Men at higher risk of type 2 diabetes due to pronounced insulin resistance of adipose tissue

Type 2 diabetes is more common in men than woman because insulin resistance of adipose cells is more pronounced, or severe, in males, researchers have said.

Presenting at the European Congress on Obesity (ECO) in Venice, Italy, scientists have revealed that men are more prone to develop type 2 diabetes at a younger age and lower weight than women.

Senior academic Dr Daniel P Andersson said: “One reason for this may be differences in how the sexes’ adipose tissue responds to insulin.

“Adipose tissue is the main organ for the storage of excess energy and this is done in lipids called triglycerides that consist of free fatty acids.

“When there is excess energy, insulin decreases the breakdown of triglycerides (lipolysis) and the release of free fatty acids to the blood and increases the storage of energy as triglycerides (lipogenesis) in fat cells.

“In insulin resistance, fat cells are less sensitive to insulin and so both of these processes are impaired.”

He added: “This can lead to more fat circulating in the bloodstream, which raises the risk of type 2 diabetes.

“If the insulin resistance of adipose cells is more pronounced, or severe, in men than in women, this could help explain why type 2 diabetes is more common in men than women.”

More than 2,000 middle-aged women and 787 middle-aged men were examined during the study.

The researchers looked at each participant’s adipose insulin resistance index (AdipolR) – a measure of insulin sensitivity of fat cells, with higher values indicating more resistance to insulin.

They found that AdipoIR values were higher in obese men than in women, according to the report.

As part of the trial, the academics also took biopsies from the adipose tissue of 259 women and 54 men living with obesity to determine how insulin impacted isolated fat cells.

They discovered that men needed a 10-fold higher concentration of insulin to stop triglycerides from breaking down into fatty acids.

“In individuals who are living with obesity, you often have an excess of energy available in the body and insulin should decrease the release of fatty acids and increase the storage of lipids in adipose tissue to reduce the free fatty acids circulating in the blood,” said Dr Anderson.

He continued: “When looking at sex differences, we found that men who were living with obesity had increased adipose insulin resistance and higher levels of free fatty acids in the blood.

“The differences seen between men and women were mainly related to decreased ability of insulin to block the breakdown of fatty acids in fat cells from men rather than sex differences in storage capacity.

“Fatty acids in the bloodstream have effects in the liver, muscle and the pancreas and could lead to further local insulin resistance in these organs, creating a vicious circle that, over time, could lead to development of type 2 diabetes.”

Read the study in the International Journal of Obesity.

Get our free newsletters

Stay up to date with the latest news, research and breakthroughs.