The Prevalence and Progression of Microvascular Complications and the Interaction With Ethnicity and Socioeconomic Status in People With Type 2 Diabetes: A Systematic Review and Meta‐Analysis

Introduction: Diabetic nephropathy (DN) and diabetic retinopathy (DR) are serious complications of type 2 diabetes mellitus (T2DM). The reported estimates of prevalence and progression of DN and DR vary widely across studies. We undertook a systematic review and meta‐analysis to determine the extent to which these variations in prevalence and progression of DN and DR may relate to different ethnic groups and socioeconomic status (SES). Methods: We searched the databases Ovid MEDLINE, Global Health, APA Psych Info, Embase, and PubMed for publications from 2005 to September 2023, based on T2DM and DN or DR, which included patient’s ethnicities and SES. Prevalence estimates were summarized by meta‐analysis using random effects models for each microvascular complication, stratified by ethnicity and SES. Data on progression was summarized narratively. Results: Twenty‐seven studies were included. The overall prevalence of DN was 18% (95% CI: 14%, 22%) with no differences noted by ethnic group. Low economic status and low education levels were associated with a 4% increased risk of DN compared to higher levels. Higher prevalence of DR was noted among the Afro‐Caribbeans, 28% (95% CI: 11%, 46%), compared to the White/Caucasian 19% (95% CI: 11%, 27%), and Asian/Indo Asians 25% (95% CI: 9%, 41%). Low‐SES populations have a higher prevalence of DR than high‐SES populations. The average prevalence was 16% (95% CI: 11%, 22%) among the high economic status group, compared to 25% (95% CI:20%, 30%) for the low economic status. Our study showed that Black ethnicity was associated with a higher risk of progression to end‐stage renal disease (ESRD) and diabetic maculopathy compared to other ethnicities. People with high SES had a lower rate of DR progression than those with low SES, odds ratio (OR) (0.63, 95% CI: 53%, 74%). Conclusion: Ethnicity and SES may be associated with differential risk of development and progression of DN and DR. The available evidence was limited by the number of studies and small samples for certain ethnic/socioeconomic groups.