# Sarcopenia is associated with early postoperative cognitive decline in older adults following hip fracture surgery: a prospective cohort study

## TL;DR

This study shows that sarcopenia, or muscle loss, is linked to early cognitive decline in older adults after hip surgery, and combining it with age improves risk prediction.

## Contribution

The study identifies sarcopenia as an independent risk factor for early postoperative cognitive decline in elderly hip fracture patients.

## Key findings

- 35.6% of patients had sarcopenia, and 22.7% experienced early POCD after surgery.
- Sarcopenia was independently associated with early POCD (OR = 3.716, P = 0.005).
- Combining sarcopenia with age ≥80 improved risk prediction (AUCROC = 0.704).

## Abstract

Early postoperative cognitive decline (POCD) frequently affects elderly individuals with hip fractures, and a significant number of these patients exhibit sarcopenia prior to surgery. Identifying patients with characteristics associated with an increased risk of early POCD at an early stage is essential for managing it effectively. Sarcopenia is a condition linked to aging, marked by a progressive reduction in muscle mass and function. Previous studies revealed that having lower muscle mass is linked to the development of perioperative neurocognitive disorders. This research aims to discover the association between sarcopenia and early POCD in aged hip fractures patients.

The study is a single-center, observational cohort study of patients aged 65 and above who underwent hip fracture surgery and were enrolled. Based on the Asian Working Group for Sarcopenia (AWGS) 2019 criteria, sarcopenia was diagnosed when both handgrip strength and skeletal muscle mass (measured by the axial plane of chest CT at the level of the T12)were below the established diagnostic cutoffs. Early POCD was characterized by a decrease of at least 1.5 standard deviations (SDs) in the results of two or more neuropsychological tests on postoperative day 7. The relationship between sarcopenia and early cognitive decline after surgery was examined using multivariate logistic regression, while its discriminatory ability was evaluated through the area under the receiver operating characteristic curve (AUCROC).

A total of 132 patients were included, 35.6% of whom had preoperative sarcopenia. Early POCD was observed in thirty patients (22.7%), as indicated by a reduction in their scores on the Trail Making Tests, Digit Symbol Substitution Test, and Clock Drawing Test. Multivariable analysis showed that preoperative sarcopenia(OR = 3.716, 95% CI:1.618–8.814, P = 0.005) was independently linked to early POCD after adjusting for age 80 and above (OR = 3.364, 95% CI:1.343–8.427, P = 0.01), and high-sensitivity C-reactive protein (Hs-CRP) > 6 mg/L(OR = 3.229, 95% CI:1.308–7.968, P = 0.011). The AUCROC was 0.658 (95% CI: 0.543–0.772). Furthermore, when combining the age ≥ 80 years in the model, the AUCROC reached 0.704(95% CI: 0.584–0.823, P = 0.001), indicating enhanced discriminatory performance in identifying patients at risk.

Sarcopenia, as defined by AWGS2019 criteria was independently associated with early POCD in elderly individuals after hip fracture surgery. When combined with age ≥ 80 years, it improves the identification of patients at high risk for early POCD.

ChiCTR2200055540, January 11, 2022.