Methods. Green tea (catechins, GTC) and coffee (chlorogenic acids, CGA) polyphenols have been associated with reduced diabetes and cardio vascular risk.
EFFECTS OF GREEN TEA AND COFFEE POLYPHENOLS ON CARDIOMETABOLIC FUNCTION IN WOMEN WITH POLYCYSTIC OVARY SYNDROME
Virginia B. Tomatis1,3, Sara Wassell1, Michelle C. Venables1, Celia G. Walker1, Sumantra Ray2, Lee D. Roberts1,4, Mario Siervo1, Julian L. Griffin1,4 and Les C. Bluck1.
Insulin
13C-glucose enrichment
Glucose
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B
C
Figure 1: Salivary tracer-to-tracee ratio (TTR) as a measure of the isotopic decay of Na15NO3 during the ONT for the postplacebo and postactive treatments. Data are presented as mean ± SEM, n = 10.
Figure 2: Time courses for plasma glucose (A), 13C-glucose enrichment (B, indicative of glucose uptake) and insulin (C) during the ODILE for the post-placebo and post-active treatments. Data are presented as mean ± SEM, n = 7. Dashed lines indicate the oral glucose dose was given at t = 10 min and the intravenous 13C-glucose bolus at t = 55 min.
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1 Bluck, L. et al. (2006). A stable isotope minimal model protocol with oral glucose administration. Rapid Communications in Mass Spectrometry. 20(3): 493-498. 2 Siervo, M. et al. (2011). In-vivo nitric oxide synthesis is reduced in obese patients with metabolic syndrome: application of a novel stable isotope method. J Hypertension, 29(8): 1515-1527.
References
Combined intake of GTC and CGA for 8 weeks did not improve SI or vascular function; however, this intervention may reduce abdominal adiposity and inflammation via modulation of eicosanoid pathways. These changes may prove cardioprotective in at risk populations, in longer term intervention studies.
Conclusion
Figure 3: Difference in eicosanoid concentrations (hydroxyperoxyeicosatetraenoic acid (HpETE), hydroxyeicosatetraenoic acid (HETE), dihydroxyeicosatrienoic acid (DHET), octadienoic acid (ODE)) between placebo and active treatments. Data were normalized to the internal standard (prostaglandin E2-d4) and are presented as mean ± SE, n = 12. Values were significantly different (* p < 0.05) for the 5 out of 34 eicosanoids driving the separation between placebo and active treatments.
Difference in eicosanoid concentrations
Results continued
1: Metabolism and Metabolic Health, MRC-Human Nutrition Research, Cambridge, UK. 2: Vascular Function Assessment Laboratory, MRC-Human Nutrition Research, Cambridge, UK 3: School of the Biological Sciences, University of Cambridge, UK. 4: Department of Biochemistry, University of Cambridge, UK.
Introduction Green tea (catechins, GTC) and coffee (chlorogenic acids, CGA) polyphenols have been associated with reduced diabetes and cardiovascular risk. These polyphenols may provide protection against cardiometabolic diseases by reducing chronic inflammation, associated with abdominal adiposity. However, these observations need to be confirmed by trials, particularly in at risk populations, to better understand the underlying mechanisms.
Aims • To evaluate the effects of a novel, combined, chronic supplementation of GTC and CGA on insulin sensitivity (SI), whole-body nitric oxide (NO) production and additional cardiometabolic risk factors in overweight and obese women with polycystic ovary syndrome (PCOS), a condition characterized by insulin resistance, endothelial dysfunction and increased cardiometabolic risk. • To investigate the mechanism for the potentially beneficial cardiometabolic effects of the combined polyphenol intervention on inflammation, by measuring the eicosanoid profile of plasma samples.
Methods In a 16-week, single-blind, unilateral crossover trial, 12 women with PCOS (28 ± 10 y; BMI, 35.0 ± 7.4 kg/m2) underwent 8 weeks of placebo treatment followed by 8 weeks of active treatment (2093 mg GTC + 220 mg CGA/day). At baseline (week 0), post-placebo (week 8) and post-active treatment (week 16) visits, anthropometric and vascular function measurements were conducted, fasting blood samples were collected for evaluation of eicosanoid profile, and participants underwent an oral dose intravenous labelled experiment (ODILE)1 and an oral nitrate test (ONT)2 for assessment of SI and whole-body NO production, respectively. Decay in plasma 13C-glucose and salivary Na15NO3 were measured using GC/C/IRMS and GC/MS, respectively, with eicosanoid concentrations measured using LC/MS/MS.
Results Concomitant intake of GTC and CGA for 8 weeks did not improve whole-body NO production (Figure 1), SI (Figure 2), or any additional parameters of glucose metabolism or vascular function assessed; but it was associated with reduced waist circumference (MD ± SE: 2.4 ± 0.9 cm; p = 0.02) and altered eicosanoid profile (Figure 3).
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