Multiple Lifestyle Factors Contribute to Diabetes Risk

According to the researchers, several risk factors have each been associated with a lower risk for diabetes; however, only limited data support a combined effect of lifestyle factors on diabetes risk.

Jared P. Reis, PhD, from the Division of Cardiovascular Sciences, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, and colleagues wrote, "Our objective was to examine how combinations of several lifestyle risk factors relate to the 11-year risk for incident diabetes in a large prospective cohort study of adults aged 50 to 71 years."

In a population-based prospective cohort study, the researchers analyzed data from the National Institutes of Health-American Association of Retired Persons Diet and Health Study, including 114,996 men and 92,483 women aged 50 to 71 years. Participants were recruited from 1995 to 1996, and at the time, they had no evidence of heart disease, cancer, or diabetes.

The study involved a comprehensive survey of demographic characteristics and lifestyle factors. These included factors such as dietary intake, body weight and height, physical activity, smoking, and alcohol consumption at the beginning of the study (1995-1996). Participants were classified into low-risk and non-low-risk groups for each lifestyle factor. Physician-diagnosed diabetes was identified in a follow-up survey conducted in 2004 to 2006.

Of the men and women, 9.6% and 7.5%, respectively, developed incident diabetes during the study period. For each additional lifestyle factor in the low-risk group, the risk of developing diabetes was reduced by 31% (odds ratio [OR], 0.69; 95% confidence interval [CI], 0.68 - 0.71) for men and 39% (OR, 0.61; 95% CI, 0.60 - 0.63) for women.

When participants had 4 low-risk factors (diet score, physical activity level, smoking status, and alcohol use), the risk was reduced both for men (OR, 0.61; 95% CI, 0.56 - 0.66) and for women (OR, 0.43; 95% CI, 0.34 - 0.55). If participants were also at an optimal weight, the risk was further reduced both for men (OR, 0.28; 95% CI, 0.23 - 0.34) and for women (OR, 0.16; 95% CI, 0.10 - 0.24).

No difference was observed based on extent of adiposity or family history of diabetes.

Study limitations include its observational design with possible residual bias, the measurement of lifestyle risk factors only at baseline, and a reliance on self-report of diabetes diagnosis.

"We found that a low-risk profile that incorporated 5 lifestyle factors was strongly associated with a lower risk for new-onset diabetes among older adults," Dr. Reis and colleagues concluded. "Each additional factor in the low-risk category was associated with a substantial reduction in risk for diabetes."

According to the researchers, the combined influence of these factors had a slightly stronger association with a lower risk for diabetes among women. In addition, the findings indicate that "overweight and obese adults may benefit from adopting other low-risk lifestyle behaviors."