major cities with newly arrived, unemployed people.

Refugees were assigned to housing in 1 of 4833 neighborhoods throughout Sweden. Because they were dispersed by officers with limited information about their backgrounds, assignment was considered quasi-random by the researchers.

Neighborhoods were categorized as low-, moderate-, or high-deprivation based on residents’ education levels, income, unemployment, and social welfare assistance.

The researchers analyzed the proportion of people who developed type 2 diabetes from January 2002 to December 2010, excluding people with type 1 diabetes and those diagnosed with type 2 diabetes within 5 years of arriving in Sweden to avoid the inclusion of people with preexisting disease in their analysis.

Neighborhood and Long-Term Health Effects

Of all refugees included in the study, 7.4% had developed diabetes at follow-up.¹ In contrast, the national prevalence of diabetes in Sweden was estimated to be 4% to 6% during the same time period,¹ the researchers noted.

Of the 28 785 refugees assigned to high-deprivation neighborhoods, 7.9% developed type 2 diabetes vs 7.2% in moderate-deprivation neighborhoods and 5.8% in low-deprivation neighborhoods,¹ according to the data.

In adjusted models, results linked living in a high- vs low-deprivation neighborhood with a 22% increased risk for type 2 diabetes (odds ratio [OR]=1.22; 95% CI, 1.07-1.38).¹ Living in a moderate-deprivation neighborhood was also associated with a 15% increased risk for the disease (OR=1.15; 95% CI, 1.01-1.31), as compared with a low-deprivation neighborhood.¹

Additionally, refugees who were initially assigned to a high-deprivation neighborhood had a 1.7-percentage point increase in risk for developing type 2 diabetes.¹ Adjustment for covariates attenuated this association, dropping to a 0.8-percentage point increase.¹ These data represent a relative increase of 15% to 30%,¹ the researchers reported.

Data also showed that diabetes risk accumulated over time as opposed to occurring immediately after arrival, with 5 years of additional exposure to high- vs low-deprivation neighborhoods being associated with a 9% increase in diabetes risk.¹

“The increased risk didn’t develop immediately, which is consistent with the way neighborhoods are thought to affect health, and chronic diseases in particular,” Dr White said. “There are likely to be a number of factors explaining the link, such as increased exposure to chronic stress from living in a high-crime or segregated area, the limited income and employment opportunities that affect a person’s ability to afford healthy food, the lack of availability of healthy food in the neighborhood, or its low levels of walkability.”