Tuesday 13 July 2010

Ghrelin and Adiponectin

http://www.ncbi.nlm.nih.gov/pubmed/15231997

First, in this study we see from the graphs that ghrelin increases dramatically in response to sleep for lean people, however it remains unchanged for obese people.

We also see a marked drop in adiponectin during sleeping for lean people, while for obese people, nothing happens to thier adiponectin levels.

For breakfast and lunch, the pattern of ghrelin remained the same for obese and lean people, then we get to dinner, ghrelin goes down markedly for lean people, but stays the same for obese people, then the evening snack comes, ghrelin goes up for obese people, while for lean people it stays low, right up until sleepy time.

Then we have the leptin graph, notice it stays the same for lean people constantly, while for obese people its shooting all over the place.

There is clearly something wrong with an obese persons adipocyte functions.

Unfortauntely the study doesnt say what the dinner consisted of, as this is when the trouble starts for the obese people with ghrelin.

http://www.ncbi.nlm.nih.gov/pubmed/20464707

This study offers a discussion on ghrelin and adiponectin,

Circulating ghrelin concentrations are also regulated by longer term changes in energy homeostasis. Ghrelin levels are lower in humans with higher body weight and rise after diet-induced weight loss (31). The usual postprandial fall in plasma ghrelin is absent or attenuated in the obese, suggesting that ghrelin may be involved in the pathophysiology of obesity (32, 33). We have shown that iv ghrelin administration stimulates appetite in obese humans, suggesting that they are not ghrelin resistant

2002 Food fails to suppress ghrelin levels in obese humans. J Clin Endocrinol Metab
2005 Postprandial plasma ghrelin is suppressed proportional to meal calorie content in normal-weight but not obese subjects

The above study showed that meals high in carbs didnt really do alot for ghrelin levels in the obese, but in lean people ghrelin was surpressed more as calories went up.

Now, we have already seen that fat digestion is needed for ghrelin supression after a meal, and we have also seen that carb rich meals make ghrelin bounce back, while protein rich meals supressed ghrelin for along time.

Today we also saw that obese people secret markedly lower bile acids after food.

Could it be that obese people are not properly digesting thier food?

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