Study Examines How Age at Diabetes Diagnosis Predicts Risk of Complications Later in Life

New research from an international team of investigators is outlining the impact of age at type 2 diabetes diagnosis on mortality and risk of vascular complications later in life.

Using data from more than 25 studies and 1 million patients, investigators concluded each 1-year increase in age at diabetes diagnosis was associated with a 4%, 3% and 5% lower risk of all-cause mortality, macrovascular disease, and microvascular disease, respectively.

"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," wrote study investigators.

Led by investigators at Monash University in Melbourne, Australia, investigators designed the current study in an effort to further explore the impact of age at diabetes diagnosis on outcomes later in life. With this in mind, the team designed their study as a systematic review and meta-analysis of studies within the MEDLINE and ALL EBM databases from inception through 2018.

For inclusion in the current analysis, all studies needed to meet the following criteria: be a study of adult participants with type 2 diabetes investigating the effect of age at diabetes diagnosis on macrovascular and microvascular diabetes complications, the study need to assess one or more of the outcome variables all-cause mortality, macrovascular disease, microvascular disease, retinopathy, nephropathy, neuropathy, CVD, cerebrovascular disease and peripheral vascular disease; the study had to have an available mortality/complication rate or the methods indicated complete follow-up of participants.

Using the aforementioned criteria, investigators identified 26 studies with 1,325,493 individuals for inclusion in the study. Of the 26 studies included, 13 were cross-sectional and 13 were cohort studies by design. The mean age of participants in these studies ranged from 21.6-67.4 years, the proportion of female participants ranged from 42.5%-68.6%, and the cohort included participants from 30 countries worldwide.

Of the 26 studies included, 5 were used to assess risk of all-cause mortality, 8 were used to assess risk of microvascular disease, and 8 were used to assess the risk of microvascular disease.

Upon analysis, results indicated age at diabetes diagnosis was inversely associated with risk of all-cause mortality and macrovascular and microvascular disease (all P <.001). After adjustment for current age, results of the investigators analysis suggested each 1-year increase in age at the time of diabetes diagnosis was associated reductions of 4% (OR, 0.96; 95% CI, 0.94-0.99) for all-cause mortality, 3% (OR, 0.97; 95% CI, 0.96-0.98) for macrovascular disease, and 5% (OR, 0.95; 95% CI, 0.94-0.96) for microvascular disease.

Further analysis indicated each 1-year increase in age at diabetes diagnosis was associated with a 2% decreased risk of coronary heart disease (OR, 0.98; 95% CI, 0.97-0.98; P <.001), a 2% decreased risk of cerebrovascular disease (OR, 0.98; 95% CI, 0.97-0.99], P <.001) and a 3% decreased risk of peripheral vascular disease (OR, 0.97; 95% CI 0.96-0.99; P <.001).Additionally, each 1-year increase in age at time of diabetes diagnosis was associated with an 8% decreased risk of retinopathy (OR, 0.92; 95% CI, 0.90-0.95; P <.001), a 6% decreased risk of nephropathy (OR, 0.94; 0.92-0.96, P <.001) and a 5% decreased risk of neuropathy (OR, 0.95; 95% CI, 0.94-0.96; P <.001).

“This difference in risk between younger and older people in terms of absolute versus lifetime risks of type 2 diabetes complications, should perhaps be recognized in diabetes management guidelines, with increased promotion of screening programs in older people with type 2 diabetes and a greater emphasis on preventive measures for younger people with type 2 diabetes,” wrote investigators.

This study, “Impact of age at type 2 diabetes mellitus diagnosis on mortality and vascular complications: systematic review and meta-analyses,” was published in Diabetologia.