Do negative personality traits make women prone to diabetes?
Personality traits such as low optimism, negative emotional expressiveness (NEE) and hostility in postmenopausal women may increase their susceptibility to type 2 diabetes (T2D) independent of major health behaviours and depressive symptoms, a study has found.
“Our findings are consistent with previous studies reporting that positive psychological well-being was associated with lower risk of incident coronary heart disease and longevity … [as well as] with better glucose control and lower mortality rates in patients with T2D,” the investigators said. [Psychol Bull 2012;138:655-691; Circulation 2009;120:656-662; Exp Clin Endocr Diab 2010;118:364-367]
The present analysis included 139,924 postmenopausal women aged 50–79 years from the Women's Health Initiative study. All women were free of diabetes at baseline and completed questionnaires that assessed personality traits. Personality traits such as optimism, ambivalence over emotional expressiveness, NEE and hostility were included as exposures.
Over a mean follow-up of 14 years, 19,240 women developed T2D. Multivariable Cox regression analysis showed a significant trend toward lower diabetes risk across increasing levels of optimism (p<0.001), as well as higher risk across increasing levels of NEE and hostility (p<0.0001 for both). [Menopause 2019;doi:10.1097/GME.0000000000001296]
Compared with women who were least optimistic, those who were most optimistic had a 12-percent lower risk of T2D (lowest vs highest quartile: hazard ratio [HR], 0.88; 95 percent CI, 0.84–0.92). Meanwhile, the risk was greater by 9 percent and 17 percent in women in the highest vs lowest quartile of NEE (HR, 1.09; 1.05–1.14) or hostility (HR, 1.17; 1.12–1.23), respectively.
Relationships remained significant after adjustment for demographic characteristics, modifiable health behaviours and depressive symptoms. Notably, the association between hostility and T2D risk was more pronounced among nonobese than obese women.
“Our data suggest that … biological mechanisms related to cortisol regulation or reduced inflammation may be more likely to reside on the pathway between personality characteristics and diabetes,” according to the investigators.
Emotional stress has been implicated in the aetiology of diabetes. There is some evidence showing that an elevation in the concentration of proinflammatory cytokines and glucocorticoids, particularly cortisol, occurs under conditions involving chronic stress and, often, depression, which may contribute to accumulation of visceral fat or lipolysis or release of free fatty acids and then insulin resistance. [Discov Med 2010;9:112-118; J Psychiatry Neurosci 2009;34:4-20; Ann NY Acad Sci 2017;1391:20-34]
“A personality trait implies a style of responding or thinking. Thus, knowing how an individual typically or likely thinks or behaves allows the attentive clinician to fashion the communication or treatment accordingly. Although it may be hard to change people’s personality traits, especially for older people, we can use information about personality to guide clinical or programmatic intervention strategies,” the investigators pointed out.
Further investigation is needed to determine whether diabetes prevention intervention may be tailored according to different personality traits, they added.