Glucose tolerance, glucose utilization and insulin secretion in ageing

Area of Science:

• Gerontology
• Metabolic Diseases
• Cardiovascular Health

Background:

• Aging is linked to increased incidence of hypertension, macrovascular disease, and type 2 diabetes.
• These conditions often cluster, suggesting a common underlying mechanism.
• Insulin resistance and hyperinsulinaemia are proposed as the causal link for these metabolic and cardiovascular issues.

Purpose of the Study:

• To explore the relationship between aging, insulin resistance, and associated metabolic and cardiovascular diseases.
• To investigate the roles of biological aging versus lifestyle factors in age-related insulin resistance.
• To understand the mechanisms contributing to glucose intolerance in the elderly.

Main Methods:

• Review of epidemiological and clinical data associating insulin resistance with glucose intolerance, dyslipidemia, and hypertension.
• Analysis of the impact of adiposity, fat distribution, and physical inactivity on insulin resistance in aging populations.
• Examination of age-related changes in insulin secretion and pancreatic beta-cell sensitivity.

Main Results:

• Elderly individuals exhibit increased glucose intolerance and insulin resistance.
• Modifiable factors like increased adiposity and physical inactivity contribute to insulin resistance.
• Insulin secretion decreases with age, even after accounting for lifestyle factors.

Conclusions:

• Aging is associated with metabolic and cardiovascular risks potentially mediated by insulin resistance.
• Both biological aging and lifestyle factors contribute to age-related insulin resistance.
• Decreased insulin sensitivity of pancreatic beta-cells and altered hepatic glucose production contribute to glucose intolerance in aging.