Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (850 page)

Increased In

   Insulinoma

   Type 2 DM

Decreased In

   Exogenous insulin administration (e.g., factitious hypoglycemia)

   Type 1 DM

   Limitations

   C-peptide serum levels correlate with insulin levels in blood, except in islet cell tumors and possibly in obese patients.

C-REACTIVE PROTEIN, HIGH SENSITIVITY

   Definition

   High-sensitivity C-reactive protein (hs-CRP or cardiac CRP) is an acutephase reactant produced by hepatocytes and induced by the release of interleukin 1 and 6. It reflects activation of systemic inflammation. Blood levels of CRP are known to rise rapidly from normal baseline levels to as high as 50 mg/dL as part of the body’s nonspecific inflammatory response to infection or injury. The hs-CRP test is more sensitive than the standard CRP test.

   
Normal range:
<0.3 mg/dL (see Table 16.24).

TABLE 16–24. Cardiovascular Risk Classification by CRP
*

*
Cardiovascular disease risk assessment guidelines for CRP recommended by the CDC and the American Heart Association (CDC/AHA). Source: Pearson TA, Mensah GA, Alexander RW, et al. Markers of inflammation and cardiovascular disease. Application to clinical and public health practice. A Statement for Healthcare Professionals From the Centers for Disease Control and Prevention and the American Heart Association.
Circulation.
2003;107:499–511.

   Use

   Performing risk assessment for cardiovascular disease: Cardiac disease is believed to be the end result of interplay between minor changes in the cardiovascular endothelium and the corresponding inflammatory response to these changes.

   hs-CRP is an independent risk factor for cardiovascular disease, stroke, and peripheral vascular disease. It adds to the predictive value of total cholesterol and HDL cholesterol for future events.