Acute effect of oral nutrients on fibrinogen synthesis in healthy young and elderly subjects

Abstract

The hepatic synthesis of fibrinogen is stimulated following inflammation and trauma. However, it is not known if fibrinogen synthesis is responsive to oral nutrients and, further, whether the meal effect may be influenced by age. The aim of the study was to assess the acute effect of oral feeding on fibrinogen synthesis, in both young and elderly subjects. Fibrinogen synthesis was determined in three separate occasions from the incorporation of L[2H5]phenylalanine (43 mg/kg) in 8 young (21–35 y) and 6 elderly (>60 y) subjects following the ingestion of water (control), a complete liquid meal (15% protein, 30% fat and 55% CHO), or only the protein component of the meal. The ingestion of the complete meal significantly enhanced fibrinogen fractional synthesis rates (FSR) in both groups by 30% (P < 0.005). A comparable stimulation of FSR was observed with only the protein component of the meal in both young (+36 %) and elderly subjects (+29 %) (P<0.001). Similar results were obtained when fibrinogen synthesis was expressed as absolute synthesis rates (ASR, i.e. mg/kg/day). The results demonstrate that fibrinogen synthesis is acutely enhanced after feeding and that this effect can be elicited by the protein component of the meal alone, both in young and elderly subjects.Supported by NIH grants AG 017446 and 5‐MO1‐RR‐10710 and the NY State Empire Clinical Investigator Program (ECRIP)