Lessons from an unpleasant surprise: a biochemical strategy for the diagnosis of pheochromocytoma

OBJECTIVE

To audit the performances of the analytes used in the diagnosis of pheochromocytoma and to present a graphical guideline to help the diagnosis.

DESIGN

A 5 year retrospective study.

SETTINGS

Laboratory and departments of a university hospital.

PARTICIPANTS

In-patients, suspected of bearing a pheochromocytoma, were investigated for urinary metanephrines and catecholamines (photometric method) and vanillylmandelic acid, fractionated catecholamines and metanephrines [high pressure liquid chromatography (HPLC) coupled to electrochemical detection (ED)] urinary excretion.

MAIN OUTCOME

Patients with a pheochromocytoma (24 out of 2003 patients) were diagnosed by the combination of normetanephrine and metanephrine determination.

RESULTS

All analytes but dopamine were significantly elevated in patients with a pheochromocytoma. The area under the receiver operating characteristics (ROC) curves were the highest for total metanephrines, normetanephrine and metanephrine determinations. Because of analytical interferences in the metanephrines determination, the normetanephrine and metanephrine performed better. It is noteworthy that all pheochromocytomas had either normetanephrine or metanephrine levels above their respective optimal threshold (sensitivity 100%). The best optimal threshold performance was reached by the mean of three daily samples. Total or fractionated catecholamines or vanillylmandelic acid were less accurate tools.

CONCLUSION

Amongst urinary tests, the combined use of HPLC/ED determination of normetanephrine and metanephrine seems the most effective screening strategy for the diagnosis of pheochromocytoma. The older total metanephrine photometric assay is grieved by analytical interferences.

A case of giant malignant phaeochromocytoma

Malignant phaeochromocytoma is defined as the presence of tumour deposits at sites that are normally devoid of chromaffin cells. We report on a 63-year-old man who had a giant malignant phaeochromocytoma of the right adrenal gland that encased the inferior vena cava. The urinary excretion rates of catecholamines and their metabolites were normal, except for normetanephrine, which was excreted at a higher rate than normal. The tumour was surgically unresectable by laparotomy. Postoperatively, the patient was given a 4-month trial of subcutaneous octreotide and intravenous meta-iodobenzylguanidine I 131. Occult lung secondary tumours were first detected by meta-iodobenzylguanidine scintigraphy after 2 years, and the patient died of bone and lung metastases 1 year later. Because phaeochromocytoma is rare, local experience in managing this disease is limited. This report alerts physicians of the methods of diagnosing and managing surgically unresectable malignant phaeochromocytoma.

High-performance liquid chromatography/atmospheric pressure chemical ionization mass spectrometric method for the analysis of catecholamines and metanephrines in human urine

An assay of norepinephrine (NE), epinephrine (E), dopamine (DA), normetanephrine (NE) and metanephrine (MN) based on high-performance liquid chromatography (HPLC) in combination with atmospheric pressure chemical ionization mass spectrometry (APcI-MS) is described. The catecholamines and metanephrines were extracted from urine and aqueous samples using Bio-Rex 70 cation-exchange resin and subjected to analysis by HPLC/APcI-MS. The separation was performed on a C18 column in 50 mM ammonium formate buffer, pH 3.0, using a flow rate of 0.8 mL/min. Acetonitrile was added post-column at a flow rate of 0.2 mL/min via a post-column addition tee. The total analysis time was 6.5 min. The quantitative analysis was performed using 3,4-dihydroxybenzylamine (DHBA) as the internal standard (I.S.). Selected ion monitoring detection was applied: m/z 170 (for NE), 184 (for E and NM), 154 (for DA), 198 (for MN) and 140 (for DHBA, I.S.). The limits of quantitation were 5 ng/mL for NE, E and DA and 2.5 ng/mL for NM and MN. The recovery ranged from 75 to 83% for each analyte. The method was found to be simple and highly selective for the determination of catecholamines and metanephrines in the urine of patients suspected of pheochromocytoma.

Catecholamines in depression: a cumulative study of urinary norepinephrine and its major metabolites in unipolar and bipolar depressed patients versus healthy volunteers at the NIMH

Studies comparing urinary norepinephrine (NE) and its metabolites in unipolar or bipolar depressed patients and healthy volunteers have not yielded consistent findings. However, in unipolar depressed patients, most studies in non-elderly populations consistently report elevated concentrations of plasma NE, at least following an orthostatic challenge. Expanding upon previous studies which showed elevated plasma NE in depression, we compared the urinary excretion of NE, normetanephrine (NMN), 3-methoxy-4-hydroxyphenylglycol (MHPG), and vanillylmandelic acid (VMA) in age- and sex-matched unipolar and bipolar depressed patients versus healthy volunteers hospitalized at an inpatient unit at the National Institute of Mental Health. Only depressed subjects with a minimum 4-week drug-free period were included. Total turnover (NE + NMN + MHPG + VMA) was reduced in this sample of unipolar and bipolar depressed patients. MHPG concentration did not distinguish unipolar from bipolar depressed patients and was not significantly different from that in healthy volunteers. A construct of the average fractional extraneuronal concentration of NE (NE + NMN/NE + NMN + MHPG + VMA) was significantly higher in unipolar and bipolar depressed patients than in healthy volunteers. This finding extends data suggesting that unmedicated unipolar and bipolar depressed patients have a 'hyperresponsive' noradrenergic system and provides a framework which ties together plasma and urinary findings.

Plasma normetanephrine and metanephrine for detecting pheochromocytoma in von Hippel-Lindau disease and multiple endocrine neoplasia type 2

BACKGROUND

The detection of pheochromocytomas in patients at risk for these tumors, such as patients with von Hippel-Lindau disease or multiple endocrine neoplasia type 2 (MEN-2), is hindered by the inadequate sensitivity of commonly available biochemical tests. In this study we evaluated measurements of plasma normetanephrine and metanephrine for detecting pheochromocytomas in patients with von Hippel-Lindau disease or MEN-2.

METHODS

We studied 26 patients with von Hippel-Lindau disease and 9 patients with MEN-2 who had histologically verified pheochromocytomas and 50 patients with von Hippel-Lindau disease or MEN-2 who had no radiologic evidence of pheochromocytoma. Von Hippel-Lindau disease and MEN-2 were diagnosed on the basis of germ-line mutations of the appropriate genes. The plasma concentrations of normetanephrine and metanephrine were compared with the plasma concentrations of catecholamines (norepinephrine and epinephrine) and urinary excretion of catecholamines, metanephrines, and vanillylmandelic acid.

RESULTS

The sensitivity of measurements of plasma normetanephrine and metanephrine for the detection of tumors was 97 percent, whereas the other biochemical tests had a sensitivity of only 47 to 74 percent. All patients with MEN-2 had high plasma concentrations of metanephrine, whereas the patients with von Hippel-Lindau disease had almost exclusively high plasma concentrations of only normetanephrine. One patient with von Hippel-Lindau disease had a normal plasma normetanephrine concentration; this patient had a very small adrenal tumor (<1 cm). The high sensitivity of measurements of plasma normetanephrine and metanephrine was accompanied by a high level of specificity (96 percent).

CONCLUSIONS

Measurements of plasma normetanephrine and metanephrine are useful in screening for pheochromocytomas in patients with a familial predisposition to these tumors.

Elevated urinary norepinephrine in interstitial cystitis

OBJECTIVES

To measure urinary catecholamines and determine the extent to which they may be elevated in urine from patients with interstitial cystitis (IC).

METHODS

Random urine samples from patients with IC (n = 111) and urine from normal volunteers (n = 92) were acidified on collection (voided and catheterized specimens) and assayed for catecholamine (norepinephrine or normetanephrine) by enzyme-linked immunosorbent assay. Creatinine levels in these urine samples were also measured.

RESULTS

Analysis of the data indicated that patients with IC had a higher urinary level of the neurotransmitter norepinephrine compared with the measured levels in the urine of normal volunteers (89.1 +/- 58.3 versus 54.9 +/- 37.1 microg/g creatinine, P <0.05). The metabolite normetanephrine was similar in the urine samples from these two groups. Urine from patients with bladder outlet obstruction (n = 11) did not have elevated amounts of urinary norepinephrine. The norepinephrine levels were not statistically different in the urine samples from patients with symptomatic and asymptomatic IC. The elevated urinary levels in patients with IC did not decrease after treatment with sodium pentosanpolysulfate (Elmiron), heparinoids, dimethyl sulfoxide, or combinations of these during 1 to 15 months of treatment.

CONCLUSIONS

Norepinephrine was found to be elevated in the urine from patients with IC compared with urine from normal controls. This would be consistent with increased sympathetic (adrenergic) activity from the bladders of patients with IC or possibly from increased adrenal activity, since stress is associated with symptom increase in some patients with IC. Norepinephrine levels did not decrease with treatment nor did they differ between symptomatic and asymptomatic patients at the time of urine collection.

Randomised controlled trial of low dose fentanyl infusion in preterm infants with hyaline membrane disease

AIM

To evaluate the effects of low dose fentanyl infusion analgesia on behavioural and neuroendocrine stress response and short term outcome in premature infants ventilated for hyaline membrane disease.

METHODS

Twenty seven ventilated preterm infants were randomly assigned to receive a mean fentanyl infusion of 1.1 (0.08 SE) micrograms/kg/h for 75 (5) hours, and 28 untreated infants were considered a control group. A behavioural sedation score was used to assess the infants' behaviour. Urinary metanephrine and the normetanephrine:creatinine molar ratio were determined at 0, 24, 48 and 72 hours. Outcome data and ventilatory indexes were recorded for each infant.

RESULTS

The fentanyl group showed significantly lower behavioural stress scores and O2 desaturations than controls and lower urinary concentrations of metanephrine and normetanephrine at 24, 48, 72 hours. The two groups showed no significant difference in ventilatory variables or short term outcome.

CONCLUSIONS

A short course of low dose fentanyl infusion reduces behavioural sedation scores, O2 desaturations and neuroendocrine stress response in preterm ventilated infants.

Biological and psychological processes in recovery from depression during cognitive therapy

This study investigated the relationship between biological and psychological processes in the recovery phase of depression during treatment with cognitive therapy. In particular, we tested the hypothesis that biological and psychological processes are independent; the hypothesis that they are related in a linear or sequential process; and the hypothesis that there is a circular relationship between them. 35 depressed patients completed a 12 week program of cognitive therapy. Changes in measures of negative thinking and amine dysfunction over the course of therapy were compared for those who improved and those who did not. There was a significant relationship between improvement in symptoms and change for ATQ scores, DAS scores, and epinephrine levels. There was significant change in metanephrine levels during therapy which was not related to improvement. The changes were not consistent across indices. Although the results did not provide definite support for any of the four models of the relationship between biological and psychological variables during recovery from depression, the finding that there was some change in some of the indices of amine dysfunction during cognitive therapy indicates that the interface between biological and psychological processes in depression should continue to be studied.

Efficacy of single-voided urine metanephrine and normetanephrine assay for diagnosing pheochromocytoma

Urinary catecholamines (CAs) and their metabolites are usually measured during the process of diagnosing pheochromocytoma (pheo), but a 24-hour urine collection is not convenient for outpatients. Since 1987 we have utilized "spot" urine metanephrine (MN) and normetanephrine (NMN) assays for management of patients with pheo or adrenal incidentaloma. MN and NMN were measured by radioimmunoassay in 82 patients with surgically proved pheo and 15 patients with incidentaloma. In 10 patients with pheo, MN and NMN were measured with fractional every-3-hour urine samples, which were accumulated and then measured as a 24-hour urinary specimen. Fractions of 3-hour MN and NMN excretion were constant (MN 98.5 +/- 9.6%, NMN 97.6 +/- 10.8%; 24-hour MN and NMN 100%). The average levels of MN and NMN in patients with pheo were 6801 ng/mg creatinine (Cr) (range 93-88,248, median 1426) and 5627 ng/mg Cr (range 219-31,528, mean 3190), whereas the MN and NMN levels in patients with incidentaloma were 123 ng/mg Cr (range 36-246, mean 133) and 251 ng/mg Cr (range 84-472, mean 220), respectively. When we selected a cutoff value for MN + NMN of 1000 ng/mg Cr, the sensitivity was 97.6% and the specificity 100% for diagnosing pheo. When the standard was set as > 500 ng/mg Cr for either MN or NMN, both the sensitivity and specificity were 100%. The assay for MN and NMN is simple and effective, not only for screening but for diagnosing pheo and managing incidentaloma.

Monoamine oxidase A deficiency: biogenic amine metabolites in random urine samples

We have recently described an association between abnormal behaviour and monoamine oxidase A (MAO-A) deficiency in several males from a single large Dutch kindred. A characteristically abnormal excretion pattern of biogenic amine metabolites was present in 24-hour urine of affected males. Because of this strikingly abnormal metabolite pattern observed in 24 hour urine samples of MAO-A deficient males we hypothesized that it should be possible to diagnose this condition by examining random urine samples. We therefore studied multiple urine samples obtained over a two-week study period from two males with selective MAO-A deficiency. The results demonstrate that the characteristic abnormalities in the excretion of biogenic amines and their metabolites were faithfully present in every one of 12 independent samples obtained from the MAO-A deficient males over the two-week study period. We conclude that MAO-A deficiency can be reliably diagnosed by measuring the ratio of normetanephrine (NMN) to VMA (or that of NMN to MHPG) in random urine samples.

Determination of catecholamines and methoxycatecholamines excretion patterns in pig and rat urine by ion-exchange liquid chromatography with electrochemical detection

A simplified liquid chromatographic method for the simultaneous determination of free or total catecholamines and methoxycatecholamines in rat and pig urine is presented. The extraction procedure involves a two-stage batch extraction, with successive adsorption on cation- (catecholamine elution) and anion-exchange columns (methoxycatecholamine elution). The column eluates are successively monitored by reversed-phase high-performance liquid chromatography (HPLC) with electrochemical detection. The proportion of conjugates for each compound was assessed in both species, through the comparison of concentrations with or without hydrolysis pretreatment. Conjugates were found to account for a small fraction of total catecholamines and methoxycatecholamines excretion (0 to 35%). The free fraction of each compound was highly correlated with the total amount. Furthermore, the hydrolysis procedure leads to partial degradation of metanephrine (25%) and to the production of compounds giving artefactual peaks. Thus, we do not recommend hydrolysis of rat and pig urines for catecholamine and methoxycatecholamine determination.

[Secreting retroperitoneal paraganglioma. Apropos of a case]

A case of secreting, asymptomatic retroperitoneal paraganglioma is presented. Paragangliomas are rare neuroendocrine tumors and the malignant behaviour, higher than pheochromocytomas, is based on metastases or local recurrence. The treatment is complete surgical excision. Radiotherapy and chemotherapy may be used for palliation of symptoms.

Evaluation of urinary metanephrine and normetanephrine enzyme immunoassay (ELISA) kits by comparison with isotope dilution mass spectrometry

Determination of urinary 3-O-methylated catecholamines (metanephrines) is generally considered a principal test for the clinical chemical diagnosis of pheochromocytoma and is currently performed predominantly with chromatographic techniques such as gas-liquid chromatography and HPLC. Enzyme immunoassays based on microtiter plate technology have recently been developed for the quantitative determination of urinary metanephrine (M) and normetanephrine (NM). We compared the results for urinary M and NM determined by these ELISA methods with those obtained by a recently developed isotope dilution mass spectrometric method. From this comparative study we can conclude that the investigated ELISA methods are applicable in the quantification of urinary M and thus can be successfully used to establish the diagnosis of pheochromocytoma. These relatively simple methods can be executed in any clinical laboratory and in time may replace the present, more complicated, chromatographic techniques.

Day-to-day intraindividual reliability and interindividual differences in monoamines excretion

The urine of 44 normal men was collected during 2 nights to evaluate components of biological variation, i.e., intraindividual day-to-day variability and interindividual variability in monoamines excretion. Monoamines presented important interindividual variability [interindividual coefficients of variation (%): dopamine 18.3, norepinephrine 66.7, epinephrine 85.3, normetanephrine 22.4, metanephrine 76.8, 3-methoxy-4-hydroxyphenylglycol (MHPG) 77.0, vanilmandelic acid (VMA) 64.3, homovanilic acid (HVA) 71.3, 5-hydroxyindolacetic acid (5-HIAA) 20.4]. The reliability of these amounts was high, with intraclass correlation coefficients ranging from 0.43 (P < 0.001) for MHPG free form to 0.65 (P < 10(-6)) for dopamine and normetanephrine (intraindividual coefficients of variation (%): dopamine 8.5, norepinephrine 39.9, epinephrine 45.9, normetanephrine 10.3, metanephrine 46.3, MHPG 37.5, VMA 30.7, HVA 41.0, 5-HIAA 12.3).

Overnight excretion of urinary catecholamines and metabolites in the detection of pheochromocytoma

The detection and diagnosis of pheochromocytoma are highly dependent on the biochemical confirmation of excessive catecholamine release by the tumor. As the reliability of baseline plasma catecholamines in the detection of pheochromocytoma is questionable, assessment of the excretion rates of catecholamines or metabolites in 24-h urine collections remains the mainstay of initial biochemical investigation. However, diagnostic difficulties can arise from incomplete collection of 24-h specimens or equivocal increases in catecholamines due to stress. To investigate the diagnostic validity of shorter collection times for the biochemical detection of this tumor, we measured the excretion of catecholamines and metabolites after sleep, a period associated with decreased sympathetic activity. Overnight catecholamines, metanephrines, and 4-hydroxy-3-methoxymandelic acid (HMMA) levels were measured in 16 patients with histologically confirmed pheochromocytomas, 166 patients with hypertension, and 24 normotensive subjects. All measurements were performed by high performance liquid chromatography with electrochemical detection. Overnight excretion of norepinephrine in the tumor group (range, 86-1552 nmol/mmol creatinine) was significantly different (P <0.001) from that in the nontumor group (14-63 nmol/mmol creatinine). Autonomous secretion of norepinephrine was evident in all urine collections, including a patient with a predominantly epinephrine-secreting tumor. Overnight normetanephrine levels displayed a similar excretion pattern (P < 0.001), whereas overnight epinephrine and metanephrine levels were normal in 10 of the 16 patients with pheochromocytoma. In contrast, HMMA excretion in overnight urine collections was highly variable, with only 6 of the 16 patients in the tumor group having consistently elevated excretion. In the other 10 patients, overnight HMMA excretion showed a high intravariability. The measurement of catecholamines and total metanephrines after sleep is a viable approach for the exclusion of pheochromocytoma, as overnight urine collections completely differentiated patients with pheochromocytoma from hypertensive patients. Compared to 24-h results, overnight urinary norepinephrine levels provided a better diagnostic sensitivity and specificity (100% sensitivity and 98% specificity compared with 88% and 82%). Sleep urine samples simplify the collection protocol while avoiding the effects of stress and exercise.

Bilateral adrenalectomy with autotransplantation of adrenocortical tissue or unilateral adrenalectomy: treatment options for pheochromocytomas in multiple endocrine neoplasia type 2A

Surgical strategies for pheochromocytomas in patients with multiple endocrine neoplasia (MEN) type 2 syndrome have been controversial. The purpose of this study is to review the current status of patients with MEN 2 who underwent adrenalectomy with or without adrenal autotransplantation. We studied 15 patients with MEN 2A who underwent adrenal surgery between 1981 and 1992. The follow-up survey included physical examination and biochemical determinations. The median period from initial surgery to follow-up was 54 months (range, 0-145 months). Initial bilateral total adrenalectomy was performed on seven patients, and subtotal adrenalectomy was carried out on two. Among six patients who initially underwent unilateral adrenalectomy, four had remained normotensive (median follow-up, 61 months), whereas the other two patients had to undergo reoperation on the contralateral side because of recurrent symptoms. Two patients were suspected of having had a relapse of the disease after total adrenalectomy. Seven patients underwent adrenal autotransplantation; however, none of them were able to discontinue glucocorticoid replacement therapy. In MEN 2A patients having large pheochromocytomas on only one side, unilateral adrenalectomy can be a suitable alternative to bilateral adrenalectomy in terms of blood pressure control and preservation of adrenocortical function. The attempt to preserve adrenocortical function by autotransplantation is discouraged.

Changes in urinary excretion of catecholamines and their metabolites in pediatric dental patients

To explain the changes in urinary excretion of catecholamines and their metabolites in pediatric dental patients, comparative measurements of three catecholamines (dopamine, noradrenaline and adrenaline), and five metabolites (3, 4-dihydroxyphenylacetic acid, normetanephrine, metanephrine, homovanillic acid, and vanillylmandelic acid) were made before and after dental treatment. The investigations were carried out in seven healthy young children between three and five years of age. All these children had previously displayed negative behavior in dental treatment. There were statistically significant increases (P < 0.05) in urinary noradrenaline, adrenaline, and normetanephrine levels during dental treatment. These results suggest that these three substances could be a useful tool for determining the occurrence of dental stress in children.

Urinary excretion of methylated catecholamine metabolites in a child with neuroblastoma maturing into ganglioneuroma

Neuroblastomas are malignant tumors derived embryonically from the neural crest. Biological diagnosis relies on assay of urinary excretion of homovanillic acid (HVA), vanillylmandelic acid (VMA), and dopamine (DA). Spontaneous regression of these neoplasms has been reported by numerous investigators. The authors report the case of a child with neuroblastoma that illustrates the relationship between catecholamine metabolites and tumor maturation. At 1 month of age, this infant presented an adrenal neuroblastoma with multiple metastases (stage IV); the initial histological diagnosis based on examination of cutaneous metastases was neuroblastoma. At the age of 6 months, after chemotherapy, the primary tumor was resected; hepatic metastases were discovered at laparotomy. The histological diagnosis for all lesions was highly differentiated, mature ganglioneuroma-like tissue. The main biochemical abnormality at the time of diagnosis was an elevation in normetanephrine (NMN). HVA was only slightly increased but rose progressively during chemotherapy; it dropped back to normal levels after the sixth course. This case illustrates the potential benefits of separate assays of urinary methylated catecholamine metabolites for biochemical diagnosis and therapeutic management of neuroblastoma in addition to assays of HVA, VMA, and DA. Case findings suggest existence of a transformation process with maturation of the tumor involving enzymatic regulation and expression of MAO.

Simultaneous determination of catecholamines, their basic metabolites and serotonin in urine by high-performance liquid chromatography using a mixed-mode column and an eight-channel electrochemical detector

A high-performance liquid chromatographic method for simultaneous determination of free catecholamines, their basic metabolites and serotonin in human urine was developed. The compounds were separated on a precolumn of cation-exchange resin and a mixed-mode (C18/cation-exchange) column and determined by an eight-channel electrochemical detector. By this method, free norepinephrine (NE), epinephrine (E), dopamine (DA), normetanephrine (NMN), metanephrine (MN), 3-methoxy-tyramine (3-MT) and serotonin (5-HT) were determined in 40 min with inter-assay precision of 1.9, 3.2, 1.2, 1.6, 1.6, 5.5 and 3.2%, respectively. Detection limits were between 0.05 (E) and 0.3 (3-MT) pmol. The mean values of analytical recovery for NE, E, DA, NMN, MN, 3-MT, 5-HT were 99, 104, 104, 99, 102, 109 and 99%, respectively.

Pattern of elevation of urine catecholamines in intracerebral haemorrhage

Autonomic nervous system dysfunction is a common complication of severe intracranial disease. The aim of this study was to reveal the autonomic changes in patients suffering from acute intracerebral haemorrhage (ICH). 25 patients with spontaneous ICH within 24 hours of onset of symptoms were included. All patients were treated with standardised medical management and the meta- and normetanephrines were detected by high performance liquid chromatography (HPLC) in 24-hour urine every day. The mean level of normetanephrine (709 +/- 579 micrograms/day) and metanephrine (244 +/- 161 mg/day) were significantly elevated in comparison with a control group, p < or = 0.01. The norepinephrine elevation was of greater diagnostic and prognostic importance. Maximum urinary catecholamine metabolite levels occurred between day 3 to 10 after the bleeding. Normetanephrines correlated with the prognosis and the complications of ICH: intraventricular involvement resulted in significantly elevated normetanephrine levels (896 +/- 520 micrograms/day versus 311 +/- 78 micrograms/day) p < or = 0.01. Patients with a great volume of haematoma developed severe autonomic dysregulation (normetanephrines 1114 +/- 493 micrograms/day), whereas patients with smaller haematoma did not (339 +/- 125 micrograms/day) p < or = 0.0001; patients with bad outcome (1014 +/- 620 mg/day) had higher levels of normetanephrines than those with a good prognosis (322 +/- 110 micrograms/day) p < or = 0.001. A close relationship to elevated intracranial pressure was established. This study demonstrated the feasibility of detecting autonomic nervous system dysfunction in neurological intensive care patients by means of examination of the metabolites of the catecholamines in the urine.(ABSTRACT TRUNCATED AT 250 WORDS)

Urinary catecholamines in attention-deficit hyperactivity disorder with and without comorbid anxiety

OBJECTIVE

To determine whether there are differences in noradrenergic or adrenergic functioning in children with attention-deficit hyperactivity disorder (ADHD) with and without anxiety.

METHOD

ADHD children with and without a comorbid overanxious (ANX) disorder were compared to each other and to normal controls in terms of 2-hour urinary excretion of norepinephrine (NE), epinephrine (EPI), and their metabolites. All subjects performed a fixed series of mentally stressful tasks during the collection period.

RESULTS

Children with ADHD, regardless of comorbid anxiety, excreted more normetanephrine (NMN), the chief extracellular metabolite of NE, than controls, as well as more vanillylmandelic acid. Children with ADHD alone had lower NE/NMN and EPI/metanephrine ratios compared to controls. Children with ADHD/ANX excreted more EPI than ADHD children without anxiety.

CONCLUSIONS

Children with ADHD may have a higher tonic activity of the noradrenergic system than controls, while children with comorbid ADHD/ANX may be differentiated from those with ADHD alone by higher adrenergic activity.

Quantification of urinary catecholamines, their abundant metabolites, and 5-hydroxyindoleacetic acid by high performance liquid chromatography and electrochemical detection, using a single mobile phase and uniform isocratic conditions

A simple and flexible isocratic HPLC procedure was developed for the measurement of catecholamines and their abundant metabolites ( e.g. nor- metanephrine, metanephrine, methoxy-tyramine, vanillylmandelic acid, homovanillic acid) and 5-hydroxyindolacetic acid by ion-pair reversed phase chromatography on C18 columns, using a single mobile phase containing both sodium octane sulphonate and diethylamine as ion-pairing reagents.