Effects of enteral nutrition on nutritional serum markers of 161 hospital patients: a preliminary analysis

Rationale: The amount of enteral nutrition (EN) delivered determines its efficacy. Nutritional and inflammatory markers were prospectively assessed according to the level of coverage of the nutritional needs after 5 days of EN.

Method: The administration of EN (1 kcal/ml and 0.4g protein/ml) was increased by 500ml/day to cover nutritional needs: 1.1 x energy expenditure (Harris-Benedict). At baseline (D0) and after 5d of EN (D5), serum samples of C-Reactive Protein (CRP), albumin, transthyretin (TTR) and Insulin Growth Factor-1 (IGF-1) were obtained. At D5, patients were divided according to the energy target achieved (<65% or >65%).

Results: 161 consecutive patients hospitalised in medical or surgical services were enrolled. 130 successfully completed the protocol (age: 64.7±15yr; BMI: 24±6kg/m²). Mean energy needs were 1614±508kcal/d and 5d mean intake was 914±320 kcal/d. At D0, serum parameters were: CRP 110.8±83.7mg/L, albumin 30.6±6.6g/L, TTR 140±60 mg/L, IGF-1 78.2±42.3 ug/L.

Changes in serum parameters (D5-D0)

	CRPmg/L	IGF-1ug/L	TTR mg/L	Albuming/L
All patients	–25.2±83.0*	20.8±48.1*	0.02±0.1 **	–1.2±4.8*
≤65% (n=67)	–14.7±73.9	16.8±47.0*	0.02±0.1	–0.7±4.7
>65% (n=63)	–36.3±90.9*	25.3±49.3*	0.03±0.1*	–1.7±4.9 *
X: mean±SD; paired t-test *p<0.01; ** p=0.01

Conclusion: The efficacy of EN is influenced by inflammatory status. Five days of EN improve serum nutritional markers in patients receiving at least 65% of their metabolic needs. The lack of change in the <65% group (except for IGF-1) might be explained by a more persistent inflammation. IGF-1 and TTR are more sensitive parameters than albumin to assess the efficacy of the nutritional support.