# The BMI impact on thyroidectomy-related morbidity; a case-matched single institutional analysis

## TL;DR

This study found that obesity does not increase surgical complications after thyroidectomy, despite longer operation times.

## Contribution

The novel contribution is showing that BMI does not affect thyroidectomy-related morbidity after case-matching.

## Key findings

- Obese patients had longer operative times but no increased risk of hypoparathyroidism or nerve palsy.
- There was no significant difference in complication rates between non-obese and obese patients.
- BMI ≥ 30 kg/m² was associated with prolonged surgery duration.

## Abstract

Obesity is associated with an increased risk of postoperative morbidity. We aimed to analyze the impact of BMI on surgical complications in patients undergoing thyroidectomy.

This retrospective study was conducted in a single academic center. A total of 484 patients with open total thyroidectomy were considered eligible. These patients were divided in the non-obese (BMI < 30 kg/m2) and obese (BMI ≥ 30 kg/m2) groups. A 1:2 case matching based on demographic (age and gender) and clinical (benign/malignant disease) variables was performed to generate homogenous study groups. A comparative analysis was carried out to show the differences between the two groups in terms of the occurrence of surgery-related outcomes.

After case matching, 193 non-obese and 98 obese patients were included in the final analysis. There was no statistically significant difference in the rate of primary outcomes in the non-obese and obese groups: hypoparathyroidism (transient: 29% versus 21.4%, p = 0.166; permanent: 11.4% versus 15.3%, p = 0.344, respectively) and recurrent laryngeal nerve palsy (transient: 13.9% versus 11.2%, p = 0.498; permanent: 3.1% versus 2.0%, p = 0.594, respectively). A BMI ≥ 30 kg/m2 was associated with a significantly longer operative time (p = 0.018), while other secondary outcomes were not significantly affected by BMI.

Despite prolonged operative times in obese patients, total thyroidectomy could be performed safely and without increased risk of surgery-related morbidity, regardless of BMI.

Not applicable.

The online version contains supplementary material available at 10.1186/s12893-025-03018-0.