Impact of Glucose Metabolism Disorders on IGF-1 Levels in Patients with Acromegaly

Abstract

In this study, we aimed to evaluate the presence of glucose metabolism abnormalities and their impact on IGF-1 levels in patients with acromegaly. Ninety-three patients with acromegaly (n=93; 52 males/41 females) were included in this study. Patients were separated into three groups such as; normal glucose tolerance (n=23, 25%), prediabetes (n=38, 41%), and diabetes mellitus (n=32, 34%). Insulin resistance was calculated with homeostasis model assessment (HOMA). HOMA-IR > 2.5 or ≤2.5 were defined as insulin resistant or noninsulin resistant groups, respectively. Groups were compared in terms of factors that may be associated with glucose metabolism abnormalities. IGF-1% ULN (upper limit of normal)/GH ratios were used to evaluate the impact of glucose metabolism abnormalities on IGF-1 levels. Patients with diabetes mellitus were significantly older with an increased frequency of hypertension (p<0.001, p=0.01, respectively). IGF-1% ULN/GH ratio was significantly lower in prediabetes group than in normal glucose tolerance group (p=0.04). Similarly IGF-1% ULN/GH ratio was significantly lower in insulin resistant group than in noninsulin resistant group (p=0.04). Baseline and suppressed GH levels were significantly higher in insulin resistant group than in noninsulin resistant group (p=0.024, p<0.001, respectively). IGF-1% ULN/GH ratio is a useful marker indicating glucose metabolism disorders and IGF-1 levels might be inappropriately lower in acromegalic patients with insulin resistance or prediabetes. We suggest that IGF-1 levels should be re-evaluated after the improvement of insulin resistance or glycemic regulation for the successful management of patients with acromegaly.

Establishment of Reference Intervals for Serum Insulin-Like Growth Factor I in Korean Adult Population

“…Information regarding 5,010 patients (2,079 men, 2,931 women) who visited outpatient clinics (Plastic Surgery, Orthopedics, Ophthalmology, Dermatology, Family Medicine, Dentistry, Otorhinolaryngology, Allergy and Immunology) from December 2018 to July 2019 was reviewed, and excluded based on the following exclusion criteria: (1) a medical history of liver diseases, renal diseases, cancer, diabetes mellitus, cardiac disorder, pulmonary disorder, or thyroid disorder or alanine aminotransferase >54 IU/L, aspartate aminotransferase >32 IU/L, estimated glomerular filtration rate <60 mL/min/1.73 m 2 , glucose ≥126 mg/dL, or C-reactive protein >10 mg/L; (2) no test results for liver enzyme, glucose, and creatinine; (3) the use of estrogen medication; and (4) ethnicity other than Korean. We defined "healthy" subjects to be those who passed all the exclusion criteria.…”

“…The level of insulin-like growth factor I (IGF-I) is affected by various factors such as age, sex, systemic illness, ethnicity, and the type of the analytical method [1,2]. Therefore, reference intervals of IGF-I considering those factors are necessary for the interpretation of measurement values in a given population.…”

Insulin-Like Growth Factor 1 (IGF-1) Signaling in Glucose Metabolism in Colorectal Cancer

“…Insulin mediated increase in both IGFs occurs due to the transcript stability increasing effect of this hormone rather than an increase in gene transcription [ 84 ]. In turn, transcription of the IGF-1 gene directly may be influenced by glucose metabolism in the liver [ 3 ] and its disorders [ 85 ]. Similarly, hepatic uptake of certain AAs, induced by GH or insulin, facilitates the expression of IGF-1 by stabilizing IGF-1 mRNA [ 3 ].…”

“…In another study, IGF-1% upper limit of normal (ULN)/GH ratio was used to assess the effect of glucose metabolism disorders on IGF-1 levels. A reduction in this ratio was demonstrated in patients with IR (HOMA-IR > 2.5) or prediabetes [ 85 ]. Similarly, Maione et al demonstrated a positive correlation between baseline ULN IGF-1 levels and DM II, even after adjustment for age, BMI, and both factors [ 174 ].…”

Visfatin Levels May be an Early Marker of Atherosclerosis in Patients with Acromegaly

“…High GH and in-sulin-like growth factor-1 (IGF-1) levels affect many tissues, including muscle and fat, where they dysregulate carbohydrate, protein, and fat metabolism [3]. The accompanying insulin resistance (IR), prediabetes, diabetes mellitus (DM), hyperlipidemia, and concom-itant hypertension increase the risk of cardiovascular disease in acromegalic patients [4][5][6], in whom it is the most common cause of death [7].…”