In essential hypertension, elevated SUA and higher SUA/eGFR ratios are associated with early cardiac and renal structural changes even at levels below the conventional definition of hyperuricemia, with obesity amplifying urate exposure but attenuating its independent predictive value.
Key Findings
Results
SUA and SUA/eGFR ratio increased progressively across BMI groups in hypertensive patients.
326 patients with essential hypertension were studied, stratified by body mass index (BMI)
SUA and SUA/eGFR increased progressively across BMI groups (p < 0.001)
Echocardiography and laboratory analyses assessed target-organ damage including left ventricular mass index (LVMI) and albuminuria
Patients were categorized according to previously validated SUA cutoffs (5.6 mg/dL for cardiovascular mortality) from the URRAH project
Results
The proportion of patients exceeding the URRAH cardiovascular-risk SUA threshold of 5.6 mg/dL rose substantially with increasing adiposity.
35.8% of normal-weight patients exceeded the 5.6 mg/dL SUA threshold
60.3% of obese individuals exceeded the 5.6 mg/dL SUA threshold
The URRAH threshold of 5.6 mg/dL is lower than the traditional hyperuricemia threshold
Evidence from the URRAH project established that mortality risk increases at SUA concentrations lower than the traditional hyperuricemia threshold
Results
Both SUA and SUA/eGFR correlated with markers of subclinical organ damage including LVMI and albuminuria.
Both SUA and SUA/eGFR correlated with LVMI and albuminuria (p < 0.01)
These associations were observed across hypertensive patients stratified by BMI
Associations were present even at SUA levels below the conventional definition of hyperuricemia
Results
The predictive performance of SUA/eGFR for cardiac remodeling was strongest in normal-weight hypertensive patients.
AUC = 0.74 for SUA/eGFR in predicting cardiac remodeling in normal-weight patients
Obesity attenuated the independent predictive value of SUA and SUA/eGFR despite amplifying urate exposure
The authors described 'complex metabolic interactions' as the explanation for the attenuated predictive value in obese individuals
Conclusions
The authors support adopting lower, cardiovascular-oriented SUA thresholds and composite indices such as SUA/eGFR in risk assessment of hypertensive patients.
The conventional hyperuricemia threshold was considered insufficient for cardiovascular risk stratification
SUA/eGFR was identified as a useful composite index particularly in normal-weight hypertensive patients
The findings suggest SUA-related organ damage can occur at sub-hyperuricemic levels in essential hypertension
These recommendations apply to risk assessment across different degrees of adiposity in hypertension