Tolerance of the oral clonidine test in 180 patients: efficacy of the volemic expantion in controlling arterial hypotension

Clonidine stimulation test is widely used to evaluate growth hormone secretion. Side effects are somnolence (35%) and arterial hypotension (AH) (5%). The aims of this paper were to evaluate the tolerance to this test regarding blood pressure (BP) decrease, sedation and the efficacy of saline resuscitation to prevent AH. BP was measured at basal, 60 and 120 min. Sedation was determined by the Ramsay scale. Patients were divided into two groups: Group 1 (n = 80) received saline resuscitation only upon severe AH (drop of mean BP [MBP] > 20% from initial MBP) and/or postural hypotension; Group 2 (n = 100) received saline resuscitation from the beginning of the test. Both groups presented a significant MBP fall and 75% presented somnolence at 60 min. MBP drop did not correlate with either sedation or the clonidine dose. Group 1 presented more hypotension (59% x 28%) and greater MBP drop at 60 min. Only one patient had an asthma attack. We conclude that the hypotension effects caused by oral clonidine diminish with saline resuscitation since the beginning of the test. This test must have specialized medical support with strict BP evaluation and precocious intervention when needed.     

Significant thresholds for the 75-g oral glucose tolerance test in pregnancy

The significant threshold values for the 75-g oral glucose tolerance test (oGTT) during pregnancy have yet to be conclusively determined. This study aimed to identify the risk significance of various set thresholds for the oGTT result. Women undergoing a 75-g oGTT during the third trimester of pregnancy were classified into three groups: mild gestational impaired glucose tolerance (GIGT; 2-h postload glucose, 8.0–8.5 mmol/l; n=75), moderate-severe GIGT (8.6–10.9 mmol/l; n=167), and GDM (≥11.0 mmol/l; n=76). Outcome indicators of these three groups of women were compared to the parameters of the women with a presumed normal carbohydrate metabolism (n=12,185). The results show that with increasing oGTT thresholds, there was an increasing risk of maternal morbidity in the form of hypertensive disorders complicating pregnancy, as well as obstetric intervention such as induction of labor, cesarean delivery, and preterm delivery. The infant was also at increasing risk with increasing oGTT thresholds from respiratory distress, macrosomia, and associated shoulder dystocia. It would appear, therefore, that abnormal glucose tolerance in pregnancy, even as defined by the World Health Organization criteria, has proportionate risks to both mother and child.     

Mucoceles of the oral cavity in pediatric patients

Mucoceles are quite common in the oral cavity, but reports on pediatric patients are very rare. The aims of this study were to present our data and experience in the treatment of mucoceles of the oral cavity in pediatric patients, to compare them with those of other countries, and to remind the pediatric physician to devote much attention to lesions of the oral cavity in children. This retrospective study is based on the record of the patients who received surgical treatment for mucoceles of the oral cavity with pathologic confirmation at the Department of Dentistry, Kaohsiung Medical University Hospital, Taiwan, between 2000 and 2004. Patients younger than 18 years were included in this study. The analyzed data included age, gender, site, size, histopathologic findings, surgical methods, and complications. There were a total of 289 patients with mucoceles confirmed by histopathologic examination. As many as 64 patients were younger than 18 years. Of the 64, 34 were girls and 30 were boys; 89.1% of the lesions were in the lower lip; and 48.4% of the lesions were less than 5mm in diameter. Histopathologic findings showed that all mucoceles were of the extravasation type. As many as 30 patients were treated by carbon dioxide laser vaporization, and two cases recurred (6.67%); 34 patients were treated by surgical excision, and the recurrence rate (5.88%) was not statistically different for the treatment methods. The laser vaporization has the advantage of less bleeding, no sutures, and saving time, especially suitable for children with oral mucocele.     

New criteria for interpretation of the 75 g oral glucose tolerance test in pregnancy

A 75 g oral glucose tolerance test (OGTT) was performed on 135 high-risk pregnant patients. When the current World Health Organization (WHO) criteria for the diagnosis of gestational-glucose tolerance were applied, 88 patients were considered normal, 11 had gestational diabetes, and 36 patients had impaired-glucose tolerance, respectively. The plasma glucose, insulin, and C-peptide levels during the OGTT were further studied in the 88 patients (who had normal results). Two metabolically distinct groups were identified; a group (n = 53) with a 2-hour plasma glucose less than or equal to 6.6 mmol/L (118.8 mg/dL), had a normal insulin and C-peptide pattern, and a second group (n = 35) who had 2-hour plasma glucose greater than 6.6 mmol/L displayed a glycemic, insulin, and C-peptide pattern similar to that of patients with gestational diabetes mellitus. The risks of macrosomic babies and operative delivery were significantly greater in the latter group. These results suggest that in our pregnant population, a group of patients with impaired glucose tolerance will be under-diagnosed using the current WHO criteria. Based on our results new criteria for gestational glucose intolerance are suggested for our population.     

Oral nifedipine vs oral clonidine in the treatment of urgent hypertension

Fifty-one patients with urgent hypertension were treated in the emergency department with either oral nifedipine or oral clonidine in a randomized double-blind prospective study. Nifedipine was administered as a single dose of 20 mg. Clonidine was administered as an initial dose of 0.1 mg with hourly doses of 0.1 mg. Nifedipine was successful in reducing diastolic blood pressure in 83% of the patients within 45 minutes and in 96% of the patients within two hours, with a mean reduction in systolic blood pressure of 47 mm Hg and diastolic blood pressure of 29 mm Hg. Thirty percent of those who initially responded to nifedipine experienced a subsequent increase in diastolic blood pressure to pretreatment levels within three hours. Clonidine was successful in reducing diastolic blood pressure in 79% of the patients within four hours, with a mean reduction in systolic blood pressure of 51 mm Hg and diastolic blood pressure of 30 mm Hg. Our results indicate that both nifedipine and clonidine are safe and effective in the treatment of urgent hypertension. Nifedipine had a much more rapid onset of action with a greater initial success rate, and it was free from the sedative side effects of clonidine. We believe that either nifedipine or clonidine may be used as first-line therapy in the treatment of urgent hypertension.     

Comparison of oral glucose tolerance test (OGTT) 100 g with OGTT 75 g for evaluation of acromegalic patients and the impact of gender on test reproducibility

Context Growth hormone (GH) measurements during an oral glucose tolerance test (OGTT) are essential for the diagnosis and follow‐up management of acromegaly. However, both 100 g glucose (OGTT₁₀₀) and 75 g glucose (OGTT₇₅) test variants are in clinical use. Whether the tests are interchangeable concerning GH nadir and test interpretation is unclear. Furthermore, information on test reproducibility and the impact of gender is scarce. Objective To compare both tests in acromegalic patients and to evaluate test reproducibility with respect to gender. Design, subjects and methods OGTT₁₀₀ and OGTT₇₅ were performed on two consecutive days in 54 acromegalic patients (46·9 ± 1·8 years, 30 women). OGTT₇₅ was repeated on three different occasions in 11 healthy men and 13 healthy women at different phases of the menstrual cycle. Results GH nadirs were comparable between tests [2·40 ± 0·52 (OGTT₁₀₀) and 2·46 ± 0·54 μg/l (OGTT₇₅); P = 0·356]. There were no differences at any time point in the mean values of GH, serum glucose or insulin between the two test variants. Test interpretation was highly consistent between the OGTT₁₀₀ and OGTT₇₅ [area under the receiver operated curve (ROC) = 0·995]. In men, GH, insulin and glucose measurements during OGTT₇₅ were highly reproducible. In women, however, basal and GH nadirs were significantly higher midcycle (P < 0·05). Conclusions In acromegalic patients, there is no difference in GH nadirs and test interpretation after the ingestion of 100 g or 75 g glucose. The OGTT₇₅ is highly reproducible in men, but in women, it should be performed preferably in the early follicular phase.     

Overnight clonidine suppression test in the diagnosis and exclusion of pheochromocytoma

In a prospective study designed to differentiate pheochromocytoma from other forms of hypertension, urinary catecholamines were measured after sleep and clonidine administration in 12 patients with pheochromocytoma, 19 hypertensive patients in whom pheochromocytoma was suspected but later excluded, and 31 hypertensive patients in whom pheochromocytoma was never suspected. The test correctly identified all 12 patients in whom pheochromocytoma was present. Four of these had equivocal plasma levels of both norepinephrine and epinephrine, suggesting that overnight clonidine suppression may be of particular value when tumor secretion is intermittent or low. When pheochromocytoma was not present, urinary norepinephrine and epinephrine levels were suppressed below 60 and 20 nmol/mmol creatinine, respectively, after sleep and clonidine, the two in combination giving better suppression than sleep alone. Since urinary catecholamines can be determined relatively easily by high-pressure liquid chromatography with electrochemical detection, this test may be more widely applicable than suppression tests based on plasma measurements.     

The normal range of the plasma immunoreactive glucagon level during a 75 g oral glucose tolerance test

In order to establish a normal value of plasma glucagon immunoreactivity (GI) and glucagon-like immunoreactivity (GLI) during a newly adopted 75 g OGTT, 50 normals (N), 102 individuals with IGT and 20 diabetics (D) were subjected to the OGTT, and their plasma GI and GLI levels were determined at various intervals by radioimmunoassay using 2 kinds of the C-terminal region specific antibody, OAL123 and 30K, and of the antibody specific for the N-terminal and/or central region of glucagon, OAL196, respectively. The basal levels of OAL123-GI and 30K-GI and OAL196-GLI in the 3 groups were as follows; N, 114.3, 80.8, and 335.5; IGT, 107.6, 76.1, and 338.5; and D, 135.7, 76.9, and 342.2 pg/ml. After glucose administration, a significant decrease in plasma GI and increase in plasma GLI were observed in the 3 groups, although their changes from the basal levels were variable. The plasma samples of inexplicably high GI concentration were chromatographed to clarify the nature of the hyperglucagonemia. The apparent GI was mostly eluted in the Vo component, but negligibly at the 3500 mol.wt. glucagon fraction. There was a marked difference in the Vo peak depending upon the antiserum used. These facts suggest that plasma GI values are dependent on the amount of BPG present in particular samples, and the antibody used.     

Symptomatic hypotension following the clonidine suppression test for pheochromocytoma

A 42-year-old man with generalized atherosclerosis underwent surgery of the left carotid artery with eventual placement of a Dacron graft bypassing the left carotid sinus. Subsequently, symptoms suggestive of pheochromocytoma developed, and 24-hour urine catecholamine levels were elevated. Clonidine testing resulted in suppression of plasma norepinephrine levels but was complicated by severe hypotension and a transient ischemic attack. Baroreceptor dysfunction may have been involved. Caution is advised and recommendations are offered for future usage of the clonidine suppression test.     

Evaluation of sympathetic tone in essential hypertension by the clonidine suppression test

Recent evidences suggest that the sympathetic nervous system plays a major role in the pathogenesis and maintenance of several clinical forms of hypertensive disease. The clonidine suppression test allows us to uncover the subtle changes in neuronal noradrenaline release in essential hypertension. To prove this possibility, we selected 16 patients: 7 borderline hypertensives (BH) (4 males and 3 females), mean age: 24 years; and 9 established hypertensives (EH) (6 males and 3 females), mean age: 25 years. In both groups, the heart rate (HR) and blood pressure (BP) were registered every 30 min and by intravenous catheter plasma catecholamines (PCA) and plasma renin activity (PRA) were measured before and after (180 and 240 min) one oral dosis of clonidine (300 mcg) had been administered. Patients remained in clinostatism for 180 and and orthostatism for 60 min. HR and BP diminished in BH and EH after clonidine during clinostatism in comparison to preclonidine period. PCA also showed reduction in 180 min with respect to the basaline period. PRA did not present change in 180 min in either groups in relation to time O. During orthostatism, HR increased in both groups with respect to the baseline period. BP remained low in relation to baseline time. PCA were increased with respect to preclonidine period. PRA showed a slight tendency to increase in relation to time O in both groups. CAP baseline level are not reliable indexes of the role of the sympathetic tone in maintenance of high BP values in hypertensive disease.(ABSTRACT TRUNCATED AT 250 WORDS)     

Oral labetalol versus oral clonidine in the emergency treatment of severe hypertension.

This study was designed to compare the clinical efficacy and safety of oral clonidine and oral labetalol in the treatment of severe hypertension in an emergency department setting. Thirty-six patients with severely elevated blood pressure (mean baseline blood pressure 199/132 mm Hg) without acute end-organ dysfunction were treated with either oral labetalol or oral clonidine in a randomized double-blind prospective study. Labetalol was administered as an initial dose of 200 mg, followed by hourly 200 mg doses up to 1,200 mg. Clonidine was administered as an initial dose of 0.2 mg, followed by hourly 0.1 mg doses up to 0.7 mg. Labetalol reduced diastolic blood pressure in 94% of the patients within 6 hours, with a mean reduction in blood pressure of 54/37 mm Hg. Clonidine reduced diastolic blood pressure in 83% of the patients within 6 hours, with a mean reduction in blood pressure of 57/32 mm Hg. The authors conclude that oral labetalol was comparable to clonidine in efficacy, had a similar incidence of side effects, and offered the clinician a useful alternative for the treatment of severe hypertension in an emergency department setting. Further studies are indicated to determine appropriate dosing regimens for oral labetalol in the acute treatment of severe hypertension.     

Diabetes pattern on the 75 g oral glucose tolerance test is a risk factor for hepatocellular carcinoma in patients with hepatitis C virus

Background: Patients with hepatitis C virus (HCV) frequently show glucose intolerance. Diabetes mellitus (DM) has been proposed to be a risk factor for hepatocellular carcinoma (HCC). Aims: The aim of this study is to clarify the influence of glucose intolerance as evaluated by the 75 g oral glucose tolerance test (OGTT) on hepatocarcinogenesis in patients with HCV. Methods: This study was carried out in a cohort of 197 patients with HCV who had not been previously diagnosed as having DM. All patients underwent the 75 g OGTT at entry. They were also screened for HCC and, thereafter, the rate of hepatocarcinogenesis was compared between the patients with and without glucose intolerance. Results: Based on the results of the 75 g OGTT, 125 (63%) had normal glucose tolerance (NGT), 49 (25%) had impaired glucose tolerance (IGT) and 23 (12%) had the DM pattern. HCC occurred more frequently in patients with the DM pattern than in patients with either NGT or IGT. Even in patients without advanced liver fibrosis, HCC was more frequently observed in patients with DM than in patients with NGT. A multiple logistic regression analysis showed advanced liver fibrosis, the DM pattern on the 75 g OGTT, an older age and γ‐glutamyltransferase to all be independent risk factors related to hepatocarcinogenesis. Conclusions: A DM pattern on the 75 g OGTT was thus found to be associated with hepatocarcinogenesis and the 75 g OGTT is considered to be useful for identifying this risk factor for HCC in patients with HCV.     

Tolerance to reduction of oral steroid dosage in severely asthmatic patients receiving nedocromil sodium

We examined the efficacy of nedocromil sodium as an oral steroid sparing agent in a group of 37 severe, oral steroid-dependent asthmatics. All were receiving daily or alternate-day prednisone. These patients had taken part in an earlier, 12-week double-blind trial of nedocromil sodium 16 mg daily by inhalation or matching placebo. They continued with test treatment (26 patients on nedocromil sodium and 11 on placebo) on a double-blind basis for a further 12 weeks. During this time, patients visited the clinic every 2 weeks, when asthma severity and symptoms were assessed. On the basis of these assessments, the dose of oral steroid was either decreased, or maintained at the same level, or the patient was withdrawn if the asthma had deteriorated to a clinically unacceptable level. The nedocromil sodium group was able to achieve a greater percentage reduction in oral steroid dose (P less than 0.05). The rate of withdrawal due to worsening asthma was 31% from active and 55% from placebo treatment. Trends in other variables (time before withdrawal and numbers of patients able to withstand complete removal of oral steroids) favoured nedocromil sodium but the differences between the groups were not statistically significant.     

Phenylalanine loading in pediatric patients with dopa-responsive dystonia: revised test protocol and pediatric cutoff values

Objectives  

The objectives of this study were to determine the value of phenylalanine (Phe) loading for diagnosing dopa-responsive dystonia (DRD) in children.