Aim The aim of this systematic review was to examine the associations of individual-level as well as area-level socioeconomic status and area-level deprivation with glycaemic control, hypoglycaemia and diabetic ketoacidosis in people with Type 1 diabetes mellitus.Methods Ovid MEDLINE was searched to identify relevant cohort, case-control or cross-sectional studies published between January 2000 and June 2015. Search results were screened by title, abstract and keywords to identify eligible publications. Decisions on inclusion or exclusion of full texts were made independently by two reviewers. The Newcastle-Ottawa Scale was used to estimate the methodological quality of included studies. Quality assessment and extracted data of included studies were synthesized narratively and reported according to the PRISMA statement.Results Literature search in Ovid MEDLINE identified 1345 eligible studies. Twenty studies matched our inclusion and exclusion criteria. Two articles were additionally identified through hand search. According to the Newcastle-Ottawa Scale, most of the studies were of average quality. Results on associations of socio-economic status and area-level deprivation with glycaemic control and hypoglycaemia were contradictory between studies. By contrast, lower socioeconomic status and higher area-level deprivation were associated with a higher risk for diabetic ketoacidosis in all except one study.Conclusions Lower socio-economic status and higher area-level deprivation are associated with a higher risk of experiencing diabetic ketoacidosis in people with Type 1 diabetes mellitus. Access to care for socially deprived people needs to be expanded to overcome impairing effects on the course of the condition and to reduce healthcare disparities.

Aims To estimate the risk of microvascular complications and macrovascular risk factors among persons with early-onset (diagnosed at ages 0 to <5 years) and long-duration type 1 diabetes and determine temporal trends and associations with potential predictors. Methods We conducted three population-based cross-sectional surveys in Germany (N = 1789) to obtain information on exposures and five outcomes (retinopathy, nephropathy, dyslipidemia, hypertension, and a composite endpoint combining all four outcomes). For each outcome, log-binomial spline regression was applied to estimate the risk and dose-response relationship with diabetes duration and exposures. Results The risk for microvascular complications increased after 14 years since diabetes diagnosis whereas dyslipidemia and hypertension were already prevalent at 10 years. The 15-year risk (95% confidence interval) of the composite endpoint for female and male patients was 22.9% (18.8%–27.9%) and 19.2% (15.5%–23.8%), respectively. Temporal trends suggested a decreasing risk between 2009 and 2016. Glycemic control, lifestyle-related factors, and SES, but not health care-related factors, were associated with the risk of the composite endpoint. Conclusions In early-onset type 1 diabetes, there exists a considerable risk of complications and comorbidities already in young ages. Future research should focus on prevention of diabetic complications in young patients and clarification of pathways of the associations found.