Tea, coffee, caffeine intake and the risk of cardio-metabolic outcomes: findings from a population with low coffee and high tea consumption

Habitual coffee drinking and the chance of prediabetes remission: findings from a population with low coffee consumption

Introduction

We aimed to investigate the association between coffee drinking and total caffeine intakes with the chance of prediabetes (Pre-DM) regression and progression over 9-years of follow-up.

Research design and methods

This cohort study included 334 Pre-DM individuals (mean age of 49.4 ± 12.8 years and 51.5% men) who participated in the third phase of the Tehran Lipid and Glucose Study (2006-2008). A validated food frequency questionnaire at baseline assessed habitual coffee consumption. All measurements were done at baseline and all subsequent examinations with 3-year follow-up intervals. The odds ratios (OR) and 95% confidence intervals (CIs) of Pre-DM regression to normal glycemia or progression to type 2 diabetes (T2D) in coffee drinkers/non-drinkers were estimated using multinomial logistic regression analysis.

Results

During the study follow-up 39.8% of the study participants were progressed to T2D and 39.8% returned to normal glycemia. Coffee consumption nearly doubled the chance of returning to normal (OR = 2.26, 95% CI = 1.03-4.97). Total caffeine intake was not related to Pre-DM progression and regression. Compared to non-drinkers, coffee drinkers had significantly lower 2-hour serum glucose concentrations over time (152, 95% CI = 144-159 vs. 162, 95% CI = 155-169 mg/dL, P = 0.05).

Conclusions

Habitual coffee drinking may increase the chance of returning to normal glycemia in Pre-DM subjects.

Coffee Consumption Among Adolescents: A Cross-Sectional Study

The purpose of this cross-sectional study is to analyze and perform a model analysis of the scope of caffeine consumption in adolescents in Turkey. The prevalence of caffeine consumption was 65.5% (321/490), with 22% of boys and 38.45% of girls consuming foodstuffs or beverages containing it. The mean daily caffeine intake was 85.8 mg. Girls consumed all types of coffee more frequently, while boys consumed black tea and energy drinks such as Red Bull and Burn more frequently than girls. Coffee was most frequently consumed to boost concentration, and tea and energy drinks out of habit. Individuals who lived in the city center, smokers, and individuals with high income levels consumed more caffeine (P = .000, P = .000, and P = .000). The level at which energy drinks were consumed by mixing with alcohol in a party setting was 11.5%, and this was more common among boys (P = .000). Greater efforts should be made to inform parents and adolescents of the potential harm resulting from misuse of caffeine.

Green tea consumption and incidence of cardiovascular disease in type 2 diabetic patients with overweight/obesity: a community-based cohort study

BACKGROUND

Green tea has been reported to be potentially protective against the development of cardiovascular disease (CVD). This study aimed to investigate the association between green tea consumption and incident CVD in type 2 diabetes (T2D) patients with overweight/obesity.

METHODS

A total of 4756 Chinese overweight/obese T2D patients were recruited and followed up for 6.27 years. Information on green tea consumption was collected at baseline using interviewer-administered questionnaires. Hazard ratios (HRs) and 95% confidence intervals (CIs) for incident CVD according to green tea consumption were estimated using the Cox proportional hazards model.

RESULTS

Compared with non-habitual consumers, participants who consumed > 5 g/day of green tea leaves reduced the risk of CVD by 29% (95%CI: 0.55-0.92), stroke by 30% (95%CI: 0.51-0.95) and coronary heart disease (CHD) by 40% (95%CI: 0.40-0.89). Similarly, participants who consumed green tea for ≥ 40 years reduced the risk of CVD by 31% (95%CI: 0.54-0.88), stroke by 33% (95%CI: 0.50-0.90) and CHD by 39% (95%CI: 0.42-0.88). Among participants with < 5-year history of T2D, > 5 g/day of tea leaves and > 40 years of tea consumption were associated with 59% (95%CI: 0.23-0.72) and 57% (95%CI: 0.26-0.74) reduced risk of stroke, respectively. However, among participants with ≥ 5-year history of T2D, > 5 g/day of tea leaves and > 40 years of tea consumption were associated with a 50% (95%CI: 0.30-0.82) and 46% (95%CI: 0.35-0.85) reduced risk of CHD, respectively.

CONCLUSIONS

Green tea consumption is associated with reduced risk of CVD, stroke, and CHD in overweight/obese T2D patients.

Coffee consumption and risk of kidney function decline in a Dutch population-based cohort

BACKGROUND AND AIMS

Whether coffee consumption is associated with changes in estimated glomerular filtration rate (eGFR) is unknown. We investigated the relationship between coffee consumption and annual eGFR change in a large Dutch population-based study.

METHODS AND RESULTS

This study was performed in 78,346 participants without chronic kidney disease (CKD) in the population-based Lifelines Cohort Study. Coffee consumption was assessed at baseline using food frequency questionnaires. Outcomes were annual eGFR change and a composite kidney outcome (defined as eGFR <60 mL/min per 1.73 m2 or >20 % eGFR decline). Multivariable linear and logistic regression analyses were used to evaluate the associations of coffee consumption (categories and cups/day) with kidney outcomes. Overall, 90 % of the participants drank coffee daily and 36 % drank >2-4 cups/day. Unadjusted mean ± SD annual eGFR change ranged from -2.86 ± 2.96 (for non-coffee drinkers) to -2.35 ± 2.62 (for participants consuming >6 cups/day) mL/min per 1.73 m2. During 3.6 ± 0.9 years follow-up, 11.1 % of participants reached the composite kidney outcome. As compared to non-coffee drinkers, higher coffee consumption was associated with less annual eGFR decline in multivariable models (β [95 % CIs] ranged from 0.15 [0.07, 0.22] for >0-2 cups/day to 0.29 [0.20, 0.38] for >6 cups/day, P-trend <0.001). Consumption of one more cup of coffee per day was associated with a 3 % lower risk of the composite kidney outcome (OR [95%CI], 0.97 [0.96, 0.99]). The inverse association was more pronounced in a subgroup of individuals with diabetes.

CONCLUSION

Coffee consumption was inversely associated with annual eGFR change and CKD risk in a large Dutch population-based cohort.

Current therapeutic targets and multifaceted physiological impacts of caffeine

Caffeine, which shares consubstantial structural similarity with purine adenosine, has been demonstrated as a nonselective adenosine receptor antagonist for eliciting most of the biological functions at physiologically relevant dosages. Accumulating evidence supports caffeine's beneficial effects against different disorders, such as total cardiovascular diseases and type 2 diabetes. Conversely, paradoxical effects are also linked to caffeine ingestion in humans including hypertension-hypotension and tachycardia-bradycardia. These observations suggest the association of caffeine action with its ingested concentration and/or concurrent interaction with preferential molecular targets to direct explicit events in the human body. Thus, a coherent analysis of the functional targets of caffeine, relevant to normal physiology, and disease pathophysiology, is required to understand the pharmacology of caffeine. This review provides a broad overview of the experimentally validated targets of caffeine, particularly those of therapeutic interest, and the impacts of caffeine on organ-specific physiology and pathophysiology. Overall, the available empirical and epidemiological evidence supports the dose-dependent functional activities of caffeine and advocates for further studies to get insights into the caffeine-induced changes under specific conditions, such as asthma, DNA repair, and cancer, in view of its therapeutic applications.

Dietary caffeine intake is associated with favorable metabolic profile among apparently healthy overweight and obese individuals

BACKGROUND

Recent studies have revealed some conflicting results about the health effects of caffeine. These studies are inconsistent in terms of design and population and source of consumed caffeine. In the current study, we aimed to evaluate the possible health effects of dietary caffeine intake among overweight and obese individuals.

METHODS

In this cross-sectional study, 488 apparently healthy individuals with overweight and obesity were participated. Dietary intake was assessed by a Food Frequency Questionnaire (FFQ) and the amount of dietary caffeine was calculated. Body composition was determined by bioelectrical impedance analysis (BIA). Enzymatic methods were used to evaluate serum lipid, glucose, and insulin concentrations.

RESULTS

Those at the highest tertile of dietary caffeine intake had lower percentage of fat mass, higher fat free mass and appetite score (P < 0.05). Also, lower total cholesterol (TC) and low density lipoprotein cholesterol (LDL-c) was observed in higher tertiles of dietary caffeine intake compared with lower tertiles. In multinomial adjusted models, those at the second tertile of dietary caffeine intake were more likely to have higher serum insulin (P = 0.04) and lower homeostatic model assessment of insulin resistance (HOMA-IR) values compared with first tertile (P = 0.03) in crude model. While, in the age, body mass index (BMI), sex, physical activity, socio-economic status (SES) and energy intake -adjusted model (Model III), those at the third tertile of dietary caffeine intake were more likely to have low serum LDL concentrations [odds ratio (OR) = 0.957; CI = 0.918-0.997; P = 0.04]. With further adjustment to dietary vegetable, fiber and grain intake, those at the third tertile of dietary caffeine intake were more likely to have low systolic blood pressure (SBP), LDL and high HDL levels compared with those at the first tertile (P < 0.05).

CONCLUSION

High intakes of dietary caffeine was associated with lower LDL, SBP, insulin resistance and higher HDL concentrations among overweight and obese individuals. However, due to observational design of the study, causal inference is impossible and further studies are warranted to confirm our findings.

Association of unsweetened and sweetened tea consumption with the risk of new-onset chronic kidney disease: Findings from UK Biobank and Coronary Artery Risk Development in Young Adults (CARDIA) study

Background

The association between tea consumption and chronic kidney disease (CKD) remained inconsistent. We aimed to evaluate the association of tea consumption with new-onset CKD and examine the effects of common additives (milk and sweeteners) and genetic variations in caffeine metabolism on the association.

Methods

176 038 and 3104 participants free of CKD at baseline in the United Kingdom Biobank (UK Biobank) and Coronary Artery Risk Development in Young Adults (CARDIA) study were included, respectively. Dietary information was collected using 24-hour dietary recall questionnaires. The study outcome was new-onset CKD.

Results

In the UK Biobank, during a median follow-up of 12.13 years, 3535 (2.01%) participants developed CKD. Compared with tea non-consumers, the risk of new-onset CKD was significantly lower in unsweetened tea consumers (hazard ratio (HR) = 0.84, 95% confidence interval (CI) = 0.76-0.93), but not in sweetened tea consumers (HR = 0.96, 95% CI = 0.85-1.08), regardless of whether milk was added to tea. Accordingly, relative to tea non-consumers, the adjusted HRs (95% CIs) of new-onset CKD for participants who reported drinking unsweetened tea 1.5 or fewer, >1.5 to 2.5, >2.5 to 3.5, >3.5 to 4.5, and >4.5 drinks/d were HR = 0.86, 95% CI = 0.75-0.99; HR = 0.88, 95% CI = 0.78-1.00; HR = 0.83, 95% CI = 0.73-0.94; HR = 0.83, 95% CI = 0.72-0.95; and HR = 0.86, 95% CI = 0.75-0.99. Moreover, the association of unsweetened tea consumption with new-onset CKD was stronger among those with faster genetically predicted caffeine metabolism levels, although the interaction was insignificant (P-value interaction = 0.768). Consistently, in the CARDIA study, compared with tea non-consumers, a significantly lower risk of new-onset CKD was found in unsweetened tea consumers (HR = 0.80, 95% CI = 0.65-0.98) but not in sweetened tea consumers (HR = 0.97, 95% CI = 0.70-1.34).

Conclusions

Compared with tea non-consumers, consumption of unsweetened tea, but not sweetened tea, was significantly associated with a lower risk of new-onset CKD, regardless of whether milk was added.

Causal Association Between Tea Consumption and Gout: A Mendelian Randomization Study

OBJECTIVE

Evidence from prospective studies on the consumption of tea and risk of gout is conflicting and limited. We aimed to investigate the potential causal effects of tea intake on gout using Mendelian randomization (MR).

METHODS

Genome-wide association studies in UK Biobank included 349 376 individuals and successfully discovered single-nucleotide polymorphisms linked to consumption of one cup of tea per day. Summary statistics from the Chronic Kidney Disease Genetics consortium included 13 179 cases and 750 634 controls for gout. Two-sample MR analyses were used to evaluate the relationship between tea consumption and gout risk. The inverse-variance weighted (IVW) method was used for primary analysis, and sensitivity analyses were also conducted to validate the potential causal effect.

RESULTS

In this study, the genetically predicted increase in tea consumption per cup was associated with a lower risk of gout in the IVW method (OR: 0.90; 95% CI: 0.82-0.98). Similar results were found in weighted median methods (OR: 0.88; 95% CI: 0.78-1.00), while no significant associations were found in MR-Egger (OR: 0.89; 95% CI: 0.71-1.11), weighted mode (OR: 0.80; 95% CI: 0.65-0.99), and simple mode (OR: 1.01; 95% CI: 0.75-1.36). In addition, no evidence of pleiotropy was detected by MR-Egger regression (P=0.95) or MR-PRESSO analysis (P=0.07).

CONCLUSION

This study provides evidence for the daily consumption of an extra cup of tea to reduce the risk of gout.

Coffee Consumption and Risk of Hypertension in Adults: Systematic Review and Meta-Analysis

OBJECTIVES

The association between coffee intake and hypertension (HTN) risk is controversial. Therefore, this systematic review and meta-analysis aimed at summarizing the current evidence on the association of coffee with hypertension risk in observational studies.

METHODS

PubMed/Medline and Web of Science were searched for observational studies up to February 2023. Observational studies which assessed the risk of HTN in the highest category of coffee consumption in comparison with the lowest intake were included in the current meta-analysis (registration number: CRD42022371494). The pooled effect of coffee on HTN was evaluated using a random-effects model.

RESULTS

Twenty-five studies i.e., thirteen cross-sectional studies and twelve cohorts were identified to be eligible. Combining 13 extracted effect sizes from cohort studies showed that higher coffee consumption was associated with 7% reduction in the risk of HTN (95% CI: 0.88, 0.97; I²: 22.3%), whereas combining 16 effect sizes from cross-sectional studies illustrated a greater reduction in HTN risk (RR = 0.79, 95% CI: 0.72, 0.87; I² = 63.2%). These results varied by studies characteristics, such as the region of study, participants' sex, study quality, and sample size.

CONCLUSIONS

An inverse association was found between coffee consumption and hypertension risk in both cross-sectional and cohort studies. However, this association was dependent on studies characteristics. Further studies considering such factors are required to confirm the results of this study.

Coffee intake and risk of diabetic nephropathy: a Mendelian randomization study

Rationale and objective

A causal relationship concerning coffee intake and diabetic nephropathy (DN) is controversial. We conducted a Mendelian randomization study to assess the causal nature of these associations.

Methods

40 independent single nucleotide polymorphisms (SNPs) associated with coffee intake were selected from the UK Biobank study. Summary-level data for diabetic nephropathy were obtained from publicly available genome-wide association studies (GWAS) and the FinnGen consortium. Inverse variance weighted (IVW), MR-Egger, and weighted median (WM) methods were used to examine a causal association. Sensitivity analyses included Cochran's Q test, the intercept of MR-Egger, MR-PRESSO, and the Outlier method. Leave-One-Out sensitivity analyses were also conducted to reduce the heterogeneity.

Results

Our current study demonstrated positive associations of genetically predicted coffee intake with diabetic nephropathy (OR=1.939; P = 0.045 and type 2 diabetes with renal complications (OR = 2.787, P= 0.047). These findings were robust across several sensitivity analyses.

Conclusions

This study found a positive correlation between coffee consumption and the risk of diabetic nephropathy using genetic data. For a more accurate and trustworthy conclusion, subgroup analysis on coffee intake, including preparing method, variety of coffee, and quantity, is required.

The association between tea consumption and blood pressure in the adult population in Southwest China

OBJECTIVES

Prior research on the effect of tea consumption on blood pressure (BP) generated inconsistent findings. The objective of this study was to explore the effects of different types of tea consumption on BP.

METHODS

We included 76,673 participants aged 30-79 from the baseline data of the China Multi-Ethnic Cohort (CMEC) study. Binary logistic regression was used to analyze the influences of different types of tea consumption on the risk of hypertensive BP. Moreover, multiple linear regression was used to examine the association between tea drinking and BP.

RESULTS

Tea consumption was associated with a reduced risk of hypertensive BP by 10% (AOR: 0.90, 95%CI: 0.86-0.94). While dark tea was related to a 1.79-5.31 mmHg reduction in systolic blood pressure (SBP) and a 0.47-1.02 mmHg reduction in diastolic blood pressure (DBP), sweet tea, regardless of the duration, frequency, or amount of consumption, significantly was associated with a reduced SBP by 3.19-7.18 mmHg. Green tea also was associated with a reduced SBP by 1.21-2.98 mmHg. Although scented tea was related to reduced SBP by 1.26-2.48 mmHg, the greatest effect came from the long duration (> 40 years:β=-2.17 mmHg, 95%CI=-3.47 mmHg --0.87 mmHg), low frequency (1-2 d/w: β = -2.48 mmHg, 95%CI=-3.76 mmHg--1.20 mmHg), and low amount (≤ 2 g/d: β=-2.21 mmHg, 95%CI=-3.01 mmHg--1.40 mmHg). Additionally, scented tea was correlated to a decrease in DBP at the frequency of 1-2 d/w (β=-0.84 mmHg, 95%CI=-1.65 mmHg--0.02 mmHg). Drinking black tea only was associated with lowered SBP. The protective effect of black tea on SBP was characterized by the long-duration (> 15 years, -2.63--5.76 mmHg), high frequency (6-7 d/w, -2.43 mmHg), and medium amount (2.1-4.0 g/d, -3.06 mmHg).

CONCLUSION

Tea consumption was associated with lower SBP and a reduced risk of hypertensive BP. The antihypertensive effect varies across types of tea consumed.

The influence of the CYP1A2-163 C>A polymorphism on the hemostatic response to exercise following caffeine supplementation

BACKGROUND

Prior work from our group suggests that caffeine increases thrombotic potential after acute exercise. The aim of this study was to determine if hemostatic responses to exercise affected by caffeine are influenced by the CYP1A2-163 C>A polymorphism.

METHODS

Forty-two healthy men performed two trials in which a graded maximal exercise test was completed one hour after consuming either 6 mg/kg of caffeine or placebo. Subjects were categorized as possessing the C allele (N.=21) or being homozygous for the A allele (N.=21).

RESULTS

Factor VIII increased more (265%) during exercise in the caffeinated condition than the placebo condition (178%) (P<0.05). Tissue plasminogen activator (tPA) activity also increased more following caffeine as compared to placebo (increase of 8.70±4.32 IU/mL vs. 6.77±3.79 IU/mL respectively, P<0.05). There was no treatment × genotype or treatment × time × genotype interactions.

CONCLUSIONS

Although caffeine increases factor VIII and tPA responses to maximal exercise, these changes are not influenced by the CYP1A2-163 C>A polymorphism.

Association of habitual coffee consumption and kidney function: A prospective analysis in the Rotterdam Study

BACKGROUND & AIMS

Population-based studies have suggested a protective effect of coffee against development of chronic kidney disease (CKD), possibly through coffee's anti-inflammatory and antioxidant compounds. Studies on coffee and kidney function decline in the general population are scarce. We studied associations of habitual coffee consumption with repeated assessments of estimated glomerular filtration rate (eGFR) and urinary albumin-to-creatinine ratio (ACR).

METHODS

We used data from 7,914 participants of the population-based Rotterdam Study. Baseline coffee consumption data (cups/day) were obtained from home interviews and validated food frequency questionnaires (1997-2008). Repeated assessments of eGFR (ml/min per 1.73 m², 1997-2014) were calculated according to the creatinine-based CKD Epidemiology Collaboration equation of 2012. Repeated assessments of urinary albumin and creatinine were used to estimate ACR (mg/g, 2006-2014). Data were analyzed by applying linear mixed models, adjusted for sociodemographic, lifestyle and dietary factors, and cardiovascular disease risk factors. Predefined subgroup analyses were performed stratified by CKD risk factors.

RESULTS

Participants' mean (SD) baseline age was 66 (10) years, 57% were women and median [IQR] coffee consumption was 3.0 [2.0, 5.0] cups/day. Those drinking more coffee were more likely to smoke, and to have type 2 diabetes (T2D) and obesity. Mean eGFR was 79 (15) ml/min per 1.73 m². In the total study population, coffee was not associated with longitudinal eGFR during a median of 5.4 years of follow-up (β = 0.04 ml/min per 1.73 m² per one cup/day [95% CI: -0.10,0.18]). However, among those aged >70 years, one additional coffee cup/day was associated with on average 0.84 (0.51,1.18) ml/min per 1.73 m² higher longitudinal eGFR. Among obese participants this estimate was 0.32 (0.01,0.63). A protective trend was also observed among former smokers (0.17 [-0.03,0.39]) and those with T2D (0.42 [-0.05,0.88]). Coffee was not associated with longitudinal ACR (0.01 mg/ml [-0.01,0.02]).

CONCLUSION

While coffee was not associated with eGFR and ACR in the total population, more coffee consumption was associated with higher longitudinal eGFR among those at higher risk for CKD, i.e., among those aged 70+ and obese participants. These findings require confirmation in other prospective cohort studies.

Genetically predicted green tea intake and the risk of arterial embolism and thrombosis

Background

In previous observational studies, green tea intake has been demonstrated to protect against arterial embolism and thrombosis. However, whether there is a causative connection between green tea intake and arterial embolism and thrombosis is currently unclear.

Methods

A two-sample Mendelian randomization (MR) study has been designed to explore whether there is a causal association between green tea intake and arterial embolism and thrombosis by acquiring exposure and outcome data from previously published research. Data from the MRC-IEU (data on green tea intake, 64,949 participants) consortium and the FinnGen project (data on arterial embolism and thrombosis, 278 cases of arterial thrombosis and 92,349 control participants) has been utilized to determine the causal impact of green tea intake on arterial embolism and thrombosis.

Results

We found that genetically predicted green tea intake was causally associated with a lower risk of arterial embolism and thrombosis (IVW odds ratio [OR] per SD decrease in green tea intake = 0.92 [95% confidence interval, 0.85-0.99]; p = 0.032). Moreover, the sensitivity analysis (both MR Egger regression and weighted median) yielded comparable estimates but with low precision. No directional pleiotropic effect between green tea intake and arterial embolism and thrombosis was observed in both funnel plots and MR-Egger intercepts.

Conclusions

Our study provided causal evidence that genetically predicted green tea intake may be a protective factor against arterial embolism and thrombosis.

Tea Plant (Camellia sinensis): A Current Update on Use in Diabetes, Obesity, and Cardiovascular Disease

The tea plant (C. sinensis) has traditionally been consumed worldwide as "tea" for its many health benefits, with the potential for the prevention and therapy of various conditions. Regardless of its long history, the use of tea plants in modern times seems not to have changed much, as the beverage remains the most popular form. This review aimed to compile scientific information about the role and action of tea plants, as well as their status concerning clinical applications, based on the currently available evidence, with a focus on metabolic syndrome, mainly covering obesity, diabetes, and cardiovascular disease. It has been recognized that these diseases pose a significant threat to public health, and the development of effective treatment and prevention strategies is necessary but still challenging. In this article, the potential benefits of tea plants and their derived bioactive components (such as epigallocatechin-3-gallate) as anti-obesity, anti-diabetic, and anti-cardiovascular agents are clearly shown and emphasized, along with their mechanisms of action. However, according to the status of the clinical translation of tea plants, particularly in drug development, more substantial efforts in well-designed, randomized, controlled trials are required to expand their applications in treating the three major metabolic disorders and avoiding the toxicity caused by overconsumption.

Lifestyle and chronic kidney disease: A machine learning modeling study

Background

Individual lifestyle varies in the real world, and the comparative efficacy of lifestyles to preserve renal function remains indeterminate. We aimed to systematically compare the effects of lifestyles on chronic kidney disease (CKD) incidence, and establish a lifestyle scoring system for CKD risk identification.

Methods

Using the data of the UK Biobank cohort, we included 470,778 participants who were free of CKD at the baseline. We harnessed the light gradient boosting machine algorithm to rank the importance of 37 lifestyle factors (such as dietary patterns, physical activity (PA), sleep, psychological health, smoking, and alcohol) on the risk of CKD. The lifestyle score was calculated by a combination of machine learning and the Cox proportional-hazards model. A CKD event was defined as an estimated glomerular filtration rate <60 ml/min/1.73 m², mortality and hospitalization due to chronic renal failure, and self-reported chronic renal failure, initiated renal replacement therapy.

Results

During a median of the 11-year follow-up, 13,555 participants developed the CKD event. Bread, walking time, moderate activity, and vigorous activity ranked as the top four risk factors of CKD. A healthy lifestyle mainly consisted of whole grain bread, walking, moderate physical activity, oat cereal, and muesli, which have scored 12, 12, 10, 7, and 7, respectively. An unhealthy lifestyle mainly included white bread, tea >4 cups/day, biscuit cereal, low drink temperature, and processed meat, which have scored −12, −9, −7, −4, and −3, respectively. In restricted cubic spline regression analysis, a higher lifestyle score was associated with a lower risk of CKD event (p for linear relation < 0.001). Compared to participants with the lifestyle score < 0, participants scoring 0–20, 20–40, 40–60, and >60 exhibited 25, 42, 55, and 70% lower risk of CKD event, respectively. The C-statistic of the age-adjusted lifestyle score for predicting CKD events was 0.710 (0.703–0.718).

Conclusion

A lifestyle scoring system for CKD prevention was established. Based on the system, individuals could flexibly choose healthy lifestyles and avoid unhealthy lifestyles to prevent CKD.

Sex-specific association between coffee consumption and incident chronic kidney disease: a population-based analysis of 359,906 participants from the UK Biobank

BACKGROUND

The risk for chronic kidney disease (CKD) is influenced by genetic predisposition, sex, and lifestyle. Previous research indicates that coffee is a potentially protective factor in CKD. The current study aims to investigate whether sex disparity exists in the coffee-CKD association, and whether genetic risk of CKD or genetic polymorphisms of caffeine metabolism affect this association.

METHODS

A total of 359,906 participants from the UK Biobank who were enrolled between 2006 and 2010 were included in this prospective cohort study, which aimed to estimate the hazard ratios for coffee intake and incident CKD using a Cox proportional hazard model. Allele scores of CKD and caffeine metabolism were additionally adjusted for in a subsample with qualified genetic data ( n = 255,343). Analyses stratified by genetic predisposition, comorbidities, and sex hormones were performed. Tests based on Bayesian model averaging were conducted to ascertain the robustness of the results.

RESULTS

Coffee was inversely associated with CKD in a dose-dependent manner. The effects of coffee did not differ across different strata of genetic risk for CKD, but were more evident among slower genetically predicted caffeine metabolizers. Significant sex disparity was observed ( P value for interaction = 0.013), in that coffee drinking was only associated with the risk reduction of CKD in females. Subgroup analysis revealed that testosterone and sex hormone-binding globulin (SHBG), but not estradiol, modified the coffee-CKD association.

CONCLUSIONS

In addition to the overall inverse coffee-CKD association that was observed in the general population, we could also establish that a sex disparity existed, in that females were more likely to experience the benefit of the association. Testosterone and SHBG may partly account for the sex disparity.

Effect of Beverage Consumption Frequency on DMFT Index among Iranian Adult Population: An AZAR Cohort Study

Background

Given the effect of oral and dental condition on emotional and physical health and the different effects of beverage consumption on decayed, missing, and filled teeth (DMFT) as one of the indicators of oral health in different populations, this study aimed to investigate the effect of beverage consumption and its frequency on DMFT among Iranian adult population.

Materials and Methods

The data of this cross-sectional study were obtained from AZAR (Azerbaijan) cohort, conducted on 15,006 adults aged 35 to 70 years old in Shabestar County, Iran. Demographic and nutritional data were collected by nutritionists through the "Food Frequency Questionnaire," and DMFT index by general practitioners trained by a dentist according to the World Health Organization (WHO) guidelines. Beverages including milk, doogh, natural fruit juice, black tea, nonalcoholic beer, coffee, sugar-sweetened beverages, and artificial fruit juice were studied.

Results

A total of 14,966 adults with the mean age of 49.64 ± 9.28 were enrolled. The participants' mean DMFT value was 21.27 ± 8.95. Weekly consumption of tea and coffee beverages resulted in 13% (95% confidence interval: 3% to 22%) lower DMFT compared to daily consumption (p=0.01). However, there was no association between DMFT and other beverages.

Conclusion

The higher DMFT values with the daily consumption of tea and coffee beverages showed that a part of adults' oral health is affected by beverages; therefore, this should be considered by healthcare authorities in order to manage carries development in the communities.

Dietary sources, health benefits, and risks of caffeine

Dietary intake of caffeine has significantly increased in recent years, and beneficial and harmful effects of caffeine have been extensively studied. This paper reviews antioxidant and anti-inflammatory activities of caffeine as well as its protective effects on cardiovascular diseases, obesity, diabetes mellitus, cancers, and neurodegenerative and liver diseases. In addition, we summarize the side effects of long-term or excessive caffeine consumption on sleep, migraine, intraocular pressure, pregnant women, children, and adolescents. The health benefits of caffeine depend on the amount of caffeine intake and the physical condition of consumers. Moderate intake of caffeine helps to prevent and modulate several diseases. However, the long-term or over-consumption of caffeine can lead to addiction, insomnia, migraine, and other side effects. In addition, children, adolescents, pregnant women, and people who are sensitive to caffeine should be recommended to restrict/reduce their intake to avoid potential adverse effects.

A pilot study: Gut microbiota, metabolism and inflammation in hypertensive intracerebral hemorrhage

AIMS

In recent years, the incidence rate of hypertensive intracerebral hemorrhage (HICH) has been increasing, accompanied by high mortality and morbidity, which has brought a heavy burden to the social economy. However, the pathogenesis of HICH is still unclear. This study intends to explore the mechanism of gut microbiota metabolism and inflammation in the process of HICH to provide a theoretical basis for the diagnosis and treatment of HICH.

METHODS AND RESULTS

HE staining showed that the brain tissues of model group had obvious edema injury, which indicated that the HICH model was successfully constructed. ELISA analysis showed that IL-1β and TNF-α levels in blood and brain tissues were significantly increased, and IL-10 level was significantly decreased in blood. IHC analysis showed that microglia and macrophages were activated in the model group. 16S rRNA sequence showed that the diversity of gut microbiota in HICH patients decreased. And the microbiota belonged to Firmicutes, Proteobacteria and Verrucomicrobia changed significantly. LC-MS/MS analysis showed that the metabolic phenotype of HICH patients changed. And the 3,7-Dimethyluric acid and 7-Methylxanthine related metabolic pathways of caffeine metabolism pathways were down-regulated in patients with HICH. Bacteroides was negatively correlated with the IL-1β and TNF-α level. Blautia was negatively correlated with the IL-1β and TNF-α level, and positively correlated with the IL-10 level. Akkermansia was negatively correlated with the 3,7-Dimethyluric acid and 7-Methylxanthine.

CONCLUSION

Our study suggested that HICH accompanied by the increased inflammation in peripheral blood and brain, decreased gut microbiota diversity, altered gut metabolic phenotype, and down-regulation of caffeine metabolism pathway.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our study reported that HICH accompanied by the increased inflammation, decreased gut microbiota diversity, and altered gut metabolic phenotype. Due to the number of patients, this work was a pilot study.

Tea Infusions as a Source of Phenolic Compounds in the Human Diet

Phenolic compounds are components with proven beneficial effects on the human body, primarily due to their antioxidant activity. In view of the high consumption of tea and the numerous factors that affect the nutritional value of its infusions, the aim of this study was to identify the effects of tea type and duration of leaf extraction with water on the levels of phenolic compounds and other components that determine biological activity (oxalates, Ca, Na, Cu, and Mn). Based on assays, infusions of red tea prepared for 20 min were found to be the best source of phenolics (202.9 mg/100 mL), whereas the lowest level of these compounds was determined in infusions of black tea extracted from leaves for 30 min (46.9 mg/100 mL). The highest degree of increase in polyphenol content (by approx. 50%) was noted in red and green tea infused for between 10 and 20 min, whereas for black tea, polyphenol levels decreased with time. The biological activity of tea infusions appears to be determined to the greatest extent by the interactions between phenolic compounds and oxalates (r = 0.6209), calcium (r = 0.8516), and sodium (0.8045). A daily intake of three to four mugs (1 L) of tea infusions provides the human body the entire amount of phenolics recommended for health reasons (as regards red tea, this is possible at 1/3 of the volume) and covers the daily requirement for manganese, as well as (partially) copper.

Automated Detection of Caffeinated Coffee-Induced Short-Term Effects on ECG Signals Using EMD, DWT, and WPD

The effect of coffee (caffeinated) on electro-cardiac activity is not yet sufficiently researched. In the current study, the occurrence of coffee-induced short-term changes in electrocardiogram (ECG) signals was examined. Further, a machine learning model that can efficiently detect coffee-induced alterations in cardiac activity is proposed. The ECG signals were decomposed using three different joint time–frequency decomposition methods: empirical mode decomposition, discrete wavelet transforms, and wavelet packet decomposition with varying decomposition parameters. Various statistical and entropy-based features were computed from the decomposed coefficients. The statistical significance of these features was computed using Wilcoxon’s signed-rank (WSR) test for significance testing. The results of the WSR tests infer a significant change in many of these parameters after the consumption of coffee (caffeinated). Further, the analysis of the frequency bands of the decomposed coefficients reveals that most of the significant change was localized in the lower frequency band (<22.5 Hz). Herein, the performance of nine machine learning models is compared and a gradient-boosted tree classifier is proposed as the best model. The results suggest that the gradient-boosted tree (GBT) model that was developed using a db2 mother wavelet at level 2 decomposition shows the highest mean classification accuracy of 78%. The outcome of the current study will open up new possibilities in detecting the effects of drugs, various food products, and alcohol on cardiac functionality.

Relationship of coffee consumption with a decline in kidney function among patients with type 2 diabetes: the Fukuoka Diabetes Registry

Aims/Introduction

The evidence regarding the effects of coffee consumption on incident chronic kidney disease is inconclusive, and no studies have investigated the relationship in patients with diabetes. We aimed to prospectively investigate the relationship between coffee consumption and the decline in estimated glomerular function rate (eGFR) in patients with type 2 diabetes.

Materials and Methods

A total of 3,805 patients (2,112 men, 1,693 women) with type 2 diabetes (mean age 64.2 years) and eGFR ≥60 mL/min/1.73 m² were followed (completion of follow up, 97.6%; median 5.3 years). Coffee consumption was assessed at baseline. The end‐point was a decline in eGFR to <60 mL/min/1.73 m² during the follow‐up period.

Results

During follow up, 840 participants experienced a decline in eGFR to <60 mL/min/1.73 m². Higher coffee consumption reduced the risk of decline in eGFR. Compared with no coffee consumption, the multivariate‐adjusted hazard ratios (95% confidence intervals) were 0.77 (0.63–0.93) for less than one cup per day, 0.77 (0.62–0.95) for one cup per day and 0.75 (0.62–0.91) for two or more cups per day (P for trend 0.01). This trend was unaffected by further adjustment for baseline eGFR and albuminuria. The mean eGFR change per year was −2.16 mL/min/1.73 m² with no coffee consumption, −1.89 mL/min/1.73 m² with less than one cup per day, −1.80 mL/min/1.73 m² with one cup per day and −1.78 mL/min/1.73 m² with two or more cups per day (P for trend 0.03).

Conclusions

Coffee consumption is significantly associated with a lower risk of decline in eGFR in patients with type 2 diabetes.

Causal Association Between Tea Consumption and Kidney Function: A Mendelian Randomization Study

Background

Causal research concerning the consumption of tea and the risk of chronic kidney disease (CKD) is limited. This study identified the potential causal effects of tea intake on CKD, the estimated glomerular filtration rate (eGFR), and albuminuria.

Methods

Genome-wide association studies (GWASs) from UK Biobank were able to identify single-nucleotide polymorphisms (SNPs) associated with an extra cup of tea each day. The summary statistics for the kidney function from the CKDGen consortium include 11,765 participants (12,385 cases of CKD) and 54,116 participants for the urinary albumin-to-creatinine ratio who were mostly of European descent. A two-sample Mendelian randomization (MR) analysis was performed to test the relationship between the selected SNPs and the risk of CKD.

Results

A total of 2,672 SNPs associated with tea consumption (p < 5 × 10^-8) were found, 45 of which were independent and usable in CKDGen. Drinking more cups of tea per day indicates a protective effect for CKD G3-G5 [odds ratio (OR) = 0.803; p = 0.004] and increases eGFR (β = 0.019 log ml/min/1.73 m² per cup per day; p = 2.21 × 10^-5). Excluding two SNPs responsible for directional heterogeneity (Cochran Q p = 0.02), a high consumption of tea was also negatively correlated with a lower risk of albuminuria (OR = 0.758; p = 0.002).

Conclusion

From the perspective of genes, causal relationships exist between daily extra cup of tea and the reduced risk of CKD and albuminuria and increased eGFR.

Habitual tea consumption and 5-year incident metabolic syndrome among older adults: a community-based cohort study

Background

The effect of tea consumption on metabolic syndrome (MetS) remains controversial. The objective of this study is to examine the prospective association of tea consumption with 5-year incident MetS among aged population in China.

Methods

This analysis included 3005 Chinese adults aged 60 years or older who were free of MetS at baseline examination. MetS was defined according to the National Cholesterol Education Program-Adult Treatment Panel III. Information regarding tea consumption was collected via an interviewer-administrated questionnaire. The prospective associations between tea consumption at baseline and 5-year incident MetS, as well as its individual components, were assessed by multiple logistic regression models.

Results

Of the 3005 participants free of MetS at baseline, 406 participants (cumulative incidence: 13.5%) developed MetS at the 5-year follow-up examination. In multiple logistic regressions, 5-year cumulative incidence of MetS was found to be higher in those who drank tea more than 5 times per week as compared with non-habitual drinkers (OR = 1.38, 95% CI: 1.05-1.82; P = 0.02). This relationship still existed in men (OR = 1.43, 95%CI: 1.00-2.01; P = 0.05) when stratified by gender. Among the five major components of MetS, low high-density lipoprotein cholesterol was observed in men, while high body mass index, elevated blood pressure and the presence of diabetes mellitus were significant in women.

Conclusions

High-frequent tea consumption increased the risk of MetS among older Chinese adults. These findings may add novel knowledge to the current studies regarding the controversial effect of tea consumption on cardiovascular and metabolic health among the aged population.

The association between dietary fats and the incidence risk of cardiovascular outcomes: Tehran Lipid and Glucose Study

Background

The association between dietary fats and the risk of cardiovascular disease (CVD) is under debate. We aimed to determine the potential effects of dietary saturated fats (SFA), mono-unsaturated (MUFA) and poly-unsaturated (PUFA) fatty acids on the occurrence of CVD in an adult Asian population.

Methods

This study was conducted within the framework of the Tehran Lipid and Glucose Study on 2809 CVD-free adults, aged ≥ 19 years. Dietary intakes of fats were estimated using a validated 168-items semi-quantitative food frequency questionnaire, at baseline. Adjusted hazard ratios and 95% confidence intervals of CVD were calculated in tertile categories of dietary fats. The risk of CVD was estimated with multivariable Cox regression for the substitution of total fat or SFA with other macronutrients.

Results

During 10.6 years of follow up, the incidence rate of CVD events was 7.1%. Mean (± SD) age of the participants was 39 (± 14) years and 43.9% were men. Total fat, animal and plant sources of fats were not associated with risk of CVD events. No significant associations were found between total SFA, lauric acid, myristic acid, stearic acid, palmitic acid as well as MUFA and PUFA and CVD incidence. Substitutions of total fats or SFA with other macronutrients were not associated with CVD risk.

Conclusions

In this study, no significant associations were found between dietary fats and CVD risk. Considering the emerging body of literature that suggests no association between fats and CVD risk, reconsideration of dietary recommendations regarding low fat diets to prevent CVD, seems to be essential.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12986-021-00624-6.

Association between Tea Consumption and Hypertension Risk among Middle-Aged and Older Chinese Adults

BACKGROUND

Current evidence on tea consumption and hypertension is inconclusive, and prospective studies among habitual tea drinkers remain limited.

OBJECTIVE

We investigated the associations of habitual tea consumption with hypertension risk and longitudinal blood pressure changes in 2 large cohorts.

METHODS

This study included participants aged 40-75 y from the Shanghai Women's Health Study (n = 31,351) and the Shanghai Men's Health Study (n = 28,342), without hypertension, diabetes, cardiovascular disease, or cancer at baseline. Information on tea consumption was assessed during in-person interviews at enrollment and follow-up visits. Incident hypertension was identified by self-reported diagnosis, medication use, or blood pressure measurements.

RESULTS

Current tea drinkers had a 7% higher risk than the non-current tea drinker group [HRs (95% CIs): women, 1.07 (1.01, 1.14); men, 1.07 (1.02, 1.12)]. The amount of tea drinking showed significant dose-response associations with hypertension: compared with the non-current group, HRs (95% CIs) for women and men were 1.01 (0.90, 1.14) and 1.02 (0.96, 1.08) for low (women/men: <100/200 g/mo), 1.07 (1.01, 1.15) and 1.05 (0.99, 1.12) for medium (women/men: 100-250/200-250 g/mo), and 1.18 (1.01, 1.39) and 1.10 (1.03, 1.17) for the high-amount group (women/men: >250 g/mo). Among participants without hypertension, compared with non-current tea drinkers, least-squares means of 3-y changes in blood pressure were 0.3-0.4 mm Hg higher for women and men as current drinkers and 0.7-0.9 mm Hg higher for men in the high-consumption group. Compared with those who never drank tea, women who drank tea consistently had 0.5 (0.2, 0.7) mm Hg higher diastolic blood pressure (DBP), whereas men had 0.5 (0.04, 0.9) mm Hg higher systolic blood pressure and 0.3 (0.04, 0.6) mm Hg higher DBP, respectively.

CONCLUSIONS

Our findings suggest that habitual tea drinking is associated with a slightly higher risk of hypertension and a minor increase in blood pressure among middle-aged and older Chinese adults, which warrants confirmation by long-term intervention studies.

Interaction between dietary total antioxidant capacity and BDNF Val66Met polymorphism on lipid profiles and atherogenic indices among diabetic patients

Brain-derived neurotrophic factor (BDNF) belongs to the "neurotrophin" family of growth factors, and it has recently been associated to cardiovascular disease (CVD). We anticipated that BDNF Val66Met polymorphisms may alter CVD risk markers such as serum lipid profile differences, and interaction with total antioxidant capacity of diet (DTAC) could alter these clinical parameters. This cross-sectional study consisted of 667 diabetic patients (39.7% male and 60.3% female). DTAC was calculated by international databases. Biochemical markers including total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride (TG), superoxide dismutase (SOD), C-reactive protein (CRP), total antioxidant capacity (TAC), pentraxin-3 (PTX3), isoprostaneF2α (PGF2α). interleukin 18 (IL18), leptin and ghrelin were measured by standard protocol. Atherogenic indices (AIP, AC, CR-I, CR-II) were calculated. Genotyping of the BDNF Val66Met polymorphisms was conducted by the real-time PCR-RFLP method. The gene-diet interactions were evaluated using a generalized linear mode (GLMs). Carriers of the Val/Met genotype who were in the higher median intake of FRAP had lower HDL (P:0.04) and higher TG (P:0.005), AIP (P:0.02) and AC (P:0.02) index compared to Val/Val genotypes with lower median intake. Moreover, diabetic patients with Val/Met genotype who consumed higher ORAC intake had increased odds for anthropometric indices (BMI (P:0.01) and WC (P:0.03)), lipid profiles (TG) (P:0.01), and atherogenic index (AIP) (P:0.02), also decreased odds for HDL (P:0.03) concentration compared to reference group whit lower ORAC intake. Individuals with Val/Met genotype who consumed higher TRAP intake had increased odds for WC (P:0.04), TC (P:0.001), TG (P < 0.001), AIP (P < 0.001) and AC (P < 0.001). Finally, Val/Met patients with a higher median intake of TEAC had higher TG (P:0.02), AIP (P:0.009) and AC (P:0.03) compared to the reference group whit lower TEAC intake. Our study showed that Val/Met genotype had also the highest lipid profile and atherogenic indices even in the highest adherence to DTAC. While it seems that the presence of the Val/Val wild-type and BDNF Met/Met homozygotes in diabetic patients with a high DTAC is a protective factor.

Associations of tea consumption with blood pressure progression and hypertension incidence

BACKGROUND

Association between tea consumption and incident hypertension remains uncertain. This study conducted to examine the health effects of tea consumption on blood pressure progression and hypertension incidence.

METHODS

A population-based cohort of 38,913 Chinese participants without hypertension at baseline were included in the current study. Information on tea consumption was collected through standardized questionnaires. Associations of tea consumption with blood pressure progression and incident hypertension were analyzed using logistic regression models and Cox proportional hazards regression models, respectively.

RESULTS

During a median follow-up of 5.9 years, 17,657 individuals had experienced progression to a higher blood pressure stage and 5,935 individuals had developed hypertension. In multivariate analyses, habitual tea drinkers (≥ 3 times/week for at least six months) had a 17% lower risk for blood pressure progression [odds ratio (OR) = 0.83, 95% CI: 0.79–0.88] and a 14% decreased risk for incident hypertension [hazard ratio (HR) = 0.86, 95% CI: 0.80–0.91] compared with non-habitual tea drinkers. Individuals in different baseline blood pressure groups could obtain similar benefit from habitual tea drinking. In terms of tea consumption amount, an inverse, linear dose-response relation between monthly consumption of tea leaves and risk of blood pressure progression was observed, while the risk of incident hypertension did not reduce further after consuming around 100 g of tea leaves per month.

CONCLUSIONS

Our study demonstrated that habitual tea consumption could provide preventive effect against blood pressure progression and hypertension incidence.

Consumption of caffeinated beverages and kidney function decline in an elderly Mediterranean population with metabolic syndrome

It remains unclear whether caffeinated beverages could have deleterious renal effects in elderly population with underlying comorbid conditions. We investigated the associations between coffee, tea, or caffeine intake and 1-year changes in glomerular filtration rate (eGFR) in a large Spanish cohort of overweight/obese elderly with metabolic syndrome (MetS). This prospective analysis includes 5851 overweight/obese adults (55-75 years) with MetS from the PREDIMED-Plus study. We assessed coffee, tea, and caffeine consumption from a validated food-frequency questionnaire and creatinine-based eGFR using the Chronic Kidney Disease Epidemiology Collaboration equation. Multivariate-adjusted regression models were applied to test associations between baseline coffee, tea, or caffeine intake and 1-year eGFR changes. Caffeinated coffee (> 2 cups/day) and tea (at least 1 cup/day) drinkers had 0.88 and 0.93 mL/min/1.73 m² greater eGFR decrease respectively, compared to those with less than 1 cup/day of coffee consumption or non-tea drinkers. Furthermore, caffeinated coffee consumption of > 2 cups/day was associated with 1.19-fold increased risk of rapid eGFR decline > 3 mL/min/1.73 m² (95% CI 1.01-1.41). Similarly, individuals in the highest (median, 51.2 mg/day) tertile of caffeine intake had a 0.87 mL/min/1.73 m² greater eGFR decrease. Decaffeinated coffee was not associated with eGFR changes. In conclusion, higher consumption of caffeinated coffee, tea, and caffeine was associated with a greater 1-year eGFR decline in overweight/obese adults with MetS.

Tea as a Source of Biologically Active Compounds in the Human Diet

Due to the different levels of bioactive compounds in tea reported in the literature, the aim of this study was to determine whether commercially available leaf teas could be an important source of phenolics and selected minerals (copper, manganese, iron, zinc, magnesium, calcium, sodium, potassium) and if the differences in the content of these components between various types of tea are significant. It was found that both the amount of these compounds in tea and the antioxidant activity of tea infusions were largely determined by the origin of tea leaves as well as the processing method, which can modify the content of the studied components up to several hundred-fold. The group of green teas was the best source of phenolic compounds (110.73 mg/100 mL) and magnesium (1885 µg/100 mL) and was also characterised by the highest antioxidant activity (59.02%). This type of tea is a great contributor to the daily intake of the studied components. The average consumption of green tea infusions, assumed to be 3–4 cups (1 L) a day, provides the body with health-promoting polyphenol levels significantly exceeding the recommended daily dose. Moreover, drinking one litre of an unfermented tea infusion provides more than three times the recommended daily intake of manganese. Tea infusions can be a fairly adequate, but only a supplementary, source of potassium, zinc, magnesium, and copper in the diet. Moreover, it could be concluded that the antioxidant activity of all the analysed types of tea infusions results not only from the high content of phenolic compounds and manganese but is also related to the presence of magnesium and potassium.

Caffeine modulates pharmacokinetic and pharmacodynamic profiles of pioglitazone in diabetic rats: Impact on therapeutics

OBJECTIVES

To determine the influence of caffeine on pharmacokinetics and pharmacodynamics of pioglitazone (PIO) in diabetic rats.

METHODS

This was a preclinical study conducted in the College of Pharmacy, Najran University, Saudi Arabia, using 5 groups of Wistar rats: normal rats, untreated diabetic rats, diabetic rats + caffeine (20 mg/kg), diabetic rats + PIO (10 mg/kg), and diabetic rats + PIO (10 mg/kg) + caffeine (20 mg/kg). The drugs were administered for 14 days, and fasting plasma glucose concentrations were determined on the first day, and thereafter at weekly intervals. On day 14, rat sacrifice was followed with assay of levels of biomarkers. To estimate the pharmacokinetic parameters, the diabetic animals were assigned to 2 groups: one group received PIO (10 mg/kg), while the other received PIO + caffeine (20 mg/kg). Blood samples were drawn from the retro-orbital plexus at different time intervals, and pharmacokinetic parameters were measured using high performance liquid chromatography.

RESULTS

Caffeine caused statistically marked increases in area under the curve, Cmax, Tmax, and half-life of PIO, and decreased clearance. Combination of PIO and caffeine produced a synergistic effect on percentage reduction in blood glucose, with 67.1% reductions observed on day 7 and 68.9% reductions observed on day 14. Liver and cardiac biomarkers were significantly decreased, suggesting cardioprotective and hepatoprotective effects.

CONCLUSION

Co-administration of PIO with caffeine enhances its antidiabetic effect, probably due to enhanced bioavailability of PIO, leading to clinical benefits in diabetic patients.

Dietary patterns interact with the variations of 18q21.23 rs17782313 locus on regulation of hypothalamic-pituitary axis hormones and cardio-metabolic risk factors in obesity

BACKGROUND

Evidence shows the role of polymorphisms in rs17782313 MC4R gene with increased risk of obesity in Asians adult. In the current report, we investigated the interaction between rs17782313 MC4R gene and major dietary patterns on α-melanocyte stimulating hormone (α-MSH), Agouti-related peptide (AgRP), serum lipids and blood pressure among obese individuals.

METHODS

This cross-sectional study was performed in 288 obese adults between 20 and 50 years of age. Anthropometric measurements and biochemical assays were conducted with standard methods. To evaluate appetite, the Visual Analogue Scale (VAS) was used. Dietary patterns were obtained by principal component analysis (PCA). Genotyping of rs17782313 was assessed by restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

Three major dietary patterns were extracted: Prudent Dietary Pattern (PDP), Legume Dietary Pattern (LDP) and Mixed Dietary Pattern (MDP). Higher PDP score was associated with reduced SBP and insulin concentration while highest MDP score was associated with lower TG concentration (P < 0.05). Significant interactions were observed between higher adherence to PDP and rs17782313 CC genotype on increased SBP (P_Interaction = 0.04), serum insulin (P_Interaction = 0.05) and AgRP (P_Interaction = 0.03) and also between higher adherence to MDP and CC genotype of rs17782313 on reduced serum TG (P = 0.03).

CONCLUSIONS

The findings of the current study showed that being on CC genotype of rs17782313 polymorphism made obese individuals more prone to have higher SBP, insulin and AgRP even in highest adherence to PDP. However, adherence to MDP could attenuate the risky effects of being on CC genotype of rs17782313 by reducing serum TG concentrations.

LEVEL OF EVIDENCE

Level V, cross-sectional descriptive study.

Effect of Coffee Consumption on Renal Outcome: A Systematic Review and Meta-Analysis of Clinical Studies

OBJECTIVE

Drinking coffee is one of the most common daily habits, especially in the developed world. Along with caffeine, coffee has various ingredients that have been suggested to have beneficial effects, including antioxidant, antiinflammatory, anticarcinogenic, antithrombotic and antifibrotic effects. In this systematic review and meta-analysis, we investigated the relationship between coffee intake and chronic kidney disease (CKD) related outcomes.

DESIGN AND METHODS

Literature search was performed through PubMed/Medline, Web of Science, Embase (Elsevier), and the Cochrane Central Register of Controlled Trials (Wiley) from 1960 to February 2020. Incidence of CKD, the progression of CKD, and CKD-associated mortality have been evaluated in relation to coffee consumption and the amount of consumption. The Newcastle-Ottawa scale was used for quality assessment of included studies.

RESULTS

12 studies were included in the analysis (7 prospective, 5 cross-sectional) involving 505,841 subjects. 7 studies investigated the relationship between coffee consumption and incident CKD and showed that coffee consumption was associated with a significant decrease in the risk for incident CKD outcome (RR 0.86, 95% CI 0.76 to 0.97, P = .01) with a greater decrease in individuals taking ≥2 cups/day compared to those who drank ≤1 cup/day. There was a significantly lower risk of incident end stage kidney disease (ESKD) in coffee users (HR 0.82, 95% CI 0.72 to 0.94, P = .005). Coffee consumption was also associated with a lower risk of albuminuria (OR 0.81, 95% CI 0.68 to 0.97, P = .02). Overall, the risk of death related to CKD was lower in coffee users (HR 0.72, 95% CI 0.54 to 0.96, P = .02).

CONCLUSION

Coffee intake was dose-dependently associated with lower incident CKD, ESKD, and albuminuria.

Coffee Consumption is Associated with a Decreased Risk of Incident Chronic Kidney Disease: A Systematic Review and Meta-analysis of Cohort Studies

BACKGROUND

Recent studies have suggested a renal protective effect of coffee consumption against development of chronic kidney disease (CKD) although the results remain inconclusive. This systematic review and meta-analysis aimed to comprehensively investigate this association by summarizing all available data.

METHODS

A systematic review was performed using MEDLINE and EMBASE database from inception to November 2019 to identify all cohort studies that compared the risk of developing CKD after index date among coffee-drinkers versus non-drinkers. Pooled risk ratio and 95% confidence interval (CI) were calculated using random-effect, generic inverse-variance method of DerSimonian and Laird.

RESULTS

A total of 4 cohort studies comprising of 25,849 participants met the inclusion criteria and were analyzed in the meta-analysis. The meta-analysis found a significantly decreased risk of incident CKD among coffee-drinkers compared with non-drinkers with the pooled risk ratio of 0.87 (95% CI, 0.81-0.95; I² of 57%). The funnel plot of this study was relatively symmetric and was not indicative of publication bias CONCLUSIONS: A significant association between coffee consumption and a lower risk of incident CKD was demonstrated in this study.

Dose-Response Relation between Tea Consumption and Risk of Cardiovascular Disease and All-Cause Mortality: A Systematic Review and Meta-Analysis of Population-Based Studies

Tea flavonoids have been suggested to offer potential benefits to cardiovascular health. This review synthesized the evidence on the relation between tea consumption and risks of cardiovascular disease (CVD) and all-cause mortality among generally healthy adults. PubMed, EMBASE, Web of Science, Cochrane Central Register of Controlled Trials, Food Science and Technology Abstracts, and Ovid CAB Abstract databases were searched to identify English-language publications through 1 November 2019, including randomized trials, prospective cohort studies, and nested case-control (or case-cohort) studies with data on tea consumption and risk of incident cardiovascular events (cardiac or peripheral vascular events), stroke events (including mortality), CVD-specific mortality, or all-cause mortality. Data from 39 prospective cohort publications were synthesized. Linear meta-regression showed that each cup (236.6 mL)  increase in daily tea consumption (estimated 280 mg  and 338 mg  total flavonoids/d for black and green tea, respectively) was associated with an average 4% lower risk of CVD mortality, a 2% lower risk of CVD events, a 4% lower risk of stroke, and a 1.5% lower risk of all-cause mortality. Subgroup meta-analysis results showed that the magnitude of association was larger in elderly individuals for both CVD mortality (n = 4; pooled adjusted RR: 0.89; 95% CI: 0.83, 0.96; P = 0.001), with large heterogeneity (I2 = 72.4%), and all-cause mortality (n = 3; pooled adjusted RR: 0.92; 95% CI: 0.90, 0.94; P < 0.0001; I2 = 0.3%). Generally, studies with higher risk of bias appeared to show larger magnitudes of associations than studies with lower risk of bias. Strength of evidence was rated as low and moderate (depending on study population age group) for CVD-specific mortality outcome and was rated as low for CVD events, stroke, and all-cause mortality outcomes. Daily tea intake as part of a healthy habitual dietary pattern may be associated with lower risks of CVD and all-cause mortality among adults.

Effect of tea and coffee consumption on the blood pressure, pulse wave velocity and aortic pressures in young healthy individuals

Caffeine present in tea and coffee, the most commonly used beverages, has been implicated to have long term effects on cardiovascular system. The aim of this study was to document the acute and chronic effects of tea and coffee consumption on blood pressure, pulse wave velocity and aortic pressures in young, healthy individuals. This observational study was conducted on 86 healthy MBBS student volunteers of both genders between the age group of 18-27 years. Cardiovascular parameters (heart rate, peripheral blood pressure, central blood pressure, pulse wave velocity, augmentation pressure) were measured using PeriScope. Participants were divided into 3 groups based on their history of consuming tea/coffee/both/none. Data collected was analyzed using SPSS 17.0. ANOVA or Welsh test of equality of means was used for knowing the differences for scale variables. Paired sample t test was used to know the acute effect of coffee consumption among group 1 participants in a before-after design. In regular tea consumers, the bilateral brachial SBP, DBP and MAP were significantly higher than individuals who did not consume tea regularly; similar results in these parameters were also observed in regular coffee drinkers. However the lower limb arterial parameters were not markedly differently in tea/coffee group compared to non-drinkers. In both tea and coffee group, AoSP and AoDP were significantly higher than non-drinkers. Additionally, coffee drinking has acute stimulatory effects on CVS as evident by increase in peripheral and central vascular parameters.

Decaffeinated coffee and its benefits on health: focus on systemic disorders

The current literature has mainly focused on benefits and risks deriving from the consumption of caffeinated coffee and its implications for inflammation, cardiovascular diseases, neurodegenerative disorders, and cancer. Today, data about the role of caffeine in many disorders are controversial and the attention has increasingly focused on decaffeinated coffee and its non-caffeine compounds, which could have mainly beneficial effects. In fact, coffee phenolic compounds not only exhibit well-known antioxidant properties, but they can also antagonize some negative effects of caffeine, for example in inflammatory pathway and in glucose metabolism and homeostasis. In this review, we consider the literature of the last two decades and critically discuss the effects of decaffeinated coffee compounds on systemic disorders, mainly inflammation, cardiovascular diseases, hepatic dysfunctions, and cancer.

Diet and Kidney Function: a Literature Review

PURPOSE OF REVIEW

The burden of chronic kidney disease (CKD) is increasing worldwide. For CKD prevention, it is important to gain insight in commonly consumed foods and beverages in relation to kidney function.

RECENT FINDINGS

We included 21 papers of prospective cohort studies with 3-24 years of follow-up. We focused on meat, fish, dairy, vegetables, fruit, coffee, tea, soft drinks, and dietary patterns. There was convincing evidence that a healthy dietary pattern may lower CKD risk. Plant-based foods, coffee, and dairy may be beneficial. Unhealthy diets and their components, such as red (processed) meat and sugar-sweetened beverages, may promote kidney function loss. For other foods and beverages, associations with CKD were neutral and/or the number of studies was too limited to draw conclusions. Healthy dietary patterns are associated with a lower risk of CKD. More research is needed into the effects of specific food groups and beverages on kidney function.