Salivary cortisol in preterm infants: Validation of a simple method for collecting saliva for cortisol determination

Saliva biomarkers in oral disease

Saliva is a versatile biofluid that contains a wide variety of biomarkers reflecting both physiologic and pathophysiologic states. Saliva collection is noninvasive and highly applicable for tests requiring serial sampling. Furthermore, advances in test accuracy, sensitivity and precision for saliva has improved diagnostic performance as well as the identification of novel markers especially in oral disease processes. These include dental caries, periodontitis, oral squamous cell carcinoma (OSCC) and Sjögren's syndrome (SS). Numerous growth factors, enzymes, interleukins and cytokines have been identified and are the subject of much research investigation. This review highlights current procedures for successful determination of saliva biomarkers including preanalytical factors associated with sampling, storage and pretreatment as well as subsequent analysis. Moreover, it provides an overview of the diagnostic applications of these salivary biomarkers in common oral diseases.

How pesticides affect neonates? - Exposure, health implications and determination of metabolites

This review covers key information related to the effects of pesticides on fetal and child health. All humans are exposed to environmental toxicants, however child's health, due to their high vulnerability, should be of special concern. They are continuously exposed to environmental xenobiotics including a wide variety of pesticides, and other pollutants. These compounds can enter the child's body through various routes, both during fetal life, in the first days of life with breast milk, as well as during environmental exposure in later years of life. Consequently, in the body, some of them are metabolized and excreted with urine or faces, while others accumulate in tissues causing toxic effects. This review will provide information on the types of pesticides, their pathways of uptake and metabolism in children's bodies. Determination of the impact of them on children's organism performance is possible through effective identification of these compounds and their metabolites in children's tissues and biofluids. Therefore, the main procedures for the determination of pesticides are reviewed and future trends in this field are indicated. We believe that this comprehensive review can be a good starting place for the future readers interested in the impact of environmental xenobiotics on the health of children as well as the aspects relates with the analytical methods that can be used for analysis and monitoring of these pollutants in children's tissues and biofluids.

Correlation between diminished vagal tone and somatic dysfunction severity in very and extremely low birth weight preterm infants assessed with frequency spectrum heart rate variability and salivary cortisol

Osteopathic manipulative treatment (OMT) is evolving in the neonatal intensive care unit (NICU) setting. Studies showed its efficacy in length of stay and hospitalization costs reduction. Moreover, it was suggested that OMT has a modulatory effect on the preterm infants' autonomic nervous system (ANS), influencing saturation and heart rate. Even if OMT is based on the palpatory examination of the somatic dysfunctions (SD), there are controversies about its identification and clinical relevance. The objective of this study was to evaluate the inter-rater reliability, clinical characteristics, and functional correlation of the SD Grade score with the heart rate variability (HRV) and the salivary cortisol (sCor) using a multivariate linear model approach. To evaluate those features, we implemented an ad hoc SD examination for preterm infants that was performed by 2 trained osteopaths. It was based on the new variability model of SD that includes an SD Grade assessment procedure. The ANS features were assessed by frequency parameters of HRV studying high frequency (HF), low frequency (LF), and HF/LF, whereas sCor was tested with a radioimmunoassay. The ANS assessment was standardized and performed before SD testing. Sixty-nine premature infants were eligible. SD Grade showed excellent concordance between the blinded raters. Using SD Grade as a grouping variable, the infants presented differences in GA, Apgar, pathological findings, length of stay, and ventilatory assistance. In our multivariate model, HF, LF, and LF/HF resulted linearly correlated with SD Grade. Instead, sCor presented a linear correlation with 5' Apgar and respiratory distress syndrome but not with SD Grade. SD Grade was in line with the natural history of the underdevelopment due to prematurity. Our models indicate that the cardiac vagal tone is linearly related with SD Grade. This finding may improve the multidisciplinary decision making inside NICU and the management of modifiable factors, like SD, for cardiac vagal tone regulation.

The Effect of Paternal Skin-to-Skin Care: A Systematic Review and Meta-analysis of Randomized Control Trials

BACKGROUND

Research about skin-to-skin care (SSC) experiences in early period after birth has focused on mothers and infants.

PURPOSE

The purpose of this study was to determine the outcomes of paternal skin-to-skin care (P-SSC) in both fathers and infants.

METHODS

The Cochrane Central Register of Controlled Trials (CENTRAL), PubMed/MEDLINE, Embase, CINAHL, PsycInfo, Airiti Library, and Google Scholar were searched for randomized controlled trials (RCTs) that reported outcomes of P-SSC in both fathers and infants. We calculated pooled mean differences (MDs) and 95% confidence intervals (CIs) using RevMan 5.3 for the meta-analysis [PROSPERO: CRD42018106790].

RESULTS

Seven RCTs including a total of 552 participants were eligible for inclusion. Compared to the maternal skin-to-skin care (M-SSC), fathers in the P-SSC exhibited no significant differences in salivary oxytocin levels (MD: -0.35 pg/mL; 95% CI: -0.75, 0.05), salivary cortisol levels (MD: 0.25 μg/dL; 95% CI: -0.82, 1.33), or anxiety scores (MD: -0.17; 95% CI: -0.57, 0.22) during the period of SSC. Similarly, there were no significant differences in the salivary cortisol levels (MD: -0.11 μg/dL; 95% CI: -0.05, 0.28) among preterm infants between the 2 groups. However, the crying time was less among full-term infants in the P-SSC group compared with infants in the incubator care or cot care groups.

IMPLICATIONS FOR PRACTICE AND RESEARCH

P-SSC had similar effects as M-SSC on stress-related outcomes during and after SSC among fathers and infants in the early stages after birth. We recommend that P-SSC be implemented in the early stages after birth. Further RCTs with a longitudinal design and large samples are needed to better understand the long-term effects of P-SSC on fathers and infants.

Stabilization of Salivary Biomarkers

The use of saliva as a diagnostic biofluid has been increasing in recent years, thanks to the identification and validation of new biomarkers and improvements in test accuracy, sensitivity, and precision that enable the development of new noninvasive and cost-effective devices. However, the lack of standardized methods for sample collection, treatment, and storage contribute to the overall variability and lack of reproducibility across analytical evaluations. Furthermore, the instability of salivary biomarkers after sample collection hinders their translation into commercially available technologies for noninvasive monitoring of saliva in home settings. The present review aims to highlight the status of research on the challenges of collecting and using diagnostic salivary samples, emphasizing the methodologies used to preserve relevant proteins, hormones, genomic, and transcriptomic biomarkers during sample handling and analysis.

Long-Term Associations Between Prenatal Maternal Cortisol and Child Neuroendocrine-Immune Regulation

BACKGROUND

Advancing understanding of the developmental origins of neuroendocrine-immune (NEI) functioning is key to elucidating the biological mechanisms involved in health and disease risk across the lifespan. This study examined whether prenatal maternal hypothalamic-pituitary-adrenal (HPA) activity moderates child NEI relations and explored the consistency of this moderating effect across gestation.

METHODS

Pregnant women participated in five prenatal study visits from 24 to 38 weeks gestation. At each visit, women provided a saliva sample. In a 5-year follow-up study, children (n_female = 25, n_male=20) provided four saliva samples and participated in behavioral assessments and challenge tasks. Prenatal maternal saliva samples were assayed for cortisol. Child saliva samples were assayed for cortisol and cytokines (IL-1β, IL-6, IL-8, TNFα) as indices of HPA and inflammatory activity. Multilevel mixed-effects models examined the moderation of child NEI relations by prenatal maternal cortisol.

RESULTS

Among males, average prenatal maternal cortisol did not moderate child NEI relations. Among females, average prenatal maternal cortisol moderated some child NEI relations with higher prenatal cortisol associated with more positive cortisol-cytokine relations at age five. When examined by gestational time point, there were more significant NEI moderation effects by maternal cortisol from later gestation (≥ 30 weeks) than earlier.

CONCLUSIONS

The findings suggest prenatal maternal HPA activity may moderate child NEI functioning. Additional research conducted with more heterogeneous and larger samples is needed to fully understand these relations. Furthering our knowledge of NEI development has important research and clinical implications, particularly for understanding and addressing conditions with inflammatory pathophysiologies, such as depression and cardiovascular disease.

Cortisol secretion pattern in overweight/obese and normal-weight infants: a cross-sectional study

Background The salivary circadian diurnal cortisol plays an important role in growth and development. Inappropriate levels may induce changes associated with an increased risk of obesity later in life. It is unknown if there are differences in cortisol secretion pattern between overweight/obese infants when compared with theirs peers in infancy. Thus, this study aimed to compare the salivary cortisol secretion pattern in overweight/obese and normal-weight infants. Methods Thirty-three (overweight/obese = 17 and normal weight = 16) infants between 6 and 24 months of age had saliva samples collected upon awakening (T1), 30 min after waking (T2), at 12:00 am or before the baby's meal (T3), and prior to bedtime (T4). Highly sensitive enzyme immunoassays were used for cortisol analyses. Results Salivary cortisol levels were similar between the groups: T1 (p = 0.22; 95% confidence interval [CI]: -5.65, 1.37), T2 (p = 0.24; 95% CI: -8.23, 2.17), T3 (p = 0.95; 95% CI: -3.16, 2.96), and T4 (p = 0.81; 95% CI: -1.39, 1.08); and no differences were observed between area under the curve (AUC) (p = 0.80; 95% CI: -4.58-13.66). The cortisol level reduced in T4 (95% CI: 1.35-2.96) compared to T1 (95% CI: 5.15-8.49) and T2 in the overweight/obese group (p < 0.001; 95% CI: 6.02-11.04). In the normal-weight group, the cortisol reduced in T3 (95% CI: 2.86-8.18) compared to T1 (95% CI: 5.64-12.28) and decreased until T4 (p = 0.001; 95% CI: 1.25-3.37). Conclusions The overweight/obese infant group presented a different pattern of cortisol secretion, although cortisol levels did not differ between the control group.

Effects of smelling amniotic fluid on preterm infant's pain and stress during peripheral cannulation: A randomized controlled trial

AIM

To investigate the effect of smelling amniotic fluid on preterm infants' pain and stress caused by peripheral cannulation.

METHODS

This was a randomized controlled trial. The study sample consisted of 80 preterm infants meeting the case selection criteria and infants were randomly assigned to each group. However, in addition to the infants excluded from the study, total number of the infants in all the groups was 61. Infants in the amniotic fluid group smelled amniotic fluid for 15 min before, during, and after the application of peripheral cannulation while those in the control group received routine care during the procedure. The Premature Infant Pain Profile was used to assess their pain levels, and salivary cortisol analysis was performed to evaluate stress levels.

RESULTS

Preterm infants in the amniotic fluid and control groups had similar baseline characteristics. However, the pain levels of infants in the amniotic fluid group were significantly lower than of those in the control group during and after the procedure. After the procedure, cortisol levels of the infants in the amniotic fluid group were lower than of those in the control group, although this difference was not significant.

CONCLUSION

The intervention of smelling amniotic fluid is a practice that can be used for reducing pain and stress of preterm infants during peripheral cannulation.

Technical Considerations and Protocol Optimization for Neonatal Salivary Biomarker Discovery and Analysis

Non-invasive techniques to monitor and diagnose neonates, particularly those born prematurely, are a long-sought out goal of Newborn Medicine. In recent years, technical advances, combined with increased assay sensitivity, have permitted the high-throughput analysis of multiple biomarkers simultaneously from a single sample source. Multiplexed transcriptomic and proteomic platforms, along with more comprehensive assays such as RNASeq, allow for interrogation of ongoing physiology and pathology in unprecedented ways. In the fragile neonatal population, saliva is an ideal biofluid to assess clinical status serially and offers many advantages over more invasively obtained blood samples. Importantly, saliva samples are amenable to analysis on emerging proteomic and transcriptomic platforms, even at quantitatively limited volumes. However, biomarker targets are often degraded in human saliva, and as a mixed source biofluid containing both human and microbial targets, saliva presents unique challenges for the investigator. Here, we provide insight into technical considerations and protocol optimizations developed in our laboratory to quantify and discover neonatal salivary biomarkers with improved reproducibility and reliability. We will detail insights learned from years of experimentation on neonatal saliva within our laboratory ranging from salivary collection techniques to processing to downstream analyses, highlighting the need for consistency in approach and a global understanding of both the potential benefits and limitations of neonatal salivary biomarker analyses. Importantly, we will highlight the need for robust and stringent research in this population to provide the field with standardized approaches and workflows to impact neonatal care successfully.

Basal serum cortisol concentration in very low birth weight infants

BACKGROUND

The aim of our study was to measure the basal serum cortisol concentration immediately after birth and to determine its association with perinatal factors and clinical outcomes in very low birth weight (VLBW) infants.

METHODS

Basal serum cortisol level was obtained within one hour after birth in inborn VLBW infants. The association between the basal serum cortisol level and perinatal and clinical outcomes was analyzed by comparing the groups with high versus low cortisol levels.

RESULTS

In total, 80 infants were included. The median concentration of basal serum cortisol was 167 nmol/L with an interquartile range of 98-298 nmol/L. The basal serum cortisol concentration positively correlated with elapsed time from the last betamethasone dose. Low serum cortisol concentration was associated with antenatal corticosteroid therapy, low lactic acid level, and low leukocyte count at birth. Basal serum cortisol level was not associated with mortality and neonatal morbidities including hypotension and severe grade intraventricular hemorrhage.

CONCLUSION

Both maternal corticosteroid therapy and perinatal distress may affect the basal serum cortisol concentration in VLBW infants early after birth.

Are perinatal factors associated with musculoskeletal pain across the lifespan? A systematic review with meta-analysis

BACKGROUND

Musculoskeletal conditions are common health issues with great impact on individuals. Although many factors have been associated with the development of musculoskeletal pain, such as perinatal factors, its aetiology is still poorly understood.

OBJECTIVE

To systematically investigate whether perinatal factors can increase the risk of having musculoskeletal pain across the lifespan.

METHODS

MEDLINE, CINAHL, Scopus, Web of Science and EMBASE databases were searched from their inception to December 2017. Descriptors used in our search strategy were related to "perinatal factors" and "musculoskeletal pain". There were no language, age, sex or date restrictions. Meta-analysis was used to pool the estimates of association between perinatal factors and musculoskeletal pain.

RESULTS

Among the six articles included in this systematic review, three were extracted for the meta-analysis. The pooled of three and two studies showed no association between chronic musculoskeletal pain and low birth weight (OR 1.8, 95% CI 0.9-3.8, I² = 0; n = 157) or pre-term birth (OR 0.5, 95% CI 0.0-4.5; I² = 78%; n = 374) in adults, respectively. Overall, the quality of evidence after applying the GRADE approach was very low across all the studies.

CONCLUSION

In adults, our meta-analysis showed no association between birth weight or pre-term birth and musculoskeletal pain, and the quality of the evidence was very low. Thus, the very low quality of evidence and limited number of studies do not suggest a direct clear association. Further high-quality longitudinal studies accounting for more relevant confounders are needed to better understand the complex mechanism that may operate between perinatal factors and musculoskeletal pain.

Sleep and salivary cortisol in preterm neonates: a clinical, randomized, controlled, crossover study

ABSTRACT Objective: Analyze the influence of ear protectors on the baseline levels of salivary cortisol and response and total sleep time of preterm neonates during two periods of environmental management of a neonatal intermediate care unit. Method: A clinical, randomized, controlled and crossover study conducted with 12 preterm neonates. The use of ear protectors was randomized in two periods. Sleep evaluation was performed using one Alice 5 Polysomnography System and unstructured observation. Results: No significant difference was observed between the baseline levels of salivary cortisol and response in preterm neonates from the control and experimental groups, and no statistical significance was observed between the total sleep time of both groups. No relationship was observed between the baseline levels of cortisol and response and total sleep time. Conclusion: Ear protectors in preterm neonates did not influence the salivary cortisol level and total sleep time in the studied periods.

Oropharyngeal Administration of Colostrum Increases Salivary Secretory IgA Levels in Very Low-Birth-Weight Infants

AIM

Oropharyngeal administration of colostrum (OAC) has been proposed to provide mother's early milk to very low-birth-weight (VLBW) infants in the first few days of life. The aim of this study was to test the hypothesis that OAC would increase salivary secretory IgA (SsIgA).

METHODS

Overall, 30 VLBW infants randomized to receive OAC or sterile water had salivary sampling for SsIgA on the day of life (DOL) 2,7, and 14. The incidence of late-onset sepsis (LOS) and necrotizing enterocolitis (NEC) was determined prospectively. Within and between-group comparisons were made by paired and independent samples t-tests.

RESULTS

Baseline characteristics were similar between groups. SsIgA was higher in OAC versus the control group (p < 0.05) on DOL 7, but not subsequently on DOL 14. There was no difference in LOS or NEC.

CONCLUSION

OAC increased SsIgA at DOL 7. A large, multicenter trial is needed to determine if OAC decreases LOS or NEC in VLBW infants.

The feasibility of salivary sample collection in an international pediatric cohort: The the TEDDY study

Saliva offers a relatively noninvasive method for measuring analytes such as cortisol, holding particular promise for use in pediatric populations on a large scale if a rigorous collection protocol is feasible in diverse settings. The Environmental Determinants of Diabetes in the Young study protocol, conducted in centers in the United States, Sweden, Finland, and Germany, used salivary collection to assess cortisol level as a physiologic marker of stress. Saliva was collected using Sorbettes from subjects at 3.5, 4.5, and 5.5 years of age. Parents collected a morning sample, and staff collected pre- and post-blood draw samples. Feasibility was assessed based on protocol completion, adherence with instructions, factors affecting adherence, and sufficiency of saliva sample for cortisol determination. Collection of saliva samples in a diverse pediatric population is feasible. Establishing non-invasive and acceptable methods for collecting physiological parameters of stress will allow better exploration of determinants of health in this important population.

Associations between bedtime and nighttime parenting and infant cortisol in the first year

We examined how maternal care within the bedtime and nighttime contexts influences infant cortisol levels and patterning. Eighty-two mothers (M_age  = 29.4 years) and infants participated in a longitudinal study when infants were 3, 6, and 9 months old. At each time point, bedtime and nighttime parenting were recorded and infant cortisol at bedtime and the following morning was analyzed. Multilevel model analyses showed that infants had lower cortisol levels when mothers were more emotionally available at bedtime, and infants whose mothers responded more often to their non-distressed cues had lower cortisol levels on average. Less co-sleeping and more maternal responses to infant distress were linked to healthier cortisol patterning. By shedding light on parenting qualities and behaviors that influence infant cortisol, these results indicate avenues for intervention and suggest the utility of studying parenting in infant sleep contexts.

Mid-arm circumference is a reliable method to estimate adiposity in preterm and term infants

BACKGROUND

Premature birth is associated with increased adipose deposition after birth. Standard anthropometry (body weight, length, and head circumference) may not adequately assess fat deposition. Validated methods to assess adiposity are needed to optimize growth quality in preterm infants. The purpose of this study was to identify covariates of infant body fat.

METHODS

Air displacement plethysmography (ADP), standard anthropometry, and body circumferences were measured at hospital discharge in preterm (n = 28; 31-35 wk postmenstrual age (PMA)) and term (n = 28; 38-41 wks PMA) infants.

RESULTS

Body weight, length, and head circumference were lower for preterm infants (P < 0.05) at hospital discharge compared with that of term infants. Despite smaller body size and younger PMA, preterm infant percent body fat (%BF) by ADP was 12.33 ± 4.15% vs. 9.64 ± 4.01% in term infants (P = 0.01). Mid-arm circumference (MAC) is a covariate of %BF in both preterm and term infants (adjusted R(2) = 0.49; P < 0.001). In preterm infants alone, MAC accounted for 60.4% of the variability of percent body fat (%BF) by ADP (P < 0.01).

CONCLUSIONS

Preterm infants have increased body fat deposition as they approach term-corrected age, and MAC is a reliable, low-cost measure for monitoring infant body fat deposition in preterm and term infants.

Multidimensional response to vaccination pain in very preterm, moderate- to-late preterm and full-term infants at age three months

BACKGROUND

Very early life pain exposure and stress induces alterations in the developing brain and leads to altered pain sensitivity. In premature infants with a history of numerous early postnatal adverse events, behavioral responsiveness and hypothalamic-pituitary-adrenal (HPA) axis reactivity may show alterations as well.

AIMS

We compared a multidimensional response to a painful situation (vaccination) in three month old infants. The study involved very preterm, moderate to late preterm infants and full-term infants with varying exposure to pain and stress within the first weeks of life.

STUDY DESIGN

At the age of three months, we evaluated the infants' reactivity to intramuscular injections for immunization.

SUBJECTS

The study included 61 very preterm infants, 30 moderate to late preterm infants and 30 full-term infants.

OUTCOME MEASURES

We assessed heart rate recovery, Bernese pain Score and increase of salivary cortisol following vaccination. We also evaluated the flexor withdrawal reflex threshold as well as Prechtl's General Movements. Secondly, we assessed factors potentially influencing pain reactivity such as exposure to pain/stress, gender, use of steroids or opioids and mechanical ventilation.

RESULTS

Very preterm, moderate to late preterm and full-term infants showed different reactivity to pain in all analyzed aspects. Very preterm infants showed a lower level of behavioral and physiologic reactivity and exposure to pain/stress predicted lower cortisol increase.

CONCLUSION

At three months of age, very preterm infants show an altered level of HPA axis reactivity. Efforts aiming at minimizing pain and stress in premature infants should be taken.

Comparison of cortisol samples in the first two weeks of life in preterm infants

BACKGROUND

Growing literature on negative childhood stress emphasizes the need to understand cortisol values from varying biomarker samples.

OBJECTIVE

This work aimed to examine cortisol samples for usability, associations, and individual stability in neonates.

SUBJECTS

The sample consisted of preterm infants (n=31).

MATERIALS AND METHODS

Analyses on cortisol collected from cord blood and from saliva and urine samples on days 1, 7, and 14 included Spearman correlations and paired t-tests.

RESULTS

Usability rates were 80.6% (cord blood), 85.9% (saliva), and 93.5% (urine). Salivary and urinary cortisol levels had significant correlation on day 1 only (p=0.004). Significant differences in individual stability of cortisol concentrations existed except in urine on days 1 and 7 and in saliva on days 7 and 14.

CONCLUSIONS

Usability was highest for urine samples. We found little correlation between cortisol sample levels at each time; individual stability of cortisol concentrations was minimal. Interpretation of cortisol findings in all studies should be performed cautiously.

Maternal emotional availability at bedtime and infant cortisol at 1 and 3 months

BACKGROUND

Previous work has shown that early experience influences infant cortisol secretion. Few studies, however, have examined associations between parenting quality and cortisol levels and patterning in very young infants.

AIMS

This study examined linkages between maternal emotional availability (EA) during a routine caregiving task, bedtime, and infant cortisol in the first 3 months of life. Concurrent and longitudinal associations between maternal EA and infant cortisol were examined.

STUDY DESIGN

Families were visited when their infants were 1 and 3 months old. Video equipment was set up in order to record the infant's bedtime routine. Parents were provided with materials with which to take saliva samples from their infants at late afternoon, bedtime, and the following morning.

SUBJECTS

At 1 month, participants were 96 mothers and infants living in a rural U.S. state. Data were available for 88 mothers and infants at 3 months.

OUTCOME MEASURES

Maternal EA was scored from videotapes of bedtime at each age point. Infant cortisol was assessed from the saliva samples taken by parents.

RESULTS

Regression analyses indicated that at 1 and 3 months of age, infants of more emotionally available mothers showed lower levels of cortisol secretion across the night than infants of less emotionally available mothers. Additionally, multilevel model analyses indicated that infants of more emotionally available mothers showed greater evidence of a decline in their cortisol levels across the evening, followed by an increase across the nighttime into the morning in their cortisol at 3 months.

CONCLUSIONS

Findings suggest that maternal care in the context of a routine caregiving task is associated with lower stress reactivity and with earlier circadian patterning in very young infants.

Multiple latent viruses reactivate in astronauts during Space Shuttle missions

Latent virus reactivation and diurnal salivary cortisol and dehydroepiandrosterone were measured prospectively in 17 astronauts (16 male and 1 female) before, during, and after short-duration (12-16 days) Space Shuttle missions. Blood, urine, and saliva samples were collected during each of these phases. Antiviral antibodies and viral load (DNA) were measured for Epstein-Barr virus (EBV), varicella-zoster virus (VZV), and cytomegalovirus (CMV). Three astronauts did not shed any virus in any of their samples collected before, during, or after flight. EBV was shed in the saliva in all of the remaining 14 astronauts during all 3 phases of flight. Seven of the 14 EBV-shedding subjects also shed VZV during and after the flight in their saliva samples, and 8 of 14 EBV-shedders also shed CMV in their urine samples before, during, and after flight. In 6 of 14 crewmembers, all 3 target viruses were shed during one or more flight phases. Both EBV and VZV DNA copies were elevated during the flight phase relative to preflight or post-flight levels. EBV DNA in peripheral blood was increased preflight relative to post-flight. Eighteen healthy controls were also included in the study. Approximately 2-5% of controls shed EBV while none shed VZV or CMV. Salivary cortisol measured preflight and during flight were elevated relative to post-flight. In contrast DHEA decreased during the flight phase relative to both preflight and post-flight. As a consequence, the molar ratio of the area under the diurnal curve of cortisol to DHEA with respect to ground (AUCg) increased significantly during flight. This ratio was unrelated to viral shedding. In summary, three herpes viruses can reactivate individually or in combination during spaceflight.

Influence of acoustic stimulation on the circadian and ultradian rhythm of premature infants

The aim of the present study was to evaluate the development of the circadian rhythm of the salivary cortisol in premature infants and its correlation with the onset of the sleep-activity behavior pattern during the first 3 weeks of life under controlled light:dark conditions. Furthermore, we investigated the influence of acoustic stimulation by audiotaped lullabies or the maternal voice on the cortisol values and long-term sleep-activity patterns. The study was a block-randomized, prospective clinical trial with a study population of 62 preterm neonates (30<37 gestational age). We compared two study groups who listened either to music or to the maternal voice (music: N=20; maternal voice: N=20) with a matched control group (N=22). The acoustic stimulation took place every evening between 20:00 and 21:00 h for 30 min over a period of 2 weeks. The cortisol values and activity-rest behavior of the neonates were determined during the first 3 weeks of life on the 1st, 7th and 14th day. Actigraphic monitoring was used to record the activity pattern continuously over 24 h and a validated algorithm for neonates was used to estimate sleep and wakefulness. The saliva samples were obtained 10 min before and 10 min after the acoustic interventions for the study groups. Additionally, saliva samples were obtained from the control group seven times over a 24-h period (20:00, 21:00, 01:00, 05:00, 08:00, 13:00 and 17:00 h). The cortisol data were analyzed by fast Fourier transformation to assess periodic characteristics and frequencies. Hierarchical linear modeling was further performed for the statistical analysis.

RESULTS

The cortisol rhythm analysis indicated a circadian rhythm pattern for only one premature infant, all others of the neonates showed no circadian or ultradian rhythm in cortisol. Cortisol level of the premature neonates was significantly higher during the first day of the study period at night-time (median: 17.1 nmol/L, IQR=9.7-24.4 nmol/L) than on days 7 (median: 9.6 nmol/L, IQR=4.7-14.6 nmol/L; Tukey-HSD, z=4.12, p<0.001) and 14 (IQR=5.8-13.7 nmol/L; Tukey-HSD, z=2.89, p<0.05). No significant effect of acoustic stimulation was observed on the cortisol concentration and sleep-wake behavior. The activity-sleep rhythm of preterm neonates was dominated by ultradian rhythm patterns with a prominent period length of 4 h (30.5%). Activity frequencies of neonates were also significantly higher overnight on the first study day (mean: 329±185.1 U) than of night seven (mean: 260.2±132.4 U; Tukey-HSD, z=2.50, p<0.05). Quiet-activity patterns increased, whereas high-activity patterns decreased during the observation period. Average sleep time increased significantly during the study time from day 1 to day 7 (Tukey-HSD, z=2.51, p<0.05). In conclusion, premature infants showed higher cortisol levels - without a circadian rhythmicity - and higher activity frequencies in the first days after birth which may reflect an adaptation process of neonates after birth. Cortisol concentrations and the activity patterns were not influenced by music interventions.

Effect of holding on co-regulation in preterm infants: a randomized controlled trial

OBJECTIVE

To determine whether kangaroo holding of healthy preterm infants over the first eight weeks of an infant's life facilitates co-regulation of salivary cortisol between mother and infant.

STUDY DESIGN

Randomized control trial. Infants were assigned to receive 1h of daily kangaroo (skin-to-skin contact on the chest of mother) or blanket holding (dressed and held in mother's arms). A registered nurse visited mothers weekly for eight weeks to encourage holding and provide information about infant development. A control group had no holding restrictions and received weekly brief social visits.

SUBJECTS

The study included 79 preterm infants, born between 32 and 35weeks gestational age and were a mean of 15days (±5.7) at enrollment.

OUTCOME MEASURES

Co-regulation was conceptualized as progressive reduction in the absolute difference between mother and infant cortisol levels across 60min of holding at each holding session. Mother and infant cortisol levels were measured before holding and at 30 and 60min after holding began during three holding sessions (baseline and at two and eight weeks after study initiation). Primary analyses were conducted using hierarchical linear models.

RESULTS

There was much variability in cortisol levels. Levels of mother and infant cortisol decreased during holding. No significant co-regulation occurred in any group at any holding session or over time.

CONCLUSIONS

Decreasing level of cortisol in both mothers and infants suggests that holding promoted the expected decline in stress hormone levels. However, supported holding methods did not differentially affect co-regulation compared to controls. Holding is pleasurable and stress may need to be present in order for mothers and infants to demonstrate co-regulation in cortisol levels.

Anxiety, depression, stress, and cortisol levels in mothers of children undergoing maintenance therapy for childhood acute lymphoblastic leukemia

The purpose of this study was to compare anxiety, depression, and stress between mothers of children during maintenance treatment for acute lymphoblastic leukemia (ALL) and matched controls. Twenty-six mothers were recruited from the hematology unit at a children's hospital, and 26 mothers were recruited from the community. Participants were matched to their child's age and gender. Mothers completed the Hospital Anxiety and Depression Scale, the Perceived Stress Sale, and collected salivary cortisol 4 times a day for 3 consecutive days. Compared with mothers of healthy children, anxiety scores did not differ (P=.10), but depression scores were higher (P=.003) in mothers of children with ALL. More mothers in the ALL group scored above the cutoff of 7 indicating clinical anxiety (46%) and depressive symptoms (27%). A trend toward increased stress was found in mothers in the ALL group. No difference was found in overall daily cortisol (area under the curve), daily decrease in cortisol (slope), and cortisol awakening response. Mothers of children with ALL experienced emotional symptoms many months after the initial diagnosis.

"Anatomy of an Illness": control from a caregiver's perspective

Caregivers of loved ones with chronic illnesses experience an uncontrollable challenge with potentially negative behavioral and medical consequences. Extensive research has demonstrated immune and endocrine regulation can be significantly disrupted by negative behavioral factors based on both animal models and human studies. However, fewer studies have focused on how psychosocial interventions might reverse the negative consequences of stressors such as caregiving. The distress of caring for individuals with cancer has only recently begun to receive attention. These interventions addressing caregiver distress are rare overall and caregivers of patients receiving hematopoietic stem cell transplants (HSCT) have received even less attention. HSCT caregivers report feelings of loss of control. Animal studies suggest that control over aversive events can mitigate the negative consequences of stressors. Caregivers of allogeneic HSCT patients for blood cancers must be available 24/7 for three months or longer following stem cell infusion to closely monitor the recipients' health and well-being. Does establishing a greater sense of control have positive impacts on caregivers? A randomized control trial of a cognitive behavioral stress management intervention for allogeneic HSCT caregivers is briefly described. A model of caregiver mental health which may potentially impact the patient's quality of life is proposed. These relationships exist in a complex system that includes genetic influences, sex, social environment, and prior experience. This system fits well within recent formulations of a "complexity science" approach to health and well-being.

Detection and potential utility of C-reactive protein in saliva of neonates

OBJECTIVE

We aimed to detect C-reactive protein (CRP) in neonatal saliva and evaluate its diagnostic utility.

STUDY DESIGN

Salivary and serum samples (n = 89) were collected from 40 neonates. Salivary CRP levels were determined using an enzyme-linked immunosorbent assay; serum CRP was measured per hospital protocol. Correlation coefficients with 95% confidence intervals and robust linear regression measured association while receiver-operator characteristic curves described the accuracy of salivary CRP in discriminating abnormal serum CRP thresholds of ≥10 and 5 mg/L. Corresponding sensitivities and specificities were calculated for these salivary cutpoints.

RESULTS

The area under the curve for salivary CRP in predicting serum CRP levels of ≥10 and 5 mg/L were 0.81 and 0.76, respectively. The corresponding sensitivity and specificity for raw salivary CRP to discriminate a serum CRP of ≥5 mg/L was 0.54 and 0.95, respectively. The corresponding sensitivity and specificity for raw salivary CRP to discriminate a serum CRP of ≥10 mg/L was 0.64 and 0.94, respectively. A statistically significant correlation was observed between serum and salivary CRP (r = 0.62, p < 0.001).

CONCLUSION

C-reactive protein is detectable in neonatal saliva and can predict abnormal serum CRP thresholds. Salivary CRP analysis represents a feasible screening tool for detecting abnormal serum CRP levels.

Saliva collection by using filter paper for measuring cortisol levels in dogs

Four experiments were conducted to evaluate the accuracy and reliability of noninvasive evaluation of cortisol in saliva of dogs. In experiment 1, we measured the cortisol concentration in the filter paper on which 250-μL cortisol solutions had been quantitatively pipetted and in filter papers dipped in cortisol solution. In experiment 2, we collected the blood and saliva of dogs 3 times at 30-min intervals and compared the cortisol concentrations to examine whether the dynamics of cortisol in the blood and saliva are similar. The results of experiments 1 and 2 showed that the cortisol concentration can be quantitatively measured with this method and that the dynamics of cortisol concentration in the plasma and saliva collected by using filter paper are not different (P = 0.14 for experiment 1 and P = 0.51 for experiment 2). In experiment 3, to investigate the factors related to inducing stress in dogs by using the filter-paper method of collecting saliva, we compared the cortisol concentrations at 0 and 30 min after collecting the saliva of pet dogs. The dog owners completed a survey on their dogs, providing basic information and reporting the collection of their dog's saliva. We found that the cortisol concentrations increased significantly in dogs whose owners spent >2 min collecting saliva (P = 0.005), suggesting that prompt collection of saliva is necessary for accurate assessment of cortisol without induction of a stress response. In addition, the cortisol concentrations increased significantly in dogs whose teeth were not regularly brushed (P = 0.04), suggesting that regular teeth brushing mitigates the effect of the collection process on cortisol concentrations in the saliva, with minimal stress to the dogs. In experiment 4, we measured cortisol concentrations in pet dogs accustomed to having their teeth brushed by their owners, before and after interaction with their owners, to assess whether brushing induces stress in dogs. We detected that the cortisol concentrations significantly decreased after human-dog interaction (P = 0.008), suggesting that this method does not induce stress in dogs. Our study indicates that the method of saliva collection by using filter paper is effective in measuring the cortisol concentrations to evaluate stress, although certain steps are required to enhance accuracy.

Benefits of massage therapy for infants with symptoms of gastroesophageal reflux disease

OBJECTIVES

This randomized controlled pilot trial was conducted to evaluate the clinical efficacy of massage therapy (MT) for relief of symptoms of gastroesophageal reflux disease (GERD). The hypothesis was that, when compared to infants who received nonmassage therapy, infants who received MT would display fewer GERD symptoms, greater weight gain, greater amount of sleep, lower cortisol levels before and after treatment, and lower daily (area under the curve [AUC]) cortisol secretion.

METHODS

Participants were 36 infants born at term, 4-10 weeks of age at enrollment, healthy except for a diagnosis of GERD by their pediatrician, and with a score of at least 16 on the Infant Gastroesophageal Reflux Questionnaire-Revised (I-GERQ-R). Infants were randomized to receive either MT or a nonmassage sham treatment in their homes for 30 min twice a week for 6 weeks. Data collectors and parents were blind to study condition.

RESULTS

GERD symptoms decreased in both groups and weight increased. Pretreatment salivary cortisol levels decreased significantly over time in the massage group while increasing in the nonmassage group. Daily cortisol level also decreased in the massage group and increased in the nonmassage group, but the difference was not significant.

CONCLUSIONS

MT administered by a professional therapist did not affect symptoms of GERD differently than a sham treatment but did decrease infant stress as measured by cortisol. Research focusing on stress reduction in infants with GERD and multimodal treatments addressing GERD symptoms may yield the most effective treatment.

Approaches to salivary cortisol collection and analysis in infants

Salivary cortisol is becoming more commonly utilized as a biologic marker of stress in observational studies and intervention research. However, its use with infants (12 months of age or younger) is less widespread and poses some special challenges to researchers. In order to decide on the most suitable collection procedure for salivary cortisol in infants, a number of criteria should be considered. This article will aid investigators interested in integrating salivary cortisol measurement into their research studies by presenting (1) an overview of the patterns of cortisol secretion in infancy including the development of diurnal rhythm and response to stress; (2) a comparison of the most commonly used approaches for collecting salivary cortisol samples in infants including cotton rope, syringe aspiration technique, filter paper, hydrocellulose microsponge, and the Salimetrics children's swab; (3) a discussion of the factors contributing to heightened cortisol variability in infancy and how these can be limited; (4) analytical issues associated with cortisol measurement; and (5) examples of criteria to consider when choosing a saliva sampling method and lab for conducting assays.

Diurnal patterns of salivary cortisol and DHEA using a novel collection device: electronic monitoring confirms accurate recording of collection time using this device

The accurate indication of saliva collection time is important for defining the diurnal decline in salivary cortisol as well as characterizing the cortisol awakening response. We tested a convenient and novel collection device for collecting saliva on strips of filter paper in a specially constructed booklet for determination of both cortisol and DHEA. In the present study, 31 healthy adults (mean age 43.5 years) collected saliva samples four times a day on three consecutive days using filter paper collection devices (Saliva Procurement and Integrated Testing (SPIT) booklet) which were maintained during the collection period in a large plastic bottle with an electronic monitoring cap. Subjects were asked to collect saliva samples at awakening, 30 min after awakening, before lunch and 600 min after awakening. The time of awakening and the time of collection before lunch were allowed to vary by each subjects' schedule. A reliable relationship was observed between the time recorded by the subject directly on the booklet and the time recorded by electronic collection device (n=286 observations; r(2)=0.98). However, subjects did not consistently collect the saliva samples at the two specific times requested, 30 and 600 min after awakening. Both cortisol and DHEA revealed diurnal declines. In spite of variance in collection times at 30 min and 600 min after awakening, the slope of the diurnal decline in both salivary cortisol and DHEA was similar when we compared collection tolerances of ±7.5 and ±15 min for each steroid. These unique collection booklets proved to be a reliable method for recording collection times by subjects as well as for estimating diurnal salivary cortisol and DHEA patterns.

Endotracheal suctioning in preterm infants using four-handed versus routine care

OBJECTIVE

To evaluate the effect of four-handed care on preterm infants' physiologic and behavioral responses to and recovery from endotracheal suctioning versus routine endotracheal (ETT) suctioning.

DESIGN

Randomized crossover design with infants as their own controls.

SETTING

Single-family-room newborn intensive care unit in an academic health center.

PARTICIPANTS

Ten intubated infants on conventional ventilation with inline suctioning who were fewer than 37 weeks gestation at birth, and less than one week of age.

METHODS

Each infant was observed twice on a single day. One observation involved routine ETT suctioning and one involved four-handed care. Physiologic and behavioral response data were collected.

RESULTS

No differences were noted when comparing baseline heart rate (HR) or oxygen saturation (SpO(2)) data to those obtained during and after suctioning while in the routine care condition. In the four-handed care condition, mean SpO(2) increased from preobservation 95.49 to during observation saturation 97.75 (p = .001). Salivary cortisol levels did not differ between groups at baseline or postsuctioning. No significant difference in behavior state was observed between the two conditions. More stress and defense behaviors occurred postsuctioning when infants received routine care as opposed to four-handed care (p = .001) and more self-regulatory behaviors were exhibited by infants during (p = .019) and after suctioning (p = .016) when receiving four-handed care. No statistical difference was found in the number of monitor call-backs postsuctioning.

CONCLUSIONS

Four-handed care during suctioning was associated with a decrease in stress and defense behaviors and an increase in self-regulatory behaviors.

Concurrent levels of maternal salivary cortisol are unrelated to self-reported psychological measures in low-risk pregnant women

Associations between salivary cortisol and maternal psychological distress and well-being were examined prospectively on 112 women with normally progressing, singleton pregnancies between 24 and 38 weeks gestation. At each of 5 visits, conducted in 3-week intervals, women provided a saliva sample and completed questionnaires measuring trait anxiety, depressive symptoms, pregnancy-specific hassles and uplifts, and psychological well-being. Maternal salivary cortisol was unrelated to psychological measures with the exception of minor associations detected with measures of anxiety and depressive symptoms between 30 and 32 weeks only. Findings indicate that self-reported maternal psychological distress and well-being are not associated with significant variation in maternal salivary cortisol levels during the second half of gestation. This suggests that studies that measure psychological factors in pregnancy but do not measure maternal cortisol should exercise caution in assuming activation of the maternal hypothalamic-pituitary-adrenal axis is the mechanism through which maternal psychological factors are transduced to the fetus.

Assessing agreement between salivary alpha amylase levels collected by passive drool and eluted filter paper in adolescents with cancer

PURPOSE/OBJECTIVES

To assess the validity of filter paper (FP) against the gold standard of passive drool (PD) for collecting salivary alpha amylase as a surrogate biomarker of psychological stress in adolescents with cancer.

DESIGN

Part of a longitudinal, descriptive study of symptoms in adolescents with cancer during chemotherapy.

SETTING

A pediatric hematology/oncology treatment center.

SAMPLE

33 saliva sample pairs from nine adolescents with cancer, aged 13-18 years.

METHODS

Salivary alpha amylase was collected by PD and FP at four time points during a cycle of chemotherapy: days 1 (time 1) and 2 (time 2) of chemotherapy, day 7-10 (time 3), and day 1 of the next cycle (time 4). A random effects regression was used to assess the correlation between PD and FP values, and a Bland Altman analysis was conducted to assess agreement between the values.

MAIN RESEARCH VARIABLES

Salivary alpha amylase.

FINDINGS

The estimated correlation between PD and FP values was r = 0.91, p < 0.001. Regression results were also used to rescale FP values to the levels of the PD values because the FP values were on a different scale than the PD values. The Bland Altman analysis revealed that the agreement between the rescaled FP values and PD values was not satisfactory.

CONCLUSIONS

Eluted FP may not be a valid method for collecting salivary alpha amylase in adolescents with cancer.

IMPLICATIONS FOR NURSING

Psychological stress in adolescents with cancer may be linked to negative outcomes, such as greater symptom severity and post-traumatic stress disorder. Nurses need valid, efficient, biobehavioral measures to assess psychological stress in the clinical setting.

Measurement of salivary cortisol in 2012 - laboratory techniques and clinical indications

The utility of measuring salivary cortisol has become increasingly appreciated since the early 1980s. Salivary cortisol is a measure of active free cortisol and follows the diurnal rhythm of serum or plasma cortisol. The saliva sample may be collected by drooling or through the use of absorbent swabs which are placed into the mouth until saturated. Salivary cortisol is therefore convenient for patients and research participants to collect noninvasively on an outpatient basis. Several assay techniques have been used to measure salivary cortisol, including radioimmunoassay and more recently liquid chromatography-tandem mass spectrometry. The analytical sensitivity varies between these assay methods, as does the potential for cross-reactivity with other steroids. The interpretation of salivary cortisol levels relies on rigorous standardization of sampling equipment, sampling protocols and assay technology with establishment of a local reference range. Clinically, the commonest use for salivary cortisol is measuring late-night salivary cortisol as a screening test for Cushing's syndrome. Several studies have shown diagnostic sensitivities and specificities of over 90%, which compares very favourably with other screening tests for Cushing's syndrome such as the 24-h urinary-free cortisol and the 1-mg overnight dexamethasone suppression test. There are emerging roles for the use of salivary cortisol in diagnosing adrenal insufficiency, particularly in conditions associated with low cortisol-binding globulin levels, and in the monitoring of glucocorticoid replacement. Finally, salivary cortisol has been used extensively as a biomarker of stress in a research setting, especially in studies examining psychological stress with repeated measurements.

Comparison of biomarkers in blood and saliva in healthy adults

Researchers measure biomarkers as a reflection of patient health status or intervention outcomes. While blood is generally regarded as the best body fluid for evaluation of systemic processes, substitution of saliva samples for blood would be less invasive and more convenient. The concentration of specific biomarkers may differ between blood and saliva. The objective of this study was to compare multiple biomarkers (27 cytokines) in plasma samples, passive drool saliva samples, and filter paper saliva samples in 50 healthy adults. Demographic data and three samples were obtained from each subject: saliva collected on filter paper over 1 minute, saliva collected by passive drool over 30 seconds, and venous blood (3 mL) collected by venipuncture. Cytokines were assayed using Bio-Rad multiplex suspension array technology. Descriptive statistics and pairwise correlations were used for data analysis. The sample was 52% male and 74% white. Mean age was 26 (range = 19–63 years, sd = 9.7). The most consistent and highest correlations were between the passive drool and filter paper saliva samples, although relationships were dependent on the specific biomarker. Correlations were not robust enough to support substitution of one collection method for another. There was little correlation between the plasma and passive drool saliva samples. Caution should be used in substituting saliva for blood, and relationships differ by biomarker.

Acculturation, maternal cortisol, and birth outcomes in women of Mexican descent

OBJECTIVE

This study investigated the effects of acculturation on cortisol, a biological correlate of maternal psychological distress, and perinatal infant outcomes, specifically gestational age at birth and birth weight.

METHODS

Fifty-five pregnant women of Mexican descent were recruited from a community hospital, and their saliva samples were collected at home for 3 days during pregnancy at 15 to 18 weeks (early), 26 to 32 weeks (mid), and more than 32 weeks (late) of gestation and once in the postpartum period (4-12 weeks). These values were used to determine the diurnal cortisol slope at each phase of pregnancy. Mothers also completed an acculturation survey and gave permission for a medical chart review to obtain neonate information.

RESULTS

Multiple regression analyses determined that greater acculturation levels significantly predicted earlier infant gestational age at birth (R(2) = 0.09, p = .03). Results from t tests revealed that mothers of low-birth-weight infants (<2500 g) had significantly higher acculturation scores than mothers of infants with birth weight greater than 2500 g (t = -2.95, p = .005). A blunted maternal cortisol slope during pregnancy was also correlated with low birth weight (r = -0.29, p = .05) but not gestational age (r = -0.08, p = .59). In addition, more acculturated women had a flatter diurnal cortisol slope late in pregnancy (R(2) = 0.21, p = .01). Finally, diurnal maternal cortisol rhythms were identified as a potential mediator between increased acculturation and birth weight.

CONCLUSIONS

This study associated increased acculturation with perinatal outcomes in the US Mexican population. This relationship may be mediated by prenatal maternal diurnal cortisol, which can program the health of the fetus leading to several adverse perinatal outcomes.

Salivary cortisol in pregnant women suffering from blood and injection phobia

Stress and/or anxiety during pregnancy affect maternal and fetal well-being and can cause premature delivery and postnatal pathology in the child. Women suffering from phobias related to blood and injections are prone to high levels of stress, including anxiety and sometimes panic attacks, during pregnancy. Cortisol is amongst the mediators through which the neurohormonal expressions of maternal psychological factors may be transduced to the fetus. The aim of this study was to investigate whether pregnant women suffering from blood and injection phobia have raised cortisol levels or are characterized by unusual diurnal salivary cortisol profiles compared with healthy controls. The sample consisted of 110 pregnant women with blood and injection phobia and 110 pregnant healthy controls. Both groups provided morning and evening saliva samples in weeks 25 and 36 for the assay of cortisol. In gestational week 25, when blood was drawn for the mandatory blood testing, extra blood was taken to analyze corticotrophin-releasing factor, adrenocorticotropic hormone, and cortisol in serum. The diurnal decline in salivary cortisol as well as increased cortisol levels were observed during pregnancy. Pregnant women suffering from blood and injection phobia had a higher output of cortisol compared with women without the phobia (F = 6.25, df = 1, p = 0.014), but no marked difference in the diurnal cortisol rhythm was found between groups. Our findings indicate that untreated blood and injection phobia during pregnancy increases cortisol concentrations. Blood and injection phobia is treatable, and cognitive behavioral therapy can be used. Women with blood and injection phobia during pregnancy therefore need to be recognized and offered treatment without delay in early pregnancy.

A novelty seeking phenotype is related to chronic hypothalamic-pituitary-adrenal activity reflected by hair cortisol

Reduced hypothalamic pituitary adrenal (HPA) activity is associated with greater novelty seeking in humans. Hair cortisol represents an integrated proxy measure of total cortisol production/release over an extended period of time and may be a valuable tool for tracking the HPA system. Sampling approaches (collection of blood, saliva, urine, or feces) for socially housed nonhuman primates present a number of technical challenges for collection particularly when repeated sampling is necessary. Herein we describe a relationship between cortisol levels measured in hair collected from 230 socially housed female vervet (Chlorocebus aethiops sabaeus) monkeys and a free-choice novelty seeking phenotype. A predator-like object was placed at the periphery of the outdoor enclosures for 30 min and speed of approach (latency to approach within 1m) and persistence of interest (number of 1 min intervals within 1m) were scored. A composite Novelty Seeking score, combining these two measures, was calculated. The intra-class correlation coefficient (ICC=.68) for two different objects across years indicated that this score reflects a stable aspect of temperament. Hair samples were collected from each subject approximately 3-6 months following the second assessment; cortisol levels were determined from the hair. A significant inverse relationship of Novelty Seeking score with hair cortisol level (p<.01) was noted. The high hair cortisol groups had significantly lower Novelty Seeking scores than the low cortisol groups both years (p's<.05). These results suggest that low average cortisol levels promote novelty seeking, while high average levels inhibit novelty seeking behavior.

Oligosaccharides in feces of breast- and formula-fed babies

So far, little is known on the fate of oligosaccharides in the colon of breast- and formula-fed babies. Using capillary electrophoresis with laser induced fluorescence detector coupled to a mass spectrometer (CE-LIF-MS(n)), we studied the fecal oligosaccharide profiles of 27 two-month-old breast-, formula- and mixed-fed preterm babies. The interpretation of the complex oligosaccharide profiles was facilitated by beforehand clustering the CE-LIF data points by agglomerative hierarchical clustering (AHC). In the feces of breast-fed babies, characteristic human milk oligosaccharide (HMO) profiles, showing genetic fingerprints known for human milk of secretors and non-secretors, were recognized. Alternatively, advanced degradation and bioconversion of HMOs, resulting in an accumulation of acidic HMOs or HMO bioconversion products was observed. Independent of the prebiotic supplementation of the formula with galactooligosaccharides (GOS) at the level used, similar oligosaccharide profiles of low peak abundance were obtained for formula-fed babies. Feeding influences the presence of diet-related oligosaccharides in baby feces and gastrointestinal adaptation plays an important role herein. Four fecal oligosaccharides, characterized as HexNAc-Hex-Hex, Hex-[Fuc]-HexNAc-Hex, HexNAc-[Fuc]-Hex-Hex and HexNAc-[Fuc]-Hex-HexNAc-Hex-Hex, highlighted an active gastrointestinal metabolization of the feeding-related oligosaccharides. Their presence was linked to the gastrointestinal mucus layer and the blood-group determinant oligosaccharides therein, which are characteristic for the host's genotype.

Hair cortisol levels as a retrospective marker of hypothalamic-pituitary axis activity throughout pregnancy: comparison to salivary cortisol

Maternal stress during pregnancy is associated with negative maternal/child outcomes. One potential biomarker of the maternal stress response is cortisol, a product of activity of the hypothalamic-pituitary-adrenal axis. This study evaluated cortisol levels in hair throughout pregnancy as a marker of total cortisol release. Cortisol levels in hair have been shown to be easily quantifiable and may be representative of total cortisol release more than single saliva or serum measures. Hair cortisol provides a simple way to monitor total cortisol release over an extended period of time. Hair cortisol levels were determined from each trimester (15, 26 and 36 weeks gestation) and 3 months postpartum. Hair cortisol levels were compared to diurnal salivary cortisol collected over 3 days (3 times/day) at 14, 18, 23, 29, and 34 weeks gestational age and 6 weeks postpartum from 21 pregnant women. Both salivary and hair cortisol levels rose during pregnancy as expected. Hair cortisol and diurnal salivary cortisol area under the curve with respect to ground (AUCg) were also correlated throughout pregnancy. Levels of cortisol in hair are a valid and useful tool to measure long-term cortisol activity. Hair cortisol avoids methodological problems associated with collection other cortisol measures such as plasma, urine, or saliva and is a reliable metric of HPA activity throughout pregnancy reflecting total cortisol release over an extended period.

Exploring the complexity of cardiometabolic risk in women

Cardiovascular disease (CVD) is the leading cause of death in the United States. Women are more likely than men to present with advanced disease and experience higher CVD-related morbidity and mortality. Metabolic syndrome is a constellation of risk factors for Type 2 diabetes mellitus (T2DM) and CVD. Abdominal adiposity, a component of metabolic syndrome, is associated with insulin resistance and promotes an atherogenic inflammatory milieu. Cardiometabolic risk (CMR) encompasses metabolic syndrome and incorporates other risk factors such as lifestyle choices, gender, and genetics as risk factors for CVD yet still does not include more recently recognized physiological risk factors such as vitamin D deficiency or psychosocial risk factors such as perceived stress and lack of social support. Because a more comprehensive view of CVD risk factors may facilitate earlier identification and risk reduction, we undertook this exploratory pilot study to answer the question, How do healthy women with and without abdominal adiposity differ physiologically and psychosocially?. We recruited a total of 41 women for a single study visit and assessed a battery of baseline physiological and psychological measures. While the women in this study were free of any diagnoses associated with increased CMR, women with increased waist circumference (WC) exhibited significantly altered levels of several measures associated with impending CMR including insulin sensitivity, lipids, and adiponectin as well as lower social support. These findings suggest that a more comprehensive conceptualization of and refinement of measures for CMR may be useful for identifying and reducing CMR and ultimately CVD in women.

Randomized crossover trial of kangaroo care to reduce biobehavioral pain responses in preterm infants: a pilot study

Kangaroo care (KC), skin-to-skin contact between mother and infant, is a promising method for blunting pain responses. This crossover pilot tested KC effects on biobehavioral responses to heel stick in preterm infants (30-32 weeks' gestational age, 2-9 days old) measured by Premature Infant Pain Profile (PIPP) and salivary and serum cortisol. Mother-infant dyads were randomly assigned to KC heel stick (KCH) first or incubator heel stick (IH) first. Study 1 (80-min study, N = 18) tested the effect of 80 min of KC before and throughout the heel stick procedure versus incubator care. Study 2 (30-min study, N = 10) tested 30 min of KC before and throughout the heel stick versus incubator care. KCH and IH began during a premeasurement phase and continued through four data collection phases: baseline, heel warming, heel stick, and recovery. PIPP responses were measured every 30 s during data collection; salivary cortisol was measured at the end of baseline and recovery; and serum cortisol was measured during heel stick. Study 1 showed no differences between KCH and IH. Study 2 showed lower PIPP scores at four time points during recovery (p < .05 to p < .001), lower salivary cortisol at the end of recovery (p < .05), and lower serum cortisol during heel stick for the KCH condition (p < .05) as well as clinically lower PIPP scores in the KCH condition during heel stick. Thirty minutes of KC before and throughout the heel stick reduced biobehavioral responses to pain in preterm infants.

Saliva as an analytical matrix: state of the art and application for biomonitoring

Analytical tests to measure chemicals in saliva can be employed for numerous analytes, endogenous compounds or xenobiotics. The objective was to determine which chemicals can be analysed with this matrix, which analytical methods are applicable, and what application is possible for biomonitoring. We reviewed the literature using three databases, MEDLINE, PubMed and Scopus, collecting articles on different kinds of analysis in saliva. Studies were principally about molecules of clinical interest, xenobiotics, especially drugs of abuse, and chemicals used at workplaces; some substances show no relevant correlation with exposure data while others seems to be of particular interest for systematic use for biomonitoring. Currently, saliva is used far less than other biological fluids but its use for biomonitoring of exposure to chemicals might open up new areas for research and would certainly simplify the collection of biological samples.