Metabolism 52 : — Clin Endocrinol Oxf 65 : — Oxford University Press is a department of the University of Oxford. It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide.
Sign In or Create an Account. Sign In. Advanced Search. Search Menu. Article Navigation. Close mobile search navigation Article Navigation. Volume Article Contents Abstract. Subjects and Methods. Arafat , Ayman M.
Ayman Arafat, M. Oxford Academic. Martin O. Frank H. Johannes Purschwitz. Joachim Spranger. Christian J. Andreas F. Cite Cite Ayman M. Select Format Select format. Permissions Icon Permissions. Abstract Context: Besides the measurement of IGF-I, GH suppression during an oral glucose tolerance test is recommended to assess the biochemical status in acromegaly.
Open in new tab Download slide. Disclosure Statement: The authors have nothing to disclose. Google Scholar Crossref. Search ADS. Biochemical assessment and long-term monitoring in patients with acromegaly: statement from a joint consensus conference of the Growth Hormone Research Society and the Pituitary Society. Evaluation of disease status with sensitive measures of growth hormone secretion in 60 postoperative patients with acromegaly.
Google Scholar PubMed. Growth hormone and pituitary radiotherapy, but not serum insulin-like growth factor-I concentrations, predict excess mortality in patients with acromegaly.
Assessment of disease activity in acromegaly by means of a single blood sample: comparison of the th minute postglucose value with spontaneous GH secretion and with the IGF system. Long-term biochemical status and disease-related morbidity in 53 postoperative patients with acromegaly. Postoperative evaluation of patients with acromegaly: clinical significance and timing of oral glucose tolerance testing and measurement of free insulin-like growth factor I, acid-labile subunit, and growth hormone-binding protein levels.
Assessment of disease activity in treated acromegalic patients using a sensitive GH assay: should we achieve strict normal GH levels for a biochemical cure? The International Standard for Human Growth Hormone for Bioassay: calibration and characterization by international collaborative study. A new biometrical procedure for testing the equality of measurements from two different analytical methods.
Effect of sex and assay method on serum concentrations of growth hormone in patients with acromegaly and in healthy controls. Influence of matrix on concentrations of somatotropin measured in serum with commercial immunoradiometric assays.
Molecular forms of circulating growth hormone during spontaneous secretory episodes and in the basal state. Gender- and age-related differences in the endocrine parameters of acromegaly. Use of the oral glucose tolerance test to define remission in acromegaly. Age changes the diagnostic accuracy of mean profile and nadir growth hormone levels after oral glucose in postoperative patients with acromegaly.
Issue Section:. During this test, medicine will be used to cause blood glucose levels to rise which should make GH levels go lower. All of the medicine will need to be swallowed within 5 minutes. Samples of blood are collected in a timed manner by the infusion nurse and sent to the laboratory. The laboratory measures both growth hormone and glucose levels in the blood. Your doctor will review the test results and notify you of the results. Your child should eat however they normally eat for several days before this test.
Let your doctor know if your child follows any special diet before this test is done. This test may take up to 3 hours. Parents are asked to stay with their child during the test.
Since we have limited seating, family members other than 2 parents may be asked to sit in the waiting room during the test. When the test is over, your child may have his or her regular foods.
Feel free to bring a snack with you for your child to eat after the test. Recruitment was aimed at enrolling equal numbers of subjects in the different pubertal stages. However, at the end of the study, we had recruited seven, 16, and 41 girls, and 19, 11, and 13 boys in groups 1, 2, and 3, respectively.
Charles, MO [coefficient of variation 4. We used Cluster to determine area under the curve AUC and mean values We performed natural log transformations for data not normally distributed. The Student t test was used for two-group comparisons of means. We examined GH suppression between genders and within genders for different pubertal stages.
Table 1 shows GH data for boys based on pubertal stage. Midpubertal boys group 2 had higher log nadir GH than pre- to early pubertal group 1 and late pubertal group 3 boys. Mean testicular volume was 3. However, percent GH decrease was higher in group 1 than group 3 Five boys Data derived from comparisons using natural log-transformed values.
Natural log transformed variables were used to estimate statistical significance. Glucose peaked at 30 min in all groups, whereas GH reached its nadir at 90 min. Glucose and log GH levels after an oral glucose load in prepubertal girls A group 1: Tanner 1 , early to midpubertal girls B group 2: Tanner 2 and 3 , mid to late pubertal girls C group 3: Tanner 4 and 5 , prepubertal and early pubertal boys D group 1: Tanner 1 and 2 , midpubertal boys E group 2: Tanner 3 and 4 , and late pubertal boys F group 3: Tanner 5.
In girls, log GH levels were the lowest 30 or 60 min after oral glucose, whereas in boys, log GH levels were lowest 90 min after oral glucose in all groups. Corresponding nontransformed GH values are depicted to the right of the figure for ease of interpretation.
When pubic hair staging was used for grouping, similar trends were observed and are not reported. Grouping by chronological age and bone age quartiles or tertiles did not add to the analyses. Log nadir GH was higher in the third than fourth quartile, and trended higher in the third than the second quartile. Table 2 shows GH data for girls grouped by pubertal stage. Early to midpubertal group 2 girls had higher log nadir GH than the prepubertal group 1 girls, and trended higher than the mid to late pubertal group 3 girls.
The absolute GH decrease after oral glucose did not differ 1. One girl 1. Of these 16 girls, seven were early to midpubertal, and nine were mid to late pubertal. Thus, The girl with nadir GH of more than 1. Natural log-transformed variables were used to estimate statistical significance.
In group 1, glucose peaked, and GH reached its nadir at 60 min, whereas in group 3, the glucose peak, and GH nadir occurred 30 min after oral glucose Fig. In group 2, nadir GH occurred at 60 min, 30 min after peak glucose. As in boys, grouping by quartiles or tertiles of chronological and bone age did not add to the analyses, and we only report data for bone age quartiles.
Boys and girls did not differ for age, bone age, or anthropometric measures Table 3. Higher log nadir GH and mean GH in girls compared with boys were primarily because of differences between the genders in group 3. These variables did not differ between girls and boys in groups 1 and 2. Mean and range for log nadir GH when transformed back from the natural log scale were 0. AUC for glucose and insulin did not differ between genders.
Associations with height SDS were weaker. No associations were observed between GH and height in group 1. Diagnosis of GH excess in children has been exceedingly difficult because of the lack of normative data regarding GH suppression after oral glucose using newer assays.
Pediatricians have had to rely on IGF-I, which varies widely within a pubertal stage, and imaging studies to diagnose GH excess. Consequently, diagnosis and treatment are often delayed. Therefore, establishing normative data for GH suppression in healthy children at different pubertal stages using currently available assays is extremely important. In addition, although GH secretion during childhood is dependent upon pubertal stage, the impact of pubertal changes on GH suppressibility has not been established.
We demonstrate that early to midpubertal girls and midpubertal boys do not suppress their GH levels as much as children in other pubertal stages do after an oral glucose load, and girls have higher nadir GH levels than boys. Our findings are consistent with gender-specific data in adults that report higher nadir GH after oral glucose 19 , and higher mean GH measured over 24 h in women than men Therefore, higher nadir GH in girls is a consequence of higher baseline GH, and not gender-specific differences in suppressive effects of glucose on GH secretion.
GH increases at puberty 22 — 24 , and higher nadir GH after oral glucose in early to midpubertal group 2 girls is in agreement with the expected higher GH in Tanner stages 2—3 of puberty 15 , when peak height velocity occurs in girls Similarly, higher nadir GH after oral glucose at midpuberty in boys is consistent with highest GH and peak growth velocity occurring at Tanner 4 puberty in boys.
One study reported highest GH levels between testicular volumes of 10 and 15 ml, and consistent with these data, our group 2 boys had a mean testicular volume of Peak growth velocity was reported to occur at a mean age of In our study, group 2 girls and boys had the highest nadir GH after oral glucose, and the mean age was Of interest, we also observed a positive association between GH and absolute height in group 2 boys and girls.
Our data indicate differences in GH suppression with oral glucose in girls vs. Larger studies, particularly in midpubertal children, are necessary to confirm these data. The next blood samples are usually collected for 1 to 2 hours after you finish drinking the glucose solution. Sometimes they are taken every 30 or 60 minutes. Each sample is sent to the laboratory right away. The lab measures the glucose and GH levels in each sample. How to Prepare for the Test.
DO NOT eat anything and limit physical activity for 10 to 12 hours before the test. How the Test will Feel. Why the Test is Performed. What Abnormal Results Mean. Risks of having blood drawn are slight, but may include: Excessive bleeding Multiple punctures to locate veins Fainting or feeling lightheaded Blood accumulating under the skin hematoma Infection a slight risk any time the skin is broken.
Alternative Names. GH suppression test; Glucose loading test; Acromegaly - blood test; Gigantism - blood test. Blood test. Growth Disorders Read more.
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