Blood Pressure Variability Emerges as Independent Predictor of Kidney Disease Progression in Type 1 Diabetes, with African Caribbean Ethnicity as Key Risk Factor

Highlights

People with type 1 diabetes who experience greater fluctuations in their blood pressure readings between clinic visits face significantly higher risk of their kidney disease worsening over time. A landmark 14-year study tracking nearly 3,100 individuals has identified that visit-to-visit blood pressure variability—particularly in systolic blood pressure—acts as an independent predictor of kidney function decline, even after accounting for traditional risk factors such as baseline blood pressure, blood sugar control, and existing kidney damage. The research, conducted across two university hospital clinics, also found that African Caribbean ethnicity confers additional risk for rapid kidney disease progression in this population.

Background: The Unmet Challenge of Diabetic Kidney Disease

Diabetic kidney disease remains one of the most devastating complications of diabetes, affecting approximately 30-40% of individuals with diabetes worldwide and representing the leading cause of end-stage renal disease in developed nations. While the association between sustained hypertension and kidney disease progression is well-established, the role of blood pressure variability—the degree to which blood pressure fluctuates from one clinical visit to another—has received comparatively little attention, particularly in type 1 diabetes.

Previous research has demonstrated that blood pressure variability predicts cardiovascular events and renal outcomes in hypertension and type 2 diabetes, but whether similar patterns exist in type 1 diabetes has remained uncertain. This knowledge gap is clinically significant because type 1 diabetes presents a distinct pathophysiology, with typically earlier disease onset, different hemodynamic patterns, and a more homogeneous population in terms of diabetes duration compared to type 2 diabetes.

The current study, published in Diabetologia by researchers led by Ozdede and colleagues, aimed to address this critical gap by investigating whether blood pressure variability metrics could predict kidney disease progression in an ethnically diverse cohort of individuals with type 1 diabetes.

Study Design and Population

The investigators conducted a retrospective cohort study involving 3,079 adults with type 1 diabetes attending two university hospital clinics in the United Kingdom between 2004 and 2018. The study population had a median age of 36 years (range 18-85), with equal representation of males and females. Regarding ethnic composition, the cohort included 78.5% White participants, 10.9% African Caribbean individuals, 4.5% Asian participants, and 6.1% from other ethnic backgrounds.

All participants had established type 1 diabetes and a baseline estimated glomerular filtration rate (eGFR) exceeding 45 ml/min per 1.73 m², indicating at least mild-to-moderate kidney function at study entry. The investigators excluded individuals with more advanced kidney disease at baseline to focus on progression among those with relatively preserved renal function.

Blood pressure variability was assessed using three complementary metrics: visit-adjusted standard deviation (adj-SD), coefficient of variation (CV), and average real variability (ARV). These metrics capture different aspects of blood pressure fluctuations—adj-SD and CV reflect the dispersion of blood pressure values, while ARV specifically measures the magnitude of consecutive changes between visits, which may better reflect underlying physiological instability.

Key Findings

Over the 14-year observation period, 272 individuals (8.8% of the cohort) reached the primary endpoint, defined as a decline in eGFR of 50% or more from baseline accompanied by a final eGFR below 30 ml/min per 1.73 m², with death treated as a competing risk in the statistical analysis.

The study found that all blood pressure variability metrics for both systolic and diastolic blood pressure were significantly associated with kidney disease progression. However, in multivariable analyses that adjusted for traditional risk factors—including baseline blood pressure, eGFR, HbA1c, albuminuria status, and mean blood pressure during the exposure window—three factors emerged as independent predictors: the ARV of systolic blood pressure, the ARV of diastolic blood pressure, and African Caribbean ethnicity.

The strongest association was observed for the ARV of systolic blood pressure, which demonstrated a hazard ratio of 1.54 (95% confidence interval 1.27 to 1.87, p<0.001). This indicates that each unit increase in average real variability of systolic blood pressure conferred a 54% increased risk of kidney disease progression, independent of other established risk factors.

African Caribbean ethnicity emerged as a significant independent risk factor, with members of this population demonstrating substantially higher rates of kidney disease progression compared to White individuals. This finding suggests that ethnic background influences susceptibility to blood pressure variability-related kidney damage, potentially reflecting genetic, socioeconomic, or healthcare access factors that warrant further investigation.

Mechanistic Insights and Clinical Implications

The association between blood pressure variability and kidney disease progression likely reflects several interconnected pathophysiological mechanisms. Visit-to-visit blood pressure variability may indicate underlying vascular dysfunction, including endothelial dysfunction, arterial stiffness, and impaired autoregulation of renal blood flow. The kidneys, with their dense network of microvasculature, are particularly vulnerable to the mechanical stress imposed by fluctuating perfusion pressures.

Additionally, higher blood pressure variability may reflect greater sympathetic nervous system activation, increased renin-angiotensin system activity, or suboptimal antihypertensive treatment patterns—all of which could contribute to progressive renal damage through repeated episodes of glomerular hyperfiltration, ischemia, and barotrauma.

The identification of African Caribbean ethnicity as an independent risk factor adds an important dimension to the findings. Previous research has established that African Caribbean individuals experience higher rates of diabetic kidney disease and more rapid progression to end-stage renal disease. The current study suggests that blood pressure variability may be one mechanism contributing to this disparity, though the underlying reasons—whether genetic susceptibility, differential responses to antihypertensive therapies, or socioeconomic factors affecting blood pressure control—require further elucidation.

Expert Commentary and Clinical Perspectives

These findings carry important implications for clinical practice, suggesting that assessment of blood pressure variability should be incorporated into the risk stratification strategies for individuals with type 1 diabetes. Traditional risk assessment focuses predominantly on mean blood pressure values, but this study demonstrates that the pattern of blood pressure fluctuations over time provides additional prognostic information.

Clinicians caring for individuals with type 1 diabetes may consider implementing strategies to reduce blood pressure variability, including consistent antihypertensive therapy with long-acting agents, lifestyle modifications targeting stress reduction and sodium intake, and more frequent blood pressure monitoring to identify individuals with concerning variability patterns.

The study’s strengths include its large sample size, prolonged follow-up period, use of multiple blood pressure variability metrics, and rigorous statistical approach incorporating competing risk analysis. However, several limitations should be acknowledged. The retrospective design limits causal inference, and the reliance on clinic-based blood pressure measurements may not fully capture diurnal or situational variability. Additionally, the study was conducted in a UK population, and generalizability to other healthcare settings and ethnic groups requires confirmation.

Conclusion

This landmark study establishes blood pressure variability as a novel, independent predictor of kidney disease progression in type 1 diabetes, with the average real variability of systolic blood pressure demonstrating the strongest association. The identification of African Caribbean ethnicity as an additional independent risk factor highlights the importance of personalized approaches to kidney disease prevention in diverse populations.

While these findings require validation in prospective studies, they suggest that strategies targeting blood pressure stability—rather than solely mean blood pressure reduction—may offer new avenues for preventing diabetic kidney disease. Future research should investigate whether blood pressure variability represents a modifiable risk factor and explore interventions that could flatten the trajectory of blood pressure fluctuations in vulnerable individuals.

Funding and Study Registration

Study data were collected as part of routine clinical care at participating institutions. Specific funding sources and conflict of interest disclosures should be referenced in the original publication (PMID: 41922880).

References

Ozdede M, Pavlou P, Krasniqi V, Athanasiadou KI, Ayis S, Thomas S, Karalliedde J. The impact of blood pressure variability and African Caribbean ethnicity on the progression of diabetic kidney disease in type 1 diabetes. Diabetologia. 2026 Apr 1. PMID: 41922880.