Background Psychological attitudes reflecting expectations about the future (optimism, pessimism) and people (cynical hostility) independently predict incident cardiovascular disease and possibly diabetes, but underlying biologic pathways are incompletely understood. We examined the cross-sectional relationship between optimism, pessimism, and cynicism and biomarkers of metabolic function in the Women's Health Initiative. Methods Among 3443 postmenopausal women, biomarkers of metabolic function (fasting insulin and glucose) were measured at baseline and used to calculate insulin resistance (HOMA-IR) and pancreatic beta cell activity (HOMA-B). Psychological attitudes were assessed by the Life Orientation Test, Revised (LOT-R, full scale and optimism and pessimism subscales) and the Cook-Medley cynicism subscale. Multivariable linear regression modeled the association of psychological attitudes with biomarker levels, adjusting for sociodemographics, health conditions, and health behaviors. Because obesity promotes insulin resistance, and obese individuals tend to report higher levels of pessimism and cynical hostility, we explored an interaction with BMI. Results In fully-adjusted models, only pessimism remained independently associated with higher fasting insulin levels and insulin resistance (HOMA-IR). Scoring one point higher on the pessimism subscale was associated with a 1.2% higher fasting insulin level, while scoring one-standard deviation higher was associated with a 2.7% higher fasting insulin level (p = 0.03); (results similar for HOMA-IR). An interaction term with BMI was not significant. Conclusions In multivariable models, higher dispositional pessimism was associated with worse metabolic function, and these findings were not modified by obesity status. Results extend prior work by linking pessimism to an objective biomarker of insulin resistance in elderly women. HIGHLIGHTS In postmenopausal women, higher levels of pessimism were related to worse metabolic function. For each additional point on the pessimism scale, a woman's fasting insulin level was 1.2% higher, holding other health-related factors constant, while scoring one standard deviation higher was associated with almost 3% higher insulin levels. Future research should address whether interventions to modify pessimistic attitudes could potentially reduce a woman's risk of diabetes and/or cardiovascular disease.
