Getting Type 2 Diabetes Early Increases Mortality Risk Later in Life

Several population studies have demonstrated that when people are diagnosed with type 2 diabetes earlier in life, the risk of earlier complications including mortality related to the diabetes is significantly higher than in older populations.

To date, only limited data are available for the impact of age at diagnosis on excess mortality in people with type 2 diabetes.  Current evidence suggests that type 2 diabetes may have a greater impact on those with earlier diagnosis (longer duration of disease), but data is limited.  So, this study examined the effect of age at diagnosis of type 2 diabetes on the risk of all-cause and cause-specific mortality over 15 years.

Type 2 diabetes was once considered as a disease of middle-aged and older people, but in recent decades the prevalence of type 2 diabetes in adolescents and young adults has risen considerably around the world, driven largely by increasing obesity prevalence at younger ages. A study from Japan reported that type 2 diabetes increased tenfold in young children (aged 6–12 years) and doubled among adolescents over a 20-year period from 1976 to 1997. Similar trends have been found in many countries across the world, making young adults the fastest growing group for new-onset type 2 diabetes.

Individuals diagnosed as having type 2 diabetes at a younger age seem to have an increased risk of developing diabetes-related complications compared with those diagnosed later in life. They also possess a clustering of adverse cardiovascular risk factors at an earlier age. Recent studies have both demonstrated that obesity, dyslipidemia, hypertension and microalbuminuria are common in youth with type 2 diabetes and worsen over time. In a study by Hillier and Pedula, they found that a diagnosis of type 2 diabetes under 45 years of age was associated with a 14-fold increase in the risk of myocardial infarction compared with control individuals without diabetes. This study used the information from the Australia national health care program, National Diabetes Services Scheme (NDSS) and used the information from more than a million patients with diabetes.

The median age at registration was 60.2 years and the median follow-up was 7.2 years. The median age at diagnosis was 58.6 years. A total of 115,363 deaths occurred during 7.20 million person-years of follow-up. During the first 1.8 years after diabetes diagnosis, rates of all-cause and cancer mortality declined and CVD mortality was constant. All mortality rates increased exponentially with age. An earlier diagnosis of type 2 diabetes (longer duration of disease) was associated with a higher risk of all-cause mortality, primarily driven by CVD mortality. A 10 year earlier diagnosis (equivalent to 10 years’ longer duration of diabetes) was associated with a 1.2–1.3 times increased risk of all-cause mortality and about 1.6 times increased risk of CVD mortality. The effects were similar in men and women.

The study showed that a younger age at diagnosis of type 2 diabetes was associated with higher all-cause and CVD, ischemic heart disease and stroke mortality, but slightly lower cancer mortality (all-cause and lung and colorectal cancers), compared with diagnosis at an older age. To put these results into context, for two men of the same age but with 10 years’ difference in diabetes duration, the one with the earlier onset (and hence longer duration of diabetes) had an approximately 30% and 60% greater chance of death from any cause and from CVD, respectively, relative to the man with the shorter duration, at any age. Therefore, it is prudent to treat those diagnosed with type 2 diabetes at a younger age more aggressively in the early stages of disease to achieve ideal glycemic control with the goal of reducing the risk of future complications.

Practice Pearls:

• From the results it was determined that a diagnosis of type 2 diabetes at a younger age was associated with higher all-cause, cardiovascular, and stroke-related mortality.
• Efforts to delay the onset of type 2 diabetes will reduce mortality.
• Preventing diabetes has many benefits including a longer and a better quality of life.

 

Diabetologia  May 2018, Volume 61, Issue 5, pp 1055–1063| Cite as