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Coffee consumption and kidney function: A Mendelian randomisation study

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Original languageEnglish
JournalAmerican Journal of Kidney Diseases
Early online date11 Dec 2019
DOIs
Publication statusE-pub ahead of print - 11 Dec 2019

Abstract

Rationale & Objective: Chronic kidney disease (CKD) is a leading cause of morbidity and mortality worldwide with limited strategies for prevention and treatment. Coffee is a complex mixture of chemicals, and consumption is associated with mostly beneficial health outcomes. This work aimed to determine the impact of coffee consumption on kidney function. Study Design: Genome wide association study (GWAS) and Mendelian randomisation (MR). Setting & Participants: UK Biobank baseline data were used for a coffee consumption GWAS and included 227,666 participants. CKDGen was used for kidney outcomes and included 133,814 participants (12,385 cases of CKD) of mostly European ancestry across various countries. Exposure: Coffee consumption Outcomes: Estimated glomerular filtration rate (eGFR), CKD (MDRD eGFR <60mL/min/1.73m2) and albuminuria. Analytical Approach: GWAS to identify single nucleotide polymorphisms (SNPs) associated with coffee consumption in UK Biobank and use of those SNPs in MR analyses of coffee consumption and kidney outcomes in CKDGen. Results: 2126 SNPs were associated with coffee consumption (p-value <5 x 10-8), 25 of which were independent and available in CKDGen. Drinking an extra cup of coffee per day conferred a protective effect against CKD (OR 0.84, 95% CI 0.72-0.98, p-value 0.03) and albuminuria (OR 0.81, 0.67-0.97, p-value 0.02). An extra cup was also associated with higher eGFR (beta 0.022, p-value 1.6 x 10-6) after removal of three SNPs responsible for significant heterogeneity (Cochran’s Q p-value 3.5 x 10-15). Limitations: Assays used to measure creatinine and albumin varied between studies that contributed data and a sex-specific definition was used for albuminuria rather than KDIGO guidelines. Conclusions: This study provides evidence of a beneficial effect of coffee on kidney function. Given widespread coffee consumption and limited interventions to prevent CKD incidence and progression, this could have significant implications for global public health in view of the rising burden of CKD worldwide.

ID: 109667266