Effects of depression, diabetes distress, diabetes self-efficacy, and diabetes self-management on glycemic control among Chinese population with type 2 diabetes mellitus

Highlights

• Among the factors influencing glycemic control.

• Only diabetes self-management had a direct effect on glycemic control.

• Depression only had an indirect effect on glycemic control through both diabetes self-efficacy and self-management.

• Diabetes distress only had an indirect effects on glycemic control through both diabetes self-efficacy and self-management.

• Diabetes self-efficacy only had an indirect effect on glycemic control through diabetes self-management.

Abstract

Aim

To examine the direct and indirect effects of depression, diabetes distress, diabetes self-efficacy and diabetes self-management on glycemic control among a group of T2DM patients in China.

Method

A convenience sample of 254 participants were selected from three outpatient departments in Beijing, China. They were surveyed using a self-administered questionnaire. Diabetes-related information was retrieved from their medical records. Descriptive statistics, independent student t tests, Chi-square tests, correlation analyses and Generalized Structural Equation Modeling were used.

Results

Only 91 (35.82%) participants achieved optimal glycemic control of HbA1c < 7.0% (53 mmol/mol). Only diabetes self-management had a direct effect on glycemic control (OR = 0.95, P < 0.001). Depression and diabetes distress had only indirect effects on glycemic control through both diabetes self-efficacy and diabetes self-management. Diabetes self-efficacy only had an indirect effect on glycemic control through diabetes self-management.

Conclusions

Glycemic control among Chinese population with T2DM was suboptimal. Future interventions should focus on decreasing depressive symptoms and diabetes distress levels, and, therefore, improve diabetes self-efficacy and self-management practices and, ultimately, reach the optimal goal of glycemic control.

Introduction

China has the largest population of people with diabetes in the world. It is estimated that an approximately 109.6 million people aged 20–79 in China were diagnosed with diabetes by the end of 2016 [1]. Diabetes and its comorbidities have placed heavy economic burdens on Chinese families [2]. It has been well established [3], [4] that strict glycemic control leads to decreased risk of diabetes complications. However, large-scale studies [5], [6], [7], [8] have shown that glycemic control was suboptimal among Chinese patients with type 2 diabetes (T2DM). Only 26.21–39.7% of participants in those studies achieved optimal glycemic control and met the goal of an HbA1c < 7.0% (53 mmol/mol). Therefore, it is critically important to understand the factors influencing glycemic control to guide interventions for preventing diabetes related complications.

So far a number of studies have been conducted to investigate glycemic control and the psychological and behavioral factors influencing it. By using regression analyses, researchers have found diabetes distress [9], [10], [11], diabetes self-efficacy [12], [13], [14], [15], and diabetes self-management behaviors [13], [15], [16], [17], [18] were independent predictors of glycemic control. Structural equation modeling enables researchers to examine the direct and indirect effects of the aforementioned factors on glycemic control. For example, they found that diabetes distress [19], [20], and diabetes self-efficacy [20], [21] had direct impacts on glycemic control. Moreover, a few studies found that diabetes self-efficacy [22], [23] and diabetes distress [24], [25] may have indirect effects on glycemic control through diabetes self-management behaviors. Furthermore, diabetes distress [24], [25] also influenced glycemic control through diabetes self-efficacy. However, researchers [20] found that depression was not associated with self-efficacy nor with HbA1c among 615 T2DM patients in the US.

Based on the aforementioned literature review, the majority of the literature focused on bivariate relationships and used regression analyses to examine relationships, and ignored the interplay between factors. More importantly, there has been limited research in China investigating psychological and behavioral factors and their collective impacts on glycemic control in spite of the large amount of populations with diabetes. Given the complexity of glycemic control, it is speculated that there is a variety of interplay among these factors. Examining the mechanisms leading to inadequate glycemic control is beneficial for clinicians developing interventions targeting modifiable factors. The purpose of the study is to identify the direct and indirect effects of depression, diabetes distress, diabetes self-efficacy and diabetes self-management on glycemic control in a group of T2DM patients residing in China. A model was proposed based on the literature review to guide the analyses (Fig. 1). In this model, it is hypothesized that depression, diabetes distress, diabetes self-efficacy and diabetes self-management have direct impacts on glycemic control; and that depression and diabetes distress have indirect effects on glycemic control through diabetes self-efficacy and diabetes self-management. Additionally, it is expected that the effect of diabetes self-efficacy on glycemic control will be mediated by diabetes self-management.