Koffein och insulinkänslighet

[nubi]

Koffein höjer ju insulinnivån. Men hur är det med insulinkänsligheten. Påverkas den av ett dagligt högt koffeinintag?

[King Grub]

Ja.

Caffeine can decrease insulin sensitivity in humans.

Keijzers GB, De Galan BE, Tack CJ, Smits P.

Department of Internal Medicine, University Medical Center Nijmegen, 6500 HB Nijmegen, the Netherlands.

OBJECTIVE: Caffeine is a central stimulant that increases the release of catecholamines. As a component of popular beverages, caffeine is widely used around the world. Its pharmacological effects are predominantly due to adenosine receptor antagonism and include release of catecholamines. We hypothesized that caffeine reduces insulin sensitivity, either due to catecholamines and/or as a result of blocking adenosine-mediated stimulation of peripheral glucose uptake. RESEARCH DESIGN AND METHODS: Hyperinsulinemic-euglycemic glucose clamps were used to assess insulin sensitivity. Caffeine or placebo was administered intravenously to 12 healthy volunteers in a randomized, double-blind, crossover design. Measurements included plasma levels of insulin, catecholamines, free fatty acids (FFAs), and hemodynamic parameters. Insulin sensitivity was calculated as whole-body glucose uptake corrected for the insulin concentration. In a second study, the adenosine reuptake inhibitor dipyridamole was tested using an identical protocol in 10 healthy subjects. RESULTS: Caffeine decreased insulin sensitivity by 15% (P < 0.05 vs. placebo). After caffeine administration, plasma FFAs increased (P < 0.05) and remained higher than during placebo. Plasma epinephrine increased fivefold (P < 0.0005), and smaller increases were recorded in plasma norepinephrine (P < 0.02) and blood pressure (P < 0.001). Dipyridamole did not alter insulin sensitivity and only increased plasma norepinephrine (P < 0.01).

In conclusion, we demonstrate that acute administration of a moderate amount of caffeine decreases insulin sensitivity in healthy subjects. This effect may be explained by increased plasma epinephrine and FFA levels. Peripheral adenosine receptor antagonism is less likely to have played a role. Further investigation is required to elucidate whether this effect persists over time with chronic use of caffeine. Because tolerance may develop for the effects of caffeine, it is currently premature to advise against caffeine use in the management of insulin resistance.

[nubi]

Hur är det egentligen med insulinkänsligheten. Hur snabbt kan den förändras genom att ändra kosten och konditionsträning? Kan insulinkänsligheten sänkas permanent, eller är den "elastisk" ?

[Ludvig]

för att gå ner i vikt är det bra att koffeinet höjer insulinnivån??

[King Grub]

Originally posted by Ludvig
för att gå ner i vikt är det bra att koffeinet höjer insulinnivån??

NEJ! Höga insulinnivåer försämrar fettförbränningen. Däremot har koffein andra egenskaper som verkar gynnsamt på förbränningen, t ex ökad termogenes och ökad frisättning av fettsyror. Så nettoeffekten kanske blir närmare +-0.

[King Grub]

Originally posted by nubi
Hur är det egentligen med insulinkänsligheten. Hur snabbt kan den förändras genom att ändra kosten och konditionsträning? Kan insulinkänsligheten sänkas permanent, eller är den "elastisk" ?

Den är inte permanent fixerad, utan den kan man ändra snabbt. Problemet för den stora allmänheten är väl att deras dåliga vanor är så inrutade.

TITLE: Modulation of insulin sensitivity by short-term exercise training

AUTHORS: F.L. Beaudoin, S. Chipkin, B. Braun


Insulin resistance (impaired insulin-mediated glucose uptake) is strongly associated with obesity and is the pathophysiology underlying Type-2 diabetes mellitus. Exercise training reduces insulin resistance, at least partially by enhancing peripheral (mainly skeletal muscle) sensitivity to insulin. There are several ways to measure insulin sensitivity but few that allow quantitative assessment of both hepatic and peripheral insulin sensitivity under physiological conditions. The continuous infusion with model assessment (CIGMA) is an innovative means of assessing insulin sensitivity based on mathematical modeling of the insulin-glucose feedback loop. PURPOSE: The purpose of this study was to determine if 5 days of exercise training would elicit a measurable change in insulin sensitivity. We hypothesized that short-term training would increase insulin sensitivity using the CIGMA method. METHODS: Nine sedentary, pre-menopausal women underwent a test of insulin sensitivity, followed by 5 days of moderate-intensity exercise training (65% of VO2max) designed to increase total daily energy expenditure by 20%. Twelve to 16 hours after the last bout of exercise, subjects repeated the test of insulin sensitivity. Plasma glucose and insulin responses were incorporated into a mathematical model to evaluate insulin sensitivity. Differences between treatment means pre- and post-training were evaluated by repeated measures ANOVA.

RESULTS: Compared to baseline values, fasting insulin and steady-state glucose and insulin concentrations were significantly lower following exercise training. The CIGMA coefficient of insulin sensitivity was also significantly lower post-training.

[Hermes]

Kardio är alltså en hit för att förbättra insulinkänsligheten?

[King Grub]

Originally posted by hermes
Kardio är alltså en hit för att förbättra insulinkänsligheten?

En monsterhit! En av anledningarna till att cardio har en given plats i alla träningscheman, deff som bulk.

[200sx]

Polaren som har diabetes säger att hans insulin nivåer inte höjs då han dricker kaffe...han har givetvis mätt efter han har druckit...