Serum Fibroblast Growth Factor 23 Levels are Associated with Vascular Smooth Muscle Dysfunction in Type 2 Diabetes

Area of Science:

• Endocrinology
• Nephrology
• Cardiovascular Medicine

Background:

• Elevated serum fibroblast growth factor 23 (FGF23) is linked to phosphate metabolism abnormalities in chronic kidney disease (CKD).
• FGF23 is also associated with cardiovascular disease risk, even in individuals without CKD.
• The relationship between FGF23 and vascular function in type 2 diabetes (T2D) requires further investigation.

Purpose of the Study:

• To investigate the association between serum FGF23 levels and vascular function in patients with T2D.
• To evaluate the impact of FGF23 on vascular endothelial and smooth muscle functions.

Main Methods:

• Cross-sectional study of 283 Japanese patients with T2D.
• Assessment of brachial artery flow-mediated dilatation (FMD) and nitroglycerin-mediated dilatation (NMD) using ultrasonography.
• Measurement of serum intact FGF23 levels via enzyme-linked immunosorbent assay.

Main Results:

• Serum FGF23 levels were inversely associated with NMD (vascular smooth muscle function), but not FMD (endothelial function).
• This association was independent of traditional atherosclerotic risk factors, estimated glomerular filtration rate (eGFR), and serum phosphate.
• The inverse relationship between FGF23 and NMD was more pronounced in patients with normal kidney function (eGFR ≥ 60 mL/min/1.73 m²).

Conclusions:

• Serum FGF23 levels are independently and inversely associated with vascular smooth muscle dysfunction in T2D patients.
• Increased FGF23 may serve as a novel biomarker for vascular smooth muscle dysfunction in T2D, particularly in those with preserved kidney function.