Red blood cell distribution width is not related with inflammatory parameters in morbidly obese patients.

Clinical biochemistry

PubMedID: 24495861

Vayá A, Alis R, Hernandez-Mijares A, Solá E, Cámara R, Rivera L, Romagnoli M, Laiz B. Red blood cell distribution width is not related with inflammatory parameters in morbidly obese patients. Clin Biochem. 2014;.
OBJECTIVE
Red blood cell distribution width (RDW) is a hematological parameter that has been studied in several clinical settings and has been found to be related to both anemia and inflammatory status. As obesity is related to increased inflammatory pattern, we aimed to analyze the RDW in this setting.

METHODS
We determined hematological and inflammatory parameters in morbid obese patients before bariatric surgery (n=142) and normo-weight controls (n=144).

RESULTS
RDW was higher in patients than in controls (p<0.001), along with C-reactive protein (p<0.001) and fibrinogen, (p<0.001) while hemoglobin (p=0.026), serum iron (p<0.001), MCH (p=0.002) and MCHC (p<0.001) were lower in morbid obese patients. The the logistic correlation analysis revealed that only low serum iron (<62µg/dL) and MCH (<28.14pg) levels were associated with RDW>14% (OR 7.61, 95% CI: 1.93-30.04, p=0.004; OR 5.67, 95% CI: 1.98-16.24, p=0.001; respectively).

CONCLUSIONS
These data indicate that the elevated RDW in morbidly obese patients reflects a mild red blood cell hypochromia that does not relate to inflammatory parameters, but to hyposideremia and, consequently, to lower erythrocyte indices, possibly as a result of being on a very low-calorie diet before bariatric surgery. Therefore, RDW should not be considered as an inflammatory marker in this clinical setting.