12. Background Include sufficient scientific background to understand the rationale and context for the study, and explain the experimental approach. examples

“For decades, cardiovascular disease has remained the leading cause of mortality worldwide...[and] cardiovascular research has been performed using healthy and young, non-diseased animal models. Recent failures of cardioprotective therapies in obese insulin-resistant, diabetic, metabolic syndrome-affected and aged animals that were otherwise successful in healthy animal models has highlighted the need for the development of animal models of disease that are representative of human clinical conditions…In the clinical setting, elderly male patients often present with both testosterone deficiency (TD) and the metabolic syndrome (MetS). A strong and compounding association exists between MetS and TD which may have significant impact on cardiovascular disease and its outcomes which is not addressed by current models…their mutual presentation in the clinical setting warrants the development of appropriate animal models of the MetS with hypogonadism, especially in the context of cardiovascular disease research.” [1]