Impact of age at type 2 diabetes mellitus diagnosis on mortality and vascular complications: systematic review and meta-analyses

Diabetologia. 2021 Feb;64(2):275-287. doi: 10.1007/s00125-020-05319-w. Epub 2020 Dec 14.


Aims/hypothesis: Few studies examine the association between age at diagnosis and subsequent complications from type 2 diabetes. This paper aims to summarise the risk of mortality, macrovascular complications and microvascular complications associated with age at diagnosis of type 2 diabetes.

Methods: Data were sourced from MEDLINE and All EBM (Evidence Based Medicine) databases from inception to July 2018. Observational studies, investigating the effect of age at diabetes diagnosis on macrovascular and microvascular diabetes complications in adults with type 2 diabetes were selected according to pre-specified criteria. Two investigators independently extracted data and evaluated all studies. If data were not reported in a comparable format, data were obtained from authors, presented as minimally adjusted ORs (and 95% CIs) per 1 year increase in age at diabetes diagnosis, adjusted for current age for each outcome of interest. The study protocol was recorded with PROSPERO International Prospective Register of Systematic Reviews (CRD42016043593).

Results: Data from 26 observational studies comprising 1,325,493 individuals from 30 countries were included. Random-effects meta-analyses with inverse variance weighting were used to obtain the pooled ORs. Age at diabetes diagnosis was inversely associated with risk of all-cause mortality and macrovascular and microvascular disease (all p < 0.001). Each 1 year increase in age at diabetes diagnosis was associated with a 4%, 3% and 5% decreased risk of all-cause mortality, macrovascular disease and microvascular disease, respectively, adjusted for current age. The effects were consistent for the individual components of the composite outcomes (all p < 0.001).

Conclusions/interpretation: Younger, rather than older, age at diabetes diagnosis was associated with higher risk of mortality and vascular disease. Early and sustained interventions to delay type 2 diabetes onset and improve blood glucose levels and cardiovascular risk profiles of those already diagnosed are essential to reduce morbidity and mortality. Graphical abstract.

Keywords: Age factors; Age of onset; Diabetes; Diabetes complications; Diabetes mellitus, type 2; Disease progression; Meta-analysis; Prognosis; Systematic review.

Publication types

  • Meta-Analysis
  • Systematic Review

MeSH terms

  • Age of Onset
  • Cerebrovascular Disorders / epidemiology
  • Cerebrovascular Disorders / etiology
  • Coronary Disease / epidemiology
  • Coronary Disease / etiology
  • Diabetes Mellitus, Type 2 / complications
  • Diabetes Mellitus, Type 2 / diagnosis*
  • Diabetic Angiopathies / epidemiology*
  • Diabetic Angiopathies / etiology
  • Diabetic Nephropathies / epidemiology
  • Diabetic Nephropathies / etiology
  • Diabetic Neuropathies / epidemiology
  • Diabetic Neuropathies / etiology
  • Diabetic Retinopathy / epidemiology
  • Diabetic Retinopathy / etiology
  • Humans
  • Mortality
  • Odds Ratio
  • Peripheral Vascular Diseases / epidemiology
  • Peripheral Vascular Diseases / etiology