In addition to lifestyle factors such as physical activity, optimistic personality traits may lower diabetes risk.
A range of factors can raise the risk of developing type 2 diabetes.
Some of these factors — such as diet, physical activity, and weight — can be modified. Others, including ethnicity, genes, and age, cannot.
Some recent studies have suggested that a person's psychology can also influence their diabetes risk.
Depressive symptoms, for example, correlate strongly with a higher risk of incident diabetes, and researchers have suggested that depression be "included among risk factors that indicate intensified screening for diabetes."
Moreover, other studies have suggested that "self-reported cynical hostility" may also raise the risk of diabetes, as well as exacerbate symptoms of metabolic syndrome in postmenopausal women.
However, fewer studies have looked at the protective effect that some personality traits may have on diabetes risk in this group.
A new paper, published in Menopause, the journal of the North American Menopause Society (NAMS), aims to fill this gap in research.
Scientists have examined data from the Women's Health Initiative (WHI) to see whether positive traits such as optimism can lower the risk of type 2 diabetes in postmenopausal women. WHI is a long-term observational study aiming to prevent a range of chronic conditions in women.
Juhua Luo, Ph.D., from the School of Public Health at Indiana University in Bloomington is the first author of the new paper.
Optimism lowers diabetes risk by 12 percent
Luo and colleagues included data from 139,924 postmenopausal women who did not have diabetes at the beginning of the study. Throughout 14 years of clinical follow-up, 19,240 cases of type 2 diabetes occurred.
The scientists assessed the women's personality traits and divided them into quartiles.
They found that, compared with women in the lowest quartile of optimism, those who were the most optimistic were 12 percent less likely to develop diabetes.
Conversely, women who were the most likely to express negative emotions had a 9 percent higher risk of developing diabetes, and those who were in the highest quartile of hostility were 17 percent more likely to develop the condition.
Additionally, the study found that this correlation between hostility and diabetes risk was less strong in obese women.
Luo and colleagues conclude, "Low optimism and high [negativity] and hostility were associated with increased risk of incident diabetes among postmenopausal women, independent of major health behaviors and depressive symptoms."
"In addition to efforts to promote healthy behaviors, women's personality traits should be considered to guide clinical or programmatic intervention strategies in diabetes prevention."
Dr. JoAnn Pinkerton, the executive director of NAMS, comments, "Personality traits remain stable across one's lifetime; therefore, women at higher risk for diabetes who have low optimism, high negativity, and hostility could have prevention strategies tailored to their personality types."
"In addition to using personality traits to help us identify women at higher risk for developing diabetes, more individualized education and treatment strategies also should be used," adds Dr. Pinkerton.
In the United States, approximately 15 million — or 1 in 9 — women are currently living with diabetes.