Association between red blood cell distribution width and macrovascular and microvascular complications in diabetes.

AIMS/HYPOTHESIS: Red blood cell distribution width (RDW) has been reported to be a risk marker of morbidity and mortality for cardiovascular disease in various study populations. However, no studies have investigated the relationship between RDW and diabetes complications. We therefore evaluated RDW as a marker of macrovascular and microvascular complications in a nationally representative sample of the adult diabetes population in the USA.

METHODS

A cross-sectional study was performed using the nationwide 1988 to 1994 data set from the Third National Health and Nutrition Examination Survey. The association between RDW quartiles and macrovascular and microvascular complications was evaluated in 2,497 non-pregnant adults aged 20 years and older and affected by diabetes. Logistic regression modelling was used to adjust for potential confounding.

RESULTS

Compared with the lowest RDW quartile, higher RDW values (3rd and 4th quartiles) were associated with increased adjusted odds of any vascular complication (OR 4th quartile 2.06 [95% CI 1.11, 3.83]), myocardial infarction (OR 4th quartile 2.45 [95% CI 1.13, 5.28]), heart failure (OR 4th quartile 4.40 [95% CI 1.99, 9.72]), stroke (OR 4th quartile 2.56 [95% CI 1.21, 5.42]) and nephropathy (OR 4th quartile 2.33 [95% CI 1.42, 3.82]). The odds of developing diabetic retinopathy were not significantly increased across RDW quartiles.

CONCLUSIONS/INTERPRETATION: Higher RDW values are associated with increased odds of developing cardiovascular disease and nephropathy in a nationally representative sample of USA adults with diabetes. RDW may be an important clinical marker of vascular complications in diabetes and one that is independent of traditional risk factors and disease duration.