Association of coffee consumption with type 2 diabetes and glycemic traits: a Mendelian randomization study

Abstract

BACKGROUND/OBJECTIVES Habitual coffee consumption was inversely associated with type 2 diabetes (T2D) and hyperglycemia in observational studies, but the causality of the association remains uncertain. This study tested a causal association of genetically predicted coffee consumption with T2D using the Mendelian randomization (MR) method. SUBJECTS/METHODS We used five single-nucleotide polymorphisms (SNPs) as instrumental variables (IVs) associated with habitual coffee consumption in a previous genome-wide association study among Koreans. We analyzed the associations between IVs and T2D, fasting blood glucose (FBG), 2h-postprandial glucose (2h-PG), and glycated haemoglobin (HbA1C) levels. The MR results were further evaluated by standard sensitivity tests for possible pleiotropism. RESULTS MR analysis revealed that increased genetically predicted coffee consumption was associated with a reduced prevalence of T2D; ORs per one-unit increment of log-transformed cup per day of coffee consumption ranged from 0.75 (0.62–0.90) for the weighted mode-based method to 0.79 (0.62–0.99) for Wald ratio estimator. We also used the inverse-variance-weighted method, weighted median-based method, MR-Egger method, and MR-PRESSO method. Similarly, genetically predicted coffee consumption was inversely associated with FBG and 2h-PG levels but not with HbA1c. Sensitivity measures gave similar results without evidence of pleiotropy. CONCLUSIONS A genetic predisposition to habitual coffee consumption was inversely associated with T2D prevalence and lower levels of FBG and 2h-PG profiles. Our study warrants further exploration.

A Promising Functional Food for Diabetes Prevention, Antioxidation, and Anti-inflammation of Green Coffee Bean Extract

“…The digestive enzyme binding with GCBE is inactivated, reducing blood sugar levels. Therefore, the present results indicate that GCBE is a potential compound to act against hyperglycemia, consistent with results reported in previous studies in vitro, in vivo, and in clinical trials [13,35,37] Macrophages are usually used as a model to study the anti-inflammatory effect of drugs or plant extract because they are the principal immune cells responsible for inflammation of various organs. Macrophages produce cytokines and reactive oxygen species (ROS), producing oxidative stress and increased activation of the inflammation pathway [38].…”

“…Across the world, coffee is a popular beverage for adults, with many beneficial effects on health, including reduced incidence of diabetes, metabolic syndrome, and cancer [11,12]. Prior studies [13][14][15][16][17] have reported that coffee consumption is related to a lower risk of T2D, as observed by blood glucose levels or biomarkers in patients and animal models. Some studies indicate the ability of coffee extract, coffee components (chlorogenic acid, CGA; caffeine, CE; and caffeic acid, CA) [18][19][20][21], and green coffee bean extract (GCBE) to improve glucose and lipid metabolism [22][23][24].…”

Causal relationships between CD25 on immune cells and hip osteoarthritis

“…Conversely, the execution of randomized controlled trials (RCTs) encounters an array of practical limitations that render their implementation within clinical environments a formidable undertaking (23). Mendelian randomization (MR) emerges as an analytical methodology aimed at examining potential causal links between exposures and outcomes, utilizing data derived from genome-wide association studies (GWAS) (23)(24)(25)(26)(27)(28). MR uses exposure-related genetic variations as instrumental variables (IVs) and follows the Mendelian gamete random allocation principle as well as the principle of free combination.…”