The drop in HDL cholesterol during SIRS is likely due to increased hormone production and the adrenal glands' need for cholesterol to synthesize steroid hormones.

“it's very likely that what we were seeing was in that period of profound physiologic stress the body is greatly ramping up its hormone production glucocorticoids and it's and others and that would be one of the situations where cells were actually you know HDL was now delivering cholesterol to the adrenal glands in a period of you know because that's about the most physiologically stressful thing that an organism can respond to again I don't know if that's been documented but it seems to me pretty logical that that would be a at least the most plausible explanation for why HDL could plummet in patients who are going through that degree of stress”