The metabolic syndrome and type 2 diabetes: epidemiological figures and country specificities.

Over the last 20 years, the prevalence of the metabolic syndrome has steadily increased in all populations worldwide, changing slowly the phenotype of the human race and potentially our concept of physiological normality. Our affluent phenotype reflects progressive adaptation to the external environment, which in turn changes the standards of the metabolic variables such as body weight, blood pressure, lipid values and glucose homeostasis. The human survivors of the difficult times of the hunter-gatherer period have probably benefited from genes which have allowed for more efficient food utilization, fat deposition and weight gain, a concept referred to as the 'thrifty gene' hypothesis. This genetic background has now become detrimental in our society of high energy consumption, little physical activity and lifestyles that favour stress and anxiety. These genetic and environmental interactions explain the explosion in the prevalence of the metabolic syndrome and diabetes. If future estimates for the number of patients with diabetes and impaired glucose tolerance are valid, this will have a major and adverse impact on the number of stroke patients globally.