Structural and functional capillary integrity, arterial stiffness and central hemodynamics in CKD patients with and without nocturnal hypertension

Marieta P Theodorakopoulou; Fotini Iatridi; Konstantinos Stavropoulos; Artemios G Karagiannidis; Maria Schoina; Sophia Manti; Theodoros Dimitroulas; Michael Doumas; Pantelis Sarafidis

doi:10.1093/ajh/hpaf043

Structural and functional capillary integrity, arterial stiffness and central hemodynamics in CKD patients with and without nocturnal hypertension

Am J Hypertens. 2025 Mar 29:hpaf043. doi: 10.1093/ajh/hpaf043. Online ahead of print.

Authors

Marieta P Theodorakopoulou¹, Fotini Iatridi¹, Konstantinos Stavropoulos², Artemios G Karagiannidis¹, Maria Schoina¹, Sophia Manti¹, Theodoros Dimitroulas³, Michael Doumas², Pantelis Sarafidis¹

Affiliations

¹ First Department of Nephrology, Hippokration Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece.
² Second Propaedeutic Department of Internal Medicine, Hippokration Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece.
³ Fourth Department of Internal Medicine, Hippokration Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece.

PMID: 40156844
DOI: 10.1093/ajh/hpaf043

Abstract

Background: Nocturnal hypertension is associated with increased risk for renal and cardiovascular events in patients with chronic-kidney-disease(CKD). Endothelial dysfunction and microvascular damage are highly prevalent in CKD and related to CKD progression and adverse cardiovascular outcomes. The aim of this analysis was to compare for first time microcirculatory function parameters and central hemodynamics in CKD patients with and without nocturnal hypertension.

Methods: 96 pre-dialysis CKD patients underwent 24-h ABPM (Mobil-O-Graph-NG device) and nailfold video-capillaroscopy, during which capillary density was measured at baseline, after 4-min arterial occlusion (postocclusive-reactive-hyperemia) and following 2-min venous occlusion (congestion phase). Arterial stiffness and central hemodynamic were captured in office conditions with Sphygmocor.

Results: The two groups (with and without nocturnal hypertension) were similar in terms of age, eGFR, BMI and major comorbidities. Patients with nocturnal hypertension presented significantly lower capillary density at baseline (30.6±3.6 vs 33.1±3.2 capillaries/mm2; p=0.003), during post-occlusive reactive hyperemia (36.6±4 vs. 39.5±3.9 capillaries/mm2; p=0.003), and during venous congestion (38.1±4.2 vs. 41±3.5 capillaries/mm2; p=0.003) compared to those without nocturnal hypertension. Participants with nocturnal hypertension had significantly higher aortic BP; no differences were found in the other parameters of arterial stiffness. The above observations were more prominent in patients with diabetes.

Conclusions: Capillary density during postocclusive hyperemia and after venous congestion is lower in patients with nocturnal hypertension compared to those with normotension, suggesting that nocturnal hypertension is a factor superimposed on the microvascular changes characterizing CKD to further impair capillary recruitment.

Keywords: capillary rarefaction; chronic kidney disease; microcirculation; nocturnal hypertension; vascular dysfunction.

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