Ethnic inequalities in kidney function and progression to advanced CKD in T2D: a primary care study

Background

Chronic kidney disease (CKD) is a major complication of type 2 diabetes (T2D) and a key contributor to health inequalities. Patterns of kidney function decline are heterogeneous, yet little is known about how these trajectories differ across ethnic groups in primary care settings. Understanding early divergence in risk is essential for prevention and equitable care.

Methods

We conducted a retrospective cohort study using Lambeth DataNet, London, UK, including 24,716 adults with T2D and ≥2 eGFR measurements (2004–2018). Group-based trajectory modelling identified distinct kidney function patterns. Multinomial logistic regression examined determinants of trajectory membership, while logistic and Cox regression assessed progression to advanced CKD (stage 4–5) and all-cause mortality.

Results

Four trajectories were identified: stable (15.5%), slow decline (37.4%), moderate decline (38.1%), and rapid decline (9.0%). Ethnic disparities were evident, with Asian and Mixed groups more frequently represented in rapid decline trajectories. Within the rapid-decline group, progression to advanced CKD was highest among Mixed individuals (30.7%), followed by Asian (19.6%), Black (17.4%), and White (16.3%) participants. Macroalbuminuria was more prevalent among Asian groups (27.4%) and strongly associated with progression (OR 2.40, 95% CI 1.84–3.14). Higher HbA1c, systolic blood pressure, and baseline eGFR were independent predictors of progression. Despite higher CKD risk, Asian (HR 0.81, 95% CI 0.72–0.92) and Black individuals (HR 0.80, 95% CI 0.73–0.87) had lower mortality compared with White individuals.

Conclusions

Kidney function decline in T2D is heterogeneous, with clear ethnic inequalities emerging early in primary care. Albuminuria and modifiable risk factors remain central drivers of progression. The coexistence of higher CKD risk and lower mortality in some ethnic groups highlights complex disparities.

Key messages

• Ethnic inequalities in CKD progression begin early in primary care and require targeted prevention strategies.

• Early identification using trajectory-based approaches may improve risk stratification and reduce health disparities.