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.

Aims/hypothesis Current evidence suggests that type 2 diabetes may have a greater impact on those with earlier diagnosis (longer duration of disease), but data are limited. We examined the effect of age at diagnosis of type 2 diabetes on the risk of all-cause and cause-specific mortality over 15 years. Methods The data of 743,709 Australians with type 2 diabetes who were registered on the National Diabetes Services Scheme (NDSS) between 1997 and 2011 were examined. Mortality data were derived by linking the NDSS to the National Death Index. All-cause mortality and mortality due to cardiovascular disease (CVD), cancer and all other causes were identified. Poisson regression was used to model mortality rates by sex, current age, age at diagnosis, diabetes duration and calendar time.Results The median age at registration on the NDSS was 60.2 years (interquartile range [IQR] 50.9-69.5) and the median followup was 7.2 years (IQR 3.4-11.3). The median age at diagnosis was 58.6 years (IQR 49.4-67.9). 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. For mortality due to cancer (all cancers and colorectal and lung cancers), we found that earlier diagnosis of type 2 diabetes was associated with lower mortality compared with diagnosis at an older age. Conclusions/interpretation Our findings suggest that younger-onset type 2 diabetes increases mortality risk, and that this is mainly through earlier CVD mortality. Efforts to delay the onset of type 2 diabetes might, therefore, reduce mortality. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00125-018-4544-z) contains peer-reviewed but unedited supplementary material, which is available to authorised users.

This study explores the prevalence of, and factors associated with, likely depression and diabetes distress in adults with type 2 diabetes in a large, national sample. Australian National Diabetes Audit data were analysed from adults with type 2 diabetes attending 50 diabetes centres. The Brief Case find for Depression and Diabetes Distress Score 17 were administered to screen for likely depression and diabetes-related distress, respectively. A total of 2,552 adults with type 2 diabetes participated: (mean ± SD) age was 63 ± 13 years, diabetes duration was 12 ± 10 years, and HbA1c was 8 ± 2%. Twenty-nine percent of patients had likely depression, 7% had high diabetes distress, and 5% had both. Difficulty following dietary recommendations, smoking, forgetting medications, and diabetes distress were all associated with greater odds of depression whereas higher own health rating was associated with lower odds (all p < 0.02). Female gender, increasing HbA1c, insulin use, difficulty following dietary recommendations and depression were all associated with greater odds of diabetes distress & older age, higher own health rating and monitoring blood glucose levels as recommended were associated with lower odds (all p < 0.04). Depression was associated with sub-optimal self-care, while diabetes distress was associated with higher HbA1c and sub-optimal self-care.