Role of social interaction, exercise, diet, and age on developing and untreated diabetes in cynomolgus monkeys

Type 2 diabetes mellitus is the most common form of diabetes that occurs in both human and nonhuman primates. Although spontaneously diabetic nonhuman primates are used extensively in diabetic related research and are a proven valuable tool for the study of the natural history of diabetes, little is known about the key factors that can cause this metabolic disorder and the preventative measures that could be employed to minimize the consequences of diabetes. Using a model of developing and untreated diabetes, this study describes the effects of housing arrangement (socially group- versus individually single-housed), exercise, diet, age, and sex on fasting plasma glucose, key lipids associated with diabetes, and bodyweight in two large cohorts of nonhuman primates. Key findings include exercise/housing arrangement's contribution to significant differences in bodyweight, levels of fasting plasma glucose, total cholesterol, and high- and low-density lipoproteins. Age also had profound effects on glucose, triglyceride and high-density lipoproteins, particularly in single-caged animals. Moreover, females had higher fasting glucose, total cholesterol and triglyceride levels than male counterparts within the same housing situations. These factors may be critical to identifying preventive measures that could eventually be used to minimize obesity and diabetes in humans.