Type 2 diabetes used to be known as adult-onset diabetes because it tended to occur mainly in people over the age of 40. But as obesity levels around the world continue to soar, so has the number of young adults with the disease. The global prevalence of diabetes among teenagers and young adults (aged 10-24) has risen from an estimated 2.8% in 1990 to 3.2% in 2015.
This may not sound very much, but it is an increase of about 7m young people across the world. An important proportion of this relates to type 1 diabetes – but the increasing prevalence and impact of type 2 diabetes in this age group is a major threat to public health worldwide.
Having type 2 diabetes at a young age has major implications for a person’s future health. If not managed properly, it can lead to blindness, kidney failure or limb amputation, so preventing the disease before it takes hold is critical.
Researchers are scratching their heads trying to find solutions to this problem. While they agree that those at high risk of developing type 2 diabetes should be targeted in public health programmes, what those programmes should entail is not yet clear. Of course, diet and physical activity are important but, among children, research into what works is only just emerging.
Major research funders across the world are engaging with the issue. In the UK a recent overview of research commissioned by the National Institute for Health Research summarises where work is underway and where more needs to be done. In the US, the National Institute of Diabetes and Digestive and Kidney Diseases (part of the National Institutes for Health) provides tips for parents on prevention in children, mostly based on current evidence around diet and exercise.
Unfortunately, any behaviour change that involves major alteration in lifestyle is difficult. It takes time and requires discipline, perseverance, and support. For example, rather disappointingly, a major US trial of a complex intervention including diet and physical activity aimed at reducing obesity in more than 6,000 students at 42 middle schools (aged 12 to 14) showed no significant difference between intervention and control schools.
Public health puzzle
If you’re trying to be more healthy, it may be important to have support from someone who’s been there before. Involving people who already have type 2 diabetes to mentor those at high risk has been shown to be effective in some settings. A trial among children (averaging just under ten-years-old) living in a remote Aboriginal community in Canada (a population with a high prevalence of type 2 diabetes) compared the effect of a peer-led after-school healthy living programme with the standard curriculum on reducing waist circumference and body mass index. It seemed to be effective at reducing these measures, though it is too early to tell if this would translate into reducing diabetes and its complications.
On the other hand, Taking Action Together, another type 2 diabetes prevention programme among nine and ten-year-old African American children in California was not so successful. It involved efforts to change diet and increase physical activity and, while there was some effect in boys, the same effect was not seen in girls. Other imaginative ways have been explored to try and influence attitudes towards obesity and diabetes among young people. These include a video game teaching tool which showed promising but not definitive results.
So it’s tricky. This has led to researchers turning to the very early part of life to look for factors that could influence the chances of developing diabetes later on. This may be a promising area. Some pre-natal factors, such as diabetes in pregnancy in the mother increases the risk for children.
Researchers publishing a recent series of papers in The Lancet Diabetes and Endocrinology highlight the growing global trend of obesity among young women and say that the time before couples conceive is a key opportunity to reduce the transmission of obesity risk from one generation to the next. They suggest that working with future parents at the pre-conception phase to adopt a healthier lifestyle is the key to solving the problem in the future.
There is also evidence for a protective effect of breastfeeding on the subsequent risk of developing type 2 diabetes in adolescence. The exact mechanism for this remains a bit uncertain. Thoughts vary from the idea that breastfeeding may encourage the infant’s abilities to self-regulate intake to the suggestion that breast milk contains biologically active substances that affect energy uptake and expenditure. Whatever the mechanism, it seems that breastfeeding might help to “programme” a child to be at reduced risk of being overweight or obese later in life.
This is leading to new ways of tackling the problem, particularly in ethnic groups at high risk of developing diabetes. About a third of residents in Tower Hamlets in London are Bangladeshi – and the prevalence of obesity in British Bangladeshi children aged four to five is 12.5%, growing to 23.7% by age 10-11. Importing a proven model from South Asia, where female health workers get involved with local women’s groups to promote healthy infant diet and encourage breastfeeding, is showing promise at improving both mother and child health in this relatively deprived neighbourhood.
Ultimately, maybe behaviour change alone is never going to solve the problem. A combination of interventions that include strong population-level measures, such as taxation on unhealthy food and changes in policy, as well as individual behaviour change and efforts to prevent obesity both pre-natally and in infanthood are probably needed to turn the tide and halt the spread of this preventable harm.