The value of the oral glucose tolerance test, random serum growth hormone and mean growth hormone levels in assessing the postoperative outcome of patients with acromegaly.
BACKGROUND: The nadir GH value following an oral glucose tolerance test (OGTT) and the mean GH levels obtained from a GH day curve (GHDC) are among the tools currently used for assessing therapeutic end-points in surgically treated acromegaly. The latter test, however, is cumbersome and costly. OBJ...
| Main Authors: | , , , |
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| Format: | Journal article |
| Language: | English |
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2009
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| _version_ | 1826273967398191104 |
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| author | Karavitaki, N Fernandez, A Fazal-Sanderson, V Wass, J |
| author_facet | Karavitaki, N Fernandez, A Fazal-Sanderson, V Wass, J |
| author_sort | Karavitaki, N |
| collection | OXFORD |
| description | BACKGROUND: The nadir GH value following an oral glucose tolerance test (OGTT) and the mean GH levels obtained from a GH day curve (GHDC) are among the tools currently used for assessing therapeutic end-points in surgically treated acromegaly. The latter test, however, is cumbersome and costly. OBJECTIVES: To evaluate, by using a modern, two-site chemiluminescent immunometric GH assay, the degree of discordance between the nadir GH following an OGTT and the mean GH obtained from a GHDC after surgical treatment of acromegaly and to check whether the OGTT can replace reliably the GHDC for the assessment of the disease status postoperatively. PATIENTS AND METHODS: Forty-nine patients [25 males/24 females, median age 52 years (range 18-70)] with a GH-secreting pituitary adenoma who had been surgically treated previously underwent hormonal evaluation of their disease status. The GHDC comprised of 9 x 30-min samples for GH collected in the morning after an overnight fast and rest. RESULTS: Seven per cent of patients with mean GH <1.7 mug/l (5 mU/l) in the GHDC had nadir GH >0.7 mug/l (2 mU/l) in the OGTT, and 10% of those with mean GH >1.7 mug/l had nadir GH <0.7 mug/l in the OGTT (all cases with discrepancies had normal IGF-I). GH value at time 0 min <0.6 mug/l in the OGTT had positive predictive value 100% and negative predictive value 75% in predicting nadir GH <0.3 mug/l (1 mU/l) in the OGTT. Nadir GH <0.8 mug/l in the OGTT had positive predictive value 97% and negative predictive value 95% in predicting mean GH <1.7 mug/l in the GHDC. Mean GH in the OGTT <1.4 mug/l had a positive predictive value 90% and negative predictive value 95% in predicting mean GH <1.7 mug/l in the GHDC. Mean GH in the OGTT <2.5 mug/l had positive predictive value 100% and negative predictive value 81% in predicting normal IGF-I. GH at time 0 min in the GHDC <2.1 mug/l had positive predictive value 90% and negative predictive value 90% in predicting mean GH <1.7 mug/l in the GHDC. CONCLUSIONS: The hormonal data obtained from an OGTT (mean and nadir GH) can provide comprehensive information on the status of acromegaly following surgery and can replace the GHDC cost-effectively. Furthermore, a morning fasting GH sample has an excellent positive predictive value in predicting biochemical cure and an optimal prognostic profile in predicting "safe" mean GH levels. |
| first_indexed | 2024-03-06T22:36:17Z |
| format | Journal article |
| id | oxford-uuid:5a02e77c-b278-47e4-9269-5f979b2547f7 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T22:36:17Z |
| publishDate | 2009 |
| record_format | dspace |
| spelling | oxford-uuid:5a02e77c-b278-47e4-9269-5f979b2547f72022-03-26T17:13:07ZThe value of the oral glucose tolerance test, random serum growth hormone and mean growth hormone levels in assessing the postoperative outcome of patients with acromegaly.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:5a02e77c-b278-47e4-9269-5f979b2547f7EnglishSymplectic Elements at Oxford2009Karavitaki, NFernandez, AFazal-Sanderson, VWass, J BACKGROUND: The nadir GH value following an oral glucose tolerance test (OGTT) and the mean GH levels obtained from a GH day curve (GHDC) are among the tools currently used for assessing therapeutic end-points in surgically treated acromegaly. The latter test, however, is cumbersome and costly. OBJECTIVES: To evaluate, by using a modern, two-site chemiluminescent immunometric GH assay, the degree of discordance between the nadir GH following an OGTT and the mean GH obtained from a GHDC after surgical treatment of acromegaly and to check whether the OGTT can replace reliably the GHDC for the assessment of the disease status postoperatively. PATIENTS AND METHODS: Forty-nine patients [25 males/24 females, median age 52 years (range 18-70)] with a GH-secreting pituitary adenoma who had been surgically treated previously underwent hormonal evaluation of their disease status. The GHDC comprised of 9 x 30-min samples for GH collected in the morning after an overnight fast and rest. RESULTS: Seven per cent of patients with mean GH <1.7 mug/l (5 mU/l) in the GHDC had nadir GH >0.7 mug/l (2 mU/l) in the OGTT, and 10% of those with mean GH >1.7 mug/l had nadir GH <0.7 mug/l in the OGTT (all cases with discrepancies had normal IGF-I). GH value at time 0 min <0.6 mug/l in the OGTT had positive predictive value 100% and negative predictive value 75% in predicting nadir GH <0.3 mug/l (1 mU/l) in the OGTT. Nadir GH <0.8 mug/l in the OGTT had positive predictive value 97% and negative predictive value 95% in predicting mean GH <1.7 mug/l in the GHDC. Mean GH in the OGTT <1.4 mug/l had a positive predictive value 90% and negative predictive value 95% in predicting mean GH <1.7 mug/l in the GHDC. Mean GH in the OGTT <2.5 mug/l had positive predictive value 100% and negative predictive value 81% in predicting normal IGF-I. GH at time 0 min in the GHDC <2.1 mug/l had positive predictive value 90% and negative predictive value 90% in predicting mean GH <1.7 mug/l in the GHDC. CONCLUSIONS: The hormonal data obtained from an OGTT (mean and nadir GH) can provide comprehensive information on the status of acromegaly following surgery and can replace the GHDC cost-effectively. Furthermore, a morning fasting GH sample has an excellent positive predictive value in predicting biochemical cure and an optimal prognostic profile in predicting "safe" mean GH levels. |
| spellingShingle | Karavitaki, N Fernandez, A Fazal-Sanderson, V Wass, J The value of the oral glucose tolerance test, random serum growth hormone and mean growth hormone levels in assessing the postoperative outcome of patients with acromegaly. |
| title | The value of the oral glucose tolerance test, random serum growth hormone and mean growth hormone levels in assessing the postoperative outcome of patients with acromegaly. |
| title_full | The value of the oral glucose tolerance test, random serum growth hormone and mean growth hormone levels in assessing the postoperative outcome of patients with acromegaly. |
| title_fullStr | The value of the oral glucose tolerance test, random serum growth hormone and mean growth hormone levels in assessing the postoperative outcome of patients with acromegaly. |
| title_full_unstemmed | The value of the oral glucose tolerance test, random serum growth hormone and mean growth hormone levels in assessing the postoperative outcome of patients with acromegaly. |
| title_short | The value of the oral glucose tolerance test, random serum growth hormone and mean growth hormone levels in assessing the postoperative outcome of patients with acromegaly. |
| title_sort | value of the oral glucose tolerance test random serum growth hormone and mean growth hormone levels in assessing the postoperative outcome of patients with acromegaly |
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