# Is a high preoperative HbA1c level a risk factor for postoperative complications in patients with non-small-cell lung cancer?

## TL;DR

This study found that severe diabetes before surgery does not increase postoperative complications in lung cancer patients when managed properly.

## Contribution

The study challenges the assumption that high preoperative HbA1c levels in diabetic NSCLC patients increase surgical complications.

## Key findings

- Severe diabetes (high HbA1c) was not significantly linked to postoperative complications in NSCLC patients.
- Low BMI, long surgical time, and lymphatic invasion were significant risk factors for complications.
- Strict preoperative diabetes management may mitigate risks in diabetic NSCLC patients.

## Abstract

Diabetes mellitus (DM) is a common comorbidity of lung cancer. We hypothesized that severe DM is associated with increased complications after surgical resection of non-small-cell lung cancer (NSCLC).

A review of our retrospective thoracic database identified 1139 consecutive surgical resections for NSCLC from 2002 to 2021. Our analysis included the exploration of clinicopathological features, perioperative variables, and surgical outcomes.

In addition to lung cancer, 170 patients (14.9%) had DM. The patients included 132 (77.6%) men and 38 (22.4%) women, with a median age of 72 (range, 51–93) years old. The median preoperative fasting blood glucose and HbA1c levels were 135 mg/dL (range, 57–303) and 6.9% (range, 5.1–14.8), respectively. Eighty-one patients had DM as a single comorbidity, and 89 patients had other comorbidities or a relevant medical history. A total of 144 patients were prescribed these drugs. There were 107 patients (62.9%) who consulted a specialist diabetes endocrinology department preoperatively and 118 patients (69.4%) who required sliding-scale insulin during the perioperative period. Forty-seven patients (27.6%) developed post-operative complications. No cases of bronchopleural fistula were noted. A univariate analysis showed that the sex (p = 0.017), body mass index (BMI) (p = 0.0032), surgical procedure (p = 0.017), surgical time (p = 0.002), and lymphatic invasion (p = 0.011) were significantly different among patients stratified by postoperative complications. A multivariate analysis showed that a low BMI (odds ratio [OR]: 0.413, 95% confidence interval [CI]: 0.196–0.870, p = 0.018), long surgical time (OR: 2.690, 95% CI: 1.190–6.082, p = 0.015), and presence of lymphatic invasion (OR: 2.849, 95% CI: 1.319–6.135, p = 0.007) were risk factors for postoperative complications. In contrast, severe preoperative DM did not have a significant negative effect on the incidence of postoperative complications.

In modern respiratory surgery, severe DM does not affect the short-term outcomes under strict preoperative treatment.