Increased erythropoiesis and subclinical inflammation as part of the metabolic syndrome.

Recent studies have suggested the insulin resistance might be accompanied by enhanced erythropoiesis. We have examined this association in individuals with the metabolic syndrome (MS) who in addition to insulin resistance harbor a chronic low grade inflammation. This study is relevant because chronic inflammation might have a suppressive effect on erythropoiesis. 280 and 554 non-smoking women and men with respective age of 46.4+/-9.3 (mean+/-S.D.) and 44.0+/-11.0 years are included. A significant correlation was noted between the numbers of the components of the MS and the inflammatory biomarkers including the white blood cell count, high sensitivity C-reactive protein, fibrinogen concentrations and the erythrocyte sedimentation rate. In addition, a significant correlation (r=0.157, p=0.008) was noted between the number of components of the MS and the number of red blood cells in the peripheral blood in women. The same was true for men (r=0.192, p<0.0005). We conclude that enhanced erythropoiesis could be a new, hitherto unrecognized component of the MS. The enhanced erythropoiesis could give an erroneous impression of general "good" health in these individuals.