A case-control study on Alzheimer’s disease and exposure to anesthesia

Abstract

Aretrospective hospital-based case-control study was performed with the aim to evaluate the association between exposure to anesthesia and Alzheimer's disease (AD). A total of 115 AD patients, 230 Parkinson's disease (PD) patients and 230 patients with non-degenerative neurological disease were studied. Each AD case was matched for sex, age (+/-3 years) and geographic area of residence with four controls (2 PD patients and 2 with other neurological disease). Information about exposure to general anesthesia and other variables was gathered through hospital records. No associations were found between the risk of AD and the exposure to anesthesia in the 1 and 5 years preceding disease onset, nor between the risk of AD and the number of surgical operations. A significant difference was observed between the mean age of AD patients and controls undergoing surgical procedures. The present study reveals a lack of association between exposure to general anesthesia and AD. Prospective epidemiological studies are needed in order to investigate levels of exposure to anesthesia, as well as any possible relationships between anesthetic exposure and genetic factors (e. g. APOEepsilon4 genotype).

Cognitive decline in the elderly after surgery and anaesthesia: results from the Oxford Project to Investigate Memory and Ageing (OPTIMA) cohort

“…But the study of a sufficiently large cohort, including cognitively impaired people, with a broad interquartile range extending beyond the age of 80 years, could be valuable. We note that several of the studies that failed to find a relevant association 15, 33, 35, 39, but not all 34, 36, had a substantial proportion of participants who had surgery when < 70 years old. As the definition of the vulnerable population(s) is refined, some of the apparent contradictions above may be explained.…”

“…More studies have investigated associations of surgery or anaesthesia with either dementia 20, 21, 33, 34, 35, 36 or Alzheimer's disease 33, 37, 38, 39, 40. Several 20, 21, 38, 40 have reported increased risks for these outcomes, but several have not 33, 34, 35, 36, 39.…”

“…Several 20, 21, 38, 40 have reported increased risks for these outcomes, but several have not 33, 34, 35, 36, 39. Two very large Taiwanese studies 20, 21, both based on medical records, found an increased risk of dementia following surgery with anaesthesia, of various types 20.…”

Developmental Disability in the Young and Postoperative Cognitive Dysfunction in the Elderly After Anesthesia and Surgery: Do Data Justify Changing Clinical Practice?

“…Gasparini and coauthors also performed a retrospective case-controlled study of AD patients. In their study, the controls were Parkinson disease patients and patients with other neurological diseases 141 -but a link between general anesthesia and other neurological diseases has been hypothesized, 132 such that lack of a difference in anesthetic exposure between AD patients and patients with Parkinson or other neurological diseases does not imply a lack of a deleterious effect of anesthetic exposure.…”

On the issue of transmissibility of Alzheimer disease

“…Molecular mechanisms were hypothesized and especially volatile anesthetics were demonstrated to be associated with Aβ production, Aβ oligomerization, Tau formation and Tau phosphorylation as described thoroughly in a review by Papon et al 56 Several observational studies were designed to substantiate these experimental theories with epidemiological data. 32,47,48,[57][58][59][60] Nonetheless, a recent systematic review concluded that, despite the amount of studies available, evidence for an association of anesthesia with AD is Selected were those possibly associated with AD induction by a potentially transmissible pathogen (e.g., viral infections, blood transfusion, cns surgery). Therefore, studies regarding anesthesia, peripheral surgery, life style factors, genetics, etc., which are more abundant, are not shown.…”