Age and gender effects on the diagnostic power of the DST

Simultaneous assay of cortisol and dexamethasone improved diagnostic accuracy of the dexamethasone suppression test

OBJECTIVES

The overnight dexamethasone (DXM) suppression test (DST) has high sensitivity, but moderate specificity, for diagnosing hypercortisolism. We have evaluated if simultaneous measurement of S-DXM may correct for variable DXM bioavailability and increase the diagnostic performance of DST, and if saliva (sa) is a feasible adjunct or alternative to serum.

DESIGN AND METHODS

Prospective study of DST was carried out in patients with suspected Cushing's syndrome (CS) (n = 49), incidentaloma (n = 152) and healthy controls (n = 101). Cortisol, cortisone and DXM were assayed by liquid chromatography-tandem mass spectrometry (LC-MS/MS).

RESULTS

Three hundred and two subjects underwent DST; S-cortisol was ≥50 nmol/L in 83 patients, of whom 11 had CS and 27 had autonomous cortisol secretion. The lower 2.5 percentile of S-DXM in subjects with negative DST (n = 208) was 3.3 nmol/L, which was selected as the DXM cut-off level. Nine patients had the combination of low S-DXM and positive DST. Of these, three had been misdiagnosed as having autonomous cortisol secretion. DST results were highly reproducible and confirmed in a replication cohort (n = 58). Patients with overt CS had significantly elevated post-DST sa-cortisol and sa-cortisone levels compared with controls; 23 of 25 with autonomous cortisol secretion had elevated sa-cortisone and 14 had elevated sa-cortisol.

CONCLUSIONS

Simultaneous measurement of serum DXM and cortisol reduced false-positive DSTs by 20% and improved the specificity. S-DXM >3.3 nmol/L is sufficient for the suppression of cortisol <50 nmol/L. Measurement of glucocorticoids in saliva is a non-invasive and easy procedure and post-DST sa-cortisone was found particularly useful in the diagnosis of CS.

Daily life events influence the results of the Dexamethasone Suppression Test in healthy women

Although the Dexamethasone Suppression Test (DST) plays an important role in psychosomatic research, confounding factors limit the sensitivity and specificity of the DST. The aim of this study was to investigate the relationship between the intensity of daily life stressors and DST results in healthy participants after controlling the confounding factors. The subjects of this study consisted of 75 healthy volunteers. The intensity of daily life events was assessed using the Taiwanese version of the Recent Life Change Questionnaire (RLCQ). Neuroticism was assessed using the Maudsley Personality Inventory (MPI). The Dexamethasone Suppression Test (DST) was also performed. The regression model showed that daily life events (RLCQ score) were correlated significantly with cortisol level on day 1 and D% only in women. This finding implies that daily life events should be considered as an independent variable in women in further studies when the DST is applied.

HPA axis hyperactivity and attempted suicide in young adult mood disorder inpatients

BACKGROUND

Hyperactivity of the Hypothalamic-Pituitary-Adrenal (HPA) axis is a consistent finding in Major Depressive Disorder (MDD) and most prospective studies of HPA-axis function have found that non-suppressors in the dexamethasone suppression test (DST) are more likely to commit suicide during follow-up. The results of studies on HPA-axis function and attempted suicide are less consistent. Suicide attempts are more common among young people than the elderly, whereas suicide is more common among the elderly. The impact of age related changes in HPA-axis system activity in relation to suicidal behaviour across the lifecycle may be of importance.

METHODS

The aim of the present study was to investigate the DST results in 36 young adult (30 years or younger) inpatients with mood disorder, with (n=18) and without suicide attempt at the index episode.

RESULTS

The DST non-suppressor rate was 25% among young mood disorder inpatients. DST non-suppression was associated with suicide attempt and post-dexamethasone serum cortisol at 11:00 p.m. was significantly higher in suicide attempters compared to non-attempters. The DST non-suppressor rate was 39% in young adult suicide attempters compared with 11% in non-attempters.

CONCLUSIONS

The results add to previous evidence in support of the role of HPA axis hyperactivity and suicidal behaviour. The present findings motivate to include HPA axis measures in the assessment of depression in young adults.

Basal hypothalamo-pituitary-adrenal axis activity and corticotropin feedback in young and older men: relationships to magnetic resonance imaging-derived hippocampus and cingulate gyrus volumes

Alterations in basal cortisol secretion and feedback sensitivity are reported in aging. However, it is not known whether these hypothalamus-pituitary-adrenal (HPA) axis alterations are related to structural brain changes. This study was designed to investigate these relationships in the human. Nine young (24.0 +/- 1.2 years; mean +/- SE; range: 19-30) and 11 older (69.0 +/- 1.8 years; range: 59-76) men, in addition to having standardized magnetic resonance imaging of their brains, were given 0.5 mg/kg cortisol or placebo intravenously in a double-blind, crossover study. As expected, older men had significantly smaller volumes for all brain regions. Although the groups did not differ in baseline HPA axis activity, there were significant and specific relationships between the brain volumes and the baseline measures of HPA activity. Namely, for young and older subjects combined and after controlling for age and cerebral vault size, hippocampal volumes were inversely associated with 24-hour urinary cortisol and basal corticotropin (ACTH) levels, and the anterior cingulate gyrus volume was negatively correlated with baseline ACTH. Elderly subjects had a slower decrease in ACTH levels (percent of baseline level) during the first 30 min after cortisol administration. However, no associations were observed between the ACTH feedback indices and any brain measure. This report, although based on a small number of subjects, supports previous studies showing a blunted ACTH fast feedback during normal aging. Hippocampal atrophy appears to be related to increased basal measures of HPA axis activity, but not to fast ACTH feedback. It remains possible that age-associated changes in fast feedback may be related to changes to other brain sites, such as hypothalamus or pituitary.

The dexamethasone suppression test and sleep electroencephalogram in nonbipolar major depressed inpatients: a multivariate analysis

BACKGROUND

The present study further examined relationships between postdexamethasone cortisol plasma values and sleep electroencephalogram (EEG) parameters.

METHODS

The dexamethasone suppression test (DST) and polysomnographic recordings were performed in a sample of 300 inpatients with primary major depressive disorder (MDD) (102 men and 198 women, mean age 44 +/- 12 years, range 20-74 years) consecutively admitted to Erasme Hospital (Brussels, Belgium) between 1981 and 1992.

RESULTS

The DST was abnormal in 40% of the sample. Postdexamethasone cortisol plasma values at 4:00 PM were significantly influenced by age, but not by gender. They were also significantly and positively correlated with weight loss, total scores on the Hamilton Depression Rating Scale, total scores on the Newcastle Scale, percentage of awakenings during sleep, and percent of stage 1. They were significantly and negatively correlated with percent of stage 2, slow-wave sleep, and REM sleep. Multiple regression analyses were conducted in two successive steps. First among clinical variables, only age and depressive symptom severity remained correlated with postdexamethasone plasma cortisol values. In the second step, with age and severity held constant, postdexamethasone plasma cortisol values were positively associated with amount of wake time and stage 1, and negatively with amount of slow-wave sleep.

CONCLUSIONS

These findings provide further indirect support for an overarousal state in MDD with sympathoadrenal system hyperactivity and impaired sleep continuity. They also underline the importance of taking into account various clinical confounding factors in the interpretation of both DST and sleep EEG results.

Cortisol suppression by dexamethasone in the healthy elderly: effects of age, dexamethasone levels, and cognitive function

The effects of age, cognitive function (measured by Cambridge cognitive examination (CAM-COG) score); and dexamethasone (DEX) levels on the dexamethasone suppression test were studied in 33 healthy older subjects (age 51-96). Three subjects (9.1%) were nonsuppressors and were older and had lower CAMCOG scores than the 30 suppressors. Significant correlations were observed between natural log-transformed postdexamethasone cortisol (LNCOR) levels and age (r = 0.40) and CAMCOG score (r = -0.45). Multiple regression analysis was used to investigate the relationship between LNCOR, age, DEX levels, and CAMCOG score. Age and DEX combined explained 41% of the variance in LNCOR values, whereas CAMCOG score and DEX levels explained 44% variance. As age and CAMCOG were highly correlated (r = -0.72), both together did not significantly improve the fit of regression equation (47% variance explained). These findings suggest an association between advancing age, impaired glucocorticoid feedback, and cognitive dysfunction in healthy human subjects. Although any causal connection remains to be demonstrated, results would be consistent with the "glucocorticoid cascade" hypothesis of human aging.

Biological markers as classifiers for depression: a multivariate study

1. Delta TSH, REM latency, 4 pm and 11 pm post-dexamethasone cortisol values were determined after a wash-out period in a group of 74 non-selected depressed patients who were diagnosed (according to RDC with the SADS) as follows: 46 definite and 10 probable MD, 4 minor and 14 intermittent depression. 2. These biological variables, as well as gender, age and basal TSH were introduced in a principal component analysis. The four first PC scores explaining up to 77% of the data set were further calculated for each patients and used in a cluster analysis. A three clusters solution was retained. 3. DST escape and increased TSH response to TRH each identified subgroups of depressed patients. Conversely, blunted TSH response or REM latency were inefficient to classify patients. 4. Thus, HPA hyperactivity characterized CL-I patients (n = 29). These were more severely depressed, displayed more endogenous features and were reported as being more anxious. 5. Increased TSH response to TRH identified CL-III, exclusively composed of female patients (n = 10) that displayed more apparent sadness and tended to be older. 6. In CL-II, the usual sex-ratio for depressive illness was reversed and patients (n = 35) exhibited the least HPA axis disturbances and the same rate of blunted TSH response than in CL-I. They were also less severely depressed, displayed less endogenous characteristics and were rated as more mood reactive. 7. These results suggest heterogeneity in biological disturbances in depression and further stress the importance for controlling age, gender and severity of illness in studies investigating biological markers in depression.

Inhibition of the pituitary-adrenal axis with dexamethasone and cortisol in depressed patients and healthy subjects: a dose-response study

Different doses dexamethasone (0.25, 0.5, and 1 mg) or cortisol (30, 60, and 120 mg) were administered PO at 2230h to 39 depressed patients and 20 healthy subjects on nonsuccessive days. The inhibiting capacity of the two steroids on hypothalamo-pituitary axis (HPA) function was evaluated by measuring the plasma levels of cortisol, ACTH, and beta-endorphin at 0900h and 1530h each day following treatment. Baseline levels of the hormones were measured before starting treatment. A dose-dependent suppressive effect of both steroids on the plasma levels of cortisol, ACTH, and beta-endorphin was found both in patients and controls, except for the 0900h levels of cortisol after cortisol treatment. The effects were most profound in the morning. Differences between patients and controls were observed after cortisol treatment, but not dexamethasone, with respect to cortisol, ACTH, and beta-endorphin plasma levels in the morning. Cortisol treatment discriminated dexamethasone nonsuppressors from suppressors (patients and controls) and patients categorized as dexamethasone suppressors from controls in a way that dexamethasone treatment could not. The data favour the idea of impaired corticosteroid feedback beyond the pituitary level as part of HPA dysfunction.

Stimulation of the pituitary-adrenal axis with a low dose [Arg8]-vasopressin in depressed patients and healthy subjects

Graded doses arginine-vasopressin (AVP) were administered to depressed patients and control subjects to compare the sensitivity of the pituitary-adrenal system of these subjects for this compound. The plasma levels of cortisol, adrenocorticotropic hormone (ACTH) and beta-endorphin were measured before and after intravenous AVP injection. The hormonal output was taken as a measure of pituitary-adrenal function. In control subjects 3 doses AVP and placebo were used, whereas in patients two doses AVP, a low and a high dose, and placebo were tested. All tests were carried out in the afternoon when the pituitary-adrenal system is stable and more susceptible for stimulation. Patients were subdivided into dexamethasone suppressors and nonsuppressors based on their DST status before testing to look for differences among these groups. Control subjects showed no response of the hormones to the lowest dose AVP and a moderate response to the higher doses. Interestingly, depressed patients as compared to controls responded more to the lowest dose AVP in particular with respect to ACTH. DST status did not influence the results. These findings suggest an enhanced sensitivity of the pituitary to low doses AVP in depressed patients. Thus, AVP might play a role in HPA dysfunction in depression.

Nocturnal cortisol, thyroid stimulating hormone, and growth hormone secretory profiles in depressed adolescents

Twelve depressed adolescents and 12 controls matched for age, sex, Tanner stage, time of menstrual cycle (females), weight, and time of year assessed were studied over 3 nights. Measurements for cortisol, thyroid stimulating hormone, and growth hormone were made on serum collected at 10 P.M., 12 midnight, 1 A.M., 2 A.M., 3 A.M., 4 A.M., and 6 A.M. in eight pairs and every 20 minutes from 8 P.M. to 7 A.M. in four pairs. Cortisol secretion did not significantly differentiate the groups. Thyroid stimulating hormone secretion was significantly elevated in the depressed group at one time point. Growth hormone secretion significantly differentiated the two groups at most time points, and the depressed adolescents significantly hypersecreted growth hormone (area under the curve). Implications for the diagnosis, etiology, and treatment of adolescent depression are discussed.

The effect of age on cortisol and plasma dexamethasone concentrations in depressed patients and controls

The aim of this study was to identify any relationships between various patient factors such as age, gender and concurrent medication that may affect plasma cortisol or dexamethasone (DEX) concentrations. Multiple regression analysis was used to formulate an equation to predict plasma DEX levels to identify factors that may influence DEX bioavailability. Pre- and post-DST cortisol levels did not increase with age, but DEX levels were higher in elderly depressed patients. Neither gender nor psychotropic medication affected plasma cortisol or DEX levels. There was no indication that pre-DST cortisol levels influenced plasma DEX levels to account for the lower DEX values in non-suppressors. Age was the only significant factor found in this study to influence DEX levels and it could be argued that the dose of DEX should be lowered when administering the DST to elderly patients to reduce plasma DEX variability.

Cortisol secretion in adolescents with major depressive disorder

Plasma cortisol concentrations were determined every 20 min for 24 h, in a nonstressful environment, among 48 rigorously assessed, mostly outpatient, drug-free adolescent subjects during an episode of major depression (MDD) and among 40 normal adolescent subjects. There were no significant differences in the 24-h mean, peak, or nadir, or the time of the nocturnal rise, in plasma cortisol in the 2 groups. Analyses of different subgroups of MDD adolescents according to suicidality, severity of depression, separation anxiety, psychotic subtype, endogenicity, duration of episode, and sex also revealed no significant group differences. Only one adolescent (with MDD) was identified clearly as a hypersecretor of cortisol. These results indicate that abnormalities of spontaneous cortisol secretion are an unusual finding among adolescents with major depression when studied in a nonstressful environment.

[Relationship between dexamethasone suppression test and contingent negative variation in major depressive patients]

We tried to relate two different indexes sensitive to the perturbations induced by major depression: the Dexamethasone Suppression Test or DST (Caroll, 1982) and the Contingent Negative Variation (CNV). The question was whether abnormalities in cortisol levels, following dexamethasone would enlight the modifications observed in CNV parameters and other electrophysiological indexes (EEG spectrum, reaction time). In 61 major depressive patients, 29 being DST-non-suppressors, we calculated differences in electrophysiological variables according to DST suppression or not, but we were not able to evidence significant differences between the groups. However, there were correlations between log-transformed levels of cortisol and on the one hand, CNV slope (r = -0.34, P less than 0.03) and on the other hand, reaction time (r = 0.45, P less than 0.01). Correlations between electrophysiological variables appeared in the sole suppressors group (e.g. CNV amplitude and alpha rythm reactivity; post-imperative variation and percent beta of the EEG spectrum). These results underline the complementary aspect of the two methods.