Socioeconomic Status: The Missing Link Between Obesity and Diabetes Mellitus?

Background: Currently, there is an epidemic expansion of obesity rates worldwide. The increasing number of obese individuals associated with the aging of population leads to increasing number of individuals with type 2 diabetes mellitus (T2DM) at the same rate. The traditional factors that link obesity to T2DM are related to genetics, hypercaloric diet, sedentary lifestyle, and stress. Individuals from lower Socioeconomic Status (SES) have restricted autonomy and opportunities that could lead to more stress and consequently increase in stress hormones, such as cortisol, catecholamines, glucagon, and growth hormone, which might ultimately change fat deposition, increasing visceral fat and increasing the risk of T2DM development. Methods: We conducted a review of the literature on the effects of low SES and the risk of developing T2DM in obese persons. Results: 191 studies were found. The obesity of lower SES individuals is more central than that for individuals from higher socioeconomic position. It is also proposed that the quality of food seems to be lower, with more intake of fat and simple carbohydrates and less of fruits, vegetables and whole wheat bread, in the more disadvantaged social classes. The lower income neighborhoods, without exercise facilities and unsafety are also associated with higher indices of physical inactivity. Cross sectional and prospective studies confirm the relationship between lower socioeconomic status and obesity and diabetes. The lower SES is associated to metabolic implications that are linked to insulin resistance and possibly may also interfere with the ability of beta cell to secrete insulin and change the gut microbiota, increasing even more the future risk of developing diabetes.