Association Between Plasma and Urinary Reduced Thiols in Essential Hypertension: Evidence from a Paired Observational...

Area of Science:

• Biochemistry
• Clinical Chemistry
• Hypertension Research

Background:

• Oxidative stress and altered extracellular redox balance are implicated in essential hypertension.
• Current clinical assessment of these factors is limited by invasive blood measurements and preanalytical challenges.
• Urine offers a promising non-invasive matrix, but its relationship with plasma thiols in hypertension is not well-defined.

Purpose of the Study:

• To investigate the association between plasma and urinary reduced thiols in patients with essential hypertension.
• To determine if urinary thiol measurements can serve as a non-invasive surrogate for plasma thiol assessment in this population.

Main Methods:

• A paired observational study involving 40 treated essential hypertension patients.
• Quantification of reduced thiols using a DTNB-based colorimetric assay in both plasma and urine.
• Normalization of plasma thiols to total protein and urinary thiols to creatinine.
• Assessment of associations using non-parametric correlation analyses.

Main Results:

• A significant positive correlation was observed between protein-normalized plasma thiols and creatinine-normalized urinary thiols (Spearman's ρ ≈ 0.7, p < 0.001).
• This indicates a strong agreement between the two matrices when appropriately normalized.

Conclusions:

• Creatinine-normalized urinary reduced thiols are strongly associated with protein-normalized plasma reduced thiols in essential hypertension.
• Urinary thiols may serve as a valuable, non-invasive indicator of extracellular thiol-related redox alterations in hypertension.
• Further validation in diverse cohorts is recommended to confirm these findings.