Plasma concentration of interleukin-6 was upregulated in cancer cachexia patients and was positively correlated with plasma free fatty acid in female patients

Abstract Background Cancer cachexia is a clinical manifestation in various advanced cancers that characterized by muscle atrophy and fat loss as its main features; it is frequently associated with systemic inflammatory response. However, the differences in inflammatory response and lipid metabolism of different genders remain unclear. This study explores the difference between cachexic and non-cachexic patients in different genders and cancer types and focus on the plasma inflammation factors levels and lipid metabolism parameters in different genders. Methods We first analyzed the general characteristics in 311 cancer patients between cachexic and non-cachexic patients, with an emphasis on expression levels related to inflammatory factors and lipid metabolism parameters. We then further analyzed these characteristics in different genders and cancer types. Lastly, the correlations between plasma interleukin-6 (IL-6) and lipid metabolism parameters in cachexia patients of different genders were analyzed. Results Among 311 patients, there were 74 cancer cachexia patients (50 males and 24 females) and 237non-cachexia patients (150 males and 87 females). Body mass index (BMI), TNM stage, plasma concentration of hemoglobin, platelet, lymphocyte count, total protein, albumin, prealbumin, total cholesterol, apolipoprotein E (ApoE), free fatty acid (FFA) and IL-6 were significantly different between cachexic and non-cachexic patients (all p < 0.05). In addition, these characteristics were different in different cancer types. When compared to male non-cachexic patients, male cachexic patients showed a significant increase in plasma levels of IL-6 and platelet, later TNM stage, with marked decrease in their plasma total protein, albumin, prealbumin, ApoE as well as their lymphocyte counts and hemoglobin levels (all p < 0.05). In comparison with female non-cachexic patients, female cachexic patients’ IL-6 levels and FFA were significantly elevated with noticeable decrease in their BMI, total cholesterol, ApoE and prealbumin, as well as later TNM stage (all p < 0.05). Correlation analysis revealed that IL-6 levels in female cachexic patients had a significant positive correlation with FFA expression, but this correlation not reflected in male patients. Conclusion This study demonstrates the different metabolic characteristics of male and female cancer cachexia patients. Future study about cancer cachexia should pay attention to different genders and cancer types.