Cortisol, Insulin & Glucose and the Risk of Delirium in Older Adults with Hip Fracture

1. Cortisol, Insulin & Glucose and the Risk of Delirium in Older Adults with Hip Fracture Peter H. Bisschop, MD, PhD; Sophia E. de Rooij, MD, PhD; Aeilko H. Zwinderman, PhD; Hannah E. van Oosten, MD; and Barbara C. van Munster, MD, PhD The American Geriatrics Society 59:1692 - 1696 Lindsay Drevlow, PA-S2 November 28, 2011

2. Overview • Delirium = severe neuropsychiatric syndrome • Acute onset • Fluctuating course of inattention • Contributing factors: • Preexisting functional/cognitive impairment, acute medical illness, trauma, surgery or medications • 30 - 50% older adults with hip fx experience perioperative delirium

3. Overview • Pathophysiology of Delirium • Poorly understood • Physiologic stress response metabolic changes • Possible hypothalamic-pituitary-adrenal axis activation

4. H-P-A Axis

5. Overview • Cortisol = major stress hormone • Functions: • Increase blood sugar via gluconeogenesis • Suppress immune system • Aid in fat, protein and carbohydrate metabolism • Glucose and Insulin • Counteracts insulin, causing hyperglycemia • Inhibits peripheral utilization of glucose

6. Objective • To determine the relationship b/t perioperative delirium and cortisol, glucose and insulin in older patients acutely admitted for hip fracture

7. Design and Setting • Prospective cohort study • Tertiary University Center

8. Inclusion: Consecutive individuals aged 65+ acutely admitted for hip fx May 2005 - October 2008 143 patients Exclusion: Lack of surrogate or refusal to consent Inability to speak or understand Dutch/English 170 patients Participants

9. Methods • Confusion Assessment Scale • Presence vs. Absence of delirium • Delirium Observation Screening Scale • Delirium Symptom Interview • Subtyping • Delirium Rating Scale-98 • Severity • Charleston Comorbidity Index • Informant Questionnaire on Cognitive Decline-short form • Katz ADL Index

10. Methods • Blood Samples • 1 pre-op, 1 - 3 post-op • All collected around 11 am • Kept on ice • Centrifuged to separate plasma & serum • Cortisol, Glucose and Insulin measured

11. Statistical Analyses • T-tests and Mann-Whitney Tests • Log transformation used to fulfill normality • 4 separate analyses used to look at relationship b/t C, logG, logI and logI:G • Random effect = participant # • Fixed effects = day of sample, delirious state, age, sex, preexisting cognitive & functional impairment • Logistic Regression • Dependent variable = delirium • Independent variables = C, G, I, I:G • Samples of participants with preexisiting DM taken before/after delirium were excluded

12. Results • 143 individuals • 49% with delirium • 51% without delirium • 457 samples • 196 with delirium • 28 before • 137 during • 60 after • 232 without delirium

13. Results • Pre-admission cognitive/functional impairment more prevalent in pts WITH delirium • Pre-operative cortisol related to cognitive impairment • Delirium a/w higher cortisol and lower insulin in univariate analysis • Not significant after correction for pre-existing cognitive/functional impairment in multivariate analysis • No difference in insulin w/ or w/o delirium in either analysis

14. Results

15. Conclusion • Negative study for cortisol, insulin and glucose & the risk of delirium in people with hip fracture

16. Limitations • Results are not generalizable • Abnormal glucose levels are only “defined” for diabetes • Would suspect a correlation b/t cortisol and insulin

17. Level of Evidence: 2B

18. References • Bisschop, P. H., de Rooij, S. E., Zwinderman, A. H., van Oosten, H. E. and van Munster, B. C. (2011), Cortisol, Insulin, and Glucose and the Risk of Delirium in Older Adults with Hip Fracture. Journal of the American Geriatrics Society, 59: 1692–1696. doi: 10.1111/j.1532-5415.2011.03575.x