Biochemical markers of acromegaly: GH vs. IGF-I (original) (raw)
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Insulin-like growth factor 1 measurement in diagnosis and management of acromegaly
Annals of Clinical Biochemistry: International Journal of Laboratory Medicine, 2001
This article discusses the characteristic features of growth hormone secretion and insulin-like growth factor 1 (IGF-1) concentrations both in patients with acromegaly and in normal subjects. The therapeutic options for the treatment of acromegaly are briefly discussed, as are the current definitions of successful therapy. The article focuses on the use of serum and urinary growth hormone measurements along with the current and potential use of serum IGF-1, both at diagnosis and during long-term follow-up.
Metabolism, 1997
To evaluate the utility of measuring the serum insulin-like growth factor (IGF)-binding protein-3 (IGFBP-3) level and the IGF-I/IGFBP-3 ratio in the management of acromegalic patients, we comparatively studied the basal concentration of the aforementioned parameters with determination of plasma IGF-I levels and an index of clinical activity of acromegaly in 16 newly diagnosed acromegalic patients (aged 34 to 64 years) before and after hypophysectomy. After adenomectomy, 10 patients remained with "active" disease and six were "cured." Twenty-nine healthy sex-and age-matched volunteers were also studied. Comparison of individual values between untreated acromegalic patients and control subjects showed that none of the patients had overlapping values for IGF-I, whereas five of 16 and three of 16 patients had overlapping values for serum IGFBP-3 and IGF-I/IGFBP-3 ratio, respectively. When we compared the study parameters between the patients who remained with active disease after adenomectomy and the controls, two of 10 had overlapping values for IGF-I, but six of 10 and five of 10 had overlapping values for serum IGFBP-3 and IGF-I/IGFBP-3 ratio, respectively. Moreover, comparison of these parameters between cured and active patients after hypophysectomy showed that none had overlapping values for IGF-I, whereas three of six and one of six had overlapping values for serum IGFBP-3 and IGF-I/IGFBP-3 ratio, respectively. All biochemical variables studied showed significant relationships with an index of clinical activity of disease. In conclusion, our results seem to indicate that among determinations of plasma IGF-I, serum IGFBP-3, and the ratio IGF-I/IGFBP-3 in the evaluation of acromegalic patients, measurement of the plasma IGF-I level has the most discriminative value in the management of these patients.
The Journal of the Association of Physicians of India, 2014
Diagnosis of acromegaly in presence of uncontrolled diabetes mellitus is not well validated. The study included 10 patients of active acromegaly with uncontrolled blood glucose, 10 patients of type 2 diabetes mellitus with poor glycemic control and 10 healthy subjects. The growth hormone level following oral glucose tolerance test and insulin-like growth factor-1 (IGF-1) and insulin-like growth factor-binding protein-3 (IGFBP-3) were done at baseline in all the 3 groups and it was repeated after short term glycemic control in type 2 diabetics and acromegalics with diabetics In the acromegalic group the basal GH value was very high (36.5 + 1.6) ng/ml and it was non-suppressible (32.5 + 1.43) ng/ml after OGTT. The mean IGF-1 and IGFBP-3 values were also high at baseline (208.38 + 38.51) ng/ml, and 7322 + 370 ng/ml respectively. In the non-acromegalic diabetic patients, the basal growth hormone value was marginally elevated (2.3 + 0.02) ng/ml. However, it was suppressible to 0.2 + 0.04...
The Journal of Clinical Endocrinology & Metabolism, 1988
We measured plasma insulin-like growth factor I/somatomedin-C (IGF-I/SmC) concentrations and mean 24-h GH secretion serially before and during therapy with the longacting somatostatin analog SMS 201-995 in 21 patients with acromegaly. When mean plasma GH was elevated above 12.0 ± 0.6 (±SE) Mg/L. plasma IGF-I/SmC concentrations were uniformly high, but a decline of mean plasma GH below this value was accompanied by a linear decrease in IGF-I/SmC concentrations (r = 0.89; P < 0.001). Even mildly abnormal mean GH concentrations (>4.6 but <10 Mg/L) were accompanied by high plasma IGF-I/SmC values. The log dose-response interrelation between mean 24-h plasma GH and IGF-I/SmC concentrations was linear (r = 0.86; P < 0.001). We conclude that 1) an excellent log dose-response correlation between mean 24-h plasma GH and IGF-I/SmC concentrations is present in patients with acromegaly; 2) normalization of plasma IGF-I/SmC occurs only in patients with mean daily GH output within the normal range; and 3) determination of plasma IGF-I/SmC is an accurate indicator of normalcy of GH secretion and should be used in the diagnosis of active acromegaly as well as in monitoring the progress of therapy.
The Journal of Clinical Endocrinology & Metabolism
Context Discordant growth hormone (GH) and insulin-like growth factor-1 (IGF-1) values are frequent in acromegaly. Objective To evaluate the impact of different GH cutoffs on discordance rate. To investigate whether the mean of consecutive GH measurements impacts discordance rate when matched to the last available IGF-1 value. Design Retrospective study. Setting Referral center for pituitary diseases. Patients Ninety acromegaly patients with at least 3 consecutive evaluations for GH and IGF-1 using the same assay in the same laboratory (median follow-up 13 years). Interventions Multimodal treatment of acromegaly. Main Outcome Measures Single fasting GH (GHf) and IGF-1 (IGF-1f). Mean of 3 GH measurements (GHm), collected during consecutive routine patients’ evaluations. Results At last evaluation GHf values were 1.99 ± 2.79 µg/L and age-adjusted IGF-1f was 0.86 ± 0.44 × upper limit of normality (mean ± SD). The discordance rate using GHf was 52.2% (cutoff 1 µg/L) and 35.6% (cutoff 2....
The Journal of Clinical Endocrinology & Metabolism, 2001
In patients with treated acromegaly, improved survival is associated with serum GH concentrations below 2 g/L (5 mU/L). A principal aim of therapy in acromegaly is to achieve a GH level less than 2 g/L, as such levels are thought to be "safe." However, such GH levels do not always equate with normalization of plasma insulin-like growth factor I (IGF-I), although epidemiological data linking survival or morbidity to IGF-I levels are at present lacking. The aims of this study were 1) to further define the nature of GH release in those acromegalic patients who achieve mean GH concentrations below 2 g/L post therapy, 2) to examine the effect of different therapeutic interventions on the 24-h GH profile (surgery alone or radiotherapy), and 3) to determine the relationship between the various characteristics of the 24-h GH profile and IGF-I production in acromegalic subjects who have achieved GH below 2 g/L. Spontaneous 24-h GH secretion was measured using both a conventional immunoradiometric assay (limit of detection, 0.4 g/L) and an ultrasensitive assay (limit of detection, 0.002 g/L). The GH data have been analyzed by several methods: 1) the pulse detection algorithm Cluster, 2) a distribution method for detection of peak [the observed concentration 95%, i.e. the threshold at or below which GH concentrations are assessed to be 95% of the time, as calculated by probability analysis (OC 95%)] and trough (OC, 5%) GH activity, 3) deconvolution analysis, and 4) approximate entropy analysis. GH was sampled every 20 min for 24 h, along with basal IGF-I and IGF-binding protein-3, in 21 treated acromegalic patients with a mean GH below 2 g/L [ACR; 9 women and 12 men; median age (range), 49 (31-76) yr] and 16 healthy
2015
The diagnosis of acromegaly is based on demonstration of excess growth hormone (GH) and Insulin-Like Growth Factor-1 (IGF-1) secretion. IGF-1 is the most reliable biochemical indicator of activity of acromegaly. However, there are some pitfalls in the interpretation of change of plasma IGF-1 levels. We aim to report a case with acromegaly that has low IGF-1 levels and elevated GH levels associated with poorly controlled type 2 diabetes mellitus and malnutrition. A 38-years-old woman was admitted to emergency departmant due to hyperglycemia, weakness, cough, dyspnea, high fever. She has been complaining for enlargement of her hands and feet for ten years and she was cachectic for a long time. During oral glucose tolerance test (OGTT), serum growth hormone levels were found to be higher than normal range according to the matching age and sex subjects but IGF-1 and IGFBP-3 levels were measured lower than the reference range. A macroadenoma of 3x2.5 cm diameter was determined in magneti...
Growth Hormone & IGF Research, 2001
The aim was to evaluate, markers of disease activity in acromegaly in relation to perceived disease activity. Thirty-seven consecutively treated, acromegalic patients, classified by clinical symptoms as inactive (n = 16), slightly active (n = 10) and active (n = 11), entered the study. When evaluating the inactive and the active groups, we found that positive and negative predictive values (PV pos , PV neg ) for clinical disease activity of total and free insulin-like growth factor-I (IGF-I) were 0.59, 0.90 and 1.00, 0.82 respectively. Acid-labile subunit (ALS) showed diagnostic merit similar to insulin-like growth factor binding protein-3 (IGFBP-3) with PV pos of 0.69 and 0.71 and PV neg of 0.91 and 0.92 respectively. We conclude that free IGF-I is more closely related than total IGF-I to perceived disease activity and is as such useful when evaluating previously treated acromegaly for disease activity. Total IGF-I, IGFBP-3 and ALS possess a higher PV neg for the clinical disease activity. None of the parameters can at present be claimed to be superior to the others and thus all the measured parameters are recommended to be part of the evaluation of acromegalic patients.
Challenges in the diagnosis and management of acromegaly: a focus on comorbidities
Pituitary, 2016
Introduction Acromegaly is a rare, insidious disease resulting from the overproduction of growth hormone (GH) and insulin-like growth factor 1 (IGF-1), and is associated with a range of comorbidities. The extent of associated complications and mortality risk is related to length of exposure to the excess GH and IGF-1, thus early diagnosis and treatment is imperative. Unfortunately, acromegaly is often diagnosed late, when patients already have a wide range of comorbidities. The presence of comorbid conditions contributes significantly to patient morbidity/mortality and impaired quality of life. Methods We conducted a retrospective literature review for information relating to the diagnosis of acromegaly, and its associated comorbidities using PubMed. The main aim of this review is to highlight the issues of comorbidities in