The number of people using insulin to treat diabetes trebled between 1991 and 2010, researchers from the Universities of Bristol and Cardiff have found.
In a study published in the Journal of Diabetes, Obesity and Metabolism, a team reviewed Clinical Practice Research Data (CPRD) to estimate the prevalence of insulin use in the UK population.
They found that the number of patients receiving prescriptions for insulin increased from 136,800 in 1991 to 421,300 in 2010.
Professor Edwin Gale, from the School of Clinical Sciences at the University of Bristol, said: "The study showed a very steep rise in insulin use over the past 20 years, with some recent levelling off. Although earlier use of insulin may have contributed to this increase, it mainly reflects the fact that many more people are developing diabetes."
The study also found that the number of people receiving prescriptions for insulin for type 2 diabetes during the period, overtook the number of people with type 1 diabetes.
In 1991, more people using insulin had type 1 diabetes than had type 2 diabetes however, by 2010 this situation had reversed with the total number of people with type 2 diabetes injecting insulin increased from 37,000 in 1991 to 277,400 in 2010.
Professor Craig Currie, from Cardiff University's School of Medicine, said: "Understanding the pattern of insulin use is limited by a lack of data characterising the prevalence of insulin use in the UK. Given the limitations, our study sought to calculate - for the first time - the best possible estimate of the rates of insulin for type 1 and type 2 diabetes."
Whilst the study strikes a note of caution with its findings, most notably with early stages of the timescales of the reporting being less well recorded, the study does give a clear indication that the number of people with type 2 diabetes using insulin has risen sharply.
Professor Currie added: "The rising prevalence of insulin use probably reflects both an increase in incidence and longer survival of those who already have type 2 diabetes. The financial cost of insulin to the NHS in the UK is estimated to have increased from £156M in 2000 to £359M in 2009.
"The increase in the number of people with type 2 diabetes using insulin is a wake-up call for all - not only in terms of lifestyle choices and how we treat people with type 2 diabetes."