Recently, the number of people with diabetes has been increasing. Furthermore,
metabolic syndrome in which diabetes co-exists with obesity, hyperlipidemia
and hypertension, has become the most significant cause of redusing healthy
life expectancy among Japanese, as it promotes progression of atherosclerosis and increases the
risk of developing cardiac infarction and stroke.
}This department undertakes research to elisidate the mechanisms involved
in developing diabetes and progression of atherosclerosis at the molecular
level, and develops innovative diagnosis and treatment methods based on
the above findings, which can be applied to the clinical field.
- Section of Metabolic Syndrome
It is recognized tat lifestyle-related diseases (e.g. diabetes) develop
by a combination of genetic and environmental factors. One hypothesis is
that the rapid increase of diabetes among Japanese may be due to the lower
insulin secretion capacity of the pancreatic beta cells among Japanese,
compared to Westerners, making Japanese more lifely to accummurate energy
at fat (genetic predisposition). Consequently, it is likely that obesity and insulin
resistance induced by changes in environmental factors (e.g. westernized
diet, reduced physical activity) can not be fully compensated.
This section, therefore, investigates how genetic and environmental factors would interact to develop obesity, diabetes and metabolic syndrome.
- Section of Nutritional Therapy
Excess energy intake, especially
increased fat intake, is one of the major causes of diabetes and obesity. However,
fatty acid concentrations are essential for insulin secretion, which would increase, in
the short term, the secretion of glucose-responsive insulin. On the other hand, prolonged
excess fat intake results in triglyceride accumulation in pancreatic beta cells,
leading to decreased insulin secretion. It has been reported that fat intake
contributes to obesity more than carbohydrate and protein intakes. Individuals
with higher fat intakes are, therefore, more prone to obesity than those with
lower fat intakes, even if total energy intakes are the same.
This section examines the impacts of diets with different
nutrient compositions on insulin
tolerance, insulin resistance, and obesity in genetically modified diabetes-, insulin resistant- and obesity-model animals. In this way, we aim to identify novel clinical applications by developing the optimal nutritional therapy, in terms of nutrient-to-energy ratio, for preventing lifestyle-related diseases.