Association of serum caffeine concentrations with blood lipids in caffeine-drug users and nonusers - results of German National Health Surveys from 1984 to 1999

The association between dietary diabetic risk reduction score with anthropometric and body composition variables in overweight and obese women: a cross-sectional study

Dietary diabetes risk reduction score (DDRRs) is inversely associated with a lower risk of type 2 diabetes. Given the importance of the association between body fat and insulin resistance and the effect of diet on these parameters, this study aimed to investigate the association between DDRRS and body composition parameters, including the visceral adiposity index (VAI), lipid accumulation product (LAP), and skeletal muscle mass (SMM). This study was conducted on 291 overweight and obese women aged 18-48 years old recruited from 20 Tehran Health Centers in 2018. The anthropometric indices, biochemical parameters, and body composition were measured. A semi-quantitative food frequency questionnaire (FFQ) was used to calculate DDRRs. Linear regression analysis was used to examine the association between DDRRs and body composition indicators. The mean (SD) age of participants was 36.67 (9.10) years. After adjustment for potential confounders, VAI (β = 0.27, 95% CI = - 0.73, 1.27, P_trend = 0.052), LAP (β = 8.14, 95% CI = - 10.54, 26.82, P_trend = 0.069), TF (β = - 1.41, 95% CI = 11.45, 17.30, P_trend = 0.027), trunk fat percent (TF%) (β = - 21.55, 95% CI = - 44.51, 1.61, P_trend = 0.074), body fat mass (BFM) (β = - 3.26, 95% CI = - 6.08, - 0.44, P_trend = 0.026), visceral fat area (VFA) (β = - 45.75, 95% CI = - 86.10, - 5.41, P_trend = 0.026), waist-to-hip ratio (WHtR) (β = - 0.014, 95% CI = - 0.031, 0.004, P_trend = 0.066), visceral fat level (VFL) (β = - 0.38, 95% CI = - 5.89, 5.12, P_trend = 0.064), fat mass index (FMI) (β = - 1.15, 95% CI = - 2.28, - 0.02, P_trend = 0.048) decreased significantly over tertiles of DDRRs, and also there was no significant association between SMM and DDRRs tertiles (β = - 0.57, 95% CI = - 1.69, 0.53, P_trend = 0.322). The findings of this study demonstrated that participants with higher adherence to the DDRRs had lower VAI (β = 0.78 vs 0.27) and LAP (β = 20.73 vs 8.14). However, there was no significant association between DDRRs and VAI, LAP and SMM, which are mentioned as the primary outcomes. Future studies with larger sample of both genders are needed to investigate our findings.

Caffeine Inhibits NLRP3 Inflammasome Activation by Downregulating TLR4/MAPK/NF-κB Signaling Pathway in an Experimental NASH Model

Caffeine elicits protective effects against liver diseases, such as NASH; however, its mechanism of action involving the pyrin domain-containing-3 (NLRP3) inflammasome signaling pathway remains to be elucidated. This study aimed to evaluate the effect of caffeine on the NLRP3 inflammasome signaling pathway in a rat model of NASH. NASH was induced by feeding rats a high-fat, -sucrose, and -cholesterol diet (HFSCD) for 15 weeks along with a weekly low dose (400 mg/kg, i.p.) of CCl₄. Caffeine was administered at 50 mg/kg p.o. The effects of HFSCD+CCl₄ and caffeine on the liver were evaluated using biochemical, ultrastructural, histological, and molecular biological approaches. The HFSCD+CCl₄-treated rats showed fat accumulation in the liver, elevated levels of inflammatory mediators, NLRP3 inflammasome activation, antioxidant dysregulation, and liver fibrosis. Caffeine reduced necrosis, cholestasis, oxidative stress, and fibrosis. Caffeine exhibited anti-inflammatory effects by attenuating NLRP3 inflammasome activation. Moreover, caffeine prevented increases in toll-like receptor 4 (TLR4) and nuclear factor-κB (NF-κB) protein levels and mitigated the phosphorylation of mitogen-activated protein kinase (MAPK). Importantly, caffeine prevented the activation of hepatic stellate cells. This study is the first to report that caffeine ameliorates NASH by inhibiting NLRP3 inflammasome activation through the suppression of the TLR4/MAPK/NF-κB signaling pathway.

Investigating the Relations Between Caffeine-Derived Metabolites and Plasma Lipids in 2 Population-Based Studies

OBJECTIVE

To investigate the relations between caffeine-derived metabolites (methylxanthines) and plasma lipids by use of population-based data from 2 European countries.

METHODS

Families were randomly selected from the general population of northern Belgium (FLEMENGHO), from August 12, 1985, until November 22, 1990, and 3 Swiss cities (SKIPOGH), from November 25, 2009, through April 4, 2013. We measured plasma concentrations (FLEMENGHO, SKIPOGH) and 24-hour urinary excretions (SKIPOGH) of 4 methylxanthines-caffeine, paraxanthine, theobromine, and theophylline-using ultra-high-performance liquid chromatography-tandem mass spectrometry. We used enzymatic methods to estimate total cholesterol, high-density lipoprotein cholesterol, and triglyceride levels and the Friedewald equation for low-density lipoprotein cholesterol levels in plasma. We applied sex-specific mixed models to investigate associations between methylxanthines and plasma lipids, adjusting for major confounders.

RESULTS

In both FLEMENGHO (N=1987; 1055 [53%] female participants) and SKIPOGH (N=990; 523 [53%] female participants), total cholesterol, low-density lipoprotein cholesterol, and triglyceride levels increased across quartiles of plasma caffeine, paraxanthine, and theophylline (total cholesterol levels by caffeine quartiles in FLEMENGHO, male participants: 5.01±0.06 mmol/L, 5.05±0.06 mmol/L, 5.27±0.06 mmol/L, 5.62±0.06 mmol/L; female participants: 5.24±0.06 mmol/L, 5.15±0.05 mmol/L, 5.25±0.05 mmol/L, 5.42±0.05 mmol/L). Similar results were observed using urinary methylxanthines in SKIPOGH (total cholesterol levels by caffeine quartiles, male participants: 4.54±0.08 mmol/L, 4.94±0.08 mmol/L, 4.87±0.08 mmol/L, 5.27±0.09 mmol/L; female participants: 5.12±0.07 mmol/L, 5.21±0.07 mmol/L, 5.28±0.05 mmol/L, 5.28±0.07 mmol/L). Furthermore, urinary caffeine and theophylline were positively associated with high-density lipoprotein cholesterol in SKIPOGH male participants.

CONCLUSION

Plasma and urinary caffeine, paraxanthine, and theophylline were positively associated with plasma lipids, whereas the associations involving theobromine were less clear. We postulate that the positive association between caffeine intake and plasma lipids may be related to the sympathomimetic function of methylxanthines, mitigating the overall health-beneficial effect of caffeine intake.

Chronic Intake of Energy Drinks and Their Sugar Free Substitution Similarly Promotes Metabolic Syndrome

Energy drinks containing significant quantities of caffeine, taurine and sugar are increasingly consumed, particularly by adolescents and young adults. The putative effects of chronic ingestion of either standard energy drink, Mother^TM (ED), or its sugar-free formulation (sfED) on metabolic syndrome were determined in wild-type C57BL/6J mice, in comparison to a soft drink, Coca-Cola (SD), a Western-styled diet enriched in saturated fatty acids (SFA), and a combination of SFA + ED. Following 13 weeks of intervention, mice treated with ED were hyperglycaemic and hypertriglyceridaemic, indicating higher triglyceride glucose index, which was similar to the mice maintained on SD. Surprisingly, the mice maintained on sfED also showed signs of insulin resistance with hyperglycaemia, hypertriglyceridaemia, and greater triglyceride glucose index, comparable to the ED group mice. In addition, the ED mice had greater adiposity primarily due to the increase in white adipose tissue, although the body weight was comparable to the control mice receiving only water. The mice maintained on SFA diet exhibited significantly greater weight gain, body fat, cholesterol and insulin, whilst blood glucose and triglyceride concentrations remained comparable to the control mice. Collectively, these data suggest that the consumption of both standard and sugar-free forms of energy drinks induces metabolic syndrome, particularly insulin resistance.

How coffee affects metabolic syndrome and its components

Metabolic syndrome, with its increasing prevalence, is becoming a major public health problem throughout the world. Many risk factors including nutrition play a role in the emergence of metabolic syndrome. Of the most-consumed beverages in the world, coffee contains more than 1000 components such as caffeine, chlorogenic acid, diterpenes and trigonelline. It has been proven in many studies that coffee consumption has a positive effect on chronic diseases. In this review, starting from the beneficial effects of coffee on health, the relationship between coffee consumption and metabolic syndrome and its components has been investigated. There are few studies investigating the relationship between coffee and metabolic syndrome, and the existing ones put forward different findings. The factors leading to the differences are thought to stem from coffee variety, the physiological effects of coffee elements, and the nutritional ingredients (such as milk and sugar) added to coffee. It is reported that consumption of coffee in adults up to three cups a day reduces the risk of Type-2 diabetes and metabolic syndrome.

Coffee, tea, and caffeine consumption and prevention of late-life cognitive decline and dementia: a systematic review

A prolonged preclinical phase of more than two decades before the onset of dementia suggested that initial brain changes of Alzheimer's disease (AD) and the symptoms of advanced AD may represent a unique continuum. Given the very limited therapeutic value of drugs currently used in the treatment of AD and dementia, preventing or postponing the onset of AD and delaying or slowing its progression are becoming mandatory. Among possible reversible risk factors of dementia and AD, vascular, metabolic, and lifestyle-related factors were associated with the development of dementia and late-life cognitive disorders, opening new avenues for the prevention of these diseases. Among diet-associated factors, coffee is regularly consumed by millions of people around the world and owing to its caffeine content, it is the best known psychoactive stimulant resulting in heightened alertness and arousal and improvement of cognitive performance. Besides its short-term effect, some case-control and cross-sectional and longitudinal population-based studies evaluated the long-term effects on brain function and provided some evidence that coffee, tea, and caffeine consumption or higher plasma caffeine levels may be protective against cognitive impairment/decline and dementia. In particular, several cross-sectional and longitudinal population-based studies suggested a protective effect of coffee, tea, and caffeine use against late-life cognitive impairment/decline, although the association was not found in all cognitive domains investigated and there was a lack of a distinct dose-response association, with a stronger effect among women than men. The findings on the association of coffee, tea, and caffeine consumption or plasma caffeine levels with incident mild cognitive impairment and its progression to dementia were too limited to draw any conclusion. Furthermore, for dementia and AD prevention, some studies with baseline examination in midlife pointed to a lack of association, although other case-control and longitudinal population-based studies with briefer follow-up periods supported favourable effects of coffee, tea, and caffeine consumption against AD. Larger studies with longer follow-up periods should be encouraged, addressing other potential bias and confounding sources, so hopefully opening new ways for diet-related prevention of dementia and AD.

Caffeine Intake from Coffee or Tea and Cognitive Disorders: A Meta-Analysis of Observational Studies

Background: Observational epidemiological studies such as cross-sectional, case-control, and cohort studies have reported inconsistent findings regarding the association between caffeine intake from coffee or tea and the risk of cognitive disorders such as dementia, Alzheimer's disease, cognitive impairment, and cognitive decline. Methods: We searched PubMed and EMBASE in September 2014. Three evaluators independently extracted and reviewed articles, based on predetermined selection criteria. Results: Out of 293 articles identified through the search and bibliographies of relevant articles, 20 epidemiological studies from 19 articles, which involved 31,479 participants (8,398 in six cross-sectional studies, 4,601 in five case-control studies, and 19,918 in nine cohort studies), were included in the final analysis. The pooled odds ratio (OR) or relative risk (RR) of caffeine intake from coffee or tea for cognitive disorders (dementia, Alzheimer's disease, cognitive impairment, and cognitive decline) was 0.82 (95% confidence interval [CI], 0.67-1.01, I2 = 63.2%) in a random-effects meta-analysis. In the subgroup meta-analysis by caffeine sources, the summary OR or RR of coffee intake was 0.83 (95% CI, 0.70-0.98; I2 = 44.8%). However, in the subgroup meta-analysis by study design, the summary estimates (RR or OR) of coffee intake for cognitive disorders were 0.70 (95% CI, 0.50-0.98; I2 = 42.0%) for cross-sectional studies, 0.82 (95% CI, 0.55-1.24; I2 = 33.4%) for case-control studies, and 0.90 (95% CI, 0.59-1.36; I2 = 60.0%) for cohort studies. Conclusions: This meta-analysis found that caffeine intake from coffee or tea was not associated with the risk of cognitive disorders.

Effect of smoking and caffeine consumption on polybrominated diphenyl ethers (PBDE) and polybrominated biphenyls (PBB)

Effect of smoking and caffeine consumption (CC) on the levels of polybrominated diphenyl ethers (PBDE) and polybrominated biphenyls (PBB) has not been adequately studied. Data from 2003-2004 National Health and Nutrition Examination Survey (n = 1013) to simultaneously evaluate the effect of smoking and CC on levels of serum 2,2',4,4'-tetrabromodiphenyl ether (PBDE-47), 2,2',4,4',5-pentabromodiphenyl ether (PBDE-99), 2,2',4,4',6-pentabromodiphenyl ether (PBDE-100), 2,2',4,4',5,5'-hexabromodiphenyl ether (PBDE-153), and their sum and 2,2',4,4',5,5'-hexabromobiphenyl (PBB-153) were used. Regression models were fitted with logs of PBDE and PBB as dependent variables and age, age(2), gender, body mass index (BMI), race/ethnicity, smoking status, fish/shellfish consumption status during the last 30 d, and CC as independent variables. For lipid-adjusted models, age was negatively associated while age(2) was positively associated with almost all PBDE models. The reverse was the case for PBB-153. Body mass index was found to be negatively associated with PBDE-153 and PBB-153. Levels of all whole weight PBDE increased with levels of total lipid. Smoking was not markedly associated with concentrations of either PBDE or PBB. Males displayed significantly higher levels of PBDE-153 and ΣPBDE. For the whole weight PBDE congeners 47, 99, and 100 and PBB-153, non-Hispanic black (NHB) males showed significantly higher levels than NHB females.

Inverse correlation between coffee consumption and prevalence of metabolic syndrome: baseline survey of the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study in Tokushima, Japan

Background

It is unclear whether consumption of coffee and green tea is associated with metabolic syndrome.

Methods

This cross-sectional study enrolled 554 adults who had participated in the baseline survey of the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study in Tokushima Prefecture, Japan. Consumption of coffee and green tea was assessed using a questionnaire. Metabolic syndrome was diagnosed using the criteria of the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) and the Japan Society for the Study of Obesity (JASSO). Logistic regression analysis was used to examine the association between consumption of coffee and green tea and prevalence of metabolic syndrome and its components.

Results

After adjustment for sex, age, and other potential confounders, greater coffee consumption was associated with a significantly lower prevalence of metabolic syndrome, as defined by NCEP ATP III criteria (P for trend = 0.03). Participants who drank more coffee had a lower odds ratio (OR) for high serum triglycerides (P for trend = 0.02), but not for increased waist circumference or high blood pressure. Using JASSO criteria, moderate coffee consumption (1.5 to <3 cups/day) was associated with a significantly lower OR for high plasma glucose (OR = 0.51, 95% CI 0.28-0.93). Green tea consumption was not associated with the prevalence of metabolic syndrome or any of its components.

Conclusions

Coffee consumption was inversely correlated with metabolic syndrome diagnosed using NCEP ATP III criteria, mainly because it was associated with lower serum triglyceride levels. This association highlights the need for further prospective studies of the causality of these relationships.

Association of caffeine consumption and smoking status with the serum concentrations of polychlorinated biphenyls, dioxins, and furans in the general U.S. population: NHANES 2003-2004

Smoking appears to enhance the body's clearance of dioxins and dioxin-like polychlorinated biphenyls (PCB) by inducing CYP1A2 activity based on studies with a limited number of participants. This hypothesis was evaluated by using data from National Health and Nutrition Examination Survey. Specifically, adult participants were identified and the sums of their serum lipid-adjusted concentrations of 12 polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/PCDF) congeners, 33 PCB (total), 26 non-dioxin-like PCB, and 6 mono-ortho (dioxin-like) PCB were determined. In addition to evaluating the association of smoking, the association of caffeine consumption and the interaction between them was evaluated. Data analysis included regression models that were fitted with age, gender, race/ethnicity, and body mass index (BMI). R(2) varied from 34.8 to 66%. Smokers had significantly lower concentrations of total PCDD/PCDF than nonsmokers. New to this study, a siginificant interaction between caffeine consumption and smoking for total PCB was found. When caffeine was consumed less than once a day, smokers had higher concentrations of total PCB than nonsmokers. However, when caffeine was consumed at least once a day, smokers had lower concentrations than nonsmokers. A significant interaction between age and caffeine consumption frequency for each of the PCB groups was also observed. The differences in concentration between younger and older age groups were greater when caffeine was consumed at least once a day than when caffeine was consumed less frequently. Smoking and caffeine consumption need to be considered in the interpretation of human biomonitoring data because they appear to affect the serum concentrations of these chemicals.

Randomized clinical trials of weight loss maintenance: a review

The problem of overweight and obesity has reached epidemic proportions in the United States and globally, and the high prevalence is due in part to the recidivism associated with weight loss treatment. Approximately one-third of lost weight is often regained in the first year after treatment and, at times, continues. Because a plethora of comorbid diseases are associated with obesity, in particular, cardiovascular disease, hypertension, and hyperlipidemia, clinicians and researchers have attempted to find useful strategies for maintaining weight loss. This review presents the findings from 42 randomized clinical trials of weight loss maintenance from 1984 through 2007 using interventions that include (1) the Internet, (2) strategies after a very low calorie diet, (3) pharmacotherapy, (4) behavioral strategies, (5) physical activity, and (6) alternative strategies. The results of the reviewed trials revealed that treatment with orlistat or sibutramine combined with dietary modification, caffeine or protein supplementation, consuming a diet lower in fat, adherence to physical activity routines, prolonged contact with participants, problem-solving therapy, and the alternative treatment of acupressure were efficacious in reducing weight regain after weight loss treatment. The limitations of some studies may reduce the robustness of their findings, and future studies are necessary to replicate and support these results so that individuals are able to maintain weight loss and retain the health benefits associated with a lower weight.

Association of serum caffeine concentrations with serum glucose levels in caffeine-drug users and non-users - results of German National Health Surveys

The purpose of this study was to explore the association of serum caffeine concentrations with serum glucose levels in caffeine-drug users and non-users, aiming at the chronic effects of caffeine on glucose metabolism in comparison with known acute effects of caffeine. Eight hundred and fourteen caffeine-drug users and 623 non-users were identified from German National Health Surveys. Their serum caffeine concentrations and glucose levels were measured. The associations of caffeine concentrations with glucose levels were established by correlation analysis and multivariable regression analysis in caffeine-drug users and non-users separately. Antidiabetic therapy was considered. Caffeine concentrations were closely positively correlated to serum glucose levels in caffeine-drug users (Spearman r = 0.117, p = 0.001; partial r = 0.102, p = 0.020) particularly in women (Spearman r = 0.155, p < 0.001; partial r = 0.150, p = 0.005) although the correlation was weak as shown by multivariable regression analysis. The serum glucose levels were significantly higher (5.403 +/- 0.033 vs. 5.306 +/- 0.037 mmol/l) whereas the magnesium level was significantly lower (0.8941 +/- 0.0026 vs. 0.9024 +/- 0.0030 mmol/l) in caffeine-drug users than in non-users. No associations of caffeine concentrations with serum glucose levels were found in any groups of caffeine-drug non-users in our study. Whereas acute intake of caffeine-drugs may impair glucose metabolism, chronic intake of caffeine exclusively from diet has little effects on glucose metabolism and therefore may not contribute to the risk reduction of type 2 diabetes that was found in recent coffee consumption studies.

Coffee consumption and risk of total and cardiovascular mortality among patients with type 2 diabetes

AIMS/HYPOTHESIS

Higher habitual coffee drinking has been associated with a lower risk of developing type 2 diabetes. The relation between coffee consumption and risk of cardiovascular disease (CVD) has been examined in many studies, but the issue remains controversial. This study was designed to assess the association between coffee consumption and CVD mortality among patients with type 2 diabetes.

METHODS

We prospectively followed 3,837 randomly ascertained Finnish patients with type 2 diabetes aged 25 to 74 years. Coffee consumption and other study parameters were determined at baseline. The International Classification of Diseases was used to identify CHD, CVD and stroke cases using computerised record linkage to the national Death Registry. The associations between coffee consumption at baseline and risk of total, CVD, CHD, and stroke mortality were analysed by using Cox proportional hazards models.

RESULTS

During the average follow-up of 20.8 years, 1,471 deaths were recorded, of which 909 were coded as CVD, 598 as CHD and 210 as stroke. The respective multivariate-adjusted hazard ratios in participants who drank 0-2, 3-4, 5-6, and > or =7 cups of coffee daily were 1.00, 0.77, 0.68 and 0.70 for total mortality (P<0.001 for trend), 1.00, 0.79, 0.70 and 0.71 for CVD mortality (P=0.006 for trend), 1.00, 0.78, 0.70 and 0.63 for CHD mortality (p=0.01 for trend), and 1.00, 0.77, 0.64 and 0.90 for stroke mortality (p=0.12 for trend).

CONCLUSIONS/INTERPRETATION

In this large prospective study we found that in type 2 diabetic patients coffee drinking is associated with reduced total, CVD and CHD mortality.