SPECIFICITY OF INDEXES OF MALNUTRITION WHEN APPLIED TO APPARENTLY HEALTHY PEOPLE - THE EFFECT OF AGE

Protein-energy malnutrition is thought to be widespread in hospitalize d patients. However, the specificity of indexes used to assess malnutr ition is uncertain. We therefore assessed the rate of false-positive d iagnoses of malnutrition when biochemical-anthropometric indexes were applied to healthy subjects. Nutritional status was assessed in 175 he althy blood donors (aged 44.2 +/- 13.4 y) and in 34 highly fit elderly volunteers (aged 74.7 +/- 3.6 y) participating in the Nijmegen Four D ays Walking March. We investigated both the Nutritional Risk Index [(1 .489 x albumin) + (41.7 x present/usual weight)] and the Maastricht In dex [20.68 - (0.24 x albumin, g/L) - (19.21 x serum transthyretin, g/L )- (1.86 x lymphocytes, 10(6)/L) - (0.04 x ideal weight)]. We found pr eviously that 52-64% of nonsurgical hospitalized patients were malnour ished according to these indexes. In the present study, 1.9% of the 20 9 volunteers had apparent;malnutrition according to the Nutritional Ri sk Index and 3.8% according to the Maastricht Index. The prevalence of apparent malnutrition in the elderly volunteers was 5.9% and 20.6%, r espectively. The rate of false-positive diagnoses was acceptably low i n those aged < 70 y with both the Nutritional Risk Index and the Maast richt Index; therefore, the use of these indexes will not cause a clin ically significant increase in the prevalence of malnutrition because patients who are not malnourished are included. The high percentage of spurious malnutrition in the elderly limits the use of the Maastricht Index to subjects aged < 70 y.