Monitoring treatment in congenital adrenal hyperplasia

Monitoring treatment in pediatric patients with 21-hydroxylase deficiency

21-hydroxylase deficiency (21-OHD) is the most common form of congenital adrenal hyperplasia. In most developed countries, newborn screening enables diagnosis of 21-OHD in asymptomatic patients during the neonatal period. In addition, recent advances in genetic testing have facilitated diagnosing 21-OHD, particularly in patients with equivocal clinical information. On the other hand, many challenges related to treatment remain. The goals of glucocorticoid therapy for childhood 21-OHD are to maintain growth and maturation as in healthy children by compensating for cortisol deficiency and suppressing excess adrenal androgen production. It is not easy to calibrate the glucocorticoid dosage accurately for patients with 21-OHD. Auxological data, such as height, body weight, and bone age, are considered the gold standard for monitoring of 21-OHD, particularly in prepuberty. However, these data require months to a year to evaluate. Theoretically, biochemical monitoring using steroid metabolites allows a much shorter monitoring period (hours to days). However, there are many unsolved problems in the clinical setting. For example, many steroid metabolites are affected by the circadian rhythm and timing of medication. There is still a paucity of evidence for the utility of biochemical monitoring. In the present review, we have attempted to clarify the knowns and unknowns about treatment parameters in 21-OHD during childhood.

First Morning Pregnanetriol and 17-Hydroxyprogesterone Correlated Significantly in 21-Hydroxylase Deficiency

BACKGROUND

Biochemically monitoring 21-hydroxylase deficiency (21-OHD) is challenging. Serum/blood 17-hydroxyprogesterone (17OHP) measurements are normally used for this purpose. Urinary pregnanetriol (PT), a urinary metabolite of 17OHP, may also be used. Based on auxological data, we previously reported that the optimal first morning PT value fell in the range of 2.2-3.3 mg/gCr (95% confidence interval of the mean) and 0.59-6.0 mg/gCr (10^th - 90^th percentile) for monitoring 21-OHD treatment. No report thus far has directly compared the first morning urinary PT value with the 17OHP value at various times during the day.

OBJECTIVE

To explore the correlation between the first morning urinary PT value before glucocorticoid administration and the serum/blood 17OHP value at three time points, namely, before and two and four hours after glucocorticoid administration.

DESIGN

This was a prospective study done at two children's hospitals.

METHODS

In total, 25 patients with 21-OHD aged 3-25 years were recruited. Their urinary PT levels and 17OHP levels were measured for three days within a total period of one week. The first morning PT value was collected on all three days. Dried blood spots and serum were used to measure 17OHP.

RESULTS

The range for the first morning PT value for all the samples (n=69) was 0.10-56.1 mg/gCr. A significant, positive correlation was found between the first morning PT and 17OHP values before medication (r=0.87, p<0.01), and weaker correlation was observed between the first morning PT and 17OHP values after medication.

CONCLUSIONS

The first morning PT correlated more significantly with 17OHP before the morning medication. Measuring the first morning PT value may be more practical and useful for monitoring 21-OHD biochemically.

Monitoring of therapy in congenital adrenal hyperplasia

BACKGROUND

Congenital adrenal hyperplasia is a group of disorders caused by defects in the adrenal steroidogenic pathways. In its most common form, 21-hydroxylase deficiency, patients develop varying degrees of glucocorticoid and mineralocorticoid deficiency as well as androgen excess. Therapy is guided by monitoring clinical parameters as well as adrenal hormone and metabolite concentrations.

CONTENT

We review the evidence for clinical and biochemical parameters used in monitoring therapy for congenital adrenal hyperplasia. We discuss the utility of 24-h urine collections for pregnanetriol and 17-ketosteroids as well as serum measurements of 17-hydroxyprogesterone, androstenedione, and testosterone. In addition, we examine the added value of daily hormonal profiles obtained from salivary or blood-spot samples and discuss the limitations of the various assays.

SUMMARY

Clinical parameters such as growth velocity and bone age remain the gold standard for monitoring the adequacy of therapy in congenital adrenal hyperplasia. The use of 24-h urine collections for pregnanetriol and 17-ketosteroid may offer an integrated view of adrenal hormone production but target concentrations must be better defined. Random serum hormone measurements are of little value and fluctuate with time of day and timing relative to glucocorticoid administration. Assays of daily hormonal profiles from saliva or blood spots offer a more detailed assessment of therapeutic control, although salivary assays have variable quality.

An Evidence-Based Model of Multidisciplinary Care for Patients and Families Affected by Classical Congenital Adrenal Hyperplasia due to 21-Hydroxylase Deficiency

In 2002 a consensus statement pertaining to the management of classical congenital adrenal hyperplasia due to 21-hydroxylase deficiency was jointly produced by the Lawson Wilkins Pediatric Endocrine Society and the European Society of Pediatric Endocrinology. One of the recommendations of this consensus was that centers should maintain multidisciplinary teams for providing care and support to these patients and their families. However, the specifics for how this should be accomplished were not addressed in the original consensus statement. Here we interpret and translate the 2002 consensus statement recommendations into medical, surgical and mental health protocols. Additionally, we provide preliminary evidence that such protocols result in improved care and support for patients and families.

Diagnosis of diseases of steroid hormone production, metabolism and action

Biochemical tests have been the basis for investigations of disorders affecting steroid hormones. In recent years it has been possible however to study the genes that determine functional enzymes, cofactors, receptors, transcription factors and signaling systems that are involved in the process. Analyses of mutations are available as a diagnostic service for only a few of these genes although research laboratories may be able to provide a service. Both biochemical and genetic research have brought to light new disorders. Some genes for transcription factors involved in the development of the endocrine organs have also been identified and patients with defects in these processes have been found. This paper will review general aspects of adrenal disorders with emphasis on clinical and laboratory findings. As with all endocrine investigations there are few single measurements that provide a definitive answer to a diagnosis. Timing of samples in relation to age, gender and time of day needs to be considered.

The Range of 2.2-3.3 mg/gCr of Pregnanetriol in the First Morning Urine Sample as an Index of Optimal Control in CYP21 Deficiency

Auxological data are the gold standard indexes of the therapeutic conditions in patients with CYP21 deficiency over long-term periods, whereas urinary pregnanetriol (PT) for 24 h has been used as an index for short-term periods. We previously reported that the range of 1.2–2.1 mg/m²/day of PT for 24 h (24-h PT) could be used as an index of optimal control in patients with CYP21 deficiency. The purpose of this study was to analyze the range of PT in the first morning urine samples (morning PT) as an index of optimal control in patients with CYP21 deficiency. First, the therapeutic periods of 15 participants (aged 2 yr and 5 mo to 17 yr and 4 mo) were classified into excessive, good or poor control periods using auxological data and Cushing-like symptoms, and 24-h PT levels were analyzed in each period, retrospectively. The 95% confidence intervals for the means of 24-h PT levels in the excessive, good and poor control periods were 0.24–2.24 (n=25), 2.88–4.92 (n=114) and 13.26–21.28 (n=72) mg/gCr, respectively. Subsequently, 24-h PT and morning PT levels collected on the same day were analyzed for 14 participants (aged 9 mo to 29 yr and 8 mo). There was a significant correlation between the above two PT levels (n=25, p<0.0001). When the 24-h PT range of the good control period, 2.88–4.92 mg/gCr, was adjusted by the correlation, the ideal morning PT range became 2.15–3.34 mg/gCr. In conclusion, a morning PT in the range of 2.2–3.3 mg/gCr can be used as an index of optimal control in patients with CYP21 deficiency.

Pregnanetriol in the Range of 1.2-2.1 mg/m(2)/day as an Index of Optimal Control in CYP21A2 Deficiency

Auxological data is the gold standard index of the therapeutic condition in CYP21A2 deficiency over a long-range period, whereas urinary pregnanetriol for 24 h (PT) is variable for a shorter-range period. Ideal PT levels in comparison with auxological data have not been reported. The main purpose of this study was to analyze ideal PT values as an index of optimal control for CYP21A2 deficiency. First, inter-daily fluctuation of PT was analyzed in one participant. PT levels were distributed over a wide range of 0.44–14.7 mg/day (n=42) in this participant, suggesting that the therapeutic condition should be judged by multiple PT samples. Second, the therapeutic periods of 15 participants with CYP21A2 deficiency were classified using auxological data and Cushing-like symptoms, and the PT levels were analyzed in each period retrospectively. The 95% confidence intervals for the means of the PT levels in the excessive, good and poor control periods were 0.03–1.25 (n=26), 1.23–2.09 (n=116), and 5.35–8.37 (n=72) mg/m²/day, respectively. In conclusion, 1.2–2.1 mg/m²/day of PT values can be used as an index of optimal control in CYP21A2 deficiency.

Management of 21-hydroxylase deficiency congenital adrenal hyperplasia: A survey of Canadian paediatric endocrinologists

BACKGROUND

Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency is one of the most common autosomal recessive disorders. Many issues in the management of CAH in children still remain unresolved.

OBJECTIVE

To assess how children with CAH are treated in Canada.

METHODS

Fifty-nine paediatric endocrinologists and postgraduate trainees from across Canada took part in a survey that evaluated four areas of CAH management: type and dose of glucocorticoid therapy, current use of alternative therapies, monitoring of care, and approach/attitude to prenatal diagnosis and treatment of CAH.

RESULTS AND CONCLUSIONS

The present survey demonstrated that there is general agreement among paediatric endocrinologists in Canada regarding the management of patients with CAH, which includes very little use of newer antiandrogen therapies. The goal remains to be the optimization of currently available therapy to ensure normal growth and sexual maturation without any evidence of glucocorticoid excess or deficiency. Prenatal diagnosis and management is widely, but infrequently, used.

Blood pressure in children and adolescents with congenital adrenal hyperplasia (21-hydroxylase deficiency): a preliminary report

BACKGROUND

Classical congenital adrenal hyperplasia (CAH) is characterized by a defect in cortisol and aldosterone secretion, adrenal hyperandrogenism, impaired adrenal medullary function and insulin insensitivity. The latter along with the increased tendency towards obesity raises questions whether other cardiovascular risk factors are altered in CAH.

OBJECTIVE

To evaluate 24-h ambulatory blood pressure and obesity in patients with salt-wasting 21-hydroxylase deficiency diagnosed in the neonatal period and treated with hydrocortisone and 9alpha-fludrocortisone thereafter.

METHODS

Thirty-eight children (15 males) aged 11.2 years (range 6.1-18.2 years) underwent 24-h ambulatory blood pressure monitoring in the hospital setting. Standard anthropometric measures of height, weight and skinfold thickness were undertaken and body mass index (BMI) derived. All data were expressed as standard deviation scores (SDS) using the UK Growth Reference data.

RESULTS

Mean daytime systolic blood pressure SDS (1.8, SD 1.1) was significantly higher than the reference population (P < 0.001), and 58% of patients (67% males; 52% females) had systolic hypertension. Mean daytime diastolic blood pressure SDS (0.8, SD 0.8) was also elevated and 24% (13% males; 37% females) had diastolic hypertension. Eighty-four per cent had absence of the physiological nocturnal dip in systolic blood pressure. Height SDS was similar to the reference population but BMI SDS was higher (P < 0.001). BMI SDS was related to systolic blood pressure SDS (r = 0.34; P = 0.03) and the effect was most marked in females where it was related to measures of truncal fat (r = 0.82; P = 0.002).

CONCLUSIONS

Children with salt-wasting 21-hydroxylase deficiency have elevated 24-h ambulatory blood pressure and absence of the physiological nocturnal dip in blood pressure. These abnormalities are associated with a raised BMI, particularly in females. Regular measurement and plotting of blood pressure should be part of the management of children with classical CAH.

Early growth, pubertal development, body mass index and final height of patients with congenital adrenal hyperplasia: factors influencing the outcome

OBJECTIVE

The management of children with congenital adrenal hyperplasia (CAH) remains a challenge, especially with regard to growth potentials. The objective of our analysis was to uncover the factors that influence the growth and final height of patients with CAH.

DESIGN

The linear growth pattern and body mass index (BMI) at different developmental stages (birth to 2 years, 2 years to puberty initiation and puberty initiation to final height) and the final height achieved were analysed retrospectively in 48 patients with 21-hydroxylase deficiency; 17 with the salt-wasting (SW) form, 25 with the simple virilizing (SV) and six with the nonclassical (NC) form.

RESULTS

Mean final height (FH) and FH-SDS were, respectively, 170.8 +/- 5.6 m and -0.57 +/- 0.8 in males and 156.7 +/- 6 cm and -0.61 +/- 1 in females with the SW form, 166.1 +/- 6.1 cm and -1.05 +/- 1 in males and 151.6 +/- 5.4 cm and -1.4 +/- 1 in females with the SV form and 159.7 +/- 6.9 cm and 0.3 +/- 1.4 in females with the NC form. In subjects with the SW form, height SDS at 2 years, at puberty initiation and at FH were -0.18 +/- 0.9, 0.11 +/- 1.28 and -0.6 +/- 1.0, respectively. FH achieved was not different from target height (TH) in the SW group, but it was significantly lower than TH in the SV group (P = 0.003). FH in the SW group showed a positive correlation to the height achieved at 2 years of age (r = 0.68, P = 0.019), and height at 2 years was negatively related to the hydrocortisone dose in the birth to 2-year period (r = -0.79, P = 0.011). FH showed no correlation to hydrocortisone dose at any of the three developmental periods studied. BMI-SDS were not different in the various forms of CAH and showed no correlation to FH or hydrocortisone dose. Age at menarche was comparable to that in our general population.

CONCLUSIONS

Under our conditions of management, the final height of patients with the salt-wasting form was comparable to the target height and to the most favourable literature data. The patients with the simple virilizing form fare less well, mainly due to delayed diagnosis and consequent advancement of bone age and early puberty. In salt-wasting patients, height at 2 years is comparable to normals, it is influenced by the hydrocortisone dose and is related to the final height. Some height is lost during puberty. Hence, monitoring treatment over the first 2 years and during puberty is critical for the outcome in these patients.

Indicators of adult height outcome in classical 21-hydroxylase deficiency congenital adrenal hyperplasia

OBJECTIVE

To obtain objective information on the relationship between adult height (AH), glucocorticoid (GC) dose, and degree of hormonal suppression in a population of patients with 21-hydroxylase deficiency congenital adrenal hyperplasia (21-OHD CAH) to optimize treatment regimes.

STUDY DESIGN

Multicenter retrospective chart review of patients with salt wasting 21-OHD CAH diagnosed in the first 6 months of life, and who had reached AH (n = 54). The data were compiled into a single database.

RESULTS

Mean adult height standard deviation score - midparental height standard deviation score was -1.1 for both sexes. Growth velocity was normal during childhood but compromised during infancy and puberty. Onset and tempo of puberty were normal-to-delayed. Bone age was closely correlated with chronologic age (r = 0.93). AH was negatively correlated with androstenedione in infancy (r -0.68; P =.03) and childhood (-0.66; P <.01) and with testosterone in childhood (r -0.44; P =.01), but not with dehydroepiandrosterone or 17-hydroxyprogesterone. GC dose was not associated with AH.

CONCLUSIONS

Mean AH was in the lower range of genetic potential in this group of persons with 21-OHD CAH. Androgen levels should be used in conjunction with growth velocity measurements to optimize GC dosing in persons with 21-OHD CAH.

Serum cortisol and 17-hydroxyprogesterone interrelation in classic 21-hydroxylase deficiency: is current replacement therapy satisfactory?

One of the main aims in the management of patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency is to achieve adequate suppression of the adrenal cortex with the smallest possible dose of glucocorticoid substitution. To evaluate the administration schedule of current replacement therapy regimens, we investigated the cortisol-17-hydroxyprogesterone interrelation in 36 patients (13 males and 23 females; median age, 12.3 yr; range, 6.1-18.8 yr) with salt-wasting congenital adrenal hyperplasia. As sufficient variation in 17-hydroxyprogesterone concentrations was required to allow analysis of the cortisol-17-hydroxyprogesterone interrelation, patients were divided into 2 groups depending on the adequacy of hypothalamic-pituitary-adrenal axis suppression. The first group consisted of 17 patients with suppressed 17-hydroxyprogesterone concentrations (group 1), and the second group consisted of 19 patients with nonsuppressed 17-hydroxyprogesterone concentrations (group 2). We determined serum cortisol and 17-hydroxyprogesterone concentrations at 20-min intervals for a total of 24 h while patients were receiving their usual replacement treatment with hydrocortisone and 9alpha-fludrocortisone. We also determined the lowest dose of dexamethasone required to suppress the 0800 h serum ACTH concentrations when administered as a single dose (0.3 or 0.5 mg/m(2)) the night before. Mean 24-h cortisol and 17-hydroxyprogesterone concentrations were 3.9 microg/dl (SD = 2.1) and 66.2 ng/dl (SD = 92.7), respectively, in group 1 and 4.1 microg/dl (SD = 2.5) and 4865.7 ng/dl (SD = 6951) in group 2. The 24-h 17-hydroxyprogesterone concentrations demonstrated circadian variation, with peak values observed between 0400-0900 h. In group 2, 17-hydroxyprogesterone concentrations decreased gradually in response to the rise in cortisol concentrations during the day, but remained low during the night despite the almost undetectable cortisol concentrations between 1600-2000 h. Mean 0800 h androstenedione concentrations correlated strongly with integrated 17-hydroxyprogesterone concentrations (r = 0.81; P < 0.0001), but not with integrated cortisol concentrations. There was a significant negative correlation between cortisol and 17-hydroxyprogesterone at lag time 0 min (r = -0.187; P < 0.0001), peaking at lag time 60 min (r = -0.302; P < 0.0001), with cortisol leading 17-hydroxyprogesterone by these time intervals. Finally, 0800 h serum ACTH concentrations were sufficiently suppressed after a dexamethasone dose of 0.3 mg/m(2) in all but three patients. These findings indicate that in classic 21-hydroxylase deficiency, hydrocortisone should be administered during the period of increased hypothalamic-pituitary-adrenal axis activity, between 0400-1600 h, with the biggest dose given in the morning. Blood investigations performed as part of monitoring of congenital adrenal hyperplasia patients should include androstenedione and 17-hydroxyprogesterone concentrations determined in the morning before the administration of hydrocortisone. It should also be emphasized that blood investigations are only complementary to the overall assessment of these patients, which is primarily based on the evaluation of growth and pubertal progress.

Effect of treatment on growth in congenital adrenal hyperplasia

In 22 patients with congenital adrenal hyperplasia (CAH), the effect of treatment on growth was evaluated retrospectively. The degree of control with treatment had generally been assessed by measurements of serum 17-hydroxyprogesterone (17-OHP) and/or urinary pregnanetriol levels. In 20 patients, there were no significant differences in both height SDS for bone age (-2.05 +/- 1.89 vs -1.85 +/- 1.30) and height SDS for chronological age (CA) (0.23 +/- 1.94 vs -0.36 +/- 1.81) in a mean uninterrupted treatment period of 5.80 +/- 3.58 years. Further analysis in salt-losers and nonsalt-losers separately showed that height SDS for bone age had decreased in the salt-losers and had increased in the nonsalt-losers. Six patients had signs of early puberty. In 22 patients, there was a negative correlation between the prednisolone dose on one hand and height velocity SDS for CA and bone age velocity on the other. It was also found that the mean serum levels of 17-OHP did not always reflect the degree of long term control measured by auxological parameters. These findings indicate that our treatment in the patients did not result in a significant improvement in height prognosis. We can conclude that growth prognosis in CAH patients can be improved by relying on auxological parameters rather than serum 17-OHP and urinary pregnanetriol levels for monitoring control. Special attention should be paid to salt-losers in this respect.

Obesity in 21-hydroxylase deficient patients

OBJECTIVES

To evaluate the natural history and timing of adiposity rebound (nadir of body mass index (BMI)) in children with congenital adrenal hyperplasia 21-hydroxylase deficiency (CYP21).

STUDY DESIGN

A retrospective mixed longitudinal study.

METHODS

Height and changes in body composition (BMI; weight (kg)/height2 (m)), triceps and subscapular skinfolds) were analysed in 22 (14 girls, eight boys) prepubertal patients with CYP21 for whom continuous anthropometric data were available for at least seven years. BMI and height SD scores were compared at 1, 5, and 10 years of age. Skinfold SD scores were compared at 2.5 and 5.5 years. Thirteen children (nine girls, four boys) had records available from birth which allowed the estimation of the age at adiposity "peak" and "rebound".

RESULTS

A significant increase in BMI SD score was found at 5 and 10 years compared with those at 1 year. No significant change in height SD score was observed at these ages. Triceps and skinfold SD score were increased significantly at 5.5 compared with 2.5 years. The "rebound" in BMI SD score took place at 1.74 years (range 0.71-4.57) compared with 5.5 years (range 3.5-7.0) in the normal UK populations.

CONCLUSIONS

Normally growing patients with CYP21 increased their BMI throughout childhood. Adiposity rebound took place on average three years earlier than in the general population. These findings suggest that even when well controlled in terms of their disease process, patients with CYP21 are at risk of obesity, which may have important implications for the evolution of reproductive function (polycystic ovaries), diabetes, hypertension, and cardiovascular disease in these subjects.

Randomised controlled trial of growth effect of hydrocortisone in congenital adrenal hyperplasia

The influence of 15 or 25 mg/m2 of daily oral hydrocortisone with fludrocortisone 0.1 mg/day on growth and laboratory findings was evaluated in a prospective randomised crossover trial over 12 months in 26 children with 21-hydroxylase deficiency. Nine non-salt losers had fludrocortisone stopped for a further six month period. Height velocity was significantly decreased during treatment with 25 mg/m2 as compared with 15 mg/m2. This was the most sensitive indicator of corticosteroid treatment excess. A dose dependent effect upon plasma concentrations of 17-hydroxyprogesterone, testosterone, and androstenedione was found but increased values were still detected in more than half of the determinations made during the 25 mg/m2 period. Height velocity and 17-hydroxyprogesterone concentrations were positively correlated. Growth hormone response to clonidine stimulation and insulin-like growth factor-1 concentrations were both within reference values and there was no difference between treatment periods. Withdrawal of fludrocortisone did not result in any difference for the non-salt losers. It was concluded that 25 mg/m2 of hydrocortisone depressed growth in children with congenital adrenal hyperplasia, and that full suppression, or even normalisation, of plasma concentrations of 17-hydroxyprogesterone and androgens should not be considered a treatment goal, but instead an indication of corticosteroid treatment excess.

Growth of patients with 21-hydroxylase deficiency: an analysis of the factors influencing adult height

Growth of 92 Finnish patients with 21-hydroxylase deficiency (21-OHD) was analyzed retrospectively to study growth both before the diagnosis and during glucocorticoid substitution therapy. The patients were divided into two groups: those diagnosed at infancy (56 patients) and those diagnosed after the age of 1 y (36 patients). Birth lengths of those boys and girls diagnosed at infancy were greater than the national mean birth lengths (p < 0.001). Mean relative length diminished from +0.8 SD score (SDS) at birth to -1.0 SDS by the age of 1 y. Adult height was -1.0 SDS (159.9 cm) for women and -0.8 SDS (173.6 cm) for men. The difference from national mean height was significant only for women (p = 0.026). Mean relative weight during childhood correlated negatively with adult stature (r = -0.620; p = 0.006). In the group of children diagnosed later in their childhood, growth was already accelerated at infancy from +0.2 SDS at birth to +0.7 SDS by the age of 1 y (p = 0.023). The final height of girls diagnosed later in childhood was within normal limits (-0.5 SDS; 162.1 cm), whereas it was low in the corresponding group of boys (-2.1 SDS; 165.3 cm). Our data show increased mean birth length in babies with early diagnosis of 21-OHD and growth acceleration at infancy in children diagnosed later in their childhood, reflecting the growth accelerating effect of adrenal hyperandrogenism early during fetal life and infancy. To improve final height in patients with 21-OHD, lower doses of hydrocortisone should be used at infancy, and special attention should be paid to boys diagnosed later in childhood.

Adult height in women with early-treated congenital adrenal hyperplasia (21-hydroxylase type): relation to body mass index in earlier childhood

To investigate if obesity, as judged by increased body mass index (BMI), during childhood is associated with impaired adult stature in patients with 21-hydroxylase-type congenital adrenal hyperplasia (CAH), a retrospective analysis was carried out on outpatient records of 30 girls with CAH who had reached adult height. Height SD score for age (HtSDS(ca)), HtSDS for bone age (HtSDS(ba)), BMI and steroid dosage in early childhood (3.2-4.6 years) and later childhood (7.2-9.1 years), were compared with adult HtSDS (HtSDS(adlt)), adult HtSDS less mid-parental HtSDS (HtSDS(adlt)-HtSDS(mp)), predicted adult height SDS (HtSDS(pdct)), adult height SDS less predicted adult HtSDS (HtSDS(adlt)-HtSDS(pdct)) and age at menarche. Mean (SD) for HtSDS(adlt) was -1.13 (1.05), mean HtSDS(pdct) -0.12 (0.9) and mean age at menarche 13.5 (1.9) years. BMI in childhood was not correlated with HtSDS(adlt) but showed negative correlations with HtSDS(adlt)-HtSDS(mp) (r = -0.43; p < 0.02) and HtSDS(adlt)-HtSDS(pdct) (r-0.45; p < 0.02). BMI in later childhood showed negative correlations with HtSDS(adlt)-HtSDS(pdct) (r = -0.61; p < 0.001) and age at menarche (r = -0.63; p < 0.001). We conclude that in girls with early-treated CAH, a high BMI during early childhood is associated with loss of genetic height potential, and in later childhood with over-prediction of adult height and early menarche.

Urinary 17 alpha-hydroxyprogesterone in management of 21-hydroxylase deficiency

OBJECTIVES

The study was designed to assess the reliability of measurement of 24-hour urinary 17 alpha-hydroxyprogesterone (17-OHP) by radio-immunoassay (RIA) as an alternative biochemical assessment for monitoring the treatment of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21-OHD) and to assess the need for sample purification by column chromatography to improve assay specificity.

METHODOLOGY

Morning serum 17-OHP was measured using RIA and 24-hour urinary pregnanetriol using gas chromatography. Twenty-four-hour urinary 17-OHP was measured in samples from 17 prepubertal patients with CAH due to 21-OHD, and 20 normal prepubertal children as controls. In 24 urine samples, RIA of 17-OHP was performed with and without column chromatography.

RESULTS

There was a good correlation between 24-hour urinary 17-OHP and 24-hour urinary pregnanetriol (r = 0.962, P < 0.01) and between 24-hour urinary 17-OHP and morning serum 17-OHP (r = 0.955, P < 0.01). There was no significant difference in the RIA of the urine samples with and without purification by column chromatography.

CONCLUSIONS

The measurement of 24-hour urinary 17-OHP is a reliable alternative for the biochemical monitoring of 21-OHD, and RIA specificity is unaffected by omission of column chromatography.

17-Hydroxyprogesterone rhythms and growth velocity in congenital adrenal hyperplasia

Six patients on steroid replacement therapy for congenital adrenal hyperplasia provided capillary blood samples collected at 0800, 1200, 1700, and 2200 h, on to filter paper for 17-hydroxyprogesterone analysis. There was a strong correlation between 17-hydroxyprogesterone day profiles and height velocity over a 4 year period of study. Steroid over-replacement, identified by significantly decreased height velocity (Standard Deviation Score [SDS] 1.92), caused suppression of 17-hydroxyprogesterone concentrations to below 10 nmol/L throughout the day. Near average height velocity (Standard Deviation Score 0.245) was accompanied by suppression of 17-hydroxyprogesterone concentrations below 40 nmol/L but with significant diurnal variation. Under-replacement with rapid height velocity and bone maturation was accompanied by non-suppression of 17-hydroxyprogesterone concentrations (i.e. > 40 nmol/L). These results suggest that serial blood spot 17-hydroxyprogesterone measurements are a convenient and helpful supplement to measurements of height velocity and bone age maturation to monitor steroid replacement therapy in congenital adrenal hyperplasia. These measurements may be useful particularly in differentiating between over-replacement and appropriate replacement, and should allow adjustments in dose before abnormal growth patterns are established.

Problems in diagnosis and management of congenital adrenal hyperplasia due to 21-hydroxylase deficiency

A number of biochemical tests have been utilized to assist the diagnosis of steroid 21-hydroxylase deficiency. The specificity and accuracy of plasma 17-hydroxyprogesterone assays are important. A profile of steroids in urine by gas chromatography and mass spectrometry is the definitive test. Molecular biology is not practical for the diagnosis of a new case. The ACTH stimulation test for detection of heterozygotes is a poor discriminant. Fertility in patients with congenital adrenal hyperplasia may be due to excess of progesterone as well as of androgens. Gene amplification offers the best approach in molecular biology for the prenatal diagnosis of 21-hydroxylase deficiency.

Sodium chloride supplement at diagnosis and during infancy in children with salt-losing 21-hydroxylase deficiency

Eight infants (6 female, 2 male) with salt-losing congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency were studied to determine the sodium deficit at diagnosis and the level of salt supplement required in addition to subsequent hormone replacement. The median sodium deficit at diagnosis was 34 mmol (range 16-78) or 10.5 mmol/kg (range 4-24). A mean sodium supplement of 2.2 mmol/kg per day (range 0.5-4.9), double the amount provided with feeds, was required to maintain plasma sodium concentration and plasma renin activity (PRA) in the normal range for age. We present an equation based on sodium output (urine), sodium input (feeding plus supplement) and plasma sodium concentration to calculate the sodium supplement needed to maintain sodium balance on hormone replacement in this condition and some practical management suggestions. The necessity for salt supplements is often underestimated and the salt-losing tendency exacerbated by infection remains an unnecessary reason for hospitalization during the first months of life. In patients with salt-losing CAH life-long mineralocorticoid treatment is necessary but additional salt supplements are needed to maintain plasma sodium concentration and PRA in the normal range during infancy.

Response to treatment of congenital adrenal hyperplasia in infancy

Nine infants with congenital adrenal hyperplasia were started on replacement doses of hydrocortisone (20.6-32.6 mg/m2/day) without receiving a high dose for an initial period first. Plasma adrenal steroid concentrations fell to acceptable levels by 3 months of age. Adequate biochemical control was maintained and satisfactory growth achieved even though the mean dose of hydrocortisone had been reduced to 15 mg/m2/day by the age of 3 years. Inadvertent overtreatment and growth suppression in infants with congenital adrenal hyperplasia may be avoided by using replacement doses from the start, and by permitting the relative dose of hydrocortisone to fall as the body surface area increases during the first year of life.