Diabetes-linked disease caused by benign tumours may affect far more people than previously thought

A diabetes-linked disease caused by benign tumours in the adrenal glands may pose a risk to far more people than previously thought.

A new study suggests more than a million people in the UK are at risk of type 2 diabetes and high blood pressure due to Mild Autonomous Cortisol Secretion (Macs).

People with Macs produce too much cortisol, the stress hormone that is linked to serious health problems to do with blood sugar levels.

Macs develops from a benign tumour in the adrenal glands, which are situated on top of the kidneys and produce a variety of hormones. Around 10 per cent of adults develop this type of tumour, which is known as an adrenal incidentaloma.

Researchers at the University of Birmingham have found that Macs could affect more people than earlier thought and outcomes for patients could be worse.

The researchers analysed medical information from 1,305 patients with adrenal incidentalomas.

Nearly half the patients tested were found to have Macs, suggesting it is much more prevalent than previously reported. Earlier studies had found symptoms of Macs in just one in three patients with the tumours.

The new findings, published in the journal Annals of Internal Medicine, suggest that around 1.3 million people in the UK have Macs.

The study also found that around 70 per cent of the patients who developed the condition were women over the age of 50. Macs could prove to be a key factor in women’s metabolic health in their later years, the authors said.

They also said that healthcare policy should be changed so that any patient found to have an adrenal incidentaloma is automatically tested for Macs.

Professor Wiebke Arlt, a co-author of the study, said: “Previous studies suggested that Macs is associated with poor health.

“However, our study is the largest ever study to establish conclusively the extent of the risk and severity of high blood pressure and type 2 diabetes in patients with Macs.”

Patients with Macs were found to require higher doses of medication or stronger treatments in order to control conditions such as high blood pressure or diabetes.

For example, those with type 2 diabetes were twice as likely to be treated with insulin, indicating that other medications had not helped to manage their blood sugar levels.

Prof Arlt said: “Our hope is that this research will put a spotlight on this condition and increase awareness of its impact on health.

“We advocate that all patients who are found to carry an adrenal incidentaloma are tested for MACS and have their blood pressure and glucose levels measured regularly.”

Dr Alessandro Prete, lead author of the study, said: “Our study found that Macs is very frequent and is an important risk condition for high blood pressure and type 2 diabetes, especially in older women, and the impact of Macs on high blood pressure and type 2 diabetes risk has been underestimated until now.”

The researchers plan to carry out further research to better understand the links between cortisol, Macs and more serious health conditions.

Prof Arlt said: “First, we want to look into how Macs is linked to this increased risk by investigating how cortisol excess affects human metabolism.

“Second, we are working on a test that can be used in the clinic to identify early on which patients with Macs carry a higher risk of developing high blood pressure and type 2 diabetes.

“Third, we are testing new treatment strategies to mitigate this risk in affected individuals.”

She added: “Our ultimate aim is to improve the health of the many patients living with Macs.”