Inflammation and body composition in over- and undernutrition: Overweight and cancer cachexia

Abstract

This thesis focuses on the association between inflammation and body composition and consists of one cross sectional study in healthy overweight and in lean subjects (paper I), and one prospective study in patients with pancreatic cancer (papers II and III). In paper I, the relationship between inflammatory markers and body composition measured with anthropometry and bioelectrical impedance analysis (BIA) was examined in healthy individuals. Increasing hip circumference (HC) was associated with increasing levels of leptin and C-reactive protein (CRP) in both groups. CRP increased with increasing body mass index (BMI), also in the lean group. HC may be a proxy for fat percent measured with BIA in lean and overweight individuals, and may be useful for identification of people at risk of developing overweight-related disorders. In paper II the level of inflammatory markers, body composition, energy intake and development of cachexia was examined. Pancreatic cancer patients had higher levels of inflammatory markers compared with a healthy reference population at inclusion, and the levels increased as death approached. Weight, fat- and muscle mass were reduced during follow-up. At inclusion, there were no differences in the levels of inflammatory markers between patients who were classified as cachectic and those who were not. These results indicate that the increased levels of inflammation may be caused by the tumor and the tumor-host reactions. The third paper compared two classifications of cancer cachexia; the 3-factor classification that includes CRP as a criterion, and the consensus classification that includes sarcopenia as a criterion. Patients were categorized as cachectic and non-cachectic according to both classifications. Consistency across definitions was examined, as well as their ability to predict survival. The two classifications of cancer cachexia showed good overall agreement in defining cachectic patients, and cachexia was associated with poorer survival according to both. Inflammation in the body may be caused by fat mass and tumors. Overweight increases the risk for chronic diseases and pancreatic cancer. In cancer patients, the tumor may cause systemic inflammation, and cytokines may trigger weight loss and might be a driving force behind cachexia. Among pancreatic cancer patients, those with neither weight loss, reduced energy intake, systemic inflammation nor sarcopenia have the longest survival. We suggest that clinical interventions should be directed towards optimizing these risk factors in these patients.