Chlorogenic Acid Stimulates Glucose Transport in Skeletal Muscle via AMPK Activation: A Contributor to the Beneficial Effects of Coffee on Diabetes

Chlorogenic acid (CGA) has been shown to delay intestinal glucose absorption and inhibit gluconeogenesis. Our aim was to investigate the role of CGA in the regulation of glucose transport in skeletal muscle isolated from db/db mice and L6 skeletal muscle cells. Oral glucose tolerance test was performed on db/db mice treated with CGA and soleus muscle was isolated for 2-deoxyglucose transport study. 2DG transport was also examined in L6 myotubes with or without inhibitors such as wortmannin or compound c. AMPK was knocked down with AMPKα1/2 siRNA to study its effect on CGA-stimulated glucose transport. GLUT 4 translocation, phosphorylation of AMPK and Akt, AMPK activity, and association of IRS-1 and PI3K were investigated in the presence of CGA. In db/db mice, a significant decrease in fasting blood sugar was observed 10 minutes after the intraperitoneal administration of 250 mg/kg CGA and the effect persisted for another 30 minutes after the glucose challenge. Besides, CGA stimulated and enhanced both basal and insulin-mediated 2DG transports in soleus muscle. In L6 myotubes, CGA caused a dose- and time-dependent increase in glucose transport. Compound c and AMPKα1/2 siRNA abrogated the CGA-stimulated glucose transport. Consistent with these results, CGA was found to phosphorylate AMPK and ACC, consistent with the result of increased AMPK activities. CGA did not appear to enhance association of IRS-1 with p85. However, we observed activation of Akt by CGA. These parallel activations in turn increased translocation of GLUT 4 to plasma membrane. At 2 mmol/l, CGA did not cause any significant changes in viability or proliferation of L6 myotubes. Our data demonstrated for the first time that CGA stimulates glucose transport in skeletal muscle via the activation of AMPK. It appears that CGA may contribute to the beneficial effects of coffee on Type 2 diabetes mellitus

Factors related to reducing free sugar intake among white ethnic adults in the UK: a qualitative study

OBJECTIVE/AIMS: To determine the barriers and enablers to behavioural change to reduce free sugar intake related to dental caries in a sample of UK adults who identify their ethnicity as White.MATERIALS AND METHODS: Qualitative study comprising semi-structured interviews of 27 participants. Interviews were recorded, transcribed and analysed using thematic analysis methods. The Capability-Opportunity-Motivation-Behaviour model (COM-B) and the Theoretical Domains Framework (TDF) were used to guide the derivation of themes.RESULTS: Data saturation occurred at 27 interviews. The COM-B Model and TDF domains captured various factors that may influence the consumption of free sugar. TDF elements which are reflected in the study are: Knowledge; Psychological skills; Memory, attention, and decision processes; Behavioural regulation; Physical skills; Social influence; Environmental context and resources; Social and professional role and identity; Beliefs about capabilities; Beliefs about consequence; Intentions and goals reinforcement; and Emotions. COM-B Model elements which are reflected in the study are: psychological capabilities, physical capabilities, social opportunities, physical opportunities, reflective motivation, and automatic motivation.DISCUSSION AND CONCLUSION: The COM-B model and TDF framework provided a comprehensive account of the barriers and facilitators of reducing sugar intake among white ethnic groups

Efeitos do consumo agudo de cafeína sobre parâmetros metabólicos e de desempenho em indivíduos do sexo masculino Effects of caffeine acute consumption on the metabolic and performance parameters in male individuals

O objetivo deste estudo foi avaliar o efeito do consumo agudo de cafeína sobre a oxidação de lipídeos e desempenho durante o exercício aeróbico. Foram avaliados 15 indivíduos do sexo masculino, com idade média de 22,3 ± 2,7 anos, que realizaram teste de cargas progressivas em esteira rolante para determinação do consumo máximo de oxigênio (VO2máx) e limiares ventilatórios (LV). Cada voluntário realizou três testes submáximos na intensidade de 10% abaixo do segundo LV, sendo orientados a permanecer em exercício até a exaustão. Trinta minutos antes de cada teste submáximo, foram ingeridos 250ml de uma das bebidas compostas por: café com adoçante (CAD), café com açúcar (CA) e café descafeinado com adoçante (CD). Durante o exercício, os indivíduos foram monitorados pelo ergoespirômetro e frequencímetro. A oxidação de lipídeos foi predita pelo quociente respiratório (QR) durante o teste, e o desempenho foi verificado pelo tempo de exercício. Para comparar os resultados de QR e tempo de exercício entre os grupos, foi utilizado Anova fatorial, e considerou-se significância estatística um valor de p < 0,05. A média de VO2máx foi de 50,18 ± 9,9ml/kg/min. Com a ingestão de CAD, a média do QR foi de 0,98 ± 0,18 e o tempo médio em exercício foi de 24,1 ± 17,04 minutos. Com a ingestão de CA, a média do QR foi de 0,96 ± 0,2 e o tempo médio em exercício foi de 24,4 ± 17,8min. No teste com ingestão de CD, a média do QR foi de 1,01 ± 0,24 e a média do tempo em exercício foi de 20,6 ± 9,7min. Não houve diferença significativa entre os testes nos valores do QR e nem tempo de exercício (p = 0,697 e p = 0,598, respectivamente). A cafeína não aumentou a oxidação de lipídeos nem o desempenho de indivíduos jovens do sexo masculino.<br>The purpose of this study was to evaluate the effect of acute caffeine consumption on lipid oxidation and performance during aerobic exercise. Fifteen healthy male individuals, 22.3 ± 2.7 years old, performed a progressive test on treadmill for determination of maximal oxygen uptake (VO2max) and ventilatory thresholds. Each volunteer performed three submaximal tests at the intensity of 10% below the second ventilatory threshold, being guided to remain on exercise until exhaustion. Thirty minutes before each submaximal test, the subjects ingested 250ml of one of following drinks: coffee with sweetener (CSW), coffee with sugar (CS) or decaffeinated coffee with sweetener (CD). During the exercise, the individuals's heart rate was monitored and respiratory gases analyses were done. The lipid oxidation was predicted by the respiratory quotient (RQ) during the test and performance was verified by exercise duration. In order to compare the RQ results and time of exercise among the three groups, factorial Anova was used, and a value of p < 0.05 was considered as statistically significant. The individuals had VO2max of 50.18 ± 9.9 ml/kg/min. CAD ingestion caused RQ average of 0.98 ± 0.18, and the average exercise duration was of 24.1 ± 17.04 min; CA ingestion caused RQ average of 0.96 ± 0.2 and the average exercise duration was 24.4 ± 17.8 min. Finally, CD ingestion caused the RQ average of 1.01 ± 0.24, and the average exercise duration was of 20.6 ± 9.7 min. There were no significant differences in the RQ values or exercise duration among the three interventions (p = 0.697 and p = 0.598, respectively). Caffeine did not increase lipid oxidation or performance of young male individuals

Association between skirt size and chronic liver disease in post-menopausal women: a prospective cohort study within the United Kingdom Trial of Ovarian Cancer Screening (UKCTOCS)

Background: we investigated the association between self-reported skirt size (SS) and change in SS, and incidence of chronic liver disease (CLD) in a prospective cohort study of women recruited to the UKCTOCS trial. Methods: women recruited to UKCTOCS in England without documented CLD self-reported their current UK SS during trial participation and were asked to recall their SS when aged in 20s (via completion of a questionnaire 3-5 years after recruitment). Participants were followed up via electronic health record linkage and hazard ratios (HR) calculated for incident liver-related events (LRE). Results: three hundred twenty-two (0.3%) of 94,124 women experienced a first LRE. Compared to SS ≤ 16, rates of LRE were higher in the SS ≥ 18 groups (both when aged in 20s and at questionnaire completion). Event rates were higher if there was no change in SS or an increase in SS, compared to a decrease in SS. In the models adjusted for potential confounders, HRs for LRE were higher in the groups of women reporting SS ≥ 18 both when aged in 20s (HR = 1.39 (95% CI; 0.87-2.23)) and at questionnaire completion (HR = 1.37 (95% CI; 1.07-1.75)). Compared to a decrease in SS, HRs were higher in the no change (HR = 1.78 (95% CI; 0.95-3.34)) and increase (HR = 1.80 (95% CI; 1.01-3.21)) groups. Conclusion: CLD is associated with high SS and an increase in SS over time. These data suggest SS can be used in simple public health messages about communicating the risk of liver disease. Trial Registration: UKCTOCS is registered as an International Standard Randomised Controlled Trial, number ISRCTN22488978. Registered 06/04/2000.</p