Plasma cortisol and ACTH levels in 416 VLBW preterm infants during the first month of life: distribution in the AGA/SGA population

Predicting iatrogenic adrenal insufficiency in neonates exposed to prolonged steroid courses: do cortisol levels help?

OBJECTIVE

To determine whether random cortisol levels obtained in neonates to assess for secondary adrenal insufficiency (AI) after prolonged steroid exposure are predictive of central AI.

STUDY DESIGN

Data were collected on neonates born 2017-2022 who received ≥10 consecutive days of systemic steroids and had cortisol measured thereafter. Data were then collected on whether those neonates developed signs of AI or had a failed adrenocorticotropic hormone (ACTH) stimulation test.

RESULTS

Of the 71 cortisol levels (in 67 neonates) that were analyzed, there was no difference in cortisol levels between neonates who developed AI (median cortisol level of 6.5 mcg/dl) and those who did not (median of 9.2 mcg/dl), or between those who failed their ACTH stimulation test or passed it, using Wilcoxon ranked sum tests.

CONCLUSION

These findings demonstrate that cortisol levels may not be helpful in identifying AI in neonates exposed to prolonged steroids.

Salivary Cortisol Levels and Clinical Signs of Stress in Premature Neonates Treated with Vimala Massage: A Randomized Controlled Trial

Background: In neonatal intensive care units across the world, premature neonates are exposed to a very stressful environment with high levels of noise, bright lights, pain, infections, invasive procedures, and a lack of maternal contact. Stress is manifested by increased cortisol levels and clinical signs of stress. Objective: To assess the impact of Vimala massage on (1) salivary cortisol levels (primary outcome) and (2) clinical signs of stress (secondary outcomes) in premature neonates. Methods: Neonates (28-36 weeks gestational age) admitted to a nursery unit were randomized one-to-one to receive 15-20 min of Vimala massage administered by their parents twice daily and usual care, or to usual care alone. Salivary cortisol levels were measured by enzyme-linked immunosorbent assay (ELISA) on days 1 and 5. Heart rate, respiratory rate, caloric intake, weight gain, and growth were recorded daily. Groups were compared with t tests, U-tests, and repeated measures analysis of variance. Results: Seventy neonates, 35 in each group, were included. Groups were comparable at baseline. The median decrease in salivary cortisol levels was 0.12 μg/dL in the massage group and 0.07 μg/dL in the control group (p = 0.22). Over 5 days, the massage group had significant decreases in resting heart rate (p = 0.003) and respiratory rate (p = 0.028), and greater weight gains (p = 0.0002), relative to controls. Conclusions: In this randomized trial, adding Vimala massage to usual nursery care was not associated with a significant decrease in salivary cortisol levels in premature neonates, when compared with usual nursery care alone. There were improvements in clinical signs of stress.

Relative Adrenal Insufficiency: Crisis Averted?

Relative adrenal insufficiency (AI) is a disease process commonly associated with preterm birth and critical illness. Further, the incidence of AI is inversely proportional to gestational age. The incidence of AI is likely underreported; however, it is reported to occur in 150-280/1,000,000 live births worldwide. Functional development of the adrenal gland does not occur until after 30 weeks of gestation; however, advances made in neonatal care increase the survivability of infants born well before this period. Among infants with AI, the adrenal gland is transiently incapable of secreting physiologic levels of cortisol in response to stressors. Common and nonspecific signs include hypotension, poor perfusion, and dysregulation of fluid, electrolytes, and euglycemia. Recognition, diagnosis, and steroid therapy is critical, as inappropriately managed AI can lead to an adrenal crisis, shock, and death. Understanding the presentation and common risk factors for developing relative AI is crucial for quick diagnosis and timely management to prevent morbidity and mortality in this vulnerable population.

Age- and sex-specific reference intervals for thyroid hormones in a Chinese pediatrics: a prospective observational study of 1,279 healthy children

BACKGROUND

Thyroid hormones are essential for early neurocognitive development and growth and development in childhood and adolescence. However, the reference intervals (RIs) for thyroid hormones in Chinese pediatric individuals remain unclear. This study aimed to establish thyroid hormone RIs for a Chinese pediatric population according to appropriate age- and sex-specific partitioning.

METHODS

In this prospective observational study, a total of 1,279 healthy children (singletons, aged from 1 day to 12 years) were recruited, and serum samples were analyzed on a Mindray automated chemiluminescence immunoassay analyzer CL-6000i for thyroid hormone detection, including thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4), total triiodothyronine (T3), and total thyroxine (T4). Age and sex-specific RIs were established, and the corresponding 95% confidence intervals (CIs) were calculated in accordance with the Clinical Laboratory Standards Institute (CLSI) document C28-A3 guidelines.

RESULTS

Quantile testing revealed that the median (P50) and RIs [2.5^th percentile (P2.5)-97.5^th percentile (P97.5)] for TSH, FT3, T3, and T4 of males differed significantly from those of females (P<0.05), except for FT4 (P=0.483). For FT3 and T3, the RIs of males were higher than that of females, and the RI of T4 for males was narrower and higher than that of females [P2.5-P97.5: 72.33-171.60 vs. 72.31-176.27 nmol/L; P50: 116.75 vs. 113.47 nmol/L, P=0.011]. RIs for TSH, FT3, FT4, T3, and T4 showed sex- and age-specific properties and displayed a wide variation during the first month of life but gradually narrowed and concentrated with increasing age. In addition, RIs of TSH, FT3, FT4, and T3 in males differed significantly from females in the first month of life (TSH: 1.46-10.87 vs. 1.08-11.35 mIU/L; FT3: 2.96-7.08 vs. 2.35-7.27 pmol/L, FT4: 13.34-28.65 vs. 13.82-31.83 pmol/L; T3: 0.83-2.33 vs. 0.72-2.46 nmol/L). The RI of T4 also exhibited a difference between males and females in the 9- to 12-year age group (59.31-150.72 vs. 63.29-146.94 pmol/L for males and females, respectively).

CONCLUSIONS

Pediatric RIs of thyroid hormones display age- and sex-specific trends. The RIs established in this study will improve the accuracy of TSH assay result interpretations and clinical decision-making in clinical laboratories that utilize the Mindray analytical platform.