scholarly journals THE CUT-OFF LIMITS OF GH RESPONSE TO INSULIN TOLERANCE TEST RELATED TO BODY MASS INDEX FOR THE DIAGNOSIS OF ADULT GH DEFICIENCY

2020 ◽  
Author(s):  
Valentina Gasco ◽  
Alice Ferrero ◽  
Alessandro Bisceglia ◽  
Nunzia Prencipe ◽  
Valeria Cambria ◽  
...  
2005 ◽  
Vol 90 (3) ◽  
pp. 1563-1569 ◽  
Author(s):  
Xiao-Dan Qu ◽  
Irene T. Gaw Gonzalo ◽  
Mohammed Y. Al Sayed ◽  
Pejman Cohan ◽  
Peter D. Christenson ◽  
...  

The aim of this study is to assess whether gender and body mass index (BMI) should be considered in developing thresholds to define GH deficiency, using GH responses to GHRH + arginine (ARG) stimulation and insulin tolerance test (ITT). Thirty-nine healthy subjects (19 males, 20 females; ages 21–50 yr) underwent GHRH + ARG, and another 27 subjects (19 males, 8 females; ages 20–49 yr) underwent ITT. Peak GH response was significantly higher (P = 0.005) after GHRH + ARG than with ITT, and this difference could not be explained by age, gender, or BMI. Peak GH response was negatively correlated with BMI in both tests (GHRH + ARG, r = −0.76; and ITT, r = −0.65). Peak GH response to GHRH + ARG was higher in females than males (P = 0.004; ratio = 2.4), but it was attenuated after eliminating the influence of BMI (P = 0.13; ratio = 1.6). No significant gender differences were found in peak GH responses to ITT, which could be due to the smaller number of female subjects studied. GH response to GHRH + ARG and ITT stimulation is sensitive to BMI differences and less so to gender differences. A higher BMI is associated with a depressed GH response to both stimulation tests. BMI should therefore be considered as a factor when defining the diagnostic cut-off points in the assessment of GH deficiency, whereas whether gender should be likewise used is inconclusive from this study.


1997 ◽  
Vol 12 (Suppl_2) ◽  
pp. 334-334
Author(s):  
J.G. Dolfing ◽  
D.H. Schweitzer ◽  
M. van Vreedendaal ◽  
C. Bosman ◽  
C.A.M. Jansen

2013 ◽  
Vol 60 (1) ◽  
pp. 97-105 ◽  
Author(s):  
Yasuyuki Kinoshita ◽  
Atsushi Tominaga ◽  
Satoshi Usui ◽  
Kazunori Arita ◽  
Tetsuhiko Sakoguchi ◽  
...  

1995 ◽  
Vol 133 (3) ◽  
pp. 305-312 ◽  
Author(s):  
Hans C Hoeck ◽  
Peter Vestergaard ◽  
Poul E Jakobsen ◽  
Peter Laurberg

Hoeck HC, Vestergaard P, Jakobsen PE, Laurberg P, Test of growth hormone secretion in adults: poor reproducibility of the insulin tolerance test. Eur J Endocrinol 1995;133:305–12. ISSN 0804–4643 The insulin tolerance test (ITT) is regarded as the most reliable provocative test in the diagnosis of growth hormone (GH) deficiency in adults. In the present study the test was evaluated by investigating the range of GH responses in normal adult males and females and the intra-individual reproducibility of the test. Sixteen healthy non-obese adults, eight males (median age 31.5 years) and eight females (median age 31.8 years) were tested twice with the ITT, with a minimum of 72 h between each test. The females were tested between day 3 and day 10 of their menstrual cycles. Adequate hypoglycemia was achieved in all cases with a median nadir blood glucose of 1.3 mmol/l (range 0.8–2.0). Growth hormone in serum was measured by immunoradiometric assay and low values were confirmed by a different assay. Median peak GH concentration responses to the ITT were: in males 27.9 μg/l, range 5.0–71.1 (test 1) and 30.5 μg/l, range 7.9–69.5 (test 2); and in females 9.0 μg/l, range 4.1–17.9 (test 1) and 8.4 μg/l, range 0.09–42.4 (test 2). The rise in GH concentration during the ITT was higher in males than in females. In the males, all stimulated GH values were ≥5.0 μg/l. In the females, four out of 16 tests gave values below 5.0 μg/l and in one test the GH value was around the detection limit of the assays. There was poor reproducibility during repeated testing, with no correlation between the results of the two tests. The results did not correlate to the magnitude of the hypoglycemia. The results of this study illustrate the complexity of the regulation of GH secretion and indicate that the ITT is less useful for diagnosing GH deficiency in adults than previously anticipated. The diagnosis of GH deficiency in adults and especially in adult females should not be based on the results of a single ITT alone. Hans C Hoeck, Department of Endocrinology, Aalborg Regional Hospital, Reberbansgade, DK-9000 Aalborg, Denmark


2003 ◽  
pp. 117-122 ◽  
Author(s):  
F Cordido ◽  
P Alvarez-Castro ◽  
ML Isidro ◽  
FF Casanueva ◽  
C Dieguez

OBJECTIVE: It has been gradually realized that GH may have important physiological functions in adult humans. The biochemical diagnosis of adult GHD is established by provocative testing of GH secretion. The insulin-tolerance test (ITT) is the best validated. The ITT has been challenged because of its low degree of reproducibility and lack of normal range, and is contra-indicated in common clinical situations. Furthermore, in severely obese subjects the response to the ITT frequently overlaps with those found in non-obese adult patients with GHD. DESIGN: The aim of the present study was to evaluate the diagnostic capability of four different stimuli of GH secretion: ITT, GHRH, GHRH plus acipimox (GHRH+Ac), and GHRH plus GHRP-6 (GHRH+GHRP-6), in two pathophysiological situations: hypopituitarism and obesity, and normal subjects. METHODS: Eight adults with hypopituitarism (four female, four male) aged 41-62 Years (48.8+/-1.4 Years), ten obese normal patients (five female, five male) aged 38-62 Years (48.1+/-2.5 Years), with a body mass index of 34.2+/-1.2 kg/m(2), and ten normal subjects (five female, five male) aged 33-62 Years (48.1+/-2.8 Years) were studied. Four tests were performed on each patient or normal subject: An ITT (0.1 U/kg, 0.15 U/kg for obese, i.v., 0 min), GHRH (100 microg, i.v., 0 min), GHRH (100 microg, i.v., 0 min) preceded by acipimox (250 mg, orally, at -270 min and -60 min) (GHRH+Ac); and GHRH (100 microg, i.v., 0 min) plus GHRP-6 (100 microg, i.v., 0 min) (GHRH+GHRP-6). Serum GH was measured by radioimmunoassay. Statistical analyses were performed by Wilcoxon rank sum and by Mann-Whitney tests. RESULTS: After the ITT the mean peak GH secretion was 1.5+/-0.3 microg/l for hypopituitary, 10.1+/-1.7 microg/l (P<0.05 vs hypopituitary) for obese and 17.8+/-2.0 microg/l (P<0.05 vs hypopituitary) for normal. GHRH-induced GH secretion was 2+/-0.7 microg/l for hypopituitary, 3.9+/-1.2 microg/l (P=NS vs hypopituitary) for obese and 22.2+/-3.8 microg/l (P<0.05 vs hypopituitary) for normal. After GHRH+Ac, mean peak GH secretion was 3.3+/-1.4 microg/l for hypopituitary, 14.2+/-2.7 microg/l (P<0.05 vs hypopituitary) for obese and 35.1+/-5.2 microg/l (P<0.05 vs hypopituitary) for normal. GHRH+GHRP-6 induced mean peak GH secretion of 4.1+/-0.9 microg/l for hypopituitary, 38.5+/-6.5 microg/l (P<0.05 vs hypopituitary) for obese and 68.1+/-5.5 microg/l (P<0.05 vs hypopituitary) for normal subjects. Individually considered, after ITT, GHRH or GHRH+Ac, the maximal response in hypopituitary patients was lower than the minimal response in normal but higher than the minimal response in obese subjects. In contrast, after GHRH+GHRP-6 the maximal response in hypopituitary patients was lower than the minimal response in normal and obese subjects. CONCLUSIONS: This study suggests that, in this group of patients, although both acipimox and GHRP-6 partially reverse the functional hyposomamotropism of obesity after GHRH, but are unable to reverse the organic hyposomatotropism of hypopituitarism, the combined test GHRH+GHRP-6 most accurately distinguishes both situations, without the side effects of ITT.


2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Lucinda Gruber ◽  
Sanjeev Nanda ◽  
Todd B Nippoldt ◽  
Alice Y Chang ◽  
Irina Bancos

Abstract Introduction: Low or borderline cortisol concentrations and impaired response to dynamic testing have been reported in patients with fibromyalgia, potentially related to hypothalamus-pituitary dysfunction.1,2 Superimposed adrenal insufficiency (AI) may contribute to some fibromyalgia symptoms or delay improvement in patients enrolled in fibromyalgia treatment programs. We hypothesized that a subset of patients with fibromyalgia have: 1) partial secondary AI and concomitant growth hormone (GH) deficiency 2) a discordance in Cosyntropin stimulation test and 3) improvement in fibromyalgia symptoms with initiation of glucocorticoid and/or GH replacement. Design: This was a retrospective study of patients with fibromyalgia diagnosed with partial secondary AI based on abnormal insulin tolerance test (peak cortisol &lt; 18 mcg/dL) at our institution from June 2002 to August 2019. Patients were excluded if they had other reasons for adrenal insufficiency, including steroid exposure and opioid use. Results: We identified 22 patients (18 women, 82%) diagnosed with partial AI at a median age of 38 years (range 19-65). The fibromyalgia symptoms included fatigue (n=22, 100%), pain (n=22, 100%), sleep disturbance (n=15, 68%), and bowel changes (n=13, 59%). The median morning cortisol concentration was 8.6 mcg/dL (range 1.1-11); 9 patients (41%) had a morning cortisol concentration below the normal range (7 mcg/dL). The median ACTH level was 15.5 pg/mL (range 7.7-54). Nineteen patients had baseline IGF1 levels, with a median z-score of -0.94 (range -1.96 to 1.70). MRI pituitary imaging was performed in 20 patients and showed no significant pituitary pathology. All patients achieved hypoglycemia &lt;=40 mg/dL during the insulin tolerance test. Peak median cortisol level was 11 mcg/dL (range 5.4-17). Nineteen patients (86%) also had partial GH deficiency (defined as a peak GH &lt; 4 ng/mL) with a median GH level of 0.36 ng/mL (range 0.03-3.83). Cosyntropin stimulation test was performed in 13 patients (59%) with a 1 mcg dose in 2 patients and 250 mcg dose in 11 patients. The peak cortisol was &gt;=18 mcg/dL in 10 (77%) patients. All patients were started on physiologic glucocorticoid replacement, and 12 patients were started on GH replacement. Endocrinology follow-up information was available for 13 patients, and 8 (62%) reported symptom improvement after starting treatment. Conclusions: Patients with fibromyalgia can have co-existing partial secondary AI and GH deficiency as defined by insulin-induced hypoglycemia. Cosyntropin stimulation test can be used in patients with fibromyalgia, but a normal test does not rule out partial secondary AI. Replacing the underlying deficiency improved symptoms in some patients demonstrating certain fibromyalgia symptoms may overlap with AI and GH deficiency. 1Gur et al. Ann Rheum Dis. 2004. 63(11):1504-1506. 2Kirnap et al. Clin Endocrinol (Oxf). 2001. 55(4):455-459.


2002 ◽  
pp. 667-672 ◽  
Author(s):  
S Petersenn ◽  
R Jung ◽  
FU Beil

OBJECTIVE: The diagnosis of GH deficiency in adults should be made using provocative testing of GH secretion. The insulin tolerance test (ITT) is recommended as the gold standard investigation. Because of the risk of serious complications, patients with epilepsy or known ischemic heart disease should not undergo this test. GHRP-6 is a synthetic hexapeptide that releases GH by binding to specific hypothalamic and pituitary receptors. We assessed the diagnostic capability of GH stimulation by GHRP-6 alone or in combination with GHRH in comparison to the results of an ITT. DESIGN: Twenty patients underwent an ITT for suspected pituitary or adrenal disease. Either GHRP-6 (1 microg/kg) alone, or GHRP-6 in combination with GHRH (1 microg/kg) were administered on different days. Blood samples were obtained during a subsequent 90-min period for measurement of GH. RESULTS: Ten patients had a GH peak response of less than 3 microg/l during ITT and were considered growth hormone deficient (GHD). The GH mean peak (+/-S.E.M., range) in this group was 0.7 microg/l (+/-0.3, 0.1-2.9) compared with 14.5 microg/l (+/-3.5, 3.8-40.8) in the group of patients with a GH peak response of more than 3 microg/l (growth hormone sufficient (GS)). For the GHRP-6 test, the GH mean peak was 1.3 microg/l (+/-0.6, 0.1-6.7) in the GHD group versus 25.7 microg/l (+/-5.5, 7.7-54.2) in the GS group. After GHRP-6+GHRH, the GH mean peaks were 4.0 microg/l (+/-1.3, 0.2-11.9) versus 54.7 microg/l (+/-11.1, 13.9-136.0) respectively. During administration of GHRP-6, the only side effects observed were flush symptoms. CONCLUSIONS: Peak GH levels below 7 microg/l for the GHRP-6 test and below 13 microg/l for the combined GHRP-6+GHRH test identified all patients with GH deficiency correctly as defined by ITT. The results suggest that testing with GHRP-6 or GHRP-6+GHRH is as sensitive and specific as an ITT for the diagnosis of adult GH deficiency.


2004 ◽  
Vol 89 (7) ◽  
pp. 3397-3401 ◽  
Author(s):  
Vivien S. Bonert ◽  
Janet D. Elashoff ◽  
Philip Barnett ◽  
Shlomo Melmed

Abstract GH secretion is decreased in obese subjects, whereas age-adjusted IGF-I concentrations are normal. This study was undertaken to rigorously delineate the extent of obesity [elevated body mass index (BMI)] associated with decreased somatotrope secretory function resulting in apparent adult GH deficiency. The peak GH response evoked by combined arginine (0.5 g/kg infused iv over 30 min) and GHRH (1 μg/kg iv bolus) was measured in 59 healthy male subjects with BMIs ranging from normal to obese. BMI correlated with the peak evoked GH response (Pearson r = −0.59; P &lt; 0.01), and the percentage of subjects exhibiting an abnormal evoked GH response, i.e. less than 9 ng/ml, increased from 5% for those with a BMI less than 25 (normal), to 13% for those with a BMI of 25–26.9 (mildly overweight), to 33% for those with a BMI of 27–29.9 (moderately overweight), and to 64% for those with a BMI of 30 or more (obese). BMI is a major determinant of evoked adult GH response to provocative testing. The diagnosis of adult GH deficiency using the evoked GH response in patients with even mild BMI elevation does not accurately distinguish normal from deficient responses and may result in the erroneous classification of obese subjects as GH deficient and thus unnecessarily requiring GH replacement.


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