Studies have suggested that changing neighborhood environments can affect positive behavior change, which in turn might help prevent type 2 diabetes (T2DM). Most studies looking at this issue, though, have been cross-sectional. They couldn’t provide much information about long-term exposures, which can be particularly important for a slowly developing disease like T2DM.
Now, the first longitudinal study has shed light on this issue.1 The study ran for over ten years, and found that people who live in neighborhoods that support long-term exposure to physical activity may have 21% decreased risk for developing T2DM. It also found that having exposure to resources that encourage healthy eating is linked to 12% decreased risk for developing T2DM.
“Our results suggest that modifying specific features of neighborhood environments, including increasing the availability of healthy food and physical activity resources, may help to mitigate the risk for T2DM although additional intervention studies with measures of multiple neighborhood features are needed,” wrote first author Paul Christine, MPH of the University of Michigan School of Public Health, and colleagues.
“Such approaches may be especially important for addressing disparities in T2DM given the concentration of low-income and minority populations in neighborhoods with fewer health-promoting resources,” they added.
The study was published online on June 29, 2015 and used data from the Multi-Ethnic Study of Atherosclerosis (MESA), which included adults aged 45 to 84 years without T2DM at baseline. Participants (n=5124) lived in New York City, Baltimore, Chicago, Los Angeles, Forsyth County, North Carolina, and St. Paul Minnesota, and received five followup exams between July 2000 and February 2002.
Researchers linked participant addresses to neighborhood exposures to healthy food, physical activity resources, and social norms and safety which could affect stress levels and health behavior. They used geographic information system- and survey-based methods to measure neighborhood environments and to calculate a summary score for healthy food, physical activity, and social environment. They adjusted results for age, sex, income, educational level, race/ethnicity, alcohol, and cigarette smoking. Finally, they defined incidence of T2DM according 2003 American Diabetes Association criteria (fasting plasma glucose ≥ 126 mg/dL) or use of antidiabetes medication.
• Over a median followup of 8.9 years, 12% of participants (616/5124) developed T2DM.
• Participants who developed T2DM were more likely to be black or Hispanic, have lower income, less education, less healthy diets, lower levels of physical activity, higher BMI, and a family history of T2DM.
• Lower risk for developing T2DM was linked to increased cumulative exposure to:
♦ Healthy food (12%; HR per interquartile range [IQR] increase in summary score 0.88 [95% CI 0.79-0.98])
♦ Physical activity resources (21%; HR per IQR) increase in summary score: 0.79 [95% CI 0.71-0.88])
♦ Living close to commercial recreational facilities and better survey estimates of the walking environment were linked to lower incidence of T2DM, but living close to supermarkets and fruit and vegetable markets were not.
• No associations were found between neighborhood safety/social cohesion and T2DM (HR per IQR increase in summary score 0.96 [95% CI 0.88-1.07).
“The neighborhood effects measured by Christine and colleagues documented that individuals residing in neighborhoods marked by limited resources for healthy eating and physical activity are at higher risk for being diagnosed with T2DM. Based on a rigorous prospective, longitudinal design their research substantiates the claim that the physical and social contexts of neighborhood environments matter for disease onset,” wrote Nancy Adler, PhD and Aric Prather PhD, of the University of California San Francisco, in a linked commentary.2
Drs Adler and Aric also pointed out the “notable” finding that shared perceptions of people, as measured by the survey responses, may be more important for assessing T2DM risk than objective measures like the geographic information system used in this study.
“Unless the available resources are widely known and viewed as accessible, ‘if you build it, they will come,’ may not apply… Having markets and recreational facilities located nearby may be necessary but not sufficient to enable healthy behaviors,” they mentioned.
“Building more facilities in neighborhoods that lack them is a component of an overall strategy to address the national rise in obesity, but this strategy needs to be informed by an understanding of when such facilities are actually used and the characteristics of the individuals who use them,” they emphasized, “In brief, the risk for T2DM is a combination of both person and place, and our national strategies need to understand and intervene across these levels.”
Take Home Points
• A ten-year longitudinal study found that people who live in neighborhoods that support long-term exposure to physical activity may have 21% decreased risk for developing T2DM.
• The study also found that having exposure to resources that encourage healthy eating is linked to 12% decreased risk for developing T2DM.
• Understanding who uses markets and recreational facilities, and when they use them, may be important for designing neighborhood interventions aimed at improving health and preventing T2DM.
1. Christine PJ, et al. Longitudinal associations between neighborhood physical and social environments and incident type 2 diabetes mellitus: The Multi-Ethnic Study of Atherosclerosis (MESA). JAMA Intern Med. 2015 Aug 1;175(8):1311-1320.
2. Adler NE, Prather AA. Risk for type 2 diabetes mellitus: Person, place and precision prevention. JAMA Intern Med. 2015 Aug 1;175(8):1311-1320.