Endocrine Measures Cortisol

Endocrine effects of budesonide have been assessed in 29 asthmatic children aged 6 months to 3 years by measuring fasting plasma cortisol concentrations and performing an ACTH stimulation test in a double-blind, randomized, placebo-controlled study (69). The patients received budesonide either 2 mg followed by a stepwise reduction of 25% every second day or 0.5 mg/day or placebo for 8 days. Neither fasting nor 1-hour post-stimulation plasma cortisol concentrations differed in any group. 

In a prospective study, endocrine responses to hyperthermic stress were assessed in 10 male cocaine users after 4 weeks of abstinence and again after 1 year of abstinence (184). They sat in a sauna for 30 minutes at a temperature of 90°F and a relative humidity of 10%. At the end of the sauna, they rested for another 30 minutes at room temperature. Sublingual temperature, pulse rate, and blood pressure were recorded just before and immediately after the sauna and 30 minutes after the period at room temperature. Venous P-erythropoietin, ACTH, metenkephalin, prolactin, and cortisol were also measured. There were no significant differences between the... 

The lowered detection limits of the newer two-site immunoassays for the measurement of pituitary hormones now make it possible to distinguish an abnormally low value from the lower end of the normal reference interval. Although assessment of a particular aspect of pituitary function should also include clinical signs and symptoms of hormone deficiency and the measurement of hormones secreted by the pertinent endocrine gland (e.g., T4, cortisol, and testosterone), the newer, ultrasensitive assays for TSH, FSH, LH, and ACTH allow for an accurate distinction of a true low result from low normal. A scheme for testing of pituitary reserve is fisted in Box 50-6. 

Pituitary reserve is almost never compromised in patients with small pituitary tumors, so testing is usually limited to patients with large tumors or specific clinical indications, (see Box 50-6, A). For most patients with large pituitary tumors, in addition to history and physical examination, an adequate evaluation of endocrine function before surgery can be performed based on laboratory measurements of serum PRL, TSH, LH, FSH, sex steroids (testosterone in males and estradiol in females), serum sodium, and results of a morning serum cortisol or ACTH stimulation test. 

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