Relationship between nutritional status and the systemic inflammatory response: micronutrients

Abstract

Micronutrients such as trace elements and vitamins are important as enzyme cofactors in the metabolism of all cells in the body and therefore key to determining nutritional status. The present systematic review examined the evidence of the impact of the systemic inflammatory response on plasma micronutrient status in acute (surgical) and chronic tissue injury. A literature review using targeted subject headings was carried out. Plasma C-reactive protein was used to classify minor (80 mg/l) inflammation. The literature search produced 2344 publications and plasma vitamin D, zinc and carotenoids were most commonly studied and plasma vitamins K, B2 and B6 were least studied. In acute injury thirteen studies (all prospective) and in chronic injury twenty-four studies (largely retrospective) were included in the review. There was consistent evidence that most common measured micronutrients in the plasma (zinc, selenium, vitamins A, D, E, K, B2, B6, B12, C, lutein, lycopene, α- and β-carotene) were significantly lowered from minor to moderate to major inflammation. The results of the present systematic review indicate that most plasma micronutrients fall as part of the systemic inflammatory response irrespective of acute or chronic injury. Therefore, in the presence of a systemic inflammation, plasma micronutrient concentrations should be interpreted with caution. There are a number of methods applied to adjust plasma micronutrient concentrations to avoid misdiagnosis of deficiency. Alternatively, intracellular measurements appear to obviate the need for such plasma adjustment to assess micronutrient status.

Parenteral Provision of Micronutrients to Adult Patients: An Expert Consensus Paper

“…Currently, there is no universal approach to account for inflammation when determining micronutrient status . Micronutrient concentrations should always be determined in conjunction with an indicator of inflammatory status, such as CRP. Inflammation may be classified minor (CRP < 10 mg/L), moderate (CRP between 11–80 mg/L), and major (CRP > 80 mg/L) …”

“…19,27,28,30,35,61 r Serum iron levels should be interpreted in the context of inflammatory markers (e.g., CRP). 19 Selenium r Decreased serum levels 4,19,24,27,28,30,36,59 in proportion to the magnitude of the inflammatory response and also due to increased urinary losses. r Serum selenium levels should be interpreted in the context of inflammatory markers (e.g., CRP).…”

“…Albumin is a negative acute phase protein and since zinc is bound to albumin for transport, decreased albumin levels will result in less available zinc. 4,19,24,[27][28][29][30]36,59 r Redistribution of zinc also results in an increased accumulation of zinc in the liver where it acts as cofactor for acute phase protein (APP) synthesis. r Serum zinc levels should be interpreted in the context of inflammatory markers (e.g., CRP).…”

“…r Vitamin A decreases during the acute phase because RBP acts as a negative acute phase protein. 27,28,36…”

“…Vitamin B 12 r Serum levels not affected by periods of inflammation. 4 Vitamin C r A decrease in serum ascorbic acid 28,30,36 is seen with only a slight increase in CRP ( 5-10 mg/L). 29 r Therefore caution should be taken when interpreting true deficiency.…”