Kidney Week

Abstract: SA-PO0505

Cutaneous Microvascular Functional Reserve Is Associated with Kidney Function and Histopathologic Injury: The MAP-CKD Study

Session Information

• CKD: Clinical - Therapies, CKM Health, Special Populations, and More
  October 24, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: CKD (Non-Dialysis)

• 2202 CKD (Non-Dialysis): Clinical, Outcomes, and Trials

Authors

• Ahmadi, Armin, University of California San Diego, La Jolla, California, United States

Armin Ahmadi, PhD

• Rahaman, Masfiqur, University of California San Diego, La Jolla, California, United States

Masfiqur Rahaman, MSc

• Harsh, Amol, Mohamed bin Zayed University of Artificial Intelligence, Masdar City, Abu Dhabi, United Arab Emirates

Amol Harsh

• Ghanim, Basma, University of California San Diego, La Jolla, California, United States

Basma Ghanim

• Dasgupta, Subhasis, University of California San Diego, La Jolla, California, United States

Subhasis Dasgupta, PhD

• Weinreb, Robert N., University of California San Diego, La Jolla, California, United States

Robert N. Weinreb, MD

• Taub, Pam R., University of California San Diego, La Jolla, California, United States

Pam R. Taub, MD

• Rahman, Tauhidur, University of California San Diego, La Jolla, California, United States

Tauhidur Rahman, PhD

• Houben, Alfons Jhm, Universiteit Maastricht, Maastricht, LI, Netherlands

Alfons Jhm Houben, PhD

• Ix, Joachim H., University of California San Diego, La Jolla, California, United States

Joachim H. Ix, MD, FASN

• Malhotra, Rakesh, University of California San Diego, La Jolla, California, United States

Rakesh Malhotra, MD, MPH, FASN

Background

MicroMicrovascular dysfunction contributes to CKD progression, yet direct assessment remains limited. Laser Doppler flowmetry (LDF) provides a noninvasive measure of skin microvascular blood flow and may reflect systemic microvascular health. We evaluated its association with kidney function and histopathology in CKD.

Methods

Cutaneous microvascular function was assessed in 150 participants with CKD (eGFR <90 mL/min/1.73 m²) using a standardized forearm LDF protocol. Baseline perfusion was measured at ~30°C, followed by local heating to 44°C to induce hyperemia; the percent change in perfusion units (PU) defined microvascular functional reserve. Associations with eGFR and urine protein-to-creatinine ratio (uPCR) were evaluated using multivariable linear regression adjusted for demographic and clinical covariates. In a biopsy subset (n = 20), associations with glomerulosclerosis (GS) and interstitial fibrosis/tubular atrophy (IFTA) were assessed.

Results

The mean (SD) age was 64 (14) years, 46% were female, 38% had diabetes, and 83% had hypertension. The mean eGFR was 42 (21) mL/min/1.73 m² and median (IQR) uPCR was 0.21 (0.11-1.20) mg/mg. Lower eGFR was associated with higher baseline PU (β = -12; 95% CI, -24 to -1) and reduced percentage change in PU (β = 7; 95% CI, 2 to 13), independent of covariates. uPCR was not associated with baseline PU or percentage change in PU. Among participants with biopsy data, higher baseline PU and lower percentage change in PU were associated with greater severity of GS and IFTA.

Conclusion

Advancing CKD is associated with elevated resting perfusion and impaired microvascular reserve. LDF-derived measures may capture systemic microvascular dysfunction and serve as noninvasive biomarkers of kidney function and histopathologic injury.

Figure 1. The relationship between eGFR and CKD severity with LDF measures.

Funding

• NIDDK Support