A socioeconomic gradient related to type 2 diabetes (T2D) prevalence has been demonstrated in high-income countries. However, there is no evidence of such a socioeconomic gradient regarding diabetes complications. Thus, the aim of this systematic review was to collect data on risk of complications according to socioeconomic status in patients with T2D.

PubMed and EMBASE were searched for English-language observational studies evaluating the prevalence or incidence of micro- and macrovascular complications according to individual and geographical socioeconomic status (SES). Observational studies reporting the prevalence and risk of micro- and macrovascular diabetes complications, according to an individual or geographical index of deprivation, were selected, and estimated crude and adjusted risks for each complication were reported.

Among the 28 included studies, most described a clear relationship between SES and diabetes complications, especially retinopathy (in 9 of 14 studies) and cardiopathy (in 8 of 9 studies). Both individual and area-based low SES was associated with an increased risk of complications. However, very few studies adjusted their analyses according to HbA_1c level.

Evaluation of SES is necessary for every T2D patient, as it appears to be a risk factor for diabetes complications. However, the available studies are insufficient for gradation of the impact of low socioeconomic level on each of these complications. Regardless, strategies for the improved screening, follow-up and care of high-risk patients should now be implemented.