title: Association between Serum IGF-I levels and Postoperative Delirium in Elderly Subjects Undergoing Elective Knee Arthroplasty.
abstract: Evidence is mixed for an association between serum insulin-like growth factor-I (IGF-I) levels and postoperative delirium (POD). The current study assessed preoperative serum IGF-I levels as a predictor of incident delirium in non-demented elderly elective knee arthroplasty patients. Preoperative serum levels of total IGF-I were measured using a commercially available Human IGF-I ELISA kit. POD incidence and severity were determined using DSM-IV criteria and the Delirium Rating Scale-Revised-98 (DRS-R98), respectively. Median IGF-I levels in delirious (62.6 ng/ml) and non-delirious groups (65.9 ng/ml) were not significantly different (p = 0.141). The ratio (95% CI) of geometric means, D/ND, was 0.86 (0.70, 1.06). The Hodges-Lehmann median difference estimate was 7.23 ng/mL with 95% confidence interval (-2.32, 19.9). In multivariate logistic regression analysis IGF-I level was not a significant predictor of incident POD after correcting for medical comorbidities. IGF-I levels did not correlate with DRS-R98 scores for delirium severity. In conclusion, we report no evidence of association between serum IGF-I levels and incidence of POD, although the sample size was inadequate for a conclusive study. Further efforts to investigate IGF-I as a delirium risk factor in elderly should address comorbidities and confounders that influence IGF-I levels.
authors: Duke-NUS Graduate Medical School, Singapore.
authors: Timothy E
authors: TE
authors: Yen
authors: Duke-NUS Graduate Medical School, Singapore.
authors: John C
authors: JC
authors: Allen
authors: Duke University School of Medicine, Department of Psychiatry, Durham, NC 27710.
authors: Sarah K
authors: SK
authors: Rivelli
authors: Duke University School of Medicine, Durham, NC 27710.
authors: Stephanie C
authors: SC
authors: Patterson
authors: University of Missouri - Kansas City, Department of Surgery, Kansas City, MO 64108.
authors: Meredith R
authors: MR
authors: Metcalf
authors: Emory University School of Medicine, Department of Surgery, Atlanta, GA 30307.
authors: Benjamin J
authors: BJ
authors: Flink
authors: Saint Joseph Hospital, Department of Internal Medicine, Chicago, IL 60657.
authors: Aibek E
authors: AE
authors: Mirrakhimov
authors: Duke University School of Medicine, Department of Surgery, Durham, NC 27710.
authors: Sandhya A
authors: SA
authors: Lagoo
authors: University of California, San Francisco, San Francisco, CA 94143.
authors: Thomas P
authors: TP
authors: Vail
authors: Duke University School of Medicine, Department of Anesthesiology, Durham, NC 27710.
authors: Christopher C
authors: CC
authors: Young
authors: Duke University School of Medicine, Department of Anesthesiology, Durham, NC 27710.
authors: Richard E
authors: RE
authors: Moon
authors: Indiana University School of Medicine, Indianapolis, IN 46202.|Tufts University Medical School, Boston, MA 02111.
authors: Paula T
authors: PT
authors: Trzepacz
authors: Duke University School of Medicine, Department of Anesthesiology, Durham, NC 27710.
authors: Madan M
authors: MM
authors: Kwatra
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D003693:Delirium / Q000453:epidemiology* / Q000209:etiology / Q000378:metabolism; D017558:Elective Surgical Procedures; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D016015:Logistic Models; D011446:Prospective Studies; D012307:Risk Factors
chemical_list: C583557:IGF1 protein, human; D007334:Insulin-Like Growth Factor I