This work is licensed under a Abstract
Objective
To establish sex- and age-specific reference intervals for plasma concentrations of adrenocorticotropic hormone (ACTH) and direct renin in healthy youth.
Design
529 healthy subjects (5.8–20.4 years) were recruited as part of the third Copenhagen Puberty Study, an ongoing cross-sectional study of healthy Danish participants attending compulsory school and high school.
Method
Plasma ACTH and direct plasma renin concentrations were established using GAMLSS statistics, sex- and age-specific reference intervals and standard deviation (SD) scores. Concentrations were evaluated according to pubertal stage and oral contraceptive (OC) use.
Results
ACTH concentrations did not differ between sexes. ACTH concentrations were higher in pubertal males than in prepubertal males (P = 0.015); however, this difference was not statistically significant when analyses were restricted to samples collected before 10:00 h. In females, ACTH concentrations did not seem to differ according to pubertal status. In both sexes, renin concentrations were lower in pubertal than in prepubertal subjects (females: P < 0.001; males: P = 0.016). Renin SD scores were lower in OC users than in non-OC users (P = 0.007), while ACTH SD scores did not differ between these groups.
Conclusion
Sex- and age-specific reference intervals for plasma concentrations of ACTH and direct renin in young, healthy subjects were provided, reflecting changed levels through puberty and significantly lower renin SD scores in OC users. Application of these biomarkers’ SD scores may enhance the management of patients with adrenal disorders.
Significance statement
Reliable reference data for plasma ACTH and direct plasma renin in healthy children are limited. This large population-based cohort study of healthy participants attending compulsory school and high school provides comprehensive sex- and age-specific reference intervals for plasma ACTH and renin. Furthermore, absolute concentrations were converted to relative SD scores, thereby providing a more unified and standardized tool for clinical assessment. Reporting ACTH and renin concentrations by pubertal stage represents a novel aspect. These new reference intervals enhance the clinical utility of biomarker-based monitoring and treatment of pediatric endocrine disorders, such as congenital adrenal hyperplasia, addressing a critical gap in current clinical pediatric practice.
Clinical trial registration number
Keywords: ACTH, renin, reference interval, children, puberty, Tanner stage
Introduction
In clinical practice, reference intervals are essential for interpreting laboratory results and aiding accurate diagnosis and medical decision-making (1). Plasma adrenocorticotropic hormone (ACTH) is particularly useful for assessing pituitary–adrenal axis disturbances and, together with plasma cortisol, helps distinguish primary from secondary adrenal insufficiency (2, 3). In combination with blood pressure (BP) and electrolyte monitoring, plasma renin is used to adjust synthetic mineralocorticoid therapy in classic congenital adrenal hyperplasia (CAH) (3).
Detailed pediatric reference intervals exist for many biochemical analytes (4, 5, 6). However, reference intervals for ACTH and renin in children are limited, leading laboratories to often rely on adult reference ranges when interpreting pediatric results. Often, available reference intervals for ACTH and renin are based on small cohorts of pediatric in- or outpatients (7, 8, 9), and many are derived from plasma renin activity assays (10, 11). In clinical practice, direct renin measurement is widely used due to its operational simplicity and practical advantages, including standardized units that facilitate inter-laboratory comparability and a low sample volume requirement that is particularly suitable for pediatric use (12, 13, 14). However, as an immunoassay-based method, direct renin measurement is also subject to limitations related to antibody specificity. The scarcity of well-defined reference intervals may comprise patient care by increasing the risk of over- or undertreatment (3).
Particularly in immunoassays, differences in calibration standardization often necessitate establishment of assay-specific reference intervals, which may challenge comparisons between clinical centers (15, 16). Furthermore, absolute endocrine concentrations in childhood and adolescence can be biased by sex- and age-specific variations (5), arising from differences in adrenal maturation, gonadal hormone secretion, and pubertal timing. This underscores the importance of sex-specific reference intervals in the youth population and highlights the limitations of applying uniform or adult-based ranges. These challenges can be addressed by expressing biomarkers as sex- and age-specific standard deviation (SD) scores, which allow comparison across sex, age, assay type, and center and provide a more standardized and unified tool for clinical assessment (16).
The present study included a large population-based cohort of healthy Danish participants attending compulsory school and high school. Reliable reference values are essential throughout childhood, including early life, where rapid developmental and endocrine changes make age-specific hormonal interpretation particularly important. While the establishment of reference values for the 0- to 5-year age group represents an important clinical need, this age interval lies outside the scope of the current study. Accordingly, the aims of the present study were to evaluate the variation of plasma ACTH and renin concentrations: i) in relation to sex, age, and pubertal stage, and ii) in relation to the use of oral contraceptives (OCs).
Materials and methods
Healthy participants
Subjects were voluntarily recruited for the Third Copenhagen Puberty Study (COPUS III) from January 2023 to April 2024. COPUS III is a cross-sectional study of healthy Danish participants from schools in the Greater Copenhagen area, aimed at characterizing growth and pubertal timing. In total, 697 participants were recruited. Information about health and medical history was obtained through electronic questionnaires, completed by parents for participants under 18 years of age and self-reported by participants aged 18 years and older. To provide references representing children living in the Greater Copenhagen area, ethnicity was not an exclusion parameter. Exclusion criteria are shown in Fig. 1. In total, 529 participants (56% females) with a median age of 10.9 years (range: females: 5.9–19.9 years; males: 5.8–20.4 years) were included. This comprised 525 ACTH measurements and 528 renin measurements. In a substudy, 10 excluded female OC users (16.3–19.3 years) were age-matched with 35 female non-OC users (16.3–19.2 years) from the healthy cohort.
Figure 1.
Flow chart of consecutive exclusion steps of subjects in the current study, with the number of excluded subjects indicated at each step in the diagram. After applying the exclusion criteria, data from a total of 529 healthy subjects were included for further analysis. ACTH: adrenocorticotropic hormone; NSAID: nonsteroidal anti-inflammatory drug.
Pubertal development was assessed according to the methods by Marshall and Tanner (17, 18). In females, breast (B1–B5) stages were evaluated by palpation. In males, genital (G1–G5) stages were assessed by inspection, and testicular volume was estimated by palpation to the nearest one mL using Prader’s orchidometer. If unequal, the largest testicular volume was used for further analysis. Pubertal onset was defined as Tanner breast stage ≥ B2 in females and volume of at least one testis ≥ 4 mL in males.
Processing and analysis of ACTH and renin
Non-fasting blood samples were drawn from an antecubital vein preceded by 10 min of rest in the supine position. Samples were collected in EDTA plasma tubes between 08:00 and 14:00 h (median: 10:15 (09:30 to 11:00) h). Of these, 213 participants (54% females) were sampled before 10:00 h. Immediately after collection, the samples were centrifuged, pipetted, and stored on dry ice (∼80°C) for transport to the laboratory. ACTH was measured within three hours using a chemiluminescence immunoassay (Cobas e801, Roche Diagnostics, Germany; RRID: AB_2783634) with a lower limit of quantification (LOQ) of 0.66 pmol/L. Samples for renin analysis were stored at −20°C until measured using the IDS-iSYS Direct Renin chemiluminescence immunoassay (Immuno Diagnostic Systems (IDS)-iSYS Direct Renin assay, IDS Ltd, UK; RRID: AB_2892057) with a limit of detection (LOD) of 1.8 mIU/L. All measurements for ACTH and renin were above LOQ and LOD, respectively.
Statistical analyses
Based on the healthy cohort, reference intervals for plasma ACTH and renin were modeled using the generalized additive model for location, scale, and shape (GAMLSS) that transforms data to follow a Gaussian distribution (19, 20). Absolute concentrations of ACTH and renin in OC users were converted to relative sex- and age-related SD scores (SD score = ((X/M)L − 1)/(L × S)), with X being the measurement value, L adjusting for skewness (L ≠ 0), M corresponding to the median, and S approximating the coefficient of variation. Reference intervals were reported as 2.5, 16, 50, 84, and 97.5 percentiles corresponding to −2 SD, −1 SD, mean, 1 SD, and 2 SD, with SD scores of −2 to +2 considered as normal.
Comparisons across groups were done using the Kruskal–Wallis test and the Mann–Whitney U test. Correlations were done using Spearman’s rho correlation, where degrees of correlation were interpreted according to Schober et al. (21). A P value < 0.05 was considered statistically significant. Data were reported as medians and interquartile ranges (IQRs), unless otherwise stated. Figures and statistical analyses were performed using Excel (Microsoft Office 365), GraphPad Prism (version 10.1.2), R (version 4.3.2 and the ‘gamlss’ package, version 5.4.22), and IBM Statistics SPSS (version 29.0.1.0). To address potential diurnal variation, all comparisons and correlations involving ACTH concentrations were repeated in samples obtained before 10:00 h.
Results
Plasma concentrations of ACTH and renin in relation to age
Plasma concentrations of ACTH exhibited large interindividual variations in both females (4.0 pmol/L, range: 0.9–16.3 pmol/L) and males (4.9 pmol/L, 1.3–24.8 pmol/L) (Fig. 2). In females, there was no correlation between concentrations of ACTH and age (rs = 0.02, P = 0.702), while a weak correlation was observed in males (rs = 0.16, P = 0.013). Similarly, large interindividual variations in plasma concentrations of renin were observed in both females (45.0 mIU/L, range: 10–240 mIU/L) and males (46.0 mIU/L, 12–140 mIU/L) (Fig. 3). Weak negative correlations were observed between concentrations of renin and age in both females (rs = −0.38, P < 0.001) and males (rs = −0.19, P = 0.003). No significant correlations were found between SD scores of ACTH and renin in neither females nor males.
Figure 2.
Plasma concentrations of adrenocorticotropic hormone (ACTH) as a function of age in (A) 305 healthy females grouped according to the use of OCs (open red dots: non-OC users, n = 295; solid black dots: OC users, n = 10) and in (B) 230 healthy males (open blue dots). The black lines indicate −2 SD, −1 SD, 0 SD, 1 SD, and 2 SD, respectively. The number of measurements above the axis limits: n = 1 male.
Figure 3.
Plasma concentrations of renin as a function of age in (A) 307 healthy females grouped according to the use of OCs (open red dots: non-OC users, n = 297; solid black dots: OC users, n = 10) and in (B) 231 healthy males (open blue dots). The black lines indicate −2 SD, −1 SD, 0 SD, 1 SD, and 2 SD, respectively. The number of measurements above the axis limits: n = 5 female non-OC users.
Plasma concentrations of ACTH in relation to pubertal stage
Plasma concentrations of ACTH did not differ between prepubertal and pubertal females, P = 0.248 (Fig. 4A). In females, no significant differences were observed across Tanner breast stages, P = 0.729 (Fig. 4B and Table 1). Plasma concentrations of ACTH were significantly lower in prepubertal males (4.4 (IQR: 3.5–5.8) pmol/L) than in pubertal males (5.2 (3.7–6.8) pmol/L), P = 0.015 (Fig. 4C), and a non-significant trend with higher levels in later genital stages was observed, P = 0.063 (Fig. 4D).
Figure 4.
Plasma concentrations of adrenocorticotropic hormone (ACTH) according to pubertal development. Each dot represents a sample (red dot: female; blue dot: male). The black lines indicate medians. Females are grouped according to (A) prepuberty (Tanner breast stage B1: n = 125) and puberty (Tanner breast stage ≥ B2: n = 169) and (B) breast stages (B1: n = 125, B2: n = 48, B3: n = 36, B4: n = 39, and B5: n = 46). Males are grouped according to (C) prepuberty (testicular volume < 4 mL: n = 115) and puberty (testicular volume ≥ 4 mL: n = 113) and (D) Tanner genital stages (G1: n = 100, G2: n = 63, G3: n = 24, G4: n = 12, and G5: n = 30). The number of measurements above the axis limit: G1 = 1.
Table 1.
Plasma concentrations of adrenocorticotropic hormone (ACTH) and renin according to Tanner stage. Concentrations are shown as medians and interquartile ranges.
| Tanner stage | ACTH (pmol/L) | n | Renin (mIU/L) | n |
|---|---|---|---|---|
| Females | ||||
| B1 | 3.8 (3.3–5.1) | 125 | 55.0 (39.8–71.5) | 126 |
| B2 | 4.0 (2.9–6.1) | 48 | 42.0 (29.5–67.0)* | 48 |
| B3 | 4.1 (3.3–6.7) | 36 | 47.5 (34.3–79.3) | 36 |
| B4 | 4.2 (3.0–5.0) | 39 | 34.5 (23.3–56.5)* | 40 |
| B5 | 4.1 (3.2–5.5) | 46 | 33.5 (23.0–43.5) | 46 |
| Males | ||||
| G1 | 4.5 (3.5–6.0) | 100 | 47.0 (35.3–73.0) | 100 |
| G2 | 4.6 (3.6–6.0) | 63 | 47.0 (34.0–68.0) | 63 |
| G3 | 5.1 (3.4–8.4) | 24 | 46.5 (29.8–77.8) | 24 |
| G4 | 6.1 (4.2–9.0) | 12 | 46.5 (40.0–68.3) | 12 |
| G5 | 6.0 (4.3–7.7) | 30 | 36.0 (29.0–50.0) | 31 |
Abbreviations: ACTH, adrenocorticotropic hormone; B, Tanner breast stage; G, Tanner genital stage; n, number of available data points within each variable.
Concentration significantly different from the concentration in the previous Tanner stage: P < 0.05.
Plasma concentrations of renin in relation to pubertal stage
Plasma concentrations of renin were significantly higher in prepubertal females (55.0 (IQR: 39.8–71.5) mIU/L) than in pubertal females (39.0 (27.0–58.0) mIU/L), P < 0.001 (Fig. 5A). Renin concentrations differed significantly across Tanner breast stages, with lower levels observed in later breast stages, P < 0.001 (Fig. 5B). Significant differences were observed between B1 (55.0 mIU/L) and B2 (42.0 mIU/L) (P = 0.027) and between B3 (47.5 mIU/L) and B4 (34.5 mIU/L) (P = 0.010), while no significant differences were observed between stages B2 and B3 nor between stages B4 and B5 (Fig. 5B and Table 1). Plasma concentrations of renin were significantly higher in prepubertal males (48.0 (37.0–70.0) mIU/L) than in pubertal males (42.5 (31.0–68.3) mIU/L), P = 0.016 (Fig. 5C), while no significant differences were observed across genital stages, P = 0.082 (Fig. 5D and Table 1).
Figure 5.
Plasma concentrations of renin according to pubertal development. Each dot represents a sample (red dot: female; blue dot: male). The black lines indicate medians. Females are grouped according to (A) prepuberty (Tanner breast stage B1: n = 126) and puberty (Tanner breast stage ≥ B2: n = 170) and (B) Tanner breast stages (B1: n = 126, B2: n = 48, B3: n = 36, B4: n = 40, and B5: n = 46). Males are grouped according to (C) prepuberty (testicular volume < 4 mL: n = 115) and puberty (testicular volume ≥ 4 mL: n = 114) and (D) Tanner genital stages (G1: n = 100, G2: n = 63, G3: n = 24, G4: n = 12, and G5: n = 31). The number of measurements above the axis limit: female prepuberty (B1): n = 2, female puberty: B3: n = 2 and B4: n = 1.
Plasma concentrations of ACTH and renin in relation to use of oral contraceptives
Absolute plasma concentrations of ACTH did not differ significantly between OC users (3.1 (IQR: 1.5–4.4) pmol/L) and age-matched non-OC users (4.2 (2.9–4.7) pmol/L), P = 0.154. Similarly, no significant differences were observed between ACTH SD scores in OC users (−0.47 (−1.56–0.17)) and non-OC users (0.10 (−0.54–0.36)), P = 0.146 (Fig. 6A). However, plasma concentrations of renin were significantly lower in OC users (15.0 (11.8–26.8) mIU/L) than in non-OC users (32.0 (21.0–43.0) mIU/L), P = 0.009. Correspondingly, OC users had significantly lower SD scores (−0.75 (−1.75–−0.22)) than non-OC users (0.31 (−0.38–0.73)), P = 0.007 (Fig. 6B).
Figure 6.
SD scores of plasma concentrations of (A) adrenocorticotropic hormone (ACTH) and (B) renin in female OC users (solid black dots, n = 10) and age-matched non-OC users (open red dots, n = 35). The black lines indicate medians. The gray dotted lines indicate −2 SD and 2 SD, respectively.
Plasma concentrations of ACTH in samples collected before 10:00 h
In samples collected before 10:00 h, the correlation between ACTH concentrations and age in males (n = 96) was not statistically significant (rs = 0.13, P = 0.226). Similarly, ACTH concentrations did not differ between prepubertal and pubertal males (P = 0.140), and no differences were observed across genital stages (P = 0.442). All other analyses of ACTH concentrations were unchanged compared with the main analyses (data not shown).
Discussion
To our knowledge, this is the first study to establish sex- and age-related reference intervals for plasma ACTH and direct plasma renin concentrations in a large cohort of healthy participants attending compulsory school and high school. Most pediatric hormone reference intervals are based solely on chronological age. However, due to hormonal changes throughout childhood and adolescence, age may not accurately reflect physiological status; therefore, reference intervals should also be established based on sexual development (15, 22). Accordingly, concentrations of ACTH and renin were evaluated in relation to pubertal stage and, furthermore, standardized to SD scores for comparison across sex, age, and OC use.
The relevance of considering both age and sexual development when interpreting ACTH and renin concentrations is supported by known physiological changes during growth and puberty. Age and sexual maturation are expected to influence these hormones, as progressive adrenal and gonadal maturation during puberty alters regulation of the hypothalamic–pituitary–adrenal (HPA) axis, potentially affecting ACTH secretion. Likewise, the renin–angiotensin–aldosterone system undergoes developmental changes driven by increasing body size, plasma volume expansion, and modifications in sodium and fluid homeostasis. These physiological processes may therefore contribute to the age- and Tanner stage-related variation observed in ACTH and renin among healthy youth.
Plasma ACTH concentrations were slightly lower in females than in males. In females, ACTH concentrations remained stable at around 4 pmol/L across age and pubertal stage, showing no correlation with age. In contrast, males had higher ACTH concentrations with age and pubertal stage, with pubertal males having significantly higher levels than prepubertal males; however, this difference was not significant when analyses were restricted to samples collected before 10:00 h. Further studies are needed to establish whether this non-significant finding reflects a true absence of difference or limited statistical power. To our knowledge, only one study has reported reference intervals for plasma ACTH in children (7). This study included patients aged 4–16 years who underwent venipuncture as part of their disease evaluation, without any anamnestic or clinical signs of adrenal or pituitary disorders. However, it used a different assay and, thus, did not allow direct comparison of ACTH levels with our results.
An important consideration when establishing reference values for ACTH is its pronounced circadian rhythm, with peak levels in the early morning and nadir levels around midnight (23). Consequently, the timing of blood sampling is crucial for accurate reference intervals. In the present study, samples were collected during school hours, which may not fully account for diurnal variation. Notably, restricting analyses to samples collected before 10:00 h attenuated the previously observed associations between ACTH concentrations and age and pubertal status in males, underscoring the importance of standardized sampling conditions when establishing and applying ACTH reference values. To improve the precision of future reference intervals, blood samples should preferably be collected in the early morning (07:00–10:00 h), when ACTH levels are at their peak and less influenced by diurnal decline. Accounting for these physiological variations is particularly important in clinical contexts, such as CAH, where accurate ACTH measurement is essential for optimal disease management.
Plasma renin concentrations were slightly lower in females than in males. In both sexes, renin concentrations were lower with increasing age, consistent with the prior literature (8, 9, 14). Reporting renin concentrations by pubertal stage represents a novel aspect. In both sexes, prepubertal subjects had significantly higher renin levels than pubertal subjects, and overall, renin concentrations were lower with later pubertal stages. In previous studies, reference intervals on renin were based on absolute concentrations; however, the limitation of fixed reference intervals spanning wide age ranges is highlighted when using SD scores. For example, a renin concentration of 93 mIU/L corresponds to different SD scores dependent on age; thus, it can be 0.70 in a six-year-old female and 2.07 in a 19-year-old male, with the latter falling slightly outside the reference range. This discrepancy illustrates the importance of sex- and age-specific reference intervals.
Previous studies suggest a suppressive effect of OC use on the HPA axis, with lower ACTH levels in OC users than in non-OC users (24, 25). These lower ACTH levels were reported only during the menstrual phase of the uterine cycle (25). In our study, OC use did not significantly affect the ACTH levels, although they were slightly lower in OC users than in age-matched non-OC users. However, data on phases of uterine or OC cycles were not available in the current study. OC users had significantly lower plasma concentrations of renin than non-OC users, which contrasts with higher renin levels in OC users in a recent systematic review of ten studies (26). This discrepancy may be due to differences in methodology, sample size, or the younger age of OC users in our study. However, consistent with the existing literature (27), we found a significantly higher systolic BP and diastolic BP in OC users than in non-OC users (data not shown).
Due to the instability of ACTH (i.e., short half-life <10 min), proper handling and freezing of samples are important (28). Similarly, renin measurements presuppose correct freezing to prevent cryoactivation of prorenin, which could otherwise lead to the overestimation of renin concentrations (14, 29, 30). To minimize cryoactivation, plasma was stored on dry ice (∼80°C) immediately after sampling and during processing and was thereafter stored at −20°C until analysis. Despite these precautions, complete prevention of cryoactivation cannot be ensured. Moreover, renin measurements are influenced by factors such as age, sodium intake, and posture, with concentrations increasing in standing position (14). In all subjects, plasma concentrations of sodium were within reference ranges and blood samples were collected after 10 min of supine rest; however, a longer recumbent period could potentially further reduce renin overestimation (13).
The strengths of this study include the following: i) direct sampling from a population-based cohort of healthy individuals, ii) consistent clinical evaluation of pubertal development by trained medical doctors, iii) immediate blood sample processing and quantification with highly sensitive assays, and iv) the use of SD scores, allowing evaluation of ACTH and renin concentrations across sex and age. Limitations include the following: i) blood sample timing, which was constrained to school hours, limiting the ability to account for diurnal variations in ACTH and renin levels and deviating from our laboratory recommended sampling hours (07:00–10:00 h); ii) a skewed age distribution, with a limited number of males, especially in Tanner stage G4, possibly due to recruitment from a single high school, voluntary participation, school scheduling constraints (tests or examinations), and the sensitive nature of pubertal assessment in this age group; iii) the inclusion of only school-aged children, limiting the applicability of these reference intervals for children below five years of age; and iv) the lack of information on salt intake, timing of last feeding, and fluid status, which could potentially influence renin measurements.
In conclusion, this study provided reference intervals for plasma concentrations of ACTH and renin in a large population-based cohort of healthy participants attending compulsory school and high school. In the main analysis, ACTH concentrations were higher in males with increasing ages and later pubertal stages; however, this finding was attenuated when analyses were restricted to samples collected before 10:00 h, and these parameters did not seem to influence the concentrations in females. Concentrations of renin were lower with increasing age and pubertal stage in both sexes, underscoring the importance of sex- and age-related reference intervals. In the assessment of ACTH and renin, using sex- and age-specific SD scores for these biomarkers could enhance treatment monitoring and advance personalized medicine in pediatric patients with adrenal disorders.
Declaration of interest
The study was partly sponsored/funded by an unrestricted research grant from Lundbeck A/S (No.: CW183906). The grant provider was not involved in the study design; participant recruitment; collection, analysis, and interpretation of data; writing of the report; and the decision to submit this paper.
Funding
This work was supported by Rigshospitalet’s Scholarship, which was awarded to Pernille Edström (No.: E-22717-26, 37RJ). The Copenhagen Puberty Study received funding from the Kirsten and Freddy Johansen Foundation (No.: F-22717-55). In addition, the project received funding from the Centre on Endocrine Disruptors, the Danish Environmental Protection Agency (MST-611-00012), and Lundbeck A/S (No.: CW183906).
Data availability
Data are not publicly available but are available from the corresponding author on reasonable request.
Ethics statements
The COPUS III study was approved by the Regional Committee on Health Research Ethics (H-19087825) and the Danish Data Protection Agency (RH-2018-24/I-Suite No. 6179). All participants or their parents, if under 18 years of age, provided written informed consent.
Acknowledgments
We would like to thank all the COPUS participants and families without whom this work would not have been possible. Furthermore, we would like to thank our colleagues at the Hormone Laboratory at Department of Growth and Reproduction, Copenhagen University Hospital – Rigshospitalet, Copenhagen, Denmark, for their valuable support and contributions to this project.
References
- 1.Horn PS & Pesce AJ. Reference intervals: an update. Clin Chim Acta 2003. 334 5–23. ( 10.1016/S0009-8981(03)00133-5) [DOI] [PubMed] [Google Scholar]
- 2.Bornstein SR, Allolio B, Arlt W, et al. Diagnosis and treatment of primary adrenal insufficiency: an endocrine society clinical practice. J Clin Endocrinol Metab 2016. 101 364–389. ( 10.1210/jc.2015-1710) [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Speiser PW, Arlt W, Auchus RJ, et al. Congenital adrenal hyperplasia due to steroid 21-hydroxylase deficiency: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab 2018. 103 4043–4088. ( 10.1210/jc.2018-01865) [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Adeli K, Higgins V, Trajcevski K, et al. The Canadian laboratory initiative on pediatric reference intervals: a CALIPER white paper. Crit Rev Clin Lab Sci 2017. 54 358–413. ( 10.1080/10408363.2017.1379945) [DOI] [PubMed] [Google Scholar]
- 5.Frederiksen H, Johannsen TH, Andersen SE, et al. Sex- and age-specific reference intervals of 16 steroid metabolites quantified simultaneously by LC-MS/MS in sera from 2458 healthy subjects aged 0 to 77 years. Clin Chim Acta 2024. 562 119852. ( 10.1016/j.cca.2024.119852) [DOI] [PubMed] [Google Scholar]
- 6.Bohn MK, Horn P, League D, et al. Pediatric reference intervals for 32 routine biochemical markers using the siemens healthineers atellica® CH assays in healthy children and adolescents. Clin Biochem 2022. 99 69–77. ( 10.1016/j.clinbiochem.2021.10.006) [DOI] [PubMed] [Google Scholar]
- 7.Petersen KE. ACTH in normal children and children with pituitary and adrenal diseases. I. Measurement in plasma by radioimmunoassay – basal values. Acta Paediatr Scand 1981. 70 341–345. ( 10.1111/j.1651-2227.1981.tb16561.x) [DOI] [PubMed] [Google Scholar]
- 8.Coates JE, Chapelsky LJ & Yatscoff RW. Pediatric reference intervals for plasma renin. Clin Biochem 1994. 27 316–317. ( 10.1016/0009-9120(94)90036-1) [DOI] [PubMed] [Google Scholar]
- 9.Miller JJ, Bohn MK, Higgins V, et al. Pediatric reference intervals for endocrine markers in healthy children and adolescents on the Liaison XL (DiaSorin) immunoassay system. Clin Biochem 2023. 120 110644. ( 10.1016/j.clinbiochem.2023.110644) [DOI] [PubMed] [Google Scholar]
- 10.Fiselier TJW, Lijnen P, Monnens L, et al. Levels of renin, angiotensin I and II, angiotension-converting enzyme and aldosterone in infancy and childhood. Eur J Pediatr 1983. 141 3–7. ( 10.1007/BF00445660) [DOI] [PubMed] [Google Scholar]
- 11.Fukushige J, Shimomura K & Ueda K. Influence of upright activity on plasma renin activity and aldosterone concentration in children. Eur J Pediatr 1994. 153 284–286. ( 10.1007/BF01954521) [DOI] [PubMed] [Google Scholar]
- 12.Krüger C, Höper K, Weissörtel R, et al. Value of direct measurement of active renin concentrations in congenital adrenal hyperplasia due to 21-hydroxylase deficiency. Eur J Pediatr 1996. 155 858–861. ( 10.1007/BF02282834) [DOI] [PubMed] [Google Scholar]
- 13.Sommer L, Quade A, Hartmann K, et al. Direct measurement of immunoreactive renin during changes of posture in man. Horm Res 1992. 37 171–175. ( 10.1159/000182304) [DOI] [PubMed] [Google Scholar]
- 14.Ferrari P & Bianchetti MG. Diagnostic investigations in inherited endocrine disorders of sodium regulation. In Diagnostics of Endocrine Function in Children and Adolescents, edn 4. pp 210–234. Eds Ranke M & Mullis PE. Basel, Switzerland: Karger, 2011. ( 10.1159/000327410) [DOI] [Google Scholar]
- 15.Bae YJ, Zeidler R, Baber R, et al. Reference intervals of nine steroid hormones over the life-span analyzed by LC-MS/MS: effect of age, gender, puberty, and oral contraceptives. J Steroid Biochem Mol Biol 2019. 193 105409. ( 10.1016/j.jsbmb.2019.105409) [DOI] [PubMed] [Google Scholar]
- 16.Clausen CS, Ljubicic ML, Main KM, et al. Congenital adrenal hyperplasia in children: a pilot study of steroid hormones expressed as sex- and age-related standard deviation scores. Horm Res Paediatr 2020. 93 226–238. ( 10.1159/000509079) [DOI] [PubMed] [Google Scholar]
- 17.Marshall WA & Tanner JM. Variations in pattern of pubertal changes in girls. Arch Dis Child 1969. 44 291–303. ( 10.1136/adc.44.235.291) [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Marshall WA & Tanner JM. Variations in the pattern of pubertal changes in boys. Arch Dis Child 1970. 45 13–23. ( 10.1136/adc.45.239.13) [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19.Rigby RA & Stasinopoulos DM. Generalized additive models for location, scale and shape. J Roy Stat Soc C Appl Stat 2005. 54 507–554. ( 10.1111/j.1467-9876.2005.00510.x) [DOI] [Google Scholar]
- 20.Søeborg T, Frederiksen H, Mouritsen A, et al. Sex, age, pubertal development and use of oral contraceptives in relation to serum concentrations of DHEA, DHEAS, 17α-hydroxyprogesterone, Δ4-androstenedione, testosterone and their ratios in children, adolescents and young adults. Clin Chim Acta 2014. 437 6–13. ( 10.1016/j.cca.2014.06.018) [DOI] [PubMed] [Google Scholar]
- 21.Schober P, Boer C & Schwarte LA. Correlation coefficients: appropriate use and interpretation. Anesth Analg 2018. 126 1763–1768. ( 10.1213/ANE.0000000000002864) [DOI] [PubMed] [Google Scholar]
- 22.Elmlinger MW. Laboratory measurements of hormones and related biomarkers: technologies, quality management and validation. In Diagnostics of Endocrine Function in Children and Adolescents, edn 4. pp 1–31. Eds Ranke M & Mullis PE. Basel, Switzerland: Karger, 2011. ( 10.1159/000327398) [DOI] [Google Scholar]
- 23.Oster H, Challet E, Ott V, et al. The functional and clinical significance of the 24-hour rhythm of circulating glucocorticoids. Endocr Rev 2017. 38 3–45. ( 10.1210/er.2015-1080) [DOI] [PMC free article] [PubMed] [Google Scholar]
- 24.Garforth B, Degnbol H, Terris ET, et al. Elevated plasma oxytocin levels and higher satisfaction with life in young oral contraceptive users. Sci Rep 2020. 10 8208. ( 10.1038/s41598-020-64528-w) [DOI] [PMC free article] [PubMed] [Google Scholar]
- 25.Pedersen MV, Hansen LMB, Garforth B, et al. Adrenocorticotropic hormone secretion in response to anticipatory stress and venepuncture: the role of menstrual phase and oral contraceptive use. Behav Brain Res 2023. 452 114550. ( 10.1016/j.bbr.2023.114550) [DOI] [PubMed] [Google Scholar]
- 26.dos Santos PA, de Oliveira AM, Alves CQ, et al. Renin-angiotensin-aldosterone system in women using combined oral contraceptive: a systematic review. Rev Bras Ginecol Obstet 2022. 44 710–718. ( 10.1055/s-0042-1745790) [DOI] [PMC free article] [PubMed] [Google Scholar]
- 27.Oliveira SS, Petto J, Diogo DP, et al. Plasma renin in women using and not using combined oral contraceptive. Int J Cardiovasc Sci 2020. 33 208–214. ( 10.36660/ijcs.20180021) [DOI] [Google Scholar]
- 28.Flück CE. Assessing the function of the human adrenal cortex. In Diagnostics of Endocrine Function in Children and Adolescents, edn 4. pp 350–378. Eds Ranke M & Mullis PE. Basel, Switzerland: Karger, 2011. ( 10.1159/000327417) [DOI] [Google Scholar]
- 29.Campbell DJ, Nussberger J, Stowasser M, et al. Activity assays and immunoassays for plasma renin and prorenin: information provided and precautions necessary for accurate measurement. Clin Chem 2009. 55 867–877. ( 10.1373/clinchem.2008.118000) [DOI] [PubMed] [Google Scholar]
- 30.Özcan Ö, Hillebrand JJ, den Elzen W, et al. The clinical impact of sample storage at −20°C on renin reference intervals and aldosterone-renin ratio calculations. J Clin Endocrinol Metab 2024. 109 e1472–e1475. ( 10.1210/clinem/dgae057) [DOI] [PMC free article] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
Data are not publicly available but are available from the corresponding author on reasonable request.