Insulin-like growth factor I as an indicator of protein-energy undernutrition among metabolically stable hospitalized elderly.
OBJECTIVE
The primary objective of this cross-sectional study was to test the hypothesis that the plasma concentration of insulin-like growth factor I (IGF-I) correlates with the risk of in-hospital morbidity among metabolically stable elderly. The secondary objective was to determine whether IGF-I correlates with other putative indicators of protein-energy nutritional status.


METHODS
To meet these objectives, 110 randomly selected admissions to a Geriatric Rehabilitation Unit (GRU) of a Veterans Administration hospital were studied. The average age of the study patients was 76 years; 98% were male, and 78% were white.


METHODS
At admission, each patient completed a comprehensive medical, functional, neuropsychological, and nutritional assessment including the attainment of a plasma IGF-I determination. While in the hospital, each subject was monitored daily for development of complications.


RESULTS
Subsequent to GRU admission, 44 patients (40%) experienced at least one complication; 36 patients (33%) experienced an infectious complication, 8 patients (7%) experienced a life-threatening complication, and 5 patients (5%) experienced a life-threatening infectious complication. There was no correlation between IGF-I and development of a non-life-threatening complication ("any complication" or "any infectious complication"). However, IGF-I was a strong predictor of "life-threatening" and "life-threatening infectious" complications. The logistic regression model incorporating the independent variable IGF-I differentiated the patients who would develop a "life-threatening" complication from those who would not with a sensitivity of 75%, a specificity of 76%, and an overall predictive accuracy of 76%. IGF-I was highly correlated with admission serum albumin, transferrin, and cholesterol, triceps skinfold thickness, body weight expressed as a percent of ideal, and body mass index. There was no correlation between IGF-I and the Katz Index of Activities of Daily Living score, age, or anergy status.


CONCLUSIONS
IGF-I is a strong predictor of "life-threatening" and "life-threatening infectious" complications and may be a clinically useful marker for protein-energy undernutrition among metabolically stable hospitalized elderly patients.
Sullivan
D H
DH
Geriatric Research Education and Clinical Center, John L. McClellan Memorial Veterans Hospital, Little Rock, AR 72205.
Carter
W J
WJ
D000368:Aged; D000369:Aged, 80 and over; D001835:Body Weight; D002784:Cholesterol / Q000097:blood; D005260:Female; D006760:Hospitalization; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011502:Protein-Energy Malnutrition / Q000097:blood*; D012709:Serum Albumin / Q000378:metabolism; D012885:Skinfold Thickness; D014168:Transferrin / Q000378:metabolism
D012709:Serum Albumin; D014168:Transferrin; D007334:Insulin-Like Growth Factor I; D002784:Cholesterol