Decreased plasma fibronectin during starvation in man

Area of Science:

• Biochemistry
• Immunology
• Nutrition Science

Background:

• Investigates the impact of nutritional status on fibronectin, a key protein in immune response and tissue repair.
• Examines the relationship between starvation, refeeding, and fibronectin's opsonic activity.
• Compares fibronectin changes to other nutritional markers like albumin, iron-binding capacity, and retinol-binding protein.

Observation:

• Five days of starvation decreased plasma and serum fibronectin by 20-25% in healthy women, but did not impair opsonic activity.
• Retinol-binding protein significantly decreased by 35% during starvation, while albumin and iron-binding capacity remained stable.
• In cachectic patients, fibronectin levels were markedly reduced (25-75% of normal) before nutritional support.

Findings:

• Refeeding with a carbohydrate-containing diet normalized fibronectin levels within 5 days.
• A carbohydrate-free diet resulted in incomplete fibronectin normalization (82% of normal) after 5 days of refeeding.
• Retinol-binding protein showed incomplete recovery after 5 days of refeeding.

Implications:

• Fibronectin levels are sensitive to nutritional deficits, particularly during starvation.
• Adequate nutritional intake, emphasizing carbohydrates, is crucial for rapid restoration of fibronectin and immune function.
• These findings have implications for managing malnutrition and supporting immune recovery in clinical settings.