Type 2 diabetes at younger age ‘linked to higher risk of mortality and disease’

Type 2 diabetes diagnosis at a younger age may be associated with a higher risk of mortality and cardiovascular disease than getting diagnosed at an older age, new research suggests.

Each one-year increase in age of diabetes diagnosis was associated with a 4%, 3% and 5% lower risk of all-cause mortality, macrovascular (large blood vessels) disease, and microvascular (small blood vessels) disease respectively, adjusted for current age.

Researchers say rates of type 2 diabetes have increased in all age groups and in virtually all countries over the past three decades.

They add that a particularly worrying trend over this period was the increased rate of diabetes in those aged 20 to 44 years.

“Early and sustained interventions to improve blood glucose levels and cardiovascular risk profiles in those with established type 2 diabetes and interventions to delay the onset of type 2 diabetes in those at high risk are essential to reduce ill health and mortality associated with this condition,” the authors write.

After searching the MEDLINE and All EBM (Evidence Based Medicine) databases from inception to July 2018, the authors included data from 26 observational studies comprising 1,325,493 individuals across 30 countries.

Using statistical techniques and computer modelling, the researchers suggest that the increasing age at diabetes diagnosis was associated with a lower risk of all-cause mortality and macrovascular and microvascular disease, with all three findings statistically significant.

The researchers include first author Dr Natalie Nanayakkara and Professor Sophia Zoungas of Monash University, Australia.

They say that this was, to their knowledge, the first systematic review and meta-analysis exploring associations between age at diabetes diagnosis and subsequent outcomes.

The researchers said: “People diagnosed with diabetes at an older age may be more likely to have accumulated adverse cardiovascular risk factors compared with those diagnosed at a younger age.

“Since advancing age is a powerful predictor of cardiovascular complications, for the same diabetes duration, people diagnosed at a younger age are likely to have lower absolute risks of events as compared with people diagnosed at an older age.

“Over time, however, the effects of both ageing and disease duration may be amplified, resulting in premature complications and death in people diagnosed with type 2 diabetes at a younger age.”

To illustrate this, they say someone diagnosed with type 2 diabetes at 30 years old would have a lower absolute risk of complications compared with someone diagnosed at 50.

But by the time they both reach 60 the person diagnosed at a younger age would have a higher relative and absolute risk of complications and death due to the effects of ageing, compounded by the effects of longer diabetes duration.

Dr Nanayakkara said: “It is also important to note that people diagnosed with diabetes at a younger age have a longer lifetime risk of developing significant complications, thus achieving good blood sugar and risk factor control (such as healthy weight and normal blood pressure) is of particular importance across their lifespan.”

She added that the difference in risk between younger and older people in terms of absolute versus lifetime risks should perhaps be recognised in diabetes management guidelines.

The authors conclude that awareness of this “hidden” danger to younger adults is becoming more and more important, as new diagnoses in this younger age group continue to rise.

The research was published in Diabetologia (the journal of the European Association for the Study of Diabetes).