Nutrition as a determinant of blood rheology and fibrinogen in athletes.

Blood rheology is influenced by metabolism and nutrition. We investigated this issue in 41 elite athletes exercising 13+/-0.9 hr/wk (mean age: 23.9+/-0.67 yr; mean VO2max: 52.6+/-2.3 ml/min/kg body weight) with a standardised nutritional questionnaire suitable for sports medicine. Calorie intake (% of recommended intake) was negatively correlated with the RBC disaggregability threshold (r=-0.505, p=0.01). There were negative correlations between fibrinogen and protein intake (% of the total caloric intake r=-0.787, p=0.0008; amount in g/kg/day r=-0.597, p=0.03). Accordingly, the RBC disaggregability threshold was also correlated negatively with protein intake (r=-0.508, p=0.05). Lipid intake (g/kg/day) was negatively correlated with the RBC disaggregability threshold (r=-0.564, p=0.03) and positively to the hematocrit/viscosity ratio (r=0.531, p=0.03). Carbohydrate intake (g/kg/day) was positively correlated with whole blood viscosity (r=0.517, p=0.04) and negatively to the hematocrit/viscosity ratio (r=-0.4863, p=0.05). In addition fibrinogen was negatively correlated with hematocrit (r=-0.4129, p=0.036) and positively with a host of aggregation parameters (p<0.001). Therefore fibrinogen levels and red cell rheology exhibit correlations with the nutritional status in athletes. Low protein intake appears to be associated with (mildly) raised fibrinogen and aggregability, and low calorie intake is associated with lower RBC disaggregability.