Longitudinal Analysis of Depressive Symptoms and Glycemic Control in Type 2 Diabetes
- James E. Aikens, PHD1,2,
- Denise White Perkins, MD, PHD3,
- Bonnie Lipton, MPH4 and
- John D. Piette, PHD2,5,6
- 1Department of Family Medicine, University of Michigan, Ann Arbor, Michigan;
- 2Diabetes Research and Training Center, University of Michigan, Ann Arbor, Michigan;
- 3Institute on Multicultural Health, Henry Ford Health System, Detroit, Michigan;
- 4Orthopedic and Arthritis Center for Outcomes Research, Brigham and Women's Hospital, Boston, Massachusetts;
- 5Health Services Research and Development Center for Excellence, Department of Veterans Affairs Medical Center, Ann Arbor, Michigan;
- 6Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan.
- Corresponding author: James E. Aikens, aikensj{at}umich.edu.
Abstract
OBJECTIVE To compare whether depressive symptoms are more strongly related to subsequent or prior glycemic control in type 2 diabetes and to test whether patient characteristics modify these longitudinal associations.
RESEARCH DESIGN AND METHODS On two occasions separated by 6 months, depressive symptoms and glycemic control were assessed in 253 adults with type 2 diabetes. Regression analyses examined depressive symptoms as both a predictor and outcome of glycemic control and tested whether medication regimen (e.g., insulin versus oral drugs) was an effect modifier before and after adjusting for baseline levels of the outcome being predicted.
RESULTS Depressive symptom severity predicted poor glycemic control 6 months later (P = 0.018) but not after baseline glycemic control was taken into account (P = 0.361). Although baseline glycemic control did not generally predict depressive symptoms 6 months later (P = 0.558), it significantly interacted with regimen (P = 0.008). Specifically, glycemic control predicted depressive symptoms among patients prescribed insulin (β = 0.31, P = 0.002) but not among those prescribed oral medication alone (β = −0.10, P = 0.210). Classifying depression dichotomously produced similar but weaker findings.
CONCLUSIONS Depressive symptoms do not necessarily lead to worsened glycemic control. In contrast, insulin-treated patients in poor glycemic control are at moderate risk for worsening of depressive symptoms. These patients should be carefully monitored to determine whether depression treatment should be initiated or intensified.
Footnotes
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The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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- Received January 15, 2009.
- Accepted April 15, 2009.
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Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. See http://creativecommons.org/licenses/by-nc-nd/3.0/ for details.
- © 2009 by the American Diabetes Association.
