Short-term comparison of once- versus twice-daily administration of glimepiride in patients with non-insulin-dependent diabetes mellitus.

OBJECTIVE: To investigate the metabolic effects and frequency of adverse events with 6 mg of glimepiride, a new oral sulfonylurea, given both in once- and twice-daily dosages to patients with non-insulin-dependent diabetes mellitus (NIDDM). RESEARCH DESIGN AND METHODS: This 15-week study involved 161 subjects with NIDDM. Subjects were randomized into two groups. For 4 weeks, group 1 received glimepiride 3 mg twice daily, and group 2 received glimepiride 6 mg once daily. After a 3-week placebo-washout period, twice- and once-daily regimens were crossed over for a second 4-week treatment period. Subjects were hospitalized at the end of each placebo or active-treatment phase. Their glucose concentrations were recorded at 20 time points over a 24-hour period, and their insulin and C-peptide concentrations were recorded at 16 time points over the same period. Parameters that were calculated included fasting, 24-hour, and postprandial concentrations of glucose, insulin, and C-peptide. RESULTS: One hundred six patients were randomized to receive treatment; 94 completed the entire study. Existing physiologic mechanisms of glucose control were apparently unimpaired by glimepiride treatment. Insulin concentrations increased more during the postprandial glucose peaks than when subjects were fasting. Both twice- and once-daily regimens proved equally effective in reducing concentrations of fasting, postbreakfast, postlunch, and postdinner plasma glucose. Twenty-four-hour mean glucose concentrations showed a slightly greater decrease from baseline for the twice-daily regimen; the difference between the regimens was statistically significant but not clinically meaningful. The incidence of adverse events with glimepiride approximated that obtained with placebo, with both groups reporting only one adverse event, headache, in more than 5% of the subjects. CONCLUSIONS: Glimepiride is equally effective whether administered once or twice daily. Glimepiride seems to stimulate insulin production primarily after meals, when plasma glucose concentrations are highest, but controls blood glucose throughout the day.

Somatomedin C in treated acromegaly: poor correlation with growth hormone and clinical response.

To determine the usefulness of commercially available somatomedin C levels in the evaluation of the treatment of acromegaly, 15 patients were tested at 0.25-15.4 yr after onset of therapy. Clinical response, as determined by a numerical scoring system, was compared with RIA of GH and somatomedin C. Symptomatic response was poorly correlated with somatomedin C (r = 0.033) as well as with GH (r = 0.24). The correlation of GH and somatomedin C was also poor (r = 0.46, P greater than 0.05). Eighty-three percent of patients with clinical improvement had GH less than or equal to 10 ng/ml, 50% had GH less than or equal to 5 ng/ml, while 42% had somatomedin C less than or equal to 3.0 U/ml. All patients who were evaluated at 1 yr or less after therapy had elevated somatomedin C levels with normal or near normal GH values. In contrast only 2 of 11 patients evaluated at more than 1 yr after therapy had a mild persistence of somatomedin C elevation with normal GH levels. Determination of somatomedin c costs more than GH determinations and appears to offer no apparent advantage over GH in following patients treated for acromegaly.

Recent advances in the control and function of the anterior pituitary.

Major advances in our understanding of the synthesis and release of anterior pituitary hormones have been made over the past several years. Neurons of the hypothalamus have been found to serve as "neuroendocrine transducers" in that they have both electrical and secretory functions. Peptidergic neurons respond to appropriate stimuli with a release of hypothalamic factors into the hypophyseal-portal system. These factors or hormones ultimately control the endocrine function of anterior pituitary cells. Three hormones, Thyrotropin Releasing Hormone (TRH), Gonadotropin Releasing Hormone (GnRH or LHRH) and somatostatin have been identified, synthesized and tested for clinical applications. The clinical assessment of pituitary function has been greatly improved by new and improved radioimmunoassays. One of the recent clinical advances in the area of pituitary disease has been the determination of the relatively high frequency of prolactinomas. Prolactin secreting microadenomas are an important and treatable cause of amenorrhea and infertility in young women. In addition, many pituitary tumors previously believed to be non-functional or "chromophobe adenomas" appear to be prolactinomas. Many new diagnostic and therapeutic techniques are continuing to be developed to improve our management of patients with hypothalamic-pituitary disease.

Thrombotic thrombocytopenic purpura in carbon monoxide poisoning. Report of a case.

A young, previously healthy man was arrested for bizarre behavior outside his poorly ventilated hotel room. He was found to have carbon monoxide poisoning and thrombotic thrombocytopenic purpura complicated by respiratory dysfuntion. The occurrence of these previously unrelated diseases in the same patient may be more than coincidence.