Glucose control and fatigue in type 2 diabetes: the mediating roles of diabetes symptoms and distress.

Aim: The purpose of this study was to examine the mediating influence of diabetes health characteristics (diabetes distress, depression symptoms and diabetes symptoms) on the relationship between glucose control and fatigue in adults with type 2 diabetes.

Background: In patients with type 2 diabetes, fatigue is common and can affect diabetes self-management behaviours. Although long thought to result from hyperglycaemia, little evidence supports a relationship between fatigue and glucose control.

Design: A cross-sectional, descriptive study design was used.

Method: Data were combined from two studies conducted at a large urban university in the Midwestern United States, resulting in a total sample of 155 urban-dwelling adults with type 2 diabetes. Data were collected over the course of 6 days from 2013-March 2014. Fatigue and related biological and psychological phenomena were measured to perform path analyses using structural equation modelling methods. The STATA software was used to analyse the data.

Findings: In patients with A1C less than or equal to 7%, fatigue was related to diabetes distress and diabetes symptoms, but not to A1C directly or indirectly. In the group with A1C greater than 7%, fatigue was indirectly related to A1C; this relationship was mediated through diabetes symptoms, depression and diabetes distress.

Conclusion: Our findings suggest that fatigue is indirectly related to glucose control, but only in patients who have elevated A1C levels. In those with adequate glucose control, fatigue is mainly influenced by the presence of diabetes symptoms and distress. In both groups, the number and severity of diabetes symptoms were the strongest predictors of fatigue, regardless of blood glucose control.