Type I Angiotensin II Receptor Blockade Reduces Uremia-Induced Deterioration of Bone Material Properties

Area of Science:

• Nephrology
• Orthopedics
• Pharmacology

Background:

• Chronic kidney disease (CKD) significantly increases fracture incidence.
• The mechanisms underlying CKD-related bone fragility are not fully understood.
• Limited therapeutic options exist for preventing fractures in CKD patients.

Purpose of the Study:

• To investigate the effect of type 1 angiotensin II receptor blockade (AT-1RB) on preventing fragility fractures in CKD.
• To elucidate the pharmacological mechanisms by which AT-1RB impacts bone quality.

Main Methods:

• Retrospective analysis of 3276 hemodialysis patients treated with AT-1RB.
• In vivo study using nephrectomized rats treated with olmesartan (an AT-1RB).
• In vitro study using primary cultured osteocytes exposed to angiotensin II.

Main Results:

• AT-1RB use was linked to a reduced risk of fracture-related hospitalization in hemodialysis patients.
• Olmesartan treatment in rats suppressed osteocyte apoptosis, skeletal pentosidine accumulation, and apatite disorientation.
• Olmesartan mitigated angiotensin II-induced oxidative stress and apoptosis in osteocytes.

Conclusions:

• Angiotensin II-dependent intraskeletal oxidative stress worsens bone quality by increasing osteocyte apoptosis and pentosidine accumulation.
• AT-1RB therapy may prevent CKD-related bone fragility by targeting oxidative stress pathways.
• These findings suggest AT-1RB as a potential therapeutic strategy for abnormal bone quality in CKD.