Omega-6 fatty acids and the risk of cardiovascular disease: insights from a systematic review and meta-analysis of randomized controlled trials and a Mendelian randomization study

The association between coffee and caffeine consumption and renal function: insight from individual-level data, Mendelian randomization, and meta-analysis

INTRODUCTION

The reported relationship between coffee intake and renal function is poorly understood. By applying two-sample Mendelian randomization (MR) and systematic review and meta-analysis we investigated the association of caffeine and coffee intake with prevalent CKD and markers of renal function.

MATERIAL AND METHODS

For the individual data analysis we analyzed the National Health and Nutrition Examination Surveys (NHANES) data on renal function markers and caffeine intake. MR was implemented by using summary-level data from the largest ever genome-wide association studies (GWAS) conducted on coffee intake (N = 91,462) and kidney function (N = 133,413). The inverse variance weighted method (IVW), weighted median-based method, MR-Egger, MR-RAPS, and MR-PRESSO were applied. Random effects models and generic inverse variance methods were used to synthesize quantitative and pooled data for the meta-analysis, followed by a leave-one-out method for sensitivity analysis.

RESULTS

Finally, we included the data of 18,436 participants; 6.9% had prevalent CKD (based on eGFR). Caffeine intake for the general population was 131.1 ±1.1 mg. The percentage of participants with CKD, by caffeine quartile, was 16.6% in the first (lowest) quartile, 13.9% in the second, 12.2% in the third and 11.0% in the top quartile (p < 0.001). After adjustment, for increasing quartiles for caffeine consumption, mean urine albumin, albumin-creatinine ratio and estimated glomerular filtration rate (GFR) did not change significantly (p > 0.234). In fully adjusted logistic regression models, there was no significant difference in chances of CKD prevalence (p-trend = 0.745). In the same line, the results of MR showed no impact of coffee intake on CKD (IVW: β = -0.0191, SE = 0.069, p = 0.781) or on eGFR (overall = IVW: β = -0.0005, SE = 0.005, p = 0.926) either in diabetic (IVW: β = -0.006, SE = 0.009, p = 0.478) or non-diabetic patients (IVW: β = -6.772, SE = 0.006, p = 0.991). Results from the meta-analysis indicated that coffee consumption was not significantly associated with CKD (OR = 0.85, 95% CI: 0.71-1.02, p = 0.090, n = 6 studies, I ² = 0.32). These findings were robust in sensitivity analyses.

CONCLUSIONS

Implementing different strategies, we detected no significant association between coffee consumption and renal function or risk of CKD.

Impact of nutraceuticals on markers of systemic inflammation: Potential relevance to cardiovascular diseases - A position paper from the International Lipid Expert Panel (ILEP)

Inflammation is a marker of arterial disease stemming from cholesterol-dependent to -independent molecular mechanisms. In recent years, the role of inflammation in atherogenesis has been underpinned by pharmacological approaches targeting systemic inflammation that have led to a significant reduction in cardiovascular disease (CVD) risk. Although the use of nutraceuticals to prevent CVD has largely focused on lipid-lowering (e.g, red-yeast rice and omega-3 fatty acids), there is growing interest and need, especially now in the time of coronavirus pandemic, in the use of nutraceuticals to reduce inflammatory markers, and potentially the inflammatory CVD burden, however, there is still not enough evidence to confirm this. Indeed, diet is an important lifestyle determinant of health and can influence both systemic and vascular inflammation, to varying extents, according to the individual nutraceutical constituents. Thus, the aim of this Position Paper is to provide the first attempt at recommendations on the use of nutraceuticals with effective anti-inflammatory properties.