Adequacy of current postglucose GH nadir limit (&lt; 1 µg/l) to define long‐lasting remission of acromegalic disease

Ronchi, Cristina L.; Arosio, Maura; Rizzo, Erica; Lania, Andrea; Beck‐Peccoz, Paolo; Spada, Anna

doi:10.1111/j.1365-2265.2007.02769.x

Cited by 33 publications

(26 citation statements)

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“…Incomplete GH suppression by glucose in the presence of normal IGF1 milieu was proposed to be a potentially predictive sign of future biochemical relapse (3), although other studies did not confirm this conclusion (4,5). At the same time, it became apparent that active acromegaly with clearly elevated IGF1 concentrations may be present even in newly diagnosed, untreated patients with apparently 'normal' plasma GH concentrations (6).…”

Section: Introductionmentioning

confidence: 90%

Limited utility of oral glucose tolerance test in biochemically active acromegaly

Ribeiro‐Oliveira¹,

Faje²,

Barkan³

2011

European Journal of Endocrinology

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Context: Measurement of GH after oral glucose tolerance test (OGTT) is used for the diagnosis and surveillance of acromegaly. However, there are major discrepancies between glucose-suppressed GH and plasma IGF1 as indices of biochemical activity of acromegaly in patients with relatively mild GH oversecretion. This study was aimed to assess the performance of OGTT in patients with acromegaly and variable GH outputs. Methods: Forty adults with newly diagnosed, untreated acromegaly (15 with GH O4.3 mg/l and 25 with GH !4.3 mg/l) and elevated IGF1 levels were studied. All underwent Q10 min for 24 h sampling for GH followed by an OGTT. Results: Postglucose nadir GH (GHn) correlated significantly to 24 h GHn, mean 24 h GH, and baseline GH (P!0.001 for all comparisons). GHn correlated significantly to IGF1 z-scores for the 'low' GH group and for the entire group (P!0.0001 for both comparisons), but not for the 'high' GH group. None of the patients with mean GH O4.3 mg/l had GHn below 1 mg/l. In contrast, 13 out of 25 patients (52%) with GH !4.3 mg/l showed GHn lower than 1 mg/l, and 7 of them (28%) had GHn lower than 0.4 mg/l. These groups did not differ significantly either for average or for maximal GH suppression in OGTT. Conclusions: Our data show that suppressibility of GH by glucose in acromegaly is a function of the degree of GH hypersecretion and that OGTT has only limited diagnostic value in patients with biochemically active acromegaly but only mildly increased GH output.

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Section: Introductionmentioning

confidence: 90%

Limited utility of oral glucose tolerance test in biochemically active acromegaly

Ribeiro‐Oliveira¹,

Faje²,

Barkan³

2011

European Journal of Endocrinology

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“…Hormonal and metabolic parameters were then compared between groups. The low GH nadir group had a significantly higher BMI at the time of remission and tended to have a higher BMI after long-term follow-up than that in the control group [20]. In addition, Arafat et al divided 213 healthy subjects into lean, overweight, and obese groups and evaluated the association of BMI with GH levels.…”

Section: Discussionmentioning

confidence: 99%

“…Nevertheless, GH nadirs >0.4 ng/mL are found in some cases, despite successful complete resection of adenomas and normalization of age-and sex-adjusted IGF-1 levels. Furthermore, the adequacy of the conventional cut-off value (age-and sexadjusted normal range of IGF-1 levels and GH nadir <1.0 ng/mL) has still been indicated in several subsequent studies [18][19][20].…”

Section: Data Collection and Measurementmentioning

confidence: 99%

Low insulin resistance after surgery predicts poor GH suppression one year after complete resection for acromegaly: a retrospective study

et al. 2016

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“…(4), this correlation becomes clearly visible beyond this value. The hypothes is that the influence on n-GH becomes evident when BMI > 30 kg/m 2 explains the fact that many series (9,(12)(13)(14)(15) did not find such association since the mean BMI was < 25 kg/m 2 in all of them and almost all subjects had a BMI < 30 kg/m 2 . Another finding supporting the influence of BMI on GH secretion is the correlation observed between this variable and peak GH after stimulation with GHRH + arginine, with adjustment of the cut-off (11, 8 and 4 ng/mL for BMI < 25, 25-30 and > 30 kg/m 2 , respectively) being recommended for the diagnosis of GH deficiency in adults (16).…”

mentioning

confidence: 99%

“…Nadir GH levels vary according to the assay used (4-7) and are influenced by gender, age and body mass index [BMI (4)(5)(6)8)]. The inverse correlation with BMI observed in normal subjects (4,6,8) and acromegalic patients (9) indicates the need for adjusting the n-GH cut-off as a function of BMI (4,6,8). We have previously defined n-GH reference values in subjects with a BMI ≤ 27 kg/m 2 (5).…”

mentioning

confidence: 99%

Nadir growth hormone after oral glucose overload in obese subjects

Rosário

Salles

Bessa

et al. 2010

Arq Bras Endocrinol Metab

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T he nadir growth hormone (n-GH) in the oral glucose tolerance test (OGTT) is the gold standard for the demonstration of secretory autonomy of this hormone and a laboratory parameter necessary for the diagnosis of acromegaly (1,2). Although measurement of GH after oral glucose overload is not recommended during treatment with somatostatin analogs or GH receptor antagonists (3), normalization of n-GH continues to be necessary for the definition of "control" after surgical treatment of acromegaly (3). Nadir GH levels vary according to the assay used (4-7) and are influenced by gender, age and body mass index 8)]. The inverse correlation with BMI observed in normal subjects (4,6,8) and acromegalic patients (9) indicates the need for adjusting the n-GH cut-off as a function of BMI (4,6,8). We have previously defined n-GH reference values in subjects with a BMI ≤ 27 kg/m 2 (5). The possibility that the current reference values are inadequate (overestimated) for obese subjects led to the elaboration of the present study, for which the objective was to evaluate the n-GH in the OGTT in subjects with a BMI ≥ 30 kg/m 2 . A total of 200 volunteers (120 women and 80 men) ranging in age from 18 to 70 years (median of 44 years), matched with 200 subjects from the previous study (5), who had a BMI ≥ 30 kg/m 2 (median of 34.8 kg/m 2 ) were studied. The selection criteria, protocol and statistical analysis are described in detail in the previous study (5). Briefly, apparently healthy subjects (excluding pregnant women) without associated diseases who were not using medications that might interfere with GH levels and who presented no abnormalities upon minimum laboratory assessment (glycemia, blood count, albumin, creatinine, TSH, GOT, GPT and bilirubin) were selected. The study was approved by the Ethics Committee of Santa Casa de Belo Horizonte.The GH Immulite kit (Diagnostic Products Corporation, Los Angeles, CA) was used for the measurement of GH since it is the kit most widely used in Brazil. In addition, the kit meets the requirements of calibrated standards against > 95% pure preparations of GH 22 kDa (10), its specificity for the 22 and 20 kDa isoforms is known (4), and its intra-and interassay sensitivity and variability have been previously established (5,11). The cut-off was defined as the 97.5th percentile of the values found. The Spearman correlation test was used to analyze the correlation between n-GH and age, BMI. The nonparametric Kruskal-Wallis test and the parametric Shapiro-Wilk test were used to compare GH values obtained between groups. P values < 0.05 were considered to be statistically significant.The n-GH cut-off values for obese women and men were 0.35 µg/L and 0.15 µg/L (p < 0.05), respectively. No correlation was observed between n-GH levels and age. However, a difference was found when comparing women ≤ 35 years (n = 40) versus > 35 years (n = 80), with higher values in the former (n-GH cut-off: 0.42 µg/L versus 0

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Adequacy of current postglucose GH nadir limit (< 1 µg/l) to define long‐lasting remission of acromegalic disease

Abstract: The current GH nadir limit is still adequate to define both short- and long-lasting remission of acromegaly, independently of the type of definitive treatment. Patients with the lowest GH nadir should probably be monitored long-term for adequacy of their GH secretion.

Cited by 33 publications

References 23 publications

Limited utility of oral glucose tolerance test in biochemically active acromegaly

Limited utility of oral glucose tolerance test in biochemically active acromegaly

Low insulin resistance after surgery predicts poor GH suppression one year after complete resection for acromegaly: a retrospective study

Nadir growth hormone after oral glucose overload in obese subjects

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