Association between urinary sodium and circulating lipid levels: a Mendelian randomization study.

Area of Science:

• Genetics
• Metabolic Health
• Epidemiology

Background:

• Observational studies suggest a link between urinary sodium and dyslipidemia, but findings are inconsistent.
• Understanding the causal relationship between sodium intake and lipid profiles is crucial for public health.

Purpose of the Study:

• To investigate the causal association between urinary sodium levels and circulating lipids (LDL-C, triglycerides, HDL-C).
• Utilize Mendelian randomization to assess causality, overcoming limitations of observational studies.

Main Methods:

• Employed univariable and multivariable Mendelian randomization (UVMR and MVMR) with pleiotropy-resistant techniques.
• Utilized large-scale genome-wide association study (GWAS) data for urinary sodium and lipid profiles from European ancestry populations.
• Included discovery (UK Biobank) and replication (Global Lipids Genetics Consortium) analyses for lipid profiles.

Main Results:

• Genetically higher urinary sodium was associated with lower high-density lipoprotein cholesterol (HDL-C) levels (beta = -0.32).
• Genetically higher triglyceride levels were associated with increased urinary sodium excretion (beta = 0.030 in UVMR, beta = 0.029 in MVMR).
• These associations remained significant after multivariable adjustments and were replicated.

Conclusions:

• Increased urinary sodium may have a weak causal effect in reducing circulating HDL-C levels.
• Elevated genetically predicted triglyceride levels may causally influence increased urinary sodium excretion.
• Findings provide novel insights into the bidirectional relationship between sodium metabolism and lipid profiles.