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Biomedical subjects

P Tassoni

Publications and source records attributed to P Tassoni.

At least 19 recordsLinked to original sources

Response to growth hormone therapy in patients with growth hormone deficiency who at birth were small or appropriate in size for gestational age.

OBJECTIVE: To determine long-term growth response to growth hormone (GH) therapy in patients with isolated GH deficiency who had been small for gestational age and in those who had been appropriate in size for gestational age. DESIGN: Longitudinal, case-control study. SETTING: Pediatric clinic, endocrinology center, University of Bologna, Italy. PATIENTS: Sixteen GH-deficient children, small for gestational age with unknown cause, and 16 GH-deficient children, appropriate in size for gestational age, who were matched for chronologic age, bone age, pubertal stage, and target height at the beginning of treatment and were treated for 36 months. INTERVENTION: Recombinant human GH given subcutaneously at a dose of 20 IU/m2 per week in six doses per week for 36 months. MEASUREMENTS: Growth hormone levels (fluoroimmunoenzymatic method), levels of insulin-like growth factor I (radioimmunoassay), and complete 36-months auxologic follow-up. RESULTS: Patients who were small for gestational age had a modest improvement in height for chronologic age but no increase in predicted final height. Patients who were appropriate in size for gestational age had significantly better improvement in both measurements (multivariate analysis of variance: F = 6.3 (p < 0.001) and F = 3.8 (p < 0.05), respectively). Catch-up growth was similar during the first year of therapy for the two groups, after which the linear growth velocity decreased more rapidly in the small-for-gestational-age patients (multivariate analysis of variance: F = 4.9 (p < 0.05)). CONCLUSIONS: The constitutional component of the statural deficiency of small-for-gestational-age children seemed to prevail over hormonal deficiency during treatment with GH. Further follow-up to final height is necessary to evaluate these different responses.

Case-Control Studies↗

Value and limits of pharmacological and physiological tests to diagnose growth hormone (GH) deficiency and predict therapy response: first and second retesting during replacement therapy of patients defined as GH deficient.

There is currently a debate about the use of pharmacological and physiological tests to define GH deficiency and predict response to GH therapy. In addition, a good response to therapy has also been described in subjects without GH deficiency. For further information, we reevaluated GH secretion during replacement therapy in a group of children defined as GH deficient and examined response to therapy in the subjects subdivided according to secretion. One hundred eighty four children (113 boys and 71 girls) initially diagnosed with GH deficiency by means of pharmacological (peak < 8 micrograms/L after arginine and L-dopa tests) and physiological tests (mean nocturnal concentration < or = 3.3 micrograms/L during sleep test) underwent the same tests 2.8 +/- 1.1 yr after start of GH therapy. Sixty eight patients were retested 1.5 +/- 0.4 yr after first retesting. At diagnosis 122 subjects had pathological pharmacological and physiological tests (group A), 30 subjects normal sleep test with pathological pharmacological tests (group B), and 32 subjects pathological sleep test with normal pharmacological tests (group C). At diagnosis 140 subjects were prepubertal and 44 pubertal. To evaluate response to therapy in relation to GH secretion at diagnosis and at both retestings, a number of auxological parameters were calculated during treatment. At first retesting, 107 subjects (58.1%) changed initial group of diagnosis, 34 of whom (18.5%) presented normal secretion in both pharmacological and physiological tests (group D). At second retesting, 31 of the 68 subjects reexamined (45.6%) changed first test results, and 33 (48.5%) reverted to the initial group of diagnosis; none of the 6 subjects of group D maintained normal secretion. Although the percentage of normalized subjects was higher in pubertal subjects (36.4%; P = 0.0003) than prepubertal subjects (8.9%), puberty did not prevent a reduction of secretion in some subjects. Response treatment during the first year of therapy was similar in the various groups. GH secretion seems to change in both prepubertal and pubertal children diagnosed with GH deficiency when pharmacological and physiological tests are repeated over time. Moreover, such tests may not represent a reliable tool for predicting response to treatment. GH secretion normalization at retesting may not necessarily represent the end of a transient secretory defect.

Adolescent↗

Pitfalls in diagnosing impaired growth hormone (GH) secretion: retesting after replacement therapy of 63 patients defined as GH deficient.

Possible causes of error in the diagnosis of isolated GH deficiency are the variability of GH response to repeated tests, the existence of transient GH deficiencies, and the low GH levels found in short statured children with delayed puberty. Sixty-three patients with variously expressed GH deficiency were retested (1 sleep test and 2 pharmacological tests) after 1-3.9 yr of GH therapy (dose, 15 U/m2.week). Forty-eight subjects had arginine, L-dopa, and sleep tests (mean serum GH concentration) twice, while 15 had only arginine and L-dopa tests. All patients were retested 1 month after withdrawal from therapy. The criteria used to subdivide the patients were pubertal development and response to pharmacological and sleep tests at first diagnosis and on retesting. The initial diagnosis in 33 subjects (52.4%) was not confirmed, and 13 (20.6%) were no longer deficient on retesting. The percentage of normalization was high for the sleep test (43.9%), lower for the pharmacological test (24.5%), and lower still (12.9%) for pharmacological and sleep tests considered together. While none of the 28 subjects who remained prepubertal at retesting normalized in any of the tests, 13 of the 35 subjects retested during puberty did. When normalization was observed in pubertal subjects, it occurred predominantly in the sleep test. Growth velocity and height age/bone age increment ratio after the first year of therapy were no different for the groups of subjects classified according to GH secretion on retesting. Our study demonstrates that a number of children diagnosed as GH deficient do not have a true deficiency. However, such a diagnostic error seems to have little effect, at least in the first year of therapy, on the effectiveness of GH treatment.

Adolescent↗

Variability of growth hormone response to pharmacological and sleep tests performed twice in short children.

Forty-nine children with short stature (age range, 4.1-15.9 yr) were examined. Twenty-four (group 1) were submitted twice to an arginine and a sleep test (12-h overnight GH profile). Twenty-five patients (group 2) were submitted twice to an arginine and L-dopa test. Coefficients of variation were calculated between both the results of pharmacological (peak and area under the curve) and sleep tests [mean GH concentration (MGHC), peak, area under the curve, number of peaks above 5 micrograms/L, and peak area]. In group 1 the coefficient of variation of sleep test parameters was significantly lower than that of pharmacological tests (P less than 0.01 to less than 0.001). In the sleep test the area under the curve and MGHC were the most constant parameters. Group 2 showed no difference between the coefficients of variation of the two pharmacological tests. Considering groups 1 and 2 together, the coefficients of variation of the sleep test, in particular the MGHC and area under the curve, were lower than those of the two pharmacological tests. Eight of 24 subjects in group 1 showed a low GH level in 1 series of tests, and a normal level in the other series. Five of 18 subjects in group 2 showed an abnormally low GH response to the arginine and L-dopa tests and a normal response to the 2 repeated tests. Therefore, to prevent an erroneous interpretation of the GH test results, it is very important to perform a sleep test and repeat it whenever GH secretion seems to be deficient or at the lower limits of normalcy.

Adolescent↗

Haemorheologic and fibrinolytic evaluation in obese children and adolescents.

The haemorheologic condition was evaluated in 43 obese children and 35 controls. In 18 of the obese children and in 21 controls the euglobulin lysis time (ELT) was also studied. Blood viscosity at 94.5 and at 0.204 s-1 shear rates, plasma viscosity, fibrinogen and erythrocyte filtration time were significantly higher in obese than in control children. No significant differences were observed in haematocrit levels. Triglycerides, non-esterified fatty acids (NEFA), pre-beta-lipoprotein and insulin rates were all significantly higher in obese than in control children. There were no significant differences in glycaemia and in haemoglobin A1 values. ELT, both basal and after stimulation with 1-deamino-8-D-arginine-vasopressin (DDAVP), was significantly higher in the obese than in control children. The haemorheologic disturbances together with alterations of the haemostatic balance and fibrinolysis may be an important risk factor for the development of vascular changes at paediatric age.

Adolescent↗

Growth hormone evaluation in Duchenne muscular dystrophy.

Growth hormone (GH) release with pharmacological tests and sleep test, somatomedin C and auxological features were studied in 10 patients affected by Duchenne Muscular Dystrophy. GH release in these patients seems to be lower than normal; moreover some of them are of short stature without an evident relationship with GH deficit. The possible significance of the data obtained is discussed, particularly in relation to the clinical course of the disease, and to current therapeutic trials with a GH release inhibitor (mazindol).

Arginine↗

Growth and growth factors in diabetes mellitus.

Growth of 79 children with diabetes was analysed at diagnosis and again after one to 10.7 years of treatment with insulin. Both sexes were tall at onset, whereas at the last observation boys alone showed significant growth retardation. Height standard deviation score (SDS), however, showed no significant fall either in 32 subjects reassessed after five years of disease or in 18 subjects examined at full stature. Skeletal maturity was not significantly impaired after treatment. Pubertal growth spurt was reduced, especially in girls and in subjects with onset of disease at or around puberty. We found no significant correlation between height and height velocity SDS and glycosylated haemoglobin values or secretion of growth hormone during the arginine test. Somatomedin C values were correlated with height velocity SDS in prepubertal boys. The results of this study suggest that there are interferences in the growth of children with diabetes but that they do not seem to have a significant influence on adult height.

Adolescent↗

Differences in somatomedin-C between short-normal subjects and those of normal height.

We evaluated basal somatomedin-C (SmC) levels in 98 subjects 2 to 16.6 years of age, with height less than 3rd centile (Tanner), and in 274 healthy controls 2 to 15.8 years, with height greater than 10th centile. Growth-retarded subjects were defined as short-normal when they had normal GH release (greater than 8 ng/ml) in at least one of three tests: arginine, L-dopa, and sleep. In control subjects, there was a significant positive correlation between SmC levels and chronologic age, bone age, and pubertal stage (pubic hair, breast or testicular volume). The same correlations were present in short-normal subjects, but SmC levels were significantly lower than in normal children. The percentage of subjects with very low SmC values (less than or equal to 0.25 IU/ml in those older than 6 years, and less than 0.1 IU/ml in those younger than 6 years) was higher in the short-normal group of children older than 6 years. In growth-retarded subjects, SmC values were significantly higher (P less than 0.005) in subjects with normal GH response in at least one of the two pharmacologic tests, compared with those with normal GH response only during sleep. We conclude that short-normal subjects have, on average, low SmC values, which might indicate insufficient GH release. Therefore, current criteria to define GH deficiency and children needing treatment may be too restrictive.

Adolescent↗

Pelvic ultrasonography in premenarcheal girls: relation to puberty and sex hormone concentrations.

Real time ultrasonography of the pelvic organs was performed on 114 normal premenarcheal girls aged between 2 years and 13 years 11 months. Values were obtained for total uterine length, anteroposterior diameters of the corpus and cervix, corpus/cervix ratio, and uterine and ovarian volumes and the resultant data were grouped according to age. It was concluded that there is no change in uterine size until approximately 7 years of age. Then the uterus begins to enlarge, both in prepubertal girls, in whom this is an age related function, and in pubertal girls, whose uterine growth is influenced not only by age but also by size and, independently of these two factors, by oestradiol concentrations. The onset of a modification in uterine morphology with a greater enlargement of the corpus than the cervix is also seen at age 7 years. Ovarian maturation begins in the very first years of life and, even in pubertal girls, seems to be influenced by age only and not by hormonal stimuli.

Adolescent↗

Thyroid function and prolactin levels in insulin-dependent diabetic children and adolescents.

We evaluated serum thyroid hormones, TSH, and prolactin before and after induction of TRH and thyroid microsomal autoantibodies in 91 diabetic children and adolescents (mean age 11.11 +/- 4.13 yr), with illness ranging from a few days to 14.25 yr, and in 127 "short-normal" subjects (mean age 10.32 +/- 3.18 yr). All were clinically euthyroid. The control pubertal subjects showed T4, rT3, TBG, and rT3/T3 ratio values that were significantly lower than those of prepubertal subjects. The PRL area was significantly higher in pubertal than in prepubertal females. In diabetic patients, differences between pubertal and prepubertal subjects were similar to those of controls regarding T4 levels and PRL area only. T3, T4, and fT3 appeared to be significantly lower than in controls, while the rT3/T3 ratio was higher. A negative correlation (r = -0.277, P = 0.009) between T3 and HbA1 levels was demonstrated. Furthermore, thyroid function was not different in subjects with or without retinal changes or in subjects with or without residual B-cell function. Microsomal autoantibodies were observed in 6.25% of the subjects examined, though none showed any clinical or humoral sign of impaired thyroid function. In conclusion, the lower T4 and rT3 values detected in pubertal controls suggest an increased efficacy of peripheral thyroid activity in this particular life span. Considering the fact that, in diabetic children, such a decrease in rT3 at puberty is not present and that the T3 value in diabetic children is persistently lower than in controls, it would seem that even diabetic children show a "low T3 syndrome," as in adult diabetic subjects.

Adolescent↗

Short stature and celiac disease: a relationship to consider even in patients with no gastrointestinal tract symptoms.

To determine the incidence of celiac disease in a group of nonselected children with short stature, duodenal biopsy was performed in 60 unselected children with short stature (below third centile) and absence of gastrointestinal tract symptoms. Examination revealed probable celiac disease in five children (8.3%). Analysis of the results of other tests that might possibly be considered as alternatives to biopsy (e.g., xylose test, antireticulin antibodies, gastrointestinal tract symptoms in the first two years of life, bone age, serum iron, iron load, triglyceride load) led us to conclude that no test or clinical measurement could have allowed us 100% certainty in making the correct diagnosis. None of the children with celiac disease had growth hormone deficiency. We conclude that asymptomatic celiac disease represents a cause of short stature that cannot be ignored, and that only by intestinal biopsy can all such patients be identified.

Adolescent↗