Adrenal insufficiency in patients admitted to intensive care unit with moderate to severe traumatic brain injury

Traumatic brain injury is a cause of death in adult populations. Adrenal insufficiency has a great impact on the prognosis of patients with traumatic brain injury. However there is a lack of consensus regarding the diagnostic criteria of adrenal insufficiency. Our aim was to assess adrenal function in patients with moderate to severe traumatic brain injury. In a multicenter case-series study, 50 patients, aged 15 to 70 years, with moderate to severe traumatic brain injury were enrolled from 4 intensive care units in Tehran. Adrenal function was assessed using the 1 and 250 microg ACTH stimulation tests. The incidence of adrenal insufficiency in the first 10 days after traumatic brain injury varied from 34% to 82%, based on various definitions of adrenal insufficiency. More cases of adrenal insufficiency were detected by 1microg ACTH stimulation test compared to the basal cortisol and 250 microg ACTH tests. Since the gold standard insulin stimulation test is regarded as potentially dangerous in the acute phase of post traumatic brain injury, the sensitivity and specificity of the stimulation tests could not be assessed. Kappa test showed no agreement between the two tests [Kappa=0.17]. The incidence of hypotension and vasopressor requirement was higher in patients diagnosed by the 250 microg ACTH test. Baseline cortisol had linear correlation with the 60-minute cortisol of both the 1 and 250microg ACTH tests [P < 0.0001]. The prevalence and associated morbidity of adrenal insufficiency in patients with traumatic brain injury warrant early diagnosis of subclinical cases by dynamic stimulation tests and judicious corticosteroid therapy

[Effect of caffeine on blood pressure during exercise and at rest in overweight men]

Caffeine is a naturally occurring substance that is widely consumed in a variety of forms. The aim of this study was to assess the effect of caffeine on blood pressure in overweight men during exercise and at rest. In double-blind randomly designed study, six men [BMI 29.55 +/- 1.22 kg/m2, age 22.50 +/- 0.83 yr, height 174 +/- 9.12cm, weight 89.31 +/- 8.85kg, body fat percent 26.38 +/- 3.62] with sedentary lifestyles, performed 30 minutes running on treadmill at similar exercise intensities [60% VO2max], 1 hour after taking caffeine [5 mg/kg body weight] or placebo. Heart rate was recorded during exercise, and blood pressure [BP] was measured before and 1 hour after taking caffeine and immediately after exercise, and data analysis was conducted using student' t-test. Results indicated that systolic and diastolic BP and mean arterial pressure significantly elevated following caffeine intake at rest, but no significant differences were observed after exercise no significant differences were observed between caffeine and placebo in heart rate during exercise. The findings indicate that caffeine at this dosage level alters cardiovascular dynamics by augmenting arterial blood pressure in moderately obese men at rest. However, it seems that taking caffeine before exercise does not cause abnormal elevations in blood pressure in moderately obese men