1. Sofija Zagarins1, PhD, Garry Welch1, PhD, Jane Garb2, MS
Is improvement in blood glucose control following a diabetes education intervention associated with changes in depression or diabetes distress?
Sofija Zagarins1, PhD, Garry Welch1, PhD, Jane Garb2, MS
1Department of Behavioral Medicine Research and 2Department of Academic Affairs, Baystate Medical Center, Springfield MA
Introduction
Background
Depression is two to three more common in diabetes patients compared to the general population, and depressive symptoms have been shown in impact diabetes outcomes, including glycemic control.
In diabetes patients, depressive symptoms are highly correlated with diabetes-specific distress, and previous non-interventional studies have suggested that diabetes distress may have a greater effect on diabetes outcomes then depression itself.
Research gap
Current studies of diabetes distress, depression, and glycemic control are observational in nature; no such analyses have been conducted within a randomized controlled trial.
This is the first analysis to examine the relative effects of change in depressive symptoms and change in diabetes distress on change in glycemic control.
Figure 2a. Association between Improvement in Depression and Improvement in HbA1c
Improvement in HbA1c from R1 to R2
Improvement in Depression (CES-D Score) from R1 to R2 5 4 3 2 1 -1 -2 -3
r2 = 0.01
p = 0.20
Methods (cont.)
Statistical Analysis
Change scores for HbA1c and questionnaire scores were calculated as follow-up minus baseline values, such that positive values indicate an increase over time
Multiple linear regression was used to estimate associations between HbA1c change and changes in depression, diabetes distress, and other covariates
Models were adjusted for treatment group (MI vs. non-MI) and for other covariates, as appropriate
Covariates associated with HbA1c and dependent variables of interest at p<0.2 were included in regression models, and covariates associated with at least a 10% change in the beta coefficient for HbA1c were retained in the final model
Results
Methods
Study Design and Population
Population: n=234 patients diagnosed with type 2 diabetes for at least six months were recruited from the Springfield, MA area
Eligibility criteria:
HbA1c ≥ 7.5%
Age 30 – 80 years
No major diabetes complications or other medical conditions
No psychiatric illnesses such schizophrenia or mental retardation, as determined from diagnosis or recorded medications
Randomized controlled trial with two research assessments (R1 baseline and R2 at six months) and four diabetes education sessions with a certified diabetes educator (CDE1 – CDE4)
Patients were randomized to receive standard diabetes education delivered by a certified diabetes educator with or without motivational interviewing (MI)
Research Assessments
Hemoglobin A1c tested at Baystate Reference Laboratory (R1 and R2)
Behavioral and psychosocial information collected using published questionnaires having satisfactory reliability and construct validity (R1 and R2), as follows:
Self-care inventory (SCI-R) – Measures diabetes self-care behaviors
Range: 0 (low self-care behaviors) – 100 (high self-care behaviors)
Problem Areas in Diabetes (PAID) – Measures diabetes-related emotional distress
Range: 0 (low distress) – 100 (high distress)
Center for Epidemiologic Studies Depression scale (CES-D) – Measures major depression
Range: 0 (low depression) – 60 (high depression)
Score ≥ 16 suggestive of depression
Diabetes Treatment Satisfaction Questionnaire (DTSQ-change version)
Range: -24 (treatment is worse) – 24 (treatment has improved)
Patient perceptions of self efficacy attitudes regarding diabetes self-care behaviors (i.e., medication, glucose self-monitoring, diet, exercise)
Range: 0 (low self-efficacy) – 100 (high self-efficacy)
Figure 2b. Association between Improvement in Diabetes Distress and Improvement in HbA1c
Improvement in HbA1c from R1 to R2
Improvement in Diabetes Distress (PAID Score) from R1 to R2 5 4 3 2 1 -1 -2 -3
r2 = 0.12
p < 0.01 R1 R2
CDE1
CDE4
2 weeks
4 weeks
6 weeks
3 months
1 week
CDE3
CDE2
Discussion
This is the first analysis to examine the relative effects of change in depressive symptoms and change in diabetes-specific emotional distress on change in glycemic control in the context of an intervention study.
We found that change in diabetes distress was associated with change in HbA1c, while change in depression was not. Specifically:
A 10-point reduction on the PAID scale of diabetes distress was associated with a significant reduction in HbA1c of 0.3% (p<0.01).
Change in depression was not associated with change inHbA1c (β=0.1; p=0.23).
Reducing diabetes distress, rather than focusing on depression, may have a greater impact on blood glucose control for patients with poorly controlled type 2 diabetes.
Figure 1. Change in Self-Care Behaviors, Diabetes Distress, and Depression *
* p < 0.01