Longitudinal analysis of depressive symptoms and glycemic control in type 2 diabetes

Diabetes Care. 2009 Jul;32(7):1177-81. doi: 10.2337/dc09-0071. Epub 2009 Apr 23.

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 (beta = 0.31, P = 0.002) but not among those prescribed oral medication alone (beta = -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.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Blood Glucose / metabolism*
  • Depression / epidemiology*
  • Diabetes Mellitus, Type 2 / blood*
  • Diabetes Mellitus, Type 2 / psychology*
  • Follow-Up Studies
  • Glycated Hemoglobin / metabolism
  • Homeostasis
  • Humans
  • Longitudinal Studies
  • Middle Aged
  • Regression Analysis
  • Reproducibility of Results
  • Treatment Outcome

Substances

  • Blood Glucose
  • Glycated Hemoglobin A