With over 400 million people living with the disease and accounting for around 90% of diabetes cases worldwide, type 2 diabetes is complex and costly. It can cause blindness, cardiovascular disease, kidney failure, lower limb amputation, and other long-term consequences that substantially impact quality of life and years of life lived with disability. Worryingly, the global prevalence of type 2 diabetes is estimated to have doubled over the past 30 years and now includes rapidly rising numbers of children and adolescents. The condition is much more complex in young people, who have a higher overall risk of life-time complications with much earlier onset. Up until 2002, type 2 diabetes was not considered a paediatric condition; today, there are an estimated 3600 children and young adults diagnosed with the condition each year in the USA. In the UK, nearly 7000 cases were reported in 2018, as noted by Diabetes UK on Nov 21. Disturbingly, this trend is reflected internationally.
Recognising the shift in type 2 diabetes prevalence toward increasingly younger populations, on Nov 13, the American Diabetes Association (ADA) published new guidelines for the assessment and management of youth-onset type 2 diabetes. Young people with type 2 diabetes have a more aggressive form of the disease—including poorer response to glucose-lowering medication and greater insulin resistance. However, given evidence that young people with type 2 diabetes are less likely to become hypoglycaemic when treated with oral agents alone, the new guidelines recommend more stringent HbA1c targets than previously, and lower than those generally recommended for adults. The guidelines prioritise lifestyle management tailored to the patients and their families, as most children with type 2 diabetes also have obesity. These recommendations take into account the developmental growth stage of the child. Importantly, mental health and cultural aspects are also considered, as obesity is often associated with discrimination and stigma, and cultural norms can affect diet and lifestyle.
Although the ADA guidelines will be helpful for practising clinicians, there are still many knowledge gaps. For example, there is not enough evidence on the benefits of interventions such as metabolic surgery, intensive physical activity, and educational support programmes in young patients. Moreover, the only glucose-lowering drug other than insulin approved for patients younger than 18 years is metformin. Other therapies, such as SGLT2 inhibitors and GLP-1 receptor agonists, which are associated with cardiovascular and renal protection in adults, have not been approved for children or adolescents. Finally, there is the issue of screening and early detection of type 2 diabetes in this age group. Approaches to screen and diagnose adults who are at risk have not been thoroughly validated in young people. There is an urgent need to include young patients in future research to develop and inform strategies targeted at prevention and treatment of type 2 diabetes.

Type 2 diabetes is a progressive disease, meaning that treatment intensification, with insulin being a last resort, is required over time in a substantial proportion of patients. For patients with early-onset disease, this is more likely to be needed earlier in life. Even by prioritising lifestyle treatments and new-generation drugs, insulin will maintain a central place in the treatment of many patients with type 2 diabetes. With this fast expanding population of people who will have diabetes for longer, an increase in the

demand for insulin is inevitable. According to the results of a modelling study published last week in The Lancet Diabetes & Endocrinology, it is expected that 20% more insulin will be required to treat the global type 2 diabetes population by 2030. A key concern highlighted by this study is that availability and affordability of insulin are already inadequate in low-income and middle-income countries.

The primary risk factor for development of type 2 diabetes across all ages is obesity, which is largely preventable starting early in life. Some countries have already taken steps to tackle obesity by introducing sugar taxes and reducing exposure of children to unhealthy food advertisements. Despite these positive approaches, much more needs to be done as a matter of urgency. Diabetes is a global public health problem and can only be tackled with a concerted action to develop effective prevention strategies. Surely children and adolescents cannot be held responsible for living in obesogenic environments. If the growing prevalence of obesity and type 2 diabetes in youth is accepted as the new normal, society will have grossly failed the next generation.