I just watched an episode of House and he diagnosed a girl with Cushing’s – an illness that can cause obesity.
How is that possible? I was under the impression that our bodies use energy we get from food, and if it doesn’t get the food it’ll burn fat resulting in us getting slimmer – how can a disease change that?
How does it not go against some laws of thermodynamics? Maybe I’m just being silly.
In: Biology
Well just to start, thermodynamics has nothing to do with it. Nothing is actually being burned in your body; it’s a figure of speech.
Cushing’s syndrome is essentially any condition in which someone has excess cortisol (Cushing’s disease is one specific kind where one would have a pituitary tumor which secretes excess ACTH which stimulated excess cortisol production in the adrenal glands).
Excess cortisol can have various effects on metabolism. For example, it increases insulin resistance and gluconeogenesis. Both of which promote higher blood sugar. In the short term this is good for immediate use when exercising or whatnot but not when it’s chronic. One reason is because cortisol is acting everywhere it can to get as much glucose creates as possible, including using muscles (which is really noticeable when chronic). The extra blood sugar then stimulates extra insulin production.
This insulin (and cortisol) promotes additional fat formation with excess sugar, and the high cortisol levels also promotes a redistribution of fat in the body to more visceral fat. This inherently makes someone more likely to develop diabetes and obesity even if they eat the same as always.
However, cortisol release also promotes the release of ghrelin (hormone that promotes hunger) and inhibits leptin (hormone that promotes satiety), so the odds are really stacked against you. While something like chronic stress can also lead to increased cortisol release (which is one of the reasons why that’s a risk factor for obesity and diabetes btw), the amounts present in Cushing’s are in extreme excess, and it’s really not reasonable to expect someone to just “watch your diet, duh”.
So yeah obesity is one symptom of Cushing’s (in addition to hypertension and hyperpigmentation).
Latest Answers