Dados do Trabalho

Título

Body Composition and Insulin Sensitivity in Patients with Rectal Cancer

Introdução/Justificativa

Glucose intolerance is a metabolic abnormality recognized in patients with cancer cachexia and has been implicated in the development of low muscularity (LM). LM is an important feature associated with the poor prognosis of cancer patients, leading to a reduction in functional capacity, poor quality of life, increased treatment intolerance, and reduced overall survival. LM have been shown to correlate with insulin sensitivity. However, clinical studies evaluating the association between body composition features and insulin resistance are scarce, and the results are contradictory.

Objetivos

The purpose of this study was to evaluate the association between insulin sensitivity and the body composition features of patients recently diagnosed with rectal cancer.

Materiais e Métodos

This is a cross-sectional study involving patients diagnosed with rectal cancer. Body composition was analyzed using computed tomography (CT) images processed with the SliceOmatic software based on the difference in tissue measurements by Hounsfield Units (HU). Muscularity was categorized according to Martin’s criteria. Cachexia was categorized according to Fearon’s criteria. Insulin sensitivity was evaluated using euglycemic hyperinsulinemic clamp. Personal information, tumor characteristics, and biochemical exams were collected from medical records. Statistical analyses were conducted using Stata Corp LP® version 17.0 software. This study was approved by the Institutional Review Board (CAAE: 91217418.2.0000.5404).

Resultados

A total of 33 patients were included in the analysis. Low muscularity and cachexia diagnosis were identified in 27% of the sample (n=9). The low muscularity (LM) group consisted mostly of females aged 55–70 years. There was no difference in BMI, weight loss, tumor stage, or ECOG score between muscularity groups. The LM group had a lower skeletal muscle area (p < 0.001), lower visceral adipose tissue area (p = 0.01), and there is no difference in skeletal muscle radiodensity (p = 0.85), subcutaneous adipose tissue area (p = 0.76), and intramuscular adipose tissue area (p = 0.46) when compared to normal muscularity group. A lower handgrip strength was also observed in the LM group (p < 0.01). Regarding insulin sensitivity, the LM group had a higher M-value adjusted for Free Fat Mass (FFM) (p = 0.01) and M-value adjusted for Total Body Weight (TBW) (p = 0.0347). Additionally, a significant negative correlation was found between muscularity and M-value-FFM (rho= -0.5047, p = 0.004) and M-value-TBW (rho= -0.4742, p = 0.0076). There was no difference in M-value between cachexia and non-cachexia patients. No statistical difference was observed in inflammatory markers (C-reactive protein, Glasgow prognostic score (mGPS), and neutrophil-to-lymphocyte ratio (NLR)) according to muscularity groups.

Conclusão

There is no insulin resistance associated with LM or cachexia. It is possible that the main determinant of insulin sensitivity is the amount of visceral adipose tissue and systemic inflammation. The LM group exhibits a lower area of visceral adipose tissue, with no discernible difference in inflammatory markers. This study highlights the importance of expanding investigations into the determinants of metabolic changes and body composition in cancer cachexia.

Palavras Chave

INSULIN RESISTANCE; MUSCULARITY; CACHEXIA; METABOLISM; RECTAL NEOPLASIA