Diabetic Kidney Disease in Type 2 Diabetes: A Comprehensive Review of Epidemiology, Pathophysiology, and Therapeutic Advances

Abstract

Chronic kidney disease (CKD) is a major complication of type 2 diabetes mellitus (T2DM), affecting 20%–50% of patients and leading to end-stage kidney disease (ESKD). This review synthesizes literature on CKD in T2DM, focusing on the epidemiology, pathophysiology, and management strategies, including oral hypo-glycemic agents and emerging therapies. A systematic search across PubMed, Scopus, and Web of Science prioritized studies from 2010 to 2025. Findings high-light the multifactorial pathogenesis of diabetic kidney disease (DKD), driven by hyperglycemia, hypertension, and oxidative stress. Sodium-glucose cotransporter-2 (SGLT2) inhibitors and glucagon-like peptide-1 receptor agonists (GLP-1 RAs), show nephroprotective effects, while biomarkers like estimated glomerular filtration rate (eGFR) and urinary albumin-creatinine ratio (UACR) enable early detection. Precision medicine holds promise for personalized treatment, but gaps in clinical practice and patient adherence persist, necessitating multidisciplinary approaches.

INTRODUCTION

Chronic kidney disease (CKD) affects 20%–50% of individuals with type 2 diabetes mellitus (T2DM), making it the leading cause of end-stage kidney disease (ESKD) globally.[1] Diabetic kidney disease (DKD) increases morbidity, mortality, and healthcare costs due to its association with cardiovascular disease (CVD).[2] The pathophysiology involves hyperglycemia, hypertension, oxidative stress, and inflammatory pathways, leading to glomerular damage and renal decline. Early detection using biomarkers like eGFR and UACR, combined with timely interventions, is critical. This review examines CKD in T2DM, covering epidemiology, pathophysiology, hypoglycemic therapies, prognostic markers, and future directions, supported by tables and a figure to summarize key findings.

MATERIALS AND METHODS

A systematic literature review was conducted using PubMed, Scopus, Web of Science, and Google Scholar, with keywords including “CKD,” “T2DM,” “DKD,” “hypoglycemic agents,” and “biomarkers.” Studies from 2010 to 2025 in peer-reviewed journals were prioritized, focusing on the CKD prevalence, pathophysiology, management, and emerging therapies in T2DM. Case reports, non-English studies, and those with limited clinical relevance were excluded. Data were categorized into epidemiology, pathophysiology, therapies, prognostic markers, and research gaps. Comparative analyses of therapeutic outcomes were performed to identify advancements and limitations.

RESULTS

Epidemiology

CKD affects 20%–50% of T2DM patients, with global T2DM cases projected to rise from 537 million in 2021 to 783 million by 2045.[1] About 20% of T2DM patients develop eGFR <60 mL/min/1.73 m², and 30%–50% exhibit albuminuria. The UK Prospective Diabetes Study reported a 28% incidence of reduced eGFR and albuminuria after 15 years. Early-onset T2DM carries a neard 100% lifetime risk of moderate albuminuria. Regional studies report CKD prevalence of 8.7%–28.96% in T2DM patients.

Pathophysiology

DKD in T2DM is driven by hyperglycemia, hypertension, and oxidative stress, activating pathways like advanced glycation end-products (AGEs), protein kinase C, and cytokines (e.g., TNF-α, IL-6). Glomerular hyperfiltration and intraglomerular hypertension contribute to albuminuria and eGFR decline. RAAS inhibitors have led to the hetero-generous DKD presentations, with some patients developing reduced eGFR without prior albuminuria.

Hypoglycemic therapies

Table 1 summarizes the safety and efficacy of hypoglycemic agents in CKD. Metformin is safe in mild-to-moderate CKD (eGFR ≥ 30 mL/min/1.73 m²) with dose adjustments, reducing mortality and ESKD risk. Sulfonylureas pose high hypoglycemia risks and are contraindicated in severe CKD. DPP-4 inhibitors (e.g., linagliptin) are effective with low hypoglycemia risk; linagliptin requires no dose adjustment. SGLT2 inhibitors (e.g., empagliflozin) reduce albuminuria and ESKD risk but are limited in eGFR < 45 mL/min/1.73 m². GLP-1 RAs (e.g., semaglutide) slow eGFR decline. Dietary interventions, like the Mediterranean diet, reduce AGEs and preserve kidney function.

Table 1.

Safety and efficacy of hypoglycemic agents in CKD

Agent	Safety in CKD	Efficacy	Considerations
Metformin	Safe in eGFR ≥30 mL/min/1.73 m2 with dose adjustments	Reduces mortality, ESKD risk	Low lactic acidosis risk[3]
Sulfonylureas	High hypoglycemia risk; contraindicated in severe CKD	Effective glycemic control	Avoid in eGFR <30 mL/min/1.73 m2[1]
DPP-4 inhibitors	Low hypoglycemia risk; linagliptin requires no dose adjustment	Reduces HbA1c; potential nephroprotection	Safe across CKD stages[4]
SGLT2 inhibitors	Nephroprotective; limited in eGFR <45 mL/min/1.73 m2	Reduces albuminuria, ESKD risk	Initial eGFR dip, long-term benefits[5]
GLP-1 Ras	Potential renal benefits; cautious use in CKD	Slows eGFR decline	Increased hypoglycemia risk in some[6]

Prognostic markers

Table 2 lists key prognostic markers. eGFR and UACR are primary tools, with mi- croalbuminuria (UACR ≥ 30 mg/g) indicating early DKD. Emerging biomarkers like lactate dehydrogenase (LDH) and collagen type III degradation product (C3M) correlate with CKD progression. Inflammatory markers (e.g., SII, SIRI) are cost-effective for DKD monitoring. HbA1c variability predicts CKD and CVD outcomes.

Table 2.

Prognostic markers for CKD in T2DM

Marker	Role	Clinical relevance
eGFR	Measures kidney function	Defines CKD stages; predicts ESKD risk[7]
UACR	Detects albuminuria	Early DKD marker; ≥30 mg/g indicates microalbuminuria[7]
LDH	Indicates DKD risk	45% increased risk with higher levels[8]
C3M	Reflects fibrosis	Correlates with CKD progression[9]
SII/SIRI	Inflammatory markers	Cost-effective for DKD monitoring[10]
HbA1c variability	Predicts complications	Independent predictor of CKD, CVD[11]

DISCUSSION

The rising CKD prevalence in T2DM necessitates early detection and intervention. SGLT2 inhibitors and GLP-1 RAs offer cardiorenal benefits beyond glycemic control, yet under- utilization persists.[5] Metformin remains a safe, cost-effective first-line therapy in mild-to-moderate CKD, while DPP-4 inhibitors are preferred in advanced CKD.[3] Sulfonylureas require caution due to hypoglycemia risks. Dietary interventions complement pharmacological strategies by reducing AGEs. Emerging biomarkers like LDH and C3M enhance early detection but need validation.[5] Precision medicine, lever- aging genetic and inflammatory markers, is promising but underexplored. Limitations include healthcare access disparities and inadequate multidisciplinary coordination. Future research should focus on the long-term therapy outcomes, AI-driven risk prediction, and addressing socioeconomic barriers. Figure 1 illustrates a comprehensive management approach for CKD in T2DM.

Figure 1.

Holistic approach to managing diabetes and CKD

CONCLUSION

Chronic kidney disease in type 2 diabetes mellitus represents a complex, progressive complication requiring early detection and comprehensive management. Novel agents like SGLT2 inhibitors and GLP-1 receptor agonists provide cardiorenal protection beyond glycemic control, while biomarkers such as eGFR, UACR, LDH, and C3M aid in early diagnosis and prognosis. A multidisciplinary, precision medicine-based approach is essential to optimize outcomes, reduce ESKD risk, and address current gaps in care delivery.

Credit authorship contribution statement

All authors provided substantial contributions to the concept and design of the work, or the acquisition, analysis, or interpretation of data for the word, and drafting of the work or revising it critically for important intellectual content, and gave final approval of the version to be published, and agreed to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Data availability

All datasets generated or analyzed during this study are included in the manuscript.

Conflict of interest

The authors declare that there is no competing of interest

Funding Statement

The author(s) received no financial support for the research, authorship and/or publication of this article.