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Biomedical subjects

K Dana

Publications and source records attributed to K Dana.

8 recordsLinked to original sources

Effect of long-term recombinant growth hormone therapy in children--the National Cooperative Growth Study, USA, 1985-1994.

Over a 9-year period (1985-1994) approximately 20,000 children received recombinant human growth hormone (rhGH) while enrolled in the National Cooperative Growth Study (NCGS), an observational, longitudinal study designed to monitor the long term efficacy and safety of rhGH administered to children in North America. Forty-four percent of the patients had idiopathic growth hormone deficiency (IGHD), 13.8% organic GHD (OGHD), 25% idiopathic short stature (ISS), 9.9% Turner's syndrome (TS), and 7.3% miscellaneous disorders. Eighty-five percent of the patients enrolled were Caucasian, and approximately two-thirds of the non-Turner patients were male. For the subset of patients treated for at least 4 years and who were prepubertal throughout this period (IGHD N=308, OGHD N=93, ISS N=169, TS N=82), mean growth rates increased in all patient categories and remained at or above pretreatment growth rates through 4 consecutive years of therapy with rhGH. Growth rates during administration of rhGH were greater in children in whom the pretreatment maximum stimulated GH concentration was < or =3 microg/l. Patients treated with 6 or 7 doses of rhGH each week grew more rapidly than did those receiving thrice weekly dosages, although the ratios of the increment in bone age to the increment in height age after two years of therapy were similar in the two treatment regimens. For patients treated with rhGH for 7 consecutive years, the mean height standard deviation scores increased by 2.5 in IGHD (N=169), 2.0 in OGHD (N=50), 1.9 in ISS (N=69), and 1.3 in TS (N=19), but remained below target heights in all categories. It is concluded that administration of rhGH increases growth rates in patients with IGHD, OGHD, ISS, and TS, and that this stimulatory effect can persist for at least 4 years.

Adolescent↗

Lack of correlation between growth hormone provocative test results and subsequent growth rates during growth hormone therapy.

OBJECTIVES: To determine whether there is a relationship between the peak GH level in pituitary stimulation tests and the growth rate in response to treatment with recombinant human growth hormone (GH). METHODS: We identified 24 843 patients in the National Cooperative Growth Study database who had not been treated previously with GH therapy and divided them into three groups according to the peak GH level in pituitary stimulation testing: 1) <10 microg/L (n = 14 132); 2) >/=10 microg/L (n = 7476); and 3) no test results reported (n = 3235). Growth rates in each group in response to GH therapy were examined. RESULTS: The children in each of the groups responded to GH therapy with a vigorous increase in growth rates (means, 8.4 to 9.5 cm/y) in the first year, followed by a gradual decline and then stabilization at 1.0 to 1.9 cm/y greater than the pretreatment values. There were large overlaps in the growth rates among the groups, but the differences were significant. The growth rates in a smaller group of children (n = 187) who had normal GH responses and normal growth rates before GH therapy increased similarly in the first year of therapy (to 7.7 to 9.2 cm/y), but then declined rapidly to the pretreatment values or lower. CONCLUSION: Because the GH response to pituitary stimulation testing is inadequate for diagnosing GH deficiency, such testing also is inadequate for determining whether GH treatment should be prescribed in a child with short stature. In addition, the waning response to GH therapy in normally growing short children suggests that this treatment may not have a sustained benefit in these children.

Body Height↗

Growth hormone treatment in Noonan syndrome: the National Cooperative Growth Study experience.

We evaluated the response to growth hormone (GH) therapy in 150 children (97 boys) with Noonan syndrome (NS) by analyzing growth data from children with NS who were enrolled in the National Cooperative Growth Study and compared those data with National Cooperative Growth Study growth data from children with idiopathic growth hormone deficiency (IGHD) and Turner syndrome (TS). Children with NS were significantly shorter than those with IGHD and TS. The annualized growth rates for years 1, 2, 3, and 4 of therapy in patients with NS who were naive to previous GH therapy were significantly greater than baseline. Their growth rates for years 1, 2, 3, and 4 were intermediate between those in children with IGHD and TS and were significantly different from both. A significant improvement occurred in height SD scores for those 42 children with NS who have been monitored for at least 4 years of GH therapy. Three of six boys with NS for whom adult height data were available exceeded their pretreatment predicted heights.

Adolescent↗

Usefulness of exercise stress testing for prediction of blood pressure trends.

The purpose of this study was to determine whether values of blood pressure during exercise help predict which adolescents are prone to maintain high blood pressure. Dynamic and isometric exercise stress tests were performed on 131 adolescents who had had systolic or diastolic pressures greater than the 95th percentile on three examinations the previous year. Follow-up blood pressures were measured 1 year after the stress testing, and outcomes were classified on the basis of the blood pressure status that year. Stepwise regression analysis was used to examine the association between earlier blood pressures and exercise pressures with outcome pressures. In both male and female adolescents, the average resting systolic pressure on the earlier survey was the best predictor of systolic pressure 2 years later. Blood pressures and heart rates during dynamic and isometric exercise did not significantly contribute to the models' prediction of future systolic or diastolic pressures. The data suggest that exercise stress testing is not a valid method for predicting youths whose blood pressures will remain elevated over the next 1 to 2 years.

Adolescent↗

Kidney length correlated with age: normal values in children.

Normal kidney length was measured on the excretory urogram in 262 children 0 to 14.5 years of age (422 kidneys). While mean values were similar to those in the literature, the standard deviation (0.785 cm) was much lower than that reported previously.

Adolescent↗

Systolic blood pressure differences among pediatric epidemiological studies.

This report reviews the results of six large blood pressuree surveys done on pediatric populations and points out factors responsible for differences in the blood pressure norms. The studies were selected on the basis of there being recent examinations of large numbers of children. Important differences in mean systolic pressures and 95th percentile values were found among the studies, which may be attributed to: 1) actual differences among the populations; 2) biases due to methodological differences; or 3) increased sampling variability with small sample sizes. Actual differences in pressures among the populations surveyed may be due to differences in geographic location, racial composition, or average body sizes. Discrepancies due to methodological biases may have occurred because of associated venipuncture or exercise stress on the day of the examination; differences in selection of blood pressure cuff sizes; differences in the number of measurements averaged. In several studies, small sample sizes for each age-race-sex subclass accounted for considerable variability of the 95th percentile value. The implication of this analysis is that before the 95th percentile norms for children of different ages, races, and sexes can be more firmly established, it is necessary to collect larger sample sizes controlling for known biasing factors and using a standardized methodology.

Adolescent↗