THE EFFECT OF AGE AND FRAILTY UPON BLOOD ESTERASE-ACTIVITIES AND THEIR RESPONSE TO DIETARY SUPPLEMENTATION

1 The aims of this study were two-fold. First, to define ranges of blo od esterase activities in three groups, namely young subjects, fit com munity dwelling elderly and frail, chronically hospitalised elderly su bjects, and second, to determine whether low blood esterase activities in the frail patients could be altered by increasing their nutritiona l intake. 2 Plasma cholinesterase, aspirin esterase, paraoxonase and p henylacetate esterase activities were all significantly lower in the f rail elderly compared with the young and fit elderly volunteers. The a ctivity of red blood cell esterase was not different in the frail elde rly. 3 Fourteen frail elderly patients were randomly assigned to recei ve either hospital meal provision plus supplemental feeding with Build -up (Nestle) and Maxijul (SHS Ltd) or hospital provision alone for 8 w eeks. Dietary intake was measured for all patients at the start of the study and at week 8. Measurements of blood esterase (cholinesterase, phenylacetate esterase, paraoxonase, aspirin esterase and red blood ce ll esterase), albumin and anthropometric indices (weight, triceps skin fold thickness and mid arm circumference) were made before the study a nd repeated at week 4 and 8. 4 There was a significant increase in pla sma cholinesterase at week 4 (P < 0.05) but this was not statistically significant at week 8. There were no significant changes in any of th e other esterase activities or anthropometric measurements. 5 We concl ude that the lower esterase activities of the frail chronically hospit alised elderly do not respond to dietary supplementation for a period of 8 weeks with routinely available products. The hypothesis that lowe r esterase activities are the direct result of undernutrition which wo uld be corrected by dietary supplementation has not been supported by this study.