Perirenal Adipose Tissue and Hypertension: Observational and Genetic Analyses

BACKGROUND: Perirenal adipose tissue (PRAT) consists of white and brown adipocytes with good vascularization and dense innervation, which could influence the blood pressure. We aim to investigate the association of PRAT thickness with risks of overall and specific forms of hypertension. METHODS: We measured PRAT thickness in the UK Biobank and CONPASS (Chongqing Primary Aldosteronism Study). We prospectively examined the correlation between PRAT thickness and incident hypertension in the UK Biobank. We cross-sectionally explored associations between PRAT thickness and common forms of hypertension in CONPASS. Integrating data from GWAS (Genome-Wide Association Study), we investigated the potential causal relationship between PRAT and hypertension forms by 2-sample Mendelian randomization analyses. RESULTS: In the prospective analysis of the UK Biobank, participants whose PRAT thickness was ≥46.1 mm showed a higher risk of developing hypertension than participants whose PRAT thickness was <16.4 mm (hazard ratio, 2.91 95% CI, 1.97-4.32). In the cross-sectional analysis of CONPASS, a 1 SD increment in PRAT thickness was associated with a 2.77-fold higher adjusted odds of low-renin essential hypertension and a 3.89-fold higher adjusted odds of idiopathic hyperaldosteronism. PRAT thickness was not significantly associated with other forms of hypertension, such as aldosterone-producing adenoma and obstructive sleep apnea. In 2-sample Mendelian randomization analyses, PRAT thickness was only significantly associated with a higher risk of idiopathic hyperaldosteronism (inverse variance weighted odds ratio, 1.33 95% CI, 1.09-1.62), with no evidence of significant heterogeneity or substantial directional pleiotropy. CONCLUSIONS: PRAT is causally associated with idiopathic hyperaldosteronism rather than essential hypertension and other forms of secondary hypertension.