# Multimodal Evaluation of Body Composition and Muscle Strength in Women Before and After Bariatric Surgery: A Clinical Observational Study

## TL;DR

This study examines changes in body composition and muscle strength in women before and after bariatric surgery, highlighting the importance of muscle evaluation for better clinical monitoring.

## Contribution

The study introduces the evaluation of psoas muscle changes using CT scans in bariatric surgery patients, emphasizing its clinical relevance.

## Key findings

- Significant reductions in body weight, BMI, and muscle strength were observed after surgery.
- Psoas muscle area and index decreased, but muscle density increased significantly.
- Muscle evaluation is shown to be valuable for identifying risks and guiding post-surgery follow-up.

## Abstract

Background and Objectives: Obesity has been increasing sharply worldwide and is related to diabetes, cardiovascular diseases, liver disease, and cancer. Sleeve gastrectomy is the most used surgical approach to reduce body weight and treat metabolic implications observed in patients with moderate-to-severe obesity. On the other hand, this procedure affects the musculoskeletal system, and investigating skeletal muscle is not routinely recommended for bariatric surgery. This study aimed to evaluate the psoas muscle in patients in the preoperative period of sleeve gastrectomy and six months after the procedure using abdominal computed tomography scans. Materials and Methods: This clinical, exploratory, and observational study, with a prospective longitudinal observational study design, was conducted at a single center with 31 women who underwent sleeve gastrectomy. The evaluations were performed before and after six months of the procedures. Results: Anthropometric, muscle strength, hepatic ultrasound, and psoas computerized tomography evaluations were performed. A significant reduction in body weight, body mass index, waist, neck, and calf circumference was observed. There was also a substantial reduction in right-hand strength and the area and index of the psoas muscle (but with an increase in density). Most presented a routine abdominal ultrasound. Conclusions: Our results suggest that muscle evaluation provides valuable information for clinical monitoring before and after bariatric surgery, helping to identify potential risks and guide multidisciplinary follow-up. Psoas muscle area and psoas muscle index decreased, but psoas muscle density increased, all significantly. These results indicate that conducting a muscle evaluation is helpful for patients undergoing bariatric surgery, supporting the use of the clinical approach before and after the procedure, predicting possible complications, and providing more accurate prognoses.