Catecholamine excretion in young children and their parents as related to behavior

Aggressiveness and hyperactive behaviour as related to adrenaline excretion

The central question concerns the relationship between aspects of behaviour and physiological reactions. Measures of sympathetic‐adrenal activity in terms of adrenaline excretion in a normal and a stressful situation as well as teacher ratings of behaviour were analysed for a representative group of 86 boys aged 13. Adrenaline excretion was in both situations significantly negatively related to ratings of aggressiveness, motor restlessness, and concentration difficulties and also to the sum of the latter two, used as an indicator of hyperactive behaviour. The association between hyperactive behaviour and adrenaline excretion persisted in the stressful situation when aggressiveness was controlled, whereas there was no significant relationship between aggressiveness and adrenaline output when hyperactive behaviour was controlled. Furthermore, hyperactive boys differed significantly from non‐hyperactive boys in displaying lower adrenaline excretion in both situations. The results are discussed in terms of low sympathetic‐adrenal reactivity to external demands as a risk factor and as a possible indicator of vulnerability for social and/or pervasive conduct disturbances.

Plasma epinephrine levels in hypertension and across gender and ethnicity

Epinephrine (E) infusions raise blood pressure and there is an excess incidence of hypertension among males and blacks. However, reports of E levels by ethnicity, gender, and blood pressure status are inconsistent. Insensitive assays, variability in plasma E levels within individuals, and the small size of most studies have contributed to these conflicting reports. We measured plasma E levels in a large diverse sample of subjects, using a highly sensitive assay. A total of 361 individuals participated in the study: 61% were men and 39% women, 74% were normotensive and 26% hypertensive, 59% were white and 41% were black. Except for difference in blood pressure and body mass index between the normotensives and hypertensives, subjects had similar baseline characteristics and took no antihypertensive medications for at least five days prior to sampling. All blood samples were collected after resting for a least 30 minutes following the insertion of an indwelling i.v. catheter. Catecholamine levels were determined using a radioenzymatic assay (assay sensitivities for E and norepinephrine were 6 pg/ml and 10 pg/ml, respectively). An ethnicity by gender interaction was found (F(1,315) = 5.126, p = .024). Subsequent analysis revealed that white women had significantly lower basal plasma E levels than white men (p <0.001) and black women (p = 0.036). There were no significant differences in E levels between black men and women or between white men and black men. Uncorrected E levels were lower in normotensive than hypertensive subjects (p = .009) but this difference was not significant when corrected for body mass index (BMI). Uncorrected norepinephrine levels were higher in women than men (p = .03) but the difference was no longer significant when corrected for BMI. Plasma E levels were significantly lower among white women than men or black women. In contrast to prior studies, E levels were lower in hypertensives, but this may reflect obesity among hypertensives.

Adrenomedullary function during cognitive testing in attention-deficit/hyperactivity disorder

OBJECTIVE

Reported correlations between epinephrine (EPI) excretion and classroom performance, the cognition-enhancing effects of EPI infusion, increased EPI excretion with stimulants, and reports of decreased EPI excretion in attention-deficit/hyperactivity disorder (ADHD) suggest that sympathoadrenomedullary function might be altered in ADHD. This hypothesis was tested by examining sympathetic and adrenomedullary functioning during cognitive testing in boys with diagnosed ADHD.

METHOD

Urinary excretion of EPI and norepinephrine during a 3-hour cognitive test battery was assessed in 7- to 13-year-old boys. Excretion rates (nanograms per hour per square meter of body surface area) were determined in 200 individuals with ADHD (diagnosed according to DSM-IV criteria), with or without co-occurring oppositional defiant/conduct disorder or learning disorder. A non-ADHD contrast group (n = 51) with similar comorbidity was also studied.

RESULTS

Substantially lower (mean +/- SE) urinary EPI excretion was observed in the ADHD-inattentive subtype (n = 71) compared with the control group (200 +/- 22 versus 278 +/- 24 ng/hr/m2; F = 5.99, p = .015, critical alpha = .017). No diagnostic group differences were seen for norepinephrine excretion. Correlational analysis of both parent- and teacher-rated behaviors revealed that inattention factors consistently negatively predicted urinary EPI excretion.

CONCLUSIONS

The data extend findings of lower adrenomedullary activity during cognitive challenge in individuals with ADHD and suggest that the alteration is associated with inattentive behavior.

Sex-differences in catecholamine metabolites in human urine during development and at adulthood

Adrenergic amines (dopamine [DA], norepinephrine [NE], epinephrine [E] and related compounds (DOPA, 3-methoxytyramine [MT], normetanephrine [NMN], metanephrine [MN], 3-5-dihydroxyphenylacetic acid [DOPAC], vanilmandelic acid [VMA] were analyzed in urine of human from one day to 40 years of age, in view to investigate the sex influence on catecholamine metabolism during life. In neonatal life (1 day to 3.5 months), the total amounts of urinary (E + MN) and (NE + NMN + VMA) were lower in girls than in boys, the former two compounds being mainly of adrenal medullary origin and the latter three coming largely from the sympathetic neurons. In adulthood, women excreted epinephrine (12.5 +/- 2.2 micrograms/24 hours) at lower levels then men (22.8 +/- 4.5 micrograms/24 hours) but no sex related differences occurred in the total amounts of urinary E + MN and NE + NMN + VMA. It is concluded from our study that, during the neonatal life, girls exhibit a lesser adreno-sympathetic maturity than boys, but full maturation of peripheral adrenergic sites is reached near to the fifth year of age in both sexes. The role of testosterone has been discussed. In adults, the lower epinephrine levels found in women urine do not seem to result from a sex difference in the degree of adrenergic maturity, but perhaps partly from an increased rate of epinephrine inactivation by catechol-O-methyltransferase.

Catecholamine and cortisol excretion patterns in three-year-old children and their parents

Urinary catecholamine and cortisol excretion was studied in a group of three-year-olds, their mothers and fathers during night rest, one day at home and one day at hospital. The stay in the hospital, which was part of a longitudinal study of the families, induced a pronounced rise in adrenaline excretion and a moderate increase in noradrenaline excretion in relation to the at-home level. Although the catecholamine excretion in relation to body weight was much higher in the children, the magnitude of the increase at the hospital was about the same in all the family members. The adrenaline excretion was also affected by the diverse conditions at the hospital and showed, for example, a marked decrease during lunch hour. The cortisol excretion at the hospital tended to be elevated only in fathers. On the average, mothers excreted about the same amount of adrenaline as the fathers at the hospital, but significantly more noradrenaline. In earlier studies males have shown a greater adrenaline output than females during achievement-demanding situations. The findings of this study were interpreted within the context of the specific challenge that the situation represented to the mothers. The mothers also excreted more noradrenaline in the at-home condition. Catecholamine and cortisol excretion levels within family members tended to be positively correlated, but the correlations were generally low.

Sex differences in sympathetic-adrenal medullary reactions induced by different stressors

Male and female university students were exposed to two different stressors in each of two 110-min sessions, i.e., a cognitive task (color-word conflict) and repeated venipuncture. Catecholamine excretion, heart rate, and subjective reactions were measured. Control values were obtained under conditions of relaxation in the laboratory. Subjects of both sexes responded to both stressors by increased heart rate and feelings of unpleasantness and distress. The pattern of adrenaline excretion, however, differed between sexes: in males both stressors induced a significant increase, whereas in females adrenaline excretion remained on the same level under the two stress conditions as during relaxation; Noradrenaline excretion was not systematically affected by either stressor in either sex group.