Use of Thiazolidinediones and Risk of Heart Failure in People With Type 2 Diabetes: A Retrospective Cohort Study
Response to Delea et al.
- Andrew J. Karter, PHD,
- Ameena T. Ahmed, MD, MPH,
- Jennifer Liu, MPH,
- Howard H. Moffet, MPH,
- Melissa M. Parker, MS,
- Assiamira Ferrara, MD, PHD and
- Joe V. Selby, MD, PHD
- From the Division of Research, Kaiser Permanente, Oakland, California
- Address correspondence to Andrew J. Karter, Division of Research, Kaiser Permanente, 3505 Broadway, Oakland, CA 94611. E-mail: andy.j.karter{at}kp.org
There is a growing concern that use of thiazolidinediones (TZDs) is associated with congestive heart failure (CHF) (1), though the causality of this relationship has not been established. Commentaries and case reports about this potential side effect have frequently appeared in the press, but peer-reviewed, large-scale epidemiologic studies have been absent. A few European nations have already limited the use of TZDs despite the absence of empirical evidence. A recently published, longitudinal observational study by Delea et al. (2) reported that initiation of TZDs was associated with an increased risk of incident CHF (hazard ratio 1.7; P < 0.001). While we welcome this first population-based study of TZD use and CHF, we have serious concerns regarding the methodology employed.
Our primary concern with the study by Delea et al. (2) is the potential for residual confounding by indication or severity (3). For example, this study did not measure or adjust for levels of glycemia, a known risk factor for CHF in diabetes …
