Nearly one-in-10 people in Ireland aged over 45 years could have diabetes by 2020, according to new research.

The study, published by the Institute of Public Health in Ireland (IPH), predicts that by 2020 the number of over-45s with both diagnosed and undiagnosed type 2 diabetes is expected to rise to more than 175,000 people, or 9.1% of the population in that age bracket.

The research also shows that 3.2% of over 18s in the 26 counties had diabetes in the previous 12 months that had been diagnosed by a doctor. This included 6.2% of adults aged over 45.

By 2020, according to the study, the rate of clinically-diagnosed diabetes for over 18s is expected to rise to 3.8%, or 136,000 people. This represents a 28% increase in diagnosed diabetes in 10 years, according to the IPH.

Currently, it is estimated that 8.9% of adults over 45 have either diagnosed or undiagnosed diabetes - among this age group, 30% of all diabetes is undiagnosed. Undiagnosed diabetes is more common among men than women.

By 2020, the number of over 45s with diabetes, both undiagnosed and diagnosed, will rise to more than 175,000, according to the IPH. This represents a 30% increase in 10 years.

According to Lorraine Fahy of the IPH, the fact that large numbers of adults are living with diabetes and that this number is expected to increase has significant implications for the people concerned, their families and the health and social care system.

According to Dr Anna Clarke of Diabetes Ireland, increases in type 2 diabetes are being fed by rising obesity and inactivity levels, whereas Type 1 diabetes is an auto-immune condition that currently is not preventable.

The research was carried out by the IPH with the HRB Centre for Diet and Health Research at UCC and the Centre of Excellence for Public Health Northern Ireland.

Prof Ivan Perry from the HRB Centre, said Ireland was not immune from the current global epidemic of obesity and type 2 diabetes.

He said we need to change both out food environment and physical environment in ways that will support healthy choices through public policy.

"In this context, the current Government proposals for increased taxation on sugar-sweetened soft drinks is critical.

Diabetes occurs when the body is unable to properly use insulin, a hormone that helps to control blood sugar levels by helping glucose enter cells to be used as energy.

Type 1 diabetes tends to occur in childhood when the body is unable to produce any insulin because the immune system has destroyed the insulin-making cells of the pancreas; type 2 usually develops in adulthood when the body can still make some insulin, but not enough, or when the insulin that is produced does not work properly.