CLONIDINE STIMULATION TEST FOR GH DEFICIENCY: A NEW LOOK AT SAMPLE TIMING.

OBJECTIVE: In the glucagon stimulation test (GST), the occurrence of peak growth hormone (GH) levels at typical times is an indication of normal secretion. This has not been studied for the clonidine stimulation test (CST). The 120-minute time is rarely the peak, and previous reports suggest it can be omitted. This study aimed to evaluate the meaning and utility of peak time in the CST and the significance of shortening the test. METHODS: CSTs performed on 250 consecutive subjects in a single center were evaluated for results (GH sufficient or deficient) and result of confirmatory GST with respect to the peak time of the CST. RESULTS: Peak GH occurred typically at 30, 60, and 90 minutes (91.6% of tests, versus 60% expected) (P<.001). A total of 132 of 155 (85.15%) sufficient tests occurred at typical times, versus 66 of 97 (68%) deficient tests (P<.05). Typicality of timing did not follow in the confirmatory GST and did not predict the final result of testing. Removal of the 120-minute sample affected the final result in 0.4% of evaluations. CONCLUSION: The timing of the GH peak is not useful when interpreting the CST. The CST is equally effective when terminated at 90 minutes from stimulation.

Treatment with recombinant human growth hormone during childhood is associated with increased intraocular pressure.

OBJECTIVE: To evaluate the association between recombinant human growth hormone (rhGH) treatment and intraocular pressure (IOP) in children. STUDY DESIGN: This is an observational cohort study including comparison between children treated with rhGH for at least 12 months (treatment group), matched children prior to treatment (control group), and population age-adjusted normograms of IOP. All children underwent an ocular slit lamp assessment and Goldmann applanation tonometry. Charts were reviewed for cause of therapy, peak stimulated growth hormone level prior to therapy, treatment duration, insulin-like growth factor 1, and rhGH dosage. RESULTS: The treatment group included 55 children and the control group included 24 children. Mean age at examination was comparable at 11.4 ± 3.3 years and 10.3 ± 2.6 years, respectively (P = .13). Mean treatment duration was 37.5 ± 22.8 months and mean rhGH dose was 0.04 ± 0.01 mg/kg/d. Mean IOP was significantly increased in the treatment group compared with the control group and compared with age-matched normograms (16.09 ± 2.2 mm Hg, 13.26 ± 1.83 mm Hg and 14.6 ± 1.97 mm Hg, respectively, P < .001). IOP was positively correlated with treatment duration (r = 0.559, P < .001) and rhGH dosage (r = 0.274, P = .043). CONCLUSION: IOP in children treated with rhGH is increased compared with a similar population without treatment and compared with healthy population normograms. IOP is associated with longer treatment duration and higher dosages.

Persistent hyperthyrotropinemia in congenital hypothyroidism: successful combination treatment with levothyroxine and liothyronine.

BACKGROUND: Some children with congenital hypothyroidism (CH), have persistent hyperthyrotropinemia despite good compliance with levothyroxine. OBJECTIVE: To evaluate combination therapy of liothyronine (cytomel) with levothyroxine in CH with persistent hyperthyrotropinemia. PATIENTS AND METHODS: Files were reviewed retrospectively. Eight female patients with persistently high levels of TSH and upper normal FT4 levels were given either 6.25 or 12 microg liothyronine and the levothyroxine dose was reduced appropriately. Pre- and post-intervention hormone levels and drug doses were evaluated. RESULTS: TSH decreased in 8/8 and normalized in 6/8 patients. FT4 and free tri-iodothyronine (FT3) remained normal. The levothyroxine-equivalent dose on the combination was 5.0 +/- 0.3 microg/kg/day in infants and 3.4 +/- 0.4 microg/kg/day in children above 2.5 years. Infants required higher liothyronine doses compared with older children (0.66 +/- 0.01 vs. 0.3 +/- 0.05 microg/kg/day). CONCLUSIONS: Combined therapy can achieve normal TSH levels with normal FT4 and FT3. Further long-term research is required to investigate effects on neurodevelopmental outcome.

[The use of aromatase inhibitors in children].

Aromatase inhibitors are compounds that block aromatase which converts androgens to estrogens. These compounds have been investigated for many years in a variety of conditions in which estrogen blockade is desired. During the past decade, a third generation of aromatase inhibitors has been developed with a much more potent blockade of the enzyme and less side effects. These new aromatase inhibitors are well absorbed after oral administration and, because of a long half life, are given once daily, thereby increasing compliance. The use of aromatase inhibitors is approved for the treatment of estrogen responsive breast cancer. Estrogens play a major role in bone maturation and growth plate fusion in both sexes. Therefore, inhibition of estrogen production may increase final height in a number of conditions where the final height is compromised. Due to their ability to block estrogen production, a number of clinical studies have been conducted to investigate their efficiency in a range of situations where estrogen blockade is desired. These include: peripheral precocious puberty secondary to congenital adrenal hyperplasia, familial male-dominant precocious puberty, and McCune-Albright syndrome, short stature in boys secondary to growth hormone deficiency, familial/genetic short stature, constitutional growth delay or idiopathic short stature. The use of aromatase inhibitors has been investigated also in pubertal gynecomastia. It is important to emphasize that this treatment, although it seems to be safe and encouraging, is still investigational and is not yet approved for routine usage.

Aerosol delivery in respiratory syncytial virus bronchiolitis: hood or face mask?

OBJECTIVES: To compare the utility of the hood versus the face mask for delivery of inhaled medications to infants hospitalized with viral bronchiolitis. STUDY DESIGN: Randomized, double-blinded, controlled trial; 49 hospitalized infants with viral bronchiolitis, age 2.75 +/- 2.2 months (mean +/- SD), were grouped to either the hood (n = 25) or the mask (n = 24). Each subject received inhalation treatments with the use of both devices. Half of the Hood Group received the active drug treatment (1.5 mg epinephrine in 4 mL saline [3%]) via hood followed immediately by placebo treatment (normal saline) via mask, whereas the other half received the opposite order. Half of the Mask Group received the active drug treatment via mask followed immediately by placebo treatment via hood, whereas the other half received the opposite order. Therapy was repeated 3 times daily until discharge. Outcome measures included clinical scores and parental preference. RESULTS: Percent improvement in clinical severity scores after inhalation was significant in both groups on days 1, 2, and 3 after admission (Hood Group: 15%, 15.4%, and 16.4%, respectively; Mask Group: 17.5%, 12.1%, and 12.7%, respectively; P < .001). No significant difference in clinical scores improvement between groups was observed. Eighty percent (39/49) of parents favored the hood over the mask; 18% (9/49) preferred the mask and 2% (1/49) were indifferent. CONCLUSIONS: In infants hospitalized with viral bronchiolitis and in whom aerosol treatment is considered, aerosol delivery by hood is as effective as by mask. However, according to parents, the tolerability of the hood is significantly better than that of a mask.