Mean Cortisol Concentrations Research Articles

Comparison of VIDAS and Radioimmunoassay Methods for Measurement of Cortisol Concentration in Bovine Serum

Radioimmunoassay (RIA) is the “gold standard” method for evaluation of serum cortisol concentration. The VIDAS cortisol test is an enzyme-linked fluorescent assay designed for the MiniVidas system. The aim of this study was to compare the VIDAS method with RIA for measurement of bovine serum cortisol concentration. Cortisol concentrations were evaluated in 40 cows using both VIDAS and RIA methods, the latter as the reference method. A paired Student's t-test, Pearson's correlation analysis, Bland-Altman plot, and Deming regression analysis were used to compare the two methods. There was no statistically significant difference between mean serum cortisol concentrations measured by VIDAS or RIA methods (P = 0.6570). Both methods were able to detect significant differences in mean low and high cortisol concentrations (P < 0.00014 RIA and P < 0.0016 VIDAS). The correlation coefficient was low, but a Bland-Altman plot and Deming regression analysis show neither constant nor proportional error. The VIDAS method produced slightly higher values than RIA, but the difference was small and in no case did the mean value move the normal range. Results suggest that VIDAS method is suitable for the determination of bovine serum cortisol concentration in studies of large numbers of animals.

Haematology and serum biochemistry of adult free-ranging mountain brushtail possums (Trichosurus cunninghami), including correlations with season, sex, age, habitat type and disease status

For many wildlife species only limited data are available on haematology and blood biochemistry for free-ranging populations because these are often difficult to obtain. We collected blood samples from wild adult mountain brushtail possums (Trichosurus cunninghami) in the Strathbogie Ranges, Victoria (Australia), over two years, to provide reference values for haematological and some serum biochemical parameters (serum protein, sodium, chloride, potassium, urea, creatinine, creatine kinase and cortisol) for free-ranging animals. We also investigated patterns associated with sex, season, age, habitat type and disease status, including a form of skin disease (rumpwear – one of the major diseases of brushtail possums) and parasite loads. Values for several blood parameters correlated with sex, and most also changed significantly with season. Eosinophil counts increased significantly with the number of strongyle eggs in faeces, and packed cell volume decreased significantly with increasing numbers of ticks. Surprisingly, there was a significant negative relationship between mean population serum cortisol concentrations and the prevalence of rumpwear. Serum sodium and chloride concentrations were significantly lower in possums with moderate to severe rumpwear; however, the biological significance of this is unclear. While there is a growing body of data on the blood parameters of marsupials, these are mainly derived from captive animals, or single sample sets from wild populations, thus are unlikely to accurately reflect the changing status of wild animals/populations across seasons and under varying environmental conditions and parasite loads. More comprehensive, longer-term data from free-ranging marsupial populations, such as those presented here, provide extremely important reference data to aid in determining the health status of wild populations and interpreting data collected from individuals.

Hair cortisol levels determined at different body sites in the New Zealand White rabbit

This study was designed to determine hair cortisol levels in the New Zealand White (NZW) rabbit and to examine possible differences in the cortisol levels of hair samples collected from different body regions in stable environmental conditions. The experiment was performed on eight 18 month-old female NZW rabbits. All animals were shaved to collect hair samples from 26 different body regions. Hair cortisol levels were determined by the RIA method. The mean hair cortisol concentration for the 26 samples in the 8 animals was 2.12±0.05 pg/mg (mean±standard error). This study reveals individual hair cortisol distributions in the 8 animals (P&lt;0.001) and no statistical differences (P&gt;0.05) in hair cortisol levels among the different body sites in each of the animals.

Endocrine (plasma cortisol and glucose) and behavioral (locomotor and self-feeding activity) circadian rhythms in Senegalese sole (Solea senegalensis Kaup 1858) exposed to light/dark cycles or constant light

The existence of daily rhythms under light/dark (LD) cycles in plasma cortisol, blood glucose and locomotor and self-feeding activities, as well as their persistence (circadian nature) under constant light (LL), was investigated in Senegalese sole (Solea senegalensis). For the cortisol and glucose rhythms study, 48 soles were equally distributed in 8 tanks and exposed to a 12:12 LD cycle and natural water temperature (experiment 1). After an acclimation period, blood was sampled every 3h until a 24-h cycle was completed. Blood glucose levels were measured immediately after sampling, while plasma cortisol was measured later by ELISA. In experiment 2, the fish were exposed to LL for 11days, and after this period, the same sampling procedure was repeated. For the study of locomotor and self-feeding rhythms (experiment 3), two groups of sole were used: one exposed to LD and the other to LL. Each group was distributed within 3 tanks equipped with infrared photocells for the record of locomotor activity, and self-feeders for feeding behavior characterization. The results revealed a marked oscillation in cortisol concentrations during the daily cycle under LD, with a peak (35.65±3.14ng/ml) in the afternoon (15:00h) and very low levels during the night (5.30±1.09ng/ml). This cortisol rhythm persisted under LL conditions, with lower values (mean cortisol concentration=7.12±1.11ng/ml) and with the peak shifted by 3h. Both rhythms were confirmed by COSINOR analysis (p<0.05). The synchronizing role of temperature and feeding schedule, in addition to light, is also discussed. Diel rhythms of glucose were not evident in LD or LL. As to locomotor and self-feeding activity, a very marked rhythm was observed under LD, with higher activity observed during the night, with acrophases located at 2:14 and 3:37h, respectively. The statistical significance of daily rhythms was confirmed by COSINOR analysis. Under LL, both feeding and locomotor rhythms persisted, with an endogenous period (τ) around 22.5h. In short, our findings described for the first time the existence of circadian cortisol and behavioral circadian rhythms in flat fish. Such results revealed the importance of taking into account the time of day when assessing stress responses and evaluating physiological indicators of stress in fish.

Cortisol reactions to a social evaluative paradigm in 5- and 6-year-old children

The goal of the present study was to develop a stress paradigm to elicit cortisol secretory responses in a group of 5- and 6-year-old children as a whole. To this end, we tested a paradigm containing elements of social evaluative threat, unpredictability and uncontrollability, and with a duration of 20 min. The Children's Reactions to Evaluation Stress Test is composed of three short tasks that children have to perform in front of a judge. The tasks are rigged so as to provoke (partial) failure in the child's performance. Participants were 42 children (M = 68.0 months, SD = 4.3). Six saliva samples were taken during the testing session to obtain cortisol measurements of baseline concentrations, stress reactivity, and recovery. Our findings showed that this paradigm was effective in provoking a significant increase in salivary cortisol concentration in the group as a whole, with no effects of possible confounders (child's sex, age or school, parental educational level, time of testing, sex of experimenter, and sex of judge). The mean cortisol concentration increase for the group was 127.5% (SD = 190.9); 61% of the children could be classified as reactors (mean increase of 214%, SD = 201.5), and 39% as non-reactors (mean decrease of 7.8%, SD = 16.8). To our knowledge, this is the first study in this age group that shows a significant cortisol response for the group as a whole to a standardized laboratory paradigm. As such, this paradigm is a promising tool to be used in future research on early life interactions between physiology and psychology.

Relationship of stimulated whole saliva cortisol level with the severity of a feeling of dry mouth in menopausal women

To evaluate the relationship of stimulated whole saliva cortisol level with the severity of a feeling of dry mouth (DM) in menopausal women. A feel of DM is a major complaint for many elderly individuals and strongly associated with the menopause. The exact mechanisms that mediate sensation of DM in menopausal women have not been firmly established. A case-control study was carried out on 104 selected menopausal women with/without a feeling of DM, conducted at the Clinic of Oral Medicine, Tehran University of Medical Sciences. Xerostomia Inventory (XI) score was used as an index of DM severity. Stimulated whole saliva cortisol concentration (stimulated by chewing standard-sized paraffin for 60 s) was measured by ELISA. Statistical analysis by Student's t-test and Spearman correlation was used. The mean cortisol concentration of saliva, but not saliva cortisol output, was significantly higher in the cases than in the controls. There was significant positive correlation between XI score and concentration (r = 0.357, p = 0.000) or output (r = 0.223, p = 0.017) of stimulated whole saliva cortisol. It appears that stimulated whole saliva cortisol is high in menopausal women with a feeling of DM.

Daily endogenous cortisol production and hydrocortisone pharmacokinetics in adult horses and neonatal foals

To compare daily endogenous cortisol production rate and the pharmacokinetics of an i.v. bolus of hydrocortisone between neonatal foals and adult horses. 10 healthy full-term 2- to 4-day-old foals and 7 healthy adult horses. Blood samples were collected from each horse every 15 to 20 minutes for 24 hours for determination of 24-hour mean cortisol concentration. Afterward, dexamethasone (0.08 mg/kg) was administered i.v. to suppress endogenous cortisol production. Twelve hours afterward, hydrocortisone sodium succinate (1.0 mg/kg) was administered as a rapid i.v. bolus and serial blood samples were collected to determine hydrocortisone pharmacokinetics. Cortisol concentrations, daily cortisol production rate, and hydrocortisone pharmacokinetics were determined, and results were compared between adult horses and foals. The mean ± SD 24-hour cortisol concentration was significantly lower in foals (20 ± 4 ng/mL) than in horses (26 ± 6 ng/mL), but the daily cortisol production rate was significantly greater in foals (6,710 ± 320 ng/kg/d) than in horses (2,140 ± 400 ng/kg/d). For hydrocortisone, foals had a significantly greater volume of distribution at steady state (1.92 ± 1.11 L/kg) and total body clearance (1.39 ± 0.108 L/kg/h) and significantly lower peak plasma concentration (1,051 ± 343 ng/mL) than did horses (0.58 ± 0.15 L/kg, 0.349 ± 0.065 L/kg/h, and 8,934 ± 3,843 ng/mL, respectively). Important differences were detected in cortisol production and metabolism between neonatal foals and adult horses consistent with lower plasma protein binding of cortisol in foals. This decrease may contribute to cortisol insufficiency during prolonged critical illness in neonatal foals.

Influence of Treatment for Disruptive Behavior Disorders on Adrenal and Gonadal Hormones in Youth

The study examined whether psychosocial intervention for children diagnosed with a disruptive behavior disorder (DBD; n = 84) changed concentrations of cortisol and testosterone across a 3-year follow-up when compared to a matched, nonclinical, healthy comparison (HC; n = 69) group. Boys and girls (6–11 years) with a DBD were randomly assigned to one of two arms of a multimethod intervention. Hierarchical linear modeling revealed that children undergoing psychosocial intervention for a DBD experienced a significant decline in diurnal cortisol change over time (p < .05) when compared to the HC condition. Boys with a DBD diagnosis had significantly lower mean cortisol concentrations prior to treatment (p < .05) and showed a significantly steeper increase in mean cortisol over time (p < .05) when compared to HC boys. Treatment effects for diurnal cortisol change were replicated in the boys-only analysis. No treatment effects were noted for testosterone in either analysis.

Diurnal cortisol rhythms in Tsimane’ Amazonian foragers: New insights into ecological HPA axis research

Although a growing body of research has documented important pathways by which the HPA axis mediates the interface between the psychosocial world and individual health, there is a paucity of data from nonwestern populations, particularly from those populations with distinct nutritional and infectious disease ecologies. The specific objectives of this study are: (1) to document variation in diurnal cortisol rhythms among the Tsimane', a remote population in the Bolivian Amazon, (2) to explore this variation by age and by gender, and (3) to compare diurnal rhythms from this study to other population based studies of cortisol conducted in industrialized nations. Salivary cortisol samples were collected twice daily, immediately upon waking and before bed, for three consecutive days from 303 participants (age 1.6-82 years, 1564 samples) in conjunction with the Tsimane' Amazonian Panel Study (TAPS). Cortisol rhythms showed strong age effects across the developmental span, with basal levels and slopes increasing into adulthood, although individuals older than 60 years demonstrated a precipitous flattening of the diurnal slope. Cortisol profiles were elevated in adult females compared to their age-matched male counterparts, and diurnal slopes, as well as mean cortisol concentrations among the Tsimane' were the lowest reported in any population based study of HPA axis function. Although the within-population variation in cortisol profiles was consistent with the established correlates of time of day, age, and sex, the between-population comparisons revealed dramatically lower levels of HPA activity among the Tsimane'. This study provides a benchmark against which to reference cortisol levels from industrialized populations, and expands the range of documented variation in HPA axis function in a nonwestern context.

Relationship of unstimulated saliva cortisol level with severity of oral dryness feeling in menopausal women

Menopause may be associated with some adverse changes, such as oral dryness (OD) feeling. The exact mechanisms that mediate sensation of OD in menopausal women have not been firmly established. The purpose of this study was to assess the relationship of unstimulated whole saliva cortisol level with severity of OD feeling in menopausal women. A case control study was carried out on 70 selected menopausal women with/without OD feeling, conducted at the Clinic of Oral Medicine, Tehran University of Medical Sciences, Iran. The xerostomia inventory (XI) score was used as an index of OD feeling severity. Unstimulated whole saliva cortisol concentration was measured by ELISA. Statistical analysis of student's t-test and Spearman correlation was used. The mean cortisol concentration of saliva was significantly higher in women with OD feeling than the control. There was significant positive correlation between the XI score and the concentration of unstimulated whole saliva cortisol (r = 0.559, p = 0.025). Unstimulated whole saliva cortisol is higher in menopausal women with OD feeling than in controls and this correlates with the severity of OD.

Exercise affects both ovarian follicular dynamics and hormone concentrations in mares

The objectives were to evaluate the effects of exercise on ovarian folliculogenesis and related hormones in mares. Mares (n = 11) were randomly assigned into a control (non-exercised) or treatment (exercised) group. Treatment mares (n = 5) were moderately exercised for 30 min, 6 d/wk. All mares underwent daily transrectal ultrasonographic examinations and ovarian follicles > 6 mm were measured. Blood samples were collected during the first (Cycle 1) and last (Cycle 4) cycle, and serum concentrations of cortisol, LH, and FSH were determined. Mean cortisol concentrations were elevated (P < 0.05) in exercised mares, 6.29 ± 0.22 compared with 5.62 ± 0.16 ng/dL (mean ± SEM), 30 min post exercise. There were no significant differences between groups in mean FSH concentrations; however, exercised mares had lower (17.3 ± 6.4 vs 41.1 ± 5.5 ng/mL; P < 0.05) peak LH concentrations. Furthermore, exercised mares experienced a longer (24.7 ± 0.8 vs 22.2 ± 0.8 d; P < 0.05) mean interovulatory interval for all cycles combined, fewer (P < 0.05) follicles 6 to 20 mm in diameter, and an increased (P < 0.05) number of follicles >20 mm following deviation. The dominant and largest subordinate follicle in exercised mares had a greater (P < 0.05) mean diameter on the day of deviation, suggesting delayed deviation. Exercised mares also tended (P = 0.06) to have an increased number of cycles with at least two dominant follicles compared to control (62 vs 36%, respectively), indicating a decreased ability of the largest follicle to assert dominance. Under the conditions of this study, moderately exercising mares induced higher cortisol concentrations, lowered peak LH concentrations, and altered ovarian follicular dynamics.

Impaired Prednisolone Sensitivities of the Endocrine System and Peripheral-blood Lymphocytes are Closely Related to Clinical Incidence in Renal Transplantation

Endocrine- and immune-responses to prednisolone and their relation to clinical incidence were assessed in 19 renal transplant recipients. All of the patients were treated with prednisolone and cyclosporin. Response of the hypothalamic-pituitary-adrenal (HPA) system to prednisolone was evaluated by measuring serum cortisol concentration. Cortisol concentration before transplantation was 126.7 +/- 38.6 ng mL-1, while it decreased to 4.1 +/- 2.5 ng mL-1 within the period characterized by a cumulative dose of prednisolone from 300 to 700 mg. A statistically significant high incidence (P less than 0.01) of acute rejections was observed in low HPA responders; (mean cortisol concentration during prednisolone treatment exceeded 3.0 ng mL-1), 6 of 12 with a low HPA response to prednisolone showed signs of rejection, while none of the 7 with a high HPA response showed signs of rejection. The concentrations of prednisolone suppressing the in-vitro response of pretransplant lymphocytes to concanavalin A by 50% (ID50) were determined. Lymphocytes from 8 patients were extremely insensitive (ID50 greater than 500 ng mL-1), and 5 of the 8 showed signs of rejection. Lymphocytes from the other 11 patients showed high sensitivity (ID50 less than 500 ng mL-1), and only one of those showed signs of rejection. Thus, a significantly high incidence of rejection was observed in low lymphocyte-responders to prednisolone (P less than 0.05). The results suggest that an insensitive endocrine response to prednisolone correlates with an impaired lymphocyte response to the steroid, and that both of the indices are related to occurrence of rejection. Evaluation of these pharmacodynamic parameters in combination may serve as a guideline for successful immunosuppressive therapy in renal transplantation.

A Longitudinal Study of Plasma and Urinary Cortisol in Pregnancy and Postpartum

There is a paucity of longitudinal data on plasma and urinary cortisol levels during pregnancy using modern assays. Furthermore, conflicting data exist as to the effect of the low-dose oral contraceptive pill (OCP) on cortisol. DESIGN, SUBJECTS, AND MEASUREMENTS: We conducted a prospective longitudinal study on morning plasma cortisol (total and free), corticosteroid-binding globulin (CBG), and 24-h urinary free cortisol (UFC) levels in 20 pregnant women during the first, second, and third trimesters and 2-3 months postpartum compared with 12 subjects on low-dose OCP and 15 nonpregnant subjects not taking the OCP (control group). A progressive rise in total plasma cortisol, CBG, and 24-h UFC was demonstrated during pregnancy, peaking during the third trimester (mean 3-fold rise compared with controls). Plasma free cortisol increased 1.6-fold by the third trimester. In the OCP group, total plasma cortisol and CBG were 2.9- and 2.6-fold elevated, respectively, whereas 24-h UFC and plasma free cortisol were not significantly different from controls. Compared with liquid chromatography-mass spectrometry, a commercial immunoassay underestimated mean total plasma cortisol concentrations by 30% during second and third trimesters and in OCP users and overestimated UFC levels by 30-35% during pregnancy. Our study demonstrated elevations in total plasma cortisol and CBG concentrations during pregnancy and with low-dose OCP use. Pregnancy was also associated with significant increases in plasma free cortisol and UFC, suggesting that the rise in total plasma cortisol is contributed to by up-regulation of the maternal hypothalamic-pituitary-adrenal axis in addition to elevated CBG.

Cortisol levels in hair of East Greenland polar bears

To demonstrate the ability to assess long-term hypothalamic–pituitary–adrenocortical (HPA) axis activity in polar bears ( Ursus maritimus), a pilot study was conducted in which cortisol concentrations was analyzed in hair from 7 female (3–19 years) and 10 male (6–19 years) East Greenland polar bears sampled in 1994–2006. The hair was chosen as matrix as it is non-invasive, seasonally harmonized, and has been validated as an index of long-term changes in cortisol levels. The samples were categorized according to contamination: eight were clean (2 females, 6 males), 5 had been contaminated with bear blood (2 F, 3 M), and 4 with bear fat (3 F, 1 M). There was no significant difference in cortisol concentration between the three categories after external contamination was removed. However, contaminated hair samples should be cleaned before cortisol determination. Average hair cortisol concentration was 8.90 pg/mg (range: 5.5 to 16.4 pg/mg). There was no significant correlation between cortisol concentration and age (p = 0.81) or sampling year (p = 0.11). However, females had higher mean cortisol concentration than males (females mean: 11.0 pg/mg, males: 7.3 pg/mg; p = 0.01). The study showed that polar bear hair contains measurable amounts of cortisol and that cortisol in hair may be used in studies of long-term stress in polar bears.

Overnight variations in IL-6 in synovial fluid and plasma in patients with active rheumatoid arthritis

Aim: To investigate for the first time overnight variations in absolute values and patterns of synovial fluid IL-6, and other proinflammatory cytokines including IL-1β and TNF, and to relate them to blood concentrations of cytokines and cortisol in rheumatoid arthritis. Patients & methods: Six people with active rheumatoid arthritis and large knee effusions who had received no recent glucocorticoids were admitted overnight. Blood and synovial fluid samples were obtained at 13 time points between 21:00 and 10:00. Results: The geometric mean synovial fluid IL-6 concentration increased significantly from 1483 pg/ml at 21:00 to 5084 pg/ml at 08:00 (repeated measures ANOVA p < 0.001). The geometric mean plasma IL-6 and cortisol concentrations increased significantly overnight. In a random coefficient model including data from all participants, the estimated mean synovial fluid IL-6 value began to rise approximately 6 h before the estimated mean plasma IL-6, which in turn began to rise approximately 3 h before ...

Characteristics of temporal patterns of cortisol and luteinizing hormone in primiparous, postpartum, anovular, suckled, beef cows exposed acutely to bulls

BackgroundThe physiological mechanism by which bulls stimulate resumption of ovarian cycling activity in postpartum, anovular, suckled cows after calving may involve the concurrent activation of the hypothalamic-hypophyseal-ovarian (HPO) axis and hypothalamic-hypophyseal-adrenal (HPA) axis. Thus, the objectives of this experiment were to determine if characteristics of temporal patterns of cortisol and luteinizing hormone (LH) in postpartum, anovular, beef cows are influenced by acute exposure to bulls. The null hypotheses were that daily, temporal characteristics of cortisol and LH concentration patterns do not differ between cows exposed acutely to bulls or steers.MethodsSixteen cows were assigned randomly 67 +/- 4 (+/- SE) after calving to be exposed to bulls (EB, n = 8) or steers (ES, n = 8) 5 h daily for 9 d (D 0 to 8). Blood samples were collected daily from each cow via jugular catheters at 15-min intervals for 6 h from 1000 to 1600 h each day. The 5-h exposure period began 1 h after the start of the intensive bleeding period. Characteristics of cortisol and LH concentration patterns (mean, baseline, pulse frequency, pulse amplitude, and pulse duration) were identified by PULSAR analyses.ResultsMean cortisol concentrations decreased (P < 0.05) in cows in both treatments from D 0 to D 2. Thereafter, mean cortisol concentrations stabilized and did not differ (P > 0.10) between EB and ES cows. The decrease in mean cortisol concentrations in EB and ES cows from D 0 to D 2 was attributed to cows acclimatizing to intensive blood sampling and handling procedures. Consequently, analyses for characteristics of cortisol and LH concentration patterns included D 2 through 8 only. Cortisol mean and baseline concentrations, and pulse amplitude did not differ (P > 0.10) between EB and ES cows. However, cortisol pulse duration tended to be longer (P = 0.09) and pulse frequency was lower (P = 0.05) in EB than ES cows. LH pulse frequency was greater (P = 0.06) in EB than ES cows. All other characteristics of LH concentration patterns did not differ (P > 0.10) between EB and ES cows. Characteristics of cortisol concentration patterns were not related to characteristics of LH concentration patterns for ES cows (P > 0.10). However, as cortisol pulse amplitude increased, LH pulse amplitude decreased (b1 = -0.04; P < 0.05) for EB cows.ConclusionsIn conclusion, exposing primiparous, postpartum, anovular, suckled cows to bulls for 5-h daily over a 9-d period did not alter mean concentrations of cortisol or LH compared to mean concentrations of cortisol and LH in cows exposed to steers. However, exposing cows to bull in this manner altered characteristics of temporal patterns of both LH and cortisol by increasing LH pulse frequency and decreasing cortisol pulse frequency. Interestingly, in cows exposed to bulls, as amplitude and frequency of cortisol pulses decreased, amplitudes of LH pulses increased and frequency of LH pulses tended to increase. Thus, the physiological mechanism of the biostimulatory effect of bulls may initially involve modification of the HPA axis and these changes may facilitate activation of the HPO axis and resumption of ovulatory cycles in postpartum, anovular, suckled cows.

Saliva DHEA and cortisol responses following short‐term corticosteroid intake

Given the high correlation between the serum and saliva hormone values demonstrated at rest, saliva provides a convenient non-invasive way to determine dehydroepiandrosterone (DHEA) and cortisol concentrations. However, to our knowledge, pituitary adrenal recovery following short-term suppression with corticosteroids has never been investigated in saliva. The aim of this study was therefore to examine how steroid hormone concentrations in saliva are influenced by short-term corticosteroid administration. We studied saliva DHEA and cortisol concentrations before, during (day 1-day 7) and following (day 8-day 16) the administration of oral therapeutic doses of prednisone (50 mg daily for 1 week) in 11 healthy recreationally trained women. Mean saliva DHEA and cortisol concentrations decreased immediately after the start of prednisone treatment (P < 0.05). Three days after concluding prednisone administration, both saliva DHEA and cortisol had returned to pretreatment levels. These data are consistent with previous studies on blood samples and suggest that non-invasive saliva samples may offer a practical approach to assessing pituitary-adrenal function continuously during and after short-term corticosteroid therapy.

Early specialized foster care, developmental outcomes and home salivary cortisol patterns in prenatally substance-exposed infants

The purpose of this study was to investigate possible associations between developmental outcomes of prenatally substance-exposed infants and early specialized foster care. Participants were volunteer foster families and 22 infants from the Vancouver Coastal Safe Babies program; this specialized care program included selective recruitment of foster parents, training and support for foster infant retention. Subdivided in two gestational groups (preterm and full-term), the infants were assessed at home using BDI-2 Screening Test to determine their development in cognitive and social domains. Salivary cortisol was sampled three times (awakening, morning and evening) on two different days to determine the infants' basal cortisol patterns. No evidence of clinically significant atypical development was found in either the preterm or full-term group. The preterm group had consistently lower mean cortisol levels than the full-term group but when the mean cortisol concentrations were corrected for number of months spent in foster care, the differences between preterm and full-term groups were no longer significant. From a perspective of clinical significance, these results suggest that stable, committed and specialized early foster care may be associated with “better than expected” developmental outcomes in prenatally substance-exposed infants.

Basal, Pulsatile, Entropic (Patterned), and Spiky (Staccato-like) Properties of ACTH Secretion: Impact of Age, Gender, and Body Mass Index

Age, gender, and BMI determine ultradian modes of LH and GH secretion, viz., pulsatile, basal, pattern-defined regularity [approximate entropy (ApEn)] and spikiness (sharp, brief excursions). Whether the same determinants apply to ACTH secretion is not known. The study was conducted at a tertiary medical center. We studied normal women (n = 22) and men (n = 26) [ages, 23-77 yr; body mass index (BMI), 21-32 kg/m(2)]. Volunteers underwent 10-min blood sampling to create 24-h ACTH concentration profiles. Dynamic measures of ACTH secretion were studied. Mean ACTH concentrations (R(2) = 0.15; P = 0.006) and both pulsatile (R(2) = 0.12; P = 0.018) and basal (nonpulsatile) (R(2) = 0.16; P = 0.005) ACTH secretion correlated directly with BMI (n = 48). Men had greater basal (P = 0.047), pulsatile (P = 0.031), and total (P = 0.010) 24-h ACTH secretion than women, including when total secretion was normalized for BMI (P = 0.019). In men, both ACTH-cortisol feedforward and cortisol-ACTH feedback asynchrony (cross-ApEn) increased with age (R(2) = 0.20 and 0.22; P = 0.021 and 0.018). ACTH spikiness rose with age (P = 0.046), principally in women. Irregularity of cortisol secretion (ApEn) increased with age (n = 48; P = 0.010), especially in men. In both sexes, percentage pulsatile ACTH secretion predicted 24-h mean cortisol concentrations (R(2) = 0.14; P = 0.009). Valid comparisons of ultradian ACTH dynamics will require cohorts matched for age, gender, and BMI, conditions hitherto not satisfied in most physiological studies of this axis.

24-hour serum concentration profile of cortisol in patients with Cushing's disease.

To evaluate whether or not patients with Cushing's disease can be differentiated from those with obesity by the determination of 24-hour integrated serum concentrations of cortisol we studied healthy, nonobese males (n = 5), as well as patients with marked obesity (n = 5) and with Cushing's disease (n = 7) in whom diagnosis was established biochemically and subsequently confirmed by surgery. Serum cortisol concentrations in samples collected continuously by a portable blood withdrawal pump during 24 hours (08:00-08:00h) were 6.6 +/- 1.7 micrograms/dl and 8.4 +/- 1.5 micrograms/dl in nonobese and obese individuals, respectively. Patients with Cushing's disease presented a mean cortisol concentration of 21.4 +/- 6.4 micrograms/dl (p vs normal: less than 0.005; vs obesity: less than 0.005). Collecting consecutive samples in 4-h periods the decline of serum cortisol from peak to nadir values was 73 +/- 10% and 57 +/- 23% in normal males and obese subjects, respectively, while a decline of only 22 +/- 8% was seen in patients with Cushing's disease. Three of the patients with Cushing's disease exhibited a circadian rhythm of cortisol albeit on an elevated level. These results may reflect variable stages of autonomy in pituitary ACTH-production and hence a possible criteria for differentation of hypothalamic and pituitary forms of Cushing's disease. In regard to differential diagnosis between Cushing's disease and obesity the 24-hour cortisol profile obtained by multiple sampling did not provide additional information to that obtained by a single sample pooled for 24 hours, which was diagnostic in each case.