Patterns of Diabetes-Related Complications and Clinical Outcomes in General Medicine Settings: A Systematic Review Withour Meta Analysis

Abstract

OBJECTIVES

To systematically synthesise recent observational evidence on patterns of diabetes-related complications, clinical outcomes, glycemic-control findings, and factors associated with adverse outcomes in general medicine and related routine-care settings.

METHODOLOGY

PubMed, Web of Science, and Scopus were searched for original studies published from 2020 through 2025. Eligible studies included observational cross-sectional, cohort, retrospective, prospective, multicenter, hospital-based, and community-based studies reporting microvascular or macrovascular complications, glycemic control, multimorbidity, or related clinical outcomes among people with diabetes. Review articles, case reports/series, pilot studies, editorials, opinion articles, and reports with insufficient outcome data were excluded. Owing to substantial heterogeneity in populations, designs, definitions, and outcome reporting, findings were synthesised narratively without statistical pooling. Methodological limitations were appraised across selection, exposure/risk-factor measurement, outcome assessment, confounding, and data-completeness domains.

RESULTS
Twenty studies were included after screening 613 records. The evidence base was predominantly cross-sectional, although large retrospective and prospective cohorts were also represented. Microvascular complications, particularly nephropathy/chronic kidney disease, neuropathy, and retinopathy, were reported more consistently than macrovascular outcomes. Studies that directly assessed both complication categories generally documented an appreciable burden of both small- and large-vessel disease. Across studies, poor glycemic control, longer diabetes duration, hypertension, obesity, dyslipidemia, older age, suboptimal adherence, and irregular follow-up were repeatedly associated with greater complication burden. Most studies were judged to have low-to-moderate methodological concerns, driven mainly by cross-sectional designs, restricted recruitment settings, and incomplete control of confounding.

CONCLUSION

Recent observational evidence indicates a substantial and heterogeneous burden of diabetes-related complications in routine clinical settings. The findings support integrated surveillance of renal, retinal, neurologic, cardiovascular, peripheral vascular, and foot complications alongside sustained glycemic and cardiovascular risk-factor management. Because the included studies were methodologically heterogeneous, the review supports clinical pattern recognition rather than a single pooled prevalence estimate.