As more older adults undergo surgery, it is critical to understand the long-term effects of surgery on brain health, particularly in relation to the development of Alzheimer’s disease. This study examined the association of surgical hospitalization with subsequent brain β-amyloid deposition in nondemented older adults.
The Atherosclerosis Risk in Communities–Positron Emission Tomography (ARIC–PET) study is a prospective cohort study of 346 participants without dementia who underwent florbetapir PET imaging. Active surveillance of local hospitals and annual participant contact were used to gather hospitalization and surgical information (International Classification of Disease, Ninth Revision, Clinical Modification codes) over the preceding 24-yr period. Brain amyloid measured using florbetapir PET imaging was the primary outcome. Elevated amyloid was defined as a standardized uptake value ratio of more than 1.2.
Of the 313 participants included in this analysis (age at PET: 76.0 [SD 5.4]; 56% female), 72% had a prior hospitalization, and 50% had a prior surgical hospitalization. Elevated amyloid occurred in 87 of 156 (56%) participants with previous surgical hospitalization, compared with 45 of 87 (52%) participants who had no previous hospitalization. Participants with previous surgical hospitalizations did not show an increased odds of elevated brain amyloid (odds ratio, 1.32; 95% CI, 0.72 to 2.40; P = 0.370) after adjusting for confounders (primary analysis). Results were similar using the reference group of all participants without previous surgery (hospitalized and nonhospitalized; odds ratio, 1.58; 95% CI, 0.96 to 2.58; P = 0.070). In a prespecified secondary analysis, participants with previous surgical hospitalization did demonstrate increased odds of elevated amyloid when compared with participants hospitalized without surgery (odds ratio, 2.10; 95% CI, 1.09 to 4.05; P = 0.026). However, these results were attenuated and nonsignificant when alternative thresholds for amyloid-positive status were used.
The results do not support an association between surgical hospitalization and elevated brain amyloid.
Hospitalization for medical illness and surgical procedures has been associated with subsequent cognitive decline in some older patients
Animal models have suggested that surgery and anesthesia may lead to an increased production and accumulation of brain amyloid
This study found no differences in brain amyloid levels measured by positron emission tomography scans more than a decade after hospitalization for a surgical procedure when compared with patients who were not hospitalized and did not have a surgical procedure
When low-risk surgical procedures were removed from the analysis, there was a small but statistically significant increase in brain amyloid in patients who had high-risk surgical procedures when compared with all patients who did not have a surgical procedure
On secondary analysis, patients with two or more surgical hospitalizations had a higher odds of elevated brain amyloid during late life when compared with participants with no surgical hospitalizations regardless of whether they had been hospitalized for medical reasons
These data suggest that high-risk surgical procedures and multiple surgical procedures may be associated with increases in brain amyloid