HPA-Axis dysregulation: hormones

Dr. Klimas emphasized that it is incorrect to separate the immune, endocrine, and nervous systems. In fact, all three form one complex system where the component parts interact with intricate feedback loops.

A major portion of the hormonal or endocrine system is the hypothalamic-pituitary-adrenal (HPA) axis. The hypothalamus and the pituitary glands are in the brain, while the adrenal glands sit atop the kidneys.

The hypothalamus is the master gland; it tells the pituitary when a particular hormone is needed. The pituitary, in turn, sends signals to the adrenals and other glands. The problem in ME/CFS is that activity of the hypothalamus is blunted and hormone-producing signals are not produced properly.

At the 1998 AACFS conference in Cambridge, MA, Dr. Ted Dinan presented a preliminary but extraordinary piece of research in which CAT scans showed very shrunken adren­al glands in ME/CFS patients. In contrast, both depressed persons and healthy controls showed entirely normal-sized adrenals. Furthermore, the ME/CFS patients showed hypothalamic and pituitary dysfunction in addition to the shrunk­en adrenals.

The hypothalamus is also dysfunctional in fibromyalgia patients. Dr. Robert Bennett, a leading fibromyalgia researcher, was irked by critics of studies demonstrating organic deficits in FM. The constant criticism was that the studies were invariably too small, so he decided to respond.

In a study of 500 patients, Dr. Bennett demonstrated abnormal hypothalamic function. In a sub-sample he found that it was the hypothalamus, not the pituitary, which was not functioning properly.