Early Onset Type 2 Diabetes

How many people have you seen in the last year diagnosed with early-onset type 2 diabetes? What even is early-onset type 2 diabetes? And why do we need to consider early-onset tone 2 diabetes somewhat differently to later onset type 2 diabetes? 

Until 6 months ago I had no real understanding of what early-onset type 2 diabetes was, and even less of an understanding of it’s relevance for both the individuals who develop it,  and the impact it is going to have on primary care. But a series of articles in The Lancet in 2025 alerted me to this issue and why, in Primary Care, we all need to pay more attention to it. The draft update to the NICE type 2 diabetes guideline (due for publication later this month) specially recognises, for the first time, early-onset type 2 diabetes as an area for focussed management and more research.

What is early-onset type 2 diabetes?

Early-onset type 2 diabetes is defined as those who develop type 2 diabetes under the age of 40. The incidence is rising rapidly driven largely, but by no means exclusively, due to obesity. Although the numbers of people with type 2 diabetes is going up across the board, there is a disproportionate rise in those under 40. 

A statement paper by Diabetes UK in 2024 (Reverse The Trend), highlights that the numbers diagnosed with early-onset type 2 diabetes has risen by nearly 40% between 2016/17 and 2022/23, meaning around 168,000 people with early-onset type 2 diabetes in the UK. This is likely to be a gross under-estimate due to a large under-diagnosis rate, with ONS figures suggesting the actual numbers may be double this.

The other key background factor we need to be aware of is the socio-demographic disparities. Whilst deprivation is a factor generally for type 2 diabetes, it is much more exaggerated for those diagnosed at a younger age. And importantly those from South Asian and Black backgrounds are disproportionately more likely to have early-onset type 2 diabetes than those from other ethnicities. 

Why is early-onset type 2 diabetes such a problem? 

Whilst there is inevitably a spectrum, what is now clear is that those diagnosed at a younger age have a far more aggressive disease course than those diagnosed at an older age. Those with early-onset type 2 diabetes have far higher rates of micro and macro-vascular complications and higher mortality rates, compared to those diagnosed later in life. What really surprised me was the evidence in The Lancet stating that those with early-onset type 2 diabetes have worse outcomes than those diagnosed with type 1 diabetes. 

Early onset diabetes also affects women more than men, and given these are women of child bearing age, the disease has a huge impact on women’s reproductive health. As with vascular complications, peri-natal outcomes are worse in those with early-onset type 2 diabetes compared to those with type 1 diabetes. 

Beware of therapeutic inertia

The key message I have taken away from researching this topic is that we must beware of therapeutic inertia when managing people with early-onset type 2 diabetes. Given the early and aggressive nature of their disease course we need to intervene early and quickly to tackle both glycemic control and wider risk factors, notably obesity. 

It is clear that we can’t tackle this problem on our own. As The Lancet and Diabetes UK papers point out, this is a problem that requires a far broader public health plan together with the political will to tackle inequalities and the social determinants of health.

However, what is also clear is that in General Practice we are going to be a key part of the plan. We are going to see more and more people with early-onset type 2 diabetes, and whilst the specific evidence base for managing early-onset type 2 diabetes is very much in it’s infancy, intervening early is going to be a crucial principle.

What does this intervention look like? Well, that’s a discussion for another day! We are busy putting together the new Hot Topics course ready for the Spring launch, and how we mange people with early-onset type 2 diabetes will be very much part of the discussion.