Changes in A1C Levels Are Significantly Associated With Changes in Levels of the Cardiovascular Risk Biomarker hs-CRP
Results from SteP Study
- Oliver Schnell, MD1⇓,
- Ildiko Amann-Zalan, MD, PHD2,
- Zhihong Jelsovsky, MS3,
- Annette Moritz, PHD2,
- Justo L. Bermejo, PHD4,
- Christopher G. Parkin, MS5,
- Matthias A. Schweitzer, MD2,
- Lawrence Fisher, PHD6 and
- William H. Polonsky, PHD7
- 1Forschergruppe Diabetes e.V., Helmholtz Center Munich, Munich, Germany
- 2Roche Diagnostics Deutschland GmbH, Mannheim, Germany
- 3Biostat International, Inc., Tampa, Florida
- 4Institute of Medical Biometry and Informatics, University of Heidelberg, Heidelberg, Germany
- 5CGParkin Communications, Inc., Boulder City, Nevada
- 6Diabetes Center, University of California, San Francisco, San Francisco, California
- 7Department of Psychiatry, University of California, San Diego, San Diego, California
- Corresponding author: Oliver Schnell, .
OBJECTIVE The effect of therapeutic strategies on cardiovascular (CV) disease can be evaluated by monitoring changes in CV risk biomarkers. This study investigated the effect of a structured self-monitoring of blood glucose (SMBG) protocol and the resulting improvements in glycemic control on changes in high-sensitivity C-reactive protein (hs-CRP) in insulin-naïve patients with type 2 diabetes.
RESEARCH DESIGN AND METHODS The Structured Testing Program (STeP) study was a prospective, cluster-randomized, multicenter trial in which 483 poorly controlled, insulin-naïve patients with type 2 diabetes were randomized to active control (ACG) or structured testing (STG) that included quarterly structured SMBG. Changes in A1C, hs-CRP, and glycemic variability (STG subjects only) were measured at baseline and quarterly.
RESULTS Reductions in geometric mean hs-CRP values were significantly greater in the STG group at months 3 (P = 0.005), 6 (P = 0.0003), and 12 (P = 0.04) than in the ACG group. STG patients at high CV risk (>3 mg/L) showed significantly greater reductions in hs-CRP levels than ACG patients at high CV risk: −3.64 mg/dL (95% CI −4.21 to −3.06) versus −2.18 mg/dL (−2.93 to −1.43), respectively (P = 0.002). There was a strong correlation between reductions in hs-CRP and A1C in both groups: standardized coefficient (β) was 0.25 for the entire cohort (P < 0.0001), 0.31 for STG (P < 0.0001), and 0.16 for ACG (P = 0.02).
CONCLUSIONS Reductions in hs-CRP level are associated with reductions in A1C but not reductions in lipids or glycemic variability. Comprehensive structured SMBG-based interventions that lower A1C may translate into improvements in CV risk, as evidenced by levels of the biomarker hs-CRP.
- Received August 23, 2012.
- Accepted November 19, 2012.
- © 2013 by the American Diabetes Association.
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