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Biomedical subjects

N Weintrob

Publications and source records attributed to N Weintrob.

5 recordsLinked to original sources

Standard and low-dose short adrenocorticotropin test compared with insulin-induced hypoglycemia for assessment of the hypothalamic-pituitary-adrenal axis in children with idiopathic multiple pituitary hormone deficiencies.

Insulin-induced hypoglycemia (IIH) is the gold standard test for assessment of the integrity of the hypothalamic-pituitary-adrenal (HPA) axis, but it may be hazardous. We sought to determine whether the standard (250 micrograms) or low-dose (1 microgram/1.73 m2) short ACTH test can replace IIH in patients with idiopathic multiple pituitary hormone deficiencies (MPHD). Three groups of subjects were studied: 1) control group, children with early or accelerated puberty and no other evidence of adrenal or pituitary pathology (n = 13, age 10.1 +/- 2.2 yr, 3 males); 2) patients with idiopathic hypothalamic pituitary insufficiency and either isolated GH deficiency or MPHD and preserved HPA function (n = 20, age 13.7 +/- 4.4 yr, 13 males); and 3) MPHD patients with impaired HPA axis function (n = 10, age 16.8 +/- 4.8 yr, 9 males). IIH and the 250 micrograms and 1 microgram/1.73 m2 ACTH tests were performed in groups 2 and 3; group 1 underwent only the ACTH tests. Pass peak cortisol level was defined as 520 nmol/L. No significant difference was noted between the standard and low-dose tests in the 30-min cortisol response to ACTH. Basal and peak cortisol levels attained on both ACTH tests were similar in groups 1 and 2 and significantly lower in group 3 (P < 0.0001). Both the 250 and 1 microgram ACTH tests were highly correlated with IIH (r = 0.71, P < 0.0001 for the 250 micrograms, r = 0.7, P < 0.0001 for the 1 microgram, n = 30), and both demonstrated high sensitivity (90% each) and specificity (100% and 90%, respectively) compared with IIH. We conclude that in idiopathic MPHD patients, both the standard and low-dose ACTH tests are equivalent to IIH in detecting HPA insufficiency. We suggest that they can replace IIH as a screening test for the integrity of the HPA axis in children with suspected MPHD.

Adolescent

Non-classical 21-hydroxylase deficiency in infancy and childhood: the effect of time of initiation of therapy on puberty and final height.

OBJECTIVE: To review the characteristics of children with non-classical 21-hydroxylase deficiency (NC-21-OHD) diagnosed during infancy and childhood, and to evaluate the relationship of pubertal and bone age maturation at initiation of glucocorticoid therapy with the course of puberty and final height. DESIGN: We retrospectively compared the course of puberty, growth pattern and final height in two groups of patients: group A (two males, six females), hydrocortisone (HC) treatment 7.5-15 mg/m2 per 24 h, initiated > or = 1 year before onset of true puberty and group B (seven females), treatment started with the first signs of true puberty present. PARTICIPANTS: Thirteen girls and two boys with NC-21-OHD diagnosed at age range 0.5-10.6 years were followed-up for 9.0 +/- 3.8 years (mean +/- S.D). Therapy with HC was initiated because of signs of hyperandrogenism, accelerated growth and bone maturation, or true precocious puberty. The HC dose was adjusted according to linear growth and basal plasma androgen levels. RESULTS: Puberty and peak height velocity developed significantly earlier in the girls of group B: gonadarche at 7.9 +/- 1.4 years and peak height velocity at 9.2 +/- 1.4 years vs 10.2 +/- 0.4 years (P = 0.002) and 11.5 +/- 0.7 years (P = 0.006) in group A. Menarche, however, occurred only slightly earlier in group B (12.0 +/- 1.1 vs 12.8 +/- 0.5 years, P = 0.068). All eight children in group A achieved a final height within the range of their mean parental height standard deviation scores (SDS) in comparison with only 1/7 in group B (P = 0.0014). Seven of eight patients who started therapy before a bone age of 9 years achieved a final height within the parental height SDS range, compared with 2/7 who started therapy later (P = 0.041). The final height SDS was significantly better for group A (0.05 +/- 0.19, mean +/- S.E.M.) than group B (-1.63 +/- 0.23, P = 0.0007), even when adjusted for a significant effect of the mean parental height SDS (A. -0.63 +/- 0.28; B, -0.89 +/- 0.31, P = 0.0245, ANCOVA). CONCLUSION: Every child with signs of excess androgen activity or early puberty should be studied for the possibility of NC-21-OHD. Screening programs for populations with a high frequency of the gene for NC-21-OHD would facilitate early diagnosis and treatment. Pubertal stage and bone age at the introduction of therapy dictate height prognosis. Initiation of therapy before puberty with careful follow-up and HC dose adjustment can assure the achievement of genetic adult height.

Adrenal Hyperplasia, Congenital

Normal proinsulin processing despite beta-cell dysfunction in persistent hyperinsulinaemic hypoglycaemia of infancy (nesidioblastosis).

Persistent hyperinsulinaemic hypoglycaemia of infancy (PHHI) is a genetic disorder which causes severe hypoglycaemia in the neonate. The beta cells fail to respond to changes in blood glucose levels in all the stages of the disease, which often ends with NIDDM. Fasting insulin, intact proinsulin and des 31,32 split proinsulin levels were measured in PHHI patients with active disease, patients after partial pancreatectomy, and those in clinical remission. All but one of the pancreatectomized patients developed diabetes and were hyperglycaemic on evaluation. Fasting insulin was comparable in pancreatectomized and medically treated patients. Des 31,32 split proinsulin levels were much higher in pancreatectomized compared to non-pancreatectomized patients (10.7 +/- 2.5 vs 3.4 +/- 0.8 pmol/l, p = 0.001) and age-matched control subjects (3.8 +/- 1.4 pmol/l, p = 0.018). Also the ratio of des 31,32 split proinsulin to total insulin plus proinsulin-like peptides was higher in pancreatectomized patients (18.7 +/- 2.8 vs 7.2 +/- 0.8% in non-pancreatectomized patients, p = 0.001, and 6.8 +/- 2.1% in normal control subjects, p = 0.004). Furthermore, des 31,32 split proinsulin was the dominating species of proinsulin-like molecules in the pancreatectomized patients (62.7 +/- 1.6% vs 45.5 +/- 3.8%, and 49.0 +/- 3.2% in non-pancreatectomized patients and control subjects, respectively, p = 0.001 and p = 0.0002). Intact proinsulin levels, and the proinsulin percentage, tended to be higher in pancreatectomized patients; however, the differences did not reach statistical significance. All parameters were similar in non-pancreatectomized patients and age-matched control subjects. Subgroup analysis showed comparable proinsulin-like peptide levels in patients with active disease and those in apparent clinical remission. Fasting levels of insulin and proinsulin-like peptides were also measured in a larger group of healthy children and young adults. Insulin and des 31,32 split proinsulin increased with age, the differences being most prominent when the young age group (0-8 years) was compared to the older groups (8-16 and > 16 years). The fasting levels of plasma insulin were correlated with those of intact proinsulin and des 31,32 split proinsulin (r = 0.82 and 0.81, respectively). Fasting insulin, intact proinsulin and des 31,32 split proinsulin were correlated with BMI (r = 0.55, 0.56 and 0.53, respectively). In summary, relative hyperproinsulinaemia was noted only in PHHI patients with increased secretory demand following pancreatectomy, but not in patients with active disease or those in spontaneous clinical remission. These findings suggest that abnormal proinsulin processing is not an intrinsic feature of PHHI despite the severe beta-cell dysfunction.

Adolescent

Short- and long-range complications in offspring of diabetic mothers.

The perinatal mortality rate of infants of diabetic mothers (IDMs) has declined dramatically from 250 per 1000 live births in the 1960s to a near-normal 20 per 1000 live births in the 1980s. Five to 8% of all IDMs suffer from major congenital malformations, and it is the latter that are responsible for 50% of these perinatal deaths. It has been shown that tight glycemic control prior to conception and during pregnancy can prevent an excess rate of congenital malformations, fetal macrosomia, birth trauma, and neonatal respiratory distress syndrome. We briefly review the short- and long-range complications that occur in offspring of diabetic mothers (ODMs) from gestation through young adulthood. Short-term neonatal complications, such as hypoglycemia, hypocalcemia, hypomagnesemia, hyperbilirubinemia, and polycythemia, are related mainly to fetal hyperinsulinemia, hypoxemia, and prematurity. They are readily controllable within the setup of modern neonatal intensive care units. Long-range complications include an increased rate of childhood and adolescent obesity, impaired glucose tolerance or diabetes mellitus, and subtle neuropsychological dysfunctions. These may be related to the severity of the maternal hyperglycemia during pregnancy, the consequent fetal hyperinsulinemia, and third trimester maternal lipid metabolism disturbances. Today we have at hand the knowledge and tools to properly treat both pregestational and gestational diabetes. Increased education of the general practitioner and the target population regarding early referral of pregestational diabetic mothers and the implementation of screening programs for gestational diabetes will further reduce diabetic pregnancy-related morbidity.

Adolescent