Distress and Type 2 Diabetes: An Integrative Review

Problem: Half of all Americans are projected to be diagnosed with diabetes mellitus (DM) or prediabetes by 2020; and 2050 projections indicate that 1 in 3 Americans will develop DM. It is imperative to increase attention on the prevention of DM by identifying factors that contribute to its occurrence. While some evidence suggests that genetic predisposition and environmental factors contribute to the development of type 2 DM (T2DM), the evidence underlying the influence of distress remains inconclusive.

Purpose: The purpose of this integrated review was to identify the state of the science for the relationship between distress and insulin resistance (IR) as a precursor to the development of T2DM.

Methods: Over 1,600 articles were screened from three databases and one search engine: Cumulative Index to Nursing and Allied Health Literature, Ovid, PsycInfo, and Google Scholar.  Keywords included distress, depression, stress, psychosocial stress, insulin, prediabetes, diabetes prevention, and IR. Inclusion criteria were articles published within the last 10 years involving men and women > 18 years of age who were at risk for prediabetes or T2DM. Studies of distress post-T2DM diagnosis were excluded.

Results: Abstracts of > 60 articles were reviewed; approximately 30 full articles were read. Nine articles remained after screening: one randomized control trial (level 1 evidence) and eight cohort studies (level 2 evidence). Synthesis of Evidence: Distress resulting from a variety of sources may be a risk factor for T2DM. Depression and work stress increased the risk for T2DM approximately twofold (OR=2.56 [1.27-5.15] and OR=1.94 [1.17-3.21], 95% CI, respectively). Insomnia and smoking >10 cigarettes per day increased the risk for pre-diabetes secondary to insulin resistance (F[3, 199]=4.79, p=.004 and OR=2.63, 95% CI [2.04-3.39], p<0.05, respectively). The evidence available is highly dependent on how researchers define distress.

Conclusion: Some evidence is available for educating patients at risk for T2DM, particularly related to commonly accepted types of distress. To better guide preventive interventions, more research is needed that refines the concept of distress and tests its relationship with the development of T2DM.