Insulin-like growth factor 1 as a predictor of ischemic stroke outcome in the elderly.
OBJECTIVE
To examine whether serum insulin-like growth factor 1 (IGF-1) and IGF binding protein 3 (IGFBP-3) concentrations, determined early after the onset of stroke, are predictive of clinical outcome in elderly patients.


METHODS
The sample comprised 85 patients (mean [+/- SD] age, 83 +/- 7.4 years; range, 67 to 99 years; 34% male) who were admitted with acute stroke to a geriatric ward between January 1998 and June 2000, and 88 control patients who were similar in age and sex. Clinical and laboratory assessments, computed tomographic scan of the head, carotid ultrasonography, and electrocardiography were employed to define the clinical and etiologic stroke subtype. Fasting blood samples were collected within 24 hours of admission for IGF-I and IGFBP-3 measurement. Univariate and multiple logistic regression analyses, with adjustment for other related clinical covariates, were used to assess the relation of IGF-I and IGFBP-3 to poor outcome, defined as severe disability (Barthel index <60/100) or death, at 1 month (or at discharge), 3 months, and 6 months.


RESULTS
Mean (+/- SD) IGF-1 levels were lower in patients with stroke than in controls (69 +/- 45 ng/mL vs. 102 +/- 67 ng/mL, P adjusted for age = 0.001). The mean IGF-1/IGFBP-3 molar ratio was also lower in stroke patients (0.12 +/- 0.07 vs. 0.19 +/- 0.09, P adjusted for age <0.0001). However, there was no relation of hormone levels to either the clinical subtype of stroke or the extent of neurologic impairment. IGF-1 levels were inversely related to poor outcome (mainly death) at 3 and 6 months, independent of other clinical covariates that were highly predictive of outcome, such as age and stroke scale score on admission (hazard ratio for death at 6 months for each 20-ng/mL increase = 0.7; 95% confidence interval: 0.5 to 0.9). An independent association of the molar ratio with death at 3 and 6 months was also found.


CONCLUSIONS
Low levels of circulating IGF-1 may predict the clinical outcome of stroke in elderly patients.
Denti
Licia
L
Department of Internal Medicine and Biomedical Sciences, Section of Geriatrics, University of Parma, Parma, Italy.
Annoni
Valentina
V
Cattadori
Evelina
E
Salvagnini
Maria Angela
MA
Visioli
Sandra
S
Merli
Maria Francesca
MF
Corradi
Francesco
F
Ceresini
Graziano
G
Valenti
Giorgio
G
Hoffman
Andrew R
AR
Ceda
Gian Paolo
GP
D000203:Activities of Daily Living; D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001682:Biological Availability; D002545:Brain Ischemia / Q000150:complications*; D002140:California / Q000453:epidemiology; D016022:Case-Control Studies; D005215:Fasting; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D015592:Immunoradiometric Assay; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D012307:Risk Factors; D020521:Stroke / Q000097:blood* / Q000209:etiology / Q000401:mortality*; D016019:Survival Analysis
D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I