African Caribbean Ethnicity Is an Independent Predictor of Significant Decline in Kidney Function in People With Type 1 Diabetes

OBJECTIVE The aim of the study was to identify the demographic and clinical features in an urban cohort of people with type 1 diabetes who developed a >= 50% decline in estimated glomerular filtration rate (eGFR). RESEARCH DESIGN AND METHODS We evaluated 5,261 people with type 1 diabetes (51% female, 13.4% African Caribbean) with baseline eGFR >45 mL/min/1.73 m 2 between 2004 and 2018. The primary end point was an eGFR decline of >= 50% from baseline with a final eGFR <30 mL/min/1.73 m(2). eGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation. RESULTS Of the cohort, 263 (5%) reached the primary end point. These individuals were more likely to be of African Caribbean ethnicity, be older, have a longer duration of diabetes, have higher systolic blood pressure and HbA(1c), have more prevalent retinopathy, and have higher albuminuria (all P < 0.05). In multivariable Cox regression models, African Caribbean ethnicity emerged as a significant risk factor for the primary end point (hazard ratio 1.57, 95% CI 1.19, 2.08) compared with other ethnicities and independent of established risk factors (P < 0.01). The incidence rate for the primary end point in African Caribbean people was double that in non-African Caribbean people (16 vs. 7.7 per 1000 patient-years, P < 0.001). A similar significant independent impact of African Caribbean ethnicity for secondary end points (>= 40% and >= 30% fall in eGFR) was observed. CONCLUSIONS We report a novel observation that African Caribbean ethnicity increased the risk of kidney function loss in people with type 1 diabetes, an effect that was independent of traditional risk factors. Further studies are needed to examine the associated pathophysiology that may explain this observation.

Automated summary

African Caribbean ethnicity is associated with an increased risk of kidney function decline in individuals with type 1 diabetes, independent of other risk factors.