Low Serum Insulin-like Growth Factor-1 Levels Research Articles

Association between serum IGF‑1 levels and non-motor symptoms in Parkinson's disease.

We aimed to measure serum insulin-like growth factor 1 (IGF-1) levels in Parkinson's disease (PD) patients and assess their correlation with non-motor symptoms (NMS). Emerging evidence suggests that abnormal levels of IGF-1 play a crucial role in the development of PD. Further systematic research is needed to explore the potential roles of abnormal IGF-1 levels in NMS of PD. The study enrolled a total of 129 PD patients and 130 healthy controls (HCs). Within the PD cohort, 74 patients were classified as being in the early stage, while 55 were in the moderate stage. This study found no significant difference in serum IGF-1 levels between PD patients and HC. Further analysis revealed no significant difference in IGF-1 levels between early-stage PD and those in the moderate stages. Linear regression analysis indicated a significant association between serum IGF-1 levels and Nonmotor Symptom Scale (NMSS) scores in PD patients. Linear regression analysis revealed significant correlations between serum IGF-1 levels and general cognitive function, information processing speed, and executive function in PD patients. Furthermore, lower serum IGF-1 levels were associated with fatigue in PD patients. In summary, our study suggests a potential association between serum IGF-1 levels and specific NMS in patients with PD. These findings highlight the importance of long-term follow-up studies to determine whether serum biomarkers can serve as valuable tools for early detection of NMS in PD.

Very low serum IGF-1 levels are associated with vertebral fractures in adult males with beta-thalassemia major.

Patients with beta-thalassemia major (BTM) often develop several endocrine disorders due to chronic iron overload. They are also prone to osteoporosis and vertebral fractures. Plasmatic insulin-like growth factor-1 (IGF-1) levels are often low in subjects with BTM, which origin is multifactorial. The aim of this study was to evaluate a possible relationship between serum IGF-1 levels and the presence of osteoporosis and/or vertebral fractures. We retrospectively evaluated the occurrence of vertebral fractures in 30 adult male patients affected by BTM (mean age 43.3 ± 7.9years) with low serum IGF-1 (median value 52.4ng/ml, 38.5-83.4). Only 6 of them (20.0%) were diagnosed with GH deficiency (GHD) after GHRH/arginine stimulation test, while 23 (76.7%) had osteoporosis and 12 (40.0%) had known vertebral fractures. All patients except one also showed at least one endocrine disorder. Serum IGF-1 was significantly lower in BTM patients with vertebral fractures compared to patients without vertebral fractures (U = 41.0, p = 0.005) while it was not significantly different between patients with low bone mass compared to patients without low bone mass. The diagnosis of GHD was significantly associated with lower serum IGF-1 (p = 0.001) and vertebral fractures (p = 0.002) but not with low bone mass. After ROC analysis, we found that very low IGF-1 (≤ 50.0ng/dl) was associated with vertebral fractures (sensitivity 83.3%, specificity 75.0%) and was also predictive of GHD (sensitivity 75.0%, specificity 100.0%). Our study shows that, in male patients with BTM, serum IGF-1 ≤ 50.0ng/dl is a marker of vertebral fractures and it is predictive of a diagnosis of GHD.

Insulin-like growth factor 1 predicts decompensation and long-term prognosis in patients with compensated cirrhosis.

Insulin-like growth factor 1 (IGF-1), which is primarily produced in hepatocytes and is associated with liver functional reserve, plays a crucial role in the pathological condition of cirrhosis. This study aimed to investigate the usefulness of serum IGF-1 levels for predicting the long-term prognosis and decompensation development in patients with cirrhosis. We retrospectively evaluated 148 patients with cirrhosis and divided them into three groups according to baseline IGF-1 levels: low (L)-, intermediate (I)-, and high (H)-IGF-1 groups. The cumulative survival rates were compared among these groups in compensated and decompensated cirrhosis, respectively. Significant and independent factors associated with mortality and decompensation development were identified using Cox proportional hazards regression analysis. The median observation period was 57.1 (41.7-63.2) months. Thirty (20.3%) patients died of liver disease-related events and 21 (22.3%) patients with compensated cirrhosis developed decompensation. Multivariate analysis identified low serum IGF-1 levels as a significant and independent factor associated with mortality (all patients: hazard ratio [HR], 0.967; p = 0.004; patients with compensated cirrhosis: HR, 0.927; p = 0.002). The cumulative survival rates were significantly lower in the L-IGF-1 group than in the H-IGF-1 and I-IGF-1 groups (all patients: p < 0.001 and = 0.009; patients with compensated cirrhosis: p = 0.012 and 0.003, respectively). However, in decompensated cirrhosis, the cumulative survival rates demonstrated no significant differences among the three groups. The cumulative decompensation incidence rates were significantly higher in the L-IGF-1 group than in the H-IGF-1 and I-IGF-1 groups (p < 0.001 and = 0.009, respectively). Low serum IGF-1 levels were significantly and independently associated with decompensation development (HR, 0.939; p < 0.001). Low serum IGF-1 levels were significantly and independently associated with decompensation development and poor long-term prognosis in patients with compensated cirrhosis. Therefore, IGF-1 may be useful for predicting decompensation-related events and should be regularly monitored in the management of compensated phase.

Lower serum insulin-like growth factor-1 levels are independently associated with anemia in patients undergoing maintenance hemodialysis

The relationship between serum insulin-like growth factor-1 (IGF-1) levels and anemia in patients undergoing maintenance hemodialysis (MHD) remains unclear. This cross-sectional study included patients who underwent MHD treatment for >3 months at our dialysis center in March 2021. Demographic and clinical data were recorded. Blood samples were collected before the hemodialysis sessions, and general serum biochemical parameters, routine blood markers, and serum IGF-1 levels were measured. Patients were divided into a group without anemia (hemoglobin ≥110 g/L) and a group with anemia (hemoglobin <110 g/L), and multivariable linear and binary logistic regression analyses were performed to study the relationship between the levels of serum IGF-1 and anemia. A total of 165 patients (male/female = 99:66) with MHD were enrolled in the study, with a median age of 66.0 (58.0, 75.0) years and a median dialysis vintage of 27.0 (12.0, 55.0) months. The mean hemoglobin level was 96.38 ± 16.72 g/L, and 126 patients had anemia (76.4%). Compared to patients without anemia, patients with anemia had lower serum IGF-1 and triglyceride levels and higher intravenous iron supplementation on dialysis (all p < 0.05). After adjusting for confounding factors in different models, the nine-model multivariate binary logistic regression analyses also confirmed that lower serum IGF-1 levels and serum IGF-1 < 197.03 ng/ml were both independently associated with anemia in patients undergoing MHD. However, further multicenter studies with larger sample sizes are required to confirm these findings.

Association between Bone-Related Physiological Substances and Oral Function in Community-Dwelling Older People.

Background: Oral dysfunction is related to long-term cares including activities of daily living. The objective of this study was to determine the association between oral function and the bone-related physiological substances osteocalcin (OC) and insulin-like growth factor-1 (IGF-1). Methods: The study participants were 139 community-dwelling older people in Japan. Evaluation of oral dysfunction was based on subjective judgment by each participant. Blood analysis included OC, IGF-1, and albumin. Results: Univariate and multiple logistic analyses showed that IGF-1 was significantly associated with a “decline in masticatory function” (p = 0.0074 and p = 0.0308, respectively). Receiver operating characteristic curve analysis of IGF-1 levels revealed a threshold score of 108 ng/mL (p < 0.01) for discriminating a “decline in masticatory function”. Logistic regression analysis revealed that participants with an IGF-1 level ≤108 ng/mL had an odds ratio of 4.31 (p < 0.05) for a “decline in masticatory function”. No significant association was found between the OC level and oral dysfunction. Conclusions: These results suggest a possible relationship between lower serum IGF-1 levels and a decline in masticatory dysfunction in community-dwelling older people.

Low bone mass in Noonan syndrome children correlates with decreased muscle mass and low IGF-1 levels.

Although musculoskeletal abnormalities have long been described in patients with Noonan syndrome (NS), only a few studies have investigated the bone status of these patients. The aim of this retrospective observational study was to describe the bone health of children with NS. Thirty-five patients with a genetically confirmed diagnosis of NS were enrolled. We analyzed the axial skeleton (lumbar spine) using dual energy X-ray absorptiometry and the appendicular skeleton (hand) with the BoneXpert system. Bone metabolism markers, including mineral homeostasis parameters, serum 25-hydroxy vitamin D (25-OHD) levels and markers of bone formation and resorption were also reported. Compared to the general population, axial and appendicular bone mass was significantly decreased in children with NS (p<0.0001). Serum 25-OHD levels were low in about half of the patients and were negatively correlated with age (r=-0.52; p<0.0001). Patients with NS exhibited reduced bone formation marker levels and increased bone resorption marker levels (p<0.0001). No gender difference or genotype-phenotype correlations were found for the different bone parameters. Muscle mass and, to a lesser extent, serum insulin-like growth factor 1 (IGF-1) levels were independent predictors of whole-body bone mineral content (p<0.0001 for both parameters; adjusted R2=0.97). In conclusion, bone mass is reduced in children with NS and correlates with decreased muscle mass and low serum IGF-1 levels. These data justify addressing all potential threats to bone health including sufficient calcium and vitamin D intake, regular physical exercise, and hormone replacement therapy.

Expression of IGF-1, IGF-1 Receptor and Growth Hormone Receptor in Hepatic Tissue in Adults Across the Spectrum of Nonalcoholic Fatty Liver Disease (NAFLD)

Background: Obesity is a state of relative growth hormone (GH) and insulin-like growth factor-1 (IGF-1) deficiency, and the GH/IGF-1 axis has been implicated in the pathophysiology of nonalcoholic fatty liver disease (NAFLD) and the progression to steatohepatitis (NASH) in preclinical models and human studies. GH has both lipolytic and anti-inflammatory properties while IGF-1 has been implicated in reducing hepatic fibrosis and promoting hepatic regeneration. The GH/IGF-1 axis may be a therapeutic target in NAFLD/NASH, however, IGF-1, IGF-1 receptor (IGF-1R) and GH receptor (GHR) expression in adult human hepatic tissue has not been studied across the spectrum of disease severity. Methods: We quantified IGF-1, IGF-1R, and GHR gene expression in hepatic tissue from 318 adults with obesity using the Nanostring nCounter assay. Subjects were classified into four categories of disease severity based on histopathology: normal liver histology (NLH) (n=76, 24%), steatosis only (Steatosis) (n=88, 28%), NASH without fibrosis (NASH F0) (n=72, 23%), and NASH with fibrosis (NASH F1-F4) (n=82, 26%). Gene expression analysis is presented as normalized gene counts by group with p-value of the generalized linear model controlled for age, sex and BMI. Results: Mean (±SD) age (whole cohort 44.0±12 years) and BMI (whole cohort 46.8±7.2 kg/m2) did not differ across groups (p=0.2 for both). ALT was higher with increasing disease severity (NLH 30.1±26.7, Steatosis 31.9±15.7, NASH F0 35.7±16.5, NASH F1-4 48.4±34.9, p<0.001). IGF-1 gene expression was lower in all NAFLD/NASH groups compared to the NLH reference group (NLH 485.4±292.7; Steatosis 396.3±238.0, p=0.04; NASH F0 349.8±220.1, p=0.01 and NASH F1-4 341.2±268.6, p=0.03, all p-values vs NLH). There was no difference in IGF-1R or GHR gene expression across disease severity groups (IGF-1R NLH 43.3±10.2, Steatosis 41.4±11.6, NASH F0 38.8±8.8 and NASH F1-4 39.1±8.1, p>0.05 between any disease state; GHR NLH 6382±2366, Steatosis 6544±2699, NASH F0 7220±2542 and NASH F1-4 5997±2352, p>0.05 between any disease state). Conclusion: We demonstrated that IGF-1 gene expression was lower in liver tissue from patients with NAFLD and NASH than healthy controls. This is consistent with our prior finding that histologic NASH and fibrosis are associated with lower serum IGF-1 levels. Moreover, we demonstrated that hepatic IGF-1R and GHR gene expression is not lower in liver tissue from patients with NAFLD and does not decline across disease severity. This reinforces our prior finding that GHR staining intensity and zonality by immunohistochemistry does not change with increasing disease severity in NAFLD/NASH. These data demonstrate that the GH axis is relatively suppressed but that expression of GHR and IGF-1R receptors is stable with worsening disease severity in NAFLD/NASH, suggesting that GH augmentation may be a viable therapeutic target in NAFLD.

Low Serum Branched-Chain Amino Acid and Insulin-Like Growth Factor-1 Levels Are Associated with Sarcopenia and Slow Gait Speed in Patients with Liver Cirrhosis.

Branched-chain amino acid (BCAA) and insulin-like growth factor 1 (IGF-1) are essential for muscle protein synthesis. We investigated the association of serum BCAA and IGF-1 levels with sarcopenia and gait speed in 192 patients with liver cirrhosis (LC). Sarcopenia was diagnosed according to the Japan Society of Hepatology criteria. Slow gait speed was defined as <1.0 m/s. Subjects were divided into three groups based on baseline BCAA or IGF-1 levels: low (L), intermediate (I), and high (H) groups. The L-BCAA group had the highest prevalence of sarcopenia (60.4%, p < 0.001) and slow gait speed (56.3%, p = 0.008), whereas the H-BCAA group had the lowest prevalence of sarcopenia (8.5%, p < 0.001). The L-IGF-1 group showed the highest prevalence of sarcopenia (46.9%, p < 0.001), whereas the H-IGF-1 group had the lowest prevalence of sarcopenia (10.0%, p < 0.001) and slow gait speed (18.0%, p = 0.003). Using the optimal BCAA and IGF-1 cutoff values for predicting sarcopenia (372 μmol/L and 48.5 ng/mL, respectively), the sensitivity and specificity were 0.709 and 0.759 for BCAA and 0.636 and 0.715 for IGF-1, respectively. Low serum BCAA and IGF-1 levels were associated with sarcopenia and slow gait speed in patients with LC.

Elevated levels of IL-6 and IGFBP-1 predict low serum IGF-1 levels during continuous infusion of rhIGF-1/rhIGFBP-3 in extremely preterm infants

ObjectiveSteady state insulin-like growth factor-1 (IGF-1) levels vary significantly during continuous intravenous infusion of recombinant human insulin-like growth factor-1/recombinant human insulin-like growth factor binding protein-3 (rhIGF-1/rhIGFBP-3) in the first weeks of life in extremely preterm infants. We evaluated interleukin-6 (IL-6) and insulin-like growth factor binding protein-1 (IGFBP-1) levels as predictors of low IGF-1 levels. MethodsNineteen extremely preterm infants were enrolled in a trial, 9 received rhIGF-1/rhIGFBP-3 and 10 received standard neonatal care. Blood samples were analyzed daily for IGF-1, IL-6 and IGFBP-1 during intervention with rhIGF-1/rhIGFBP-3. ResultsThirty seven percent of IGF-1 values during active treatment were <20 μg/L. Among treated infants, higher levels of IL-6, one and two days before sampled IGF-1, were associated with IGF-1 < 20 μg/L, gestational age adjusted OR 1.30 (95% CI 1.03–1.63), p = .026, and 1.57 (95% CI 1.26–1.97), p < .001 respectively. Higher levels of IGFBP-1 one day before sampled IGF-1 was also associated with IGF-1 < 20 μg/L, gestational age adjusted OR 1.74 (95% CI 1.19–2.53), p = .004. ConclusionIn preterm infants receiving continuous infusion of rhIGF-1/rhIGFBP-3, higher levels of IL-6 and IGFBP-1 preceded lower levels of circulating IGF-1. These findings demonstrate a need to further evaluate if inflammation and/or infection suppress serum IGF-1 levels.The trial is registered at ClinicalTrials.gov (NCT01096784).

Clinical relevance of insulin-like growth factor-1 to cardiovascular risk markers

Objective Insulin-like growth factor-1 (IGF-1) is an anabolic hormone, the levels of which decline with age. The present study aimed to determine the impact of age-related declines in serum IGF-1 levels on various physiological processes. Design We retrospectively reviewed the medical records of patients whose serum IGF-1 levels were estimated in our department, and assessed the relationships between serum IGF-1 levels and various physiological parameters. Results A total of 427 patients with a mean (± standard deviation) age of 52.8 (± 17.1) years were included in the analysis. The levels of serum IGF-1 showed significant positive correlation with those of hemoglobin and hematocrit, and negative correlation with the presence of inflammatory and fibrin-related markers including C-reactive protein (CRP) and procalcitonin (PCT), and D-dimer and fibrin degradation products (FDP). These tendencies persisted after exclusion of patients with pituitary disease. Conclusions In this study population of diverse diseases and backgrounds, a decline in serum IGF-1 levels with age was associated with an increase in inflammatory and fibrin-related markers. This may explain the correlation between low serum IGF-1 levels and an increased risk of cardiovascular events. Our findings suggest that serum IGF-1 is a clinically relevant marker of cardiovascular risk, particularly in males.

Association between Insulin-Like Growth Factor-1 and Frailty among Older Adults.

Frailty is a course experienced in advanced aging. Identification of a biological factor associated with frailty is required. Although serum insulin-like growth factor-1 (IGF-1) is a potential factor related with frailty, consensus has not been reached regarding this relationship. This study aimed to investigate the association between IGF-1 and frailty in older adults. Cross-sectional study. Cohort study that was part of the "National Center for Geriatrics and Gerontology - Study of Geriatric Syndromes." The study participants were 4133 older adults (mean age, 71.8 ± 5.4 years). We assessed serum IGF-1 levels and frailty status and collected demographic variables, including cognitive function, as covariates. Frailty and pre-frailty were present in 274 subjects (7%) and 1930 subjects (47%), respectively. Subjects were divided into four groups based on quartiles of IGF-1 levels. Multinomial logistic analysis showed that the lowest group had significant odds of pre-frailty (crude model: odds ratio [OR] 1.58, 95% confidence interval [CI] 1.30-1.90, p < .001; adjusted model: OR 1.38, 95% CI 1.13-1.68, p = .002) and frailty (crude model: OR 3.42, 95% CI 2.38-4.92, p < .001; adjusted model: OR 1.54, 95% CI 1.02-2.32, p = .039), compared with the highest group. Lower serum IGF-1 levels were independently related with frailty in older adults.

Serum IGF-1 is associated with cognitive functions in early, drug-naïve Parkinson’s disease

ObjectiveCognitive deficits are common in Parkinson’s disease (PD) since the early stages and many patients eventually develop dementia. Yet, occurrence of dementia in PD is unpredictable. Evidence supports the hypothesis that insulin-like growth factor-1 (IGF-1) is involved in cognitive deficits. Our aim was to evaluate the relationship between serum IGF-1 levels and neuropsychological scores in a large cohort of drug-naïve PD patients during the earliest stages of the disease.MethodsSerum IGF-1 levels were determined in 405 early, drug-naïve PD patients and 191 healthy controls (HC) enrolled in the Parkinson’s Progression Markers Initiative (PPMI). The association between serum IGF-1 levels and neuropsychological scores was evaluated with linear regression analysis.ResultsIGF-1 levels were similar in PD and HC. In PD patients the lowest IGF-1 quartile was a predictor of lower performances at the Semantic Fluency task (β = -3.46, 95%CI: -5.87 to -1.01, p = 0.005), the Symbol Digit Modalities Score (β = -2.09, 95%CI: -4.02 to -0.15, p = 0.034), and Hopkins Verbal Learning Test Retention (β = -0.05, 95%CI: -0.09 to -0.009, p = 0.019).ConclusionsLower serum IGF-1 levels are associated to poor performances in cognitive tasks assessing executive function, attention and verbal memory in a large cohort of early PD patients. Follow-up studies are warranted to assess if IGF-1 is related to the development of dementia in PD.

The relation between insulin-like growth factor 1 levels and risk of depression in ischemic stroke.

The aim of this study is to evaluate whether lower serum levels of insulin-like growth factor 1 (IGF-1) in the acute phase of ischemic stroke are associated with higher risk of post-stroke depression (PSD) over a 1-year period. The subjects were first-ever acute ischemic stroke (AIS) patients who were hospitalized from July 1, 2014 to August 31, 2015. The study also included 120 age-matched and sex-matched healthy controls from the same geographical area. Fasting blood samples were collected within 24hours of admission for IGF-I measurement. Neurological and neuropsychological evaluations were conducted at a 1-year follow-up. Two-hundred twenty-five patients were observed for a 1-year follow-up, and 74 of these patients (32.9%, 95%CI: 26.8%-39.0%) were diagnosed with PSD. The depression distribution across the IGF-1 quartiles ranged between 61.4% (first quartile) and 8.9% (fourth quartile). In a multivariate model using the first quartiles of the IGF-1 versus quartiles 2 through 4, together with the significant clinical variables, the marker displayed prognostic information, and the odds ratio (OR) for first quartile was 3.35 [95% CI, 1.88-6.79; P=0.001]. The data showed that low serum IGF-1 levels at admission are associated with a high risk of developing PSD, suggesting that these alterations might be involved in the pathophysiology of depression symptoms in stroke patients.

Serum insulin-like growth factor-1 and its binding protein 3 as prognostic factors for the incidence, progression, and outcome of hepatocellular carcinoma: a systematic review and meta-analysis.

PurposePrevious studies have supported an association between serum insulin-like growth factor-1 (IGF1) and IGF-binding protein 3 (IGFBP3) levels and hepatocellular carcinoma (HCC), but the results were inaccurate. It has recently been proposed that IGF1 and IGFBP3 play roles in the time-to-progression (TTP) and overall survival (OS) of HCC patients. Our results revealed that serum IGF1 level is predictive of the progression and survival of HCC patients.ResultsHCC was associated with a significant reduction in serum IGF-1 and IGFBP-3 levels compared to cirrhosis (p = 0.037). Low serum IGF1 levels were predictive of a shorter TTP (OR, 2.74; 95% confidence interval [CI], 1.92–3.90) and poorer OS (odds ratio [OR], 2.20; 95% CI, 1.81–2.68) in HCC patients. The IGF1/IGFBP3 molar ratio was not significantly associated with the risk of HCC (OR, 1.311; 95% CI, 0.761–2.260).Materials and MethodsWe conducted a comprehensive literature search in PubMed, EMBASE, and the Cochrane Library. Twenty studies met the inclusion criteria and were subjected to statistical analysis. The geometric mean and standard deviation (SD) of serum IGF1 and IGFBP3 levels in the healthy, cirrhosis, and HCC groups were calculated. Pooled odds ratios (ORs) were calculated using a fixed-effects model to analyse the association of serum IGF1 level with the progression and survival of HCC patients.ConclusionsSerum IGF1 and IGFBP3 levels were positively associated with the incidence of HCC. Serum IGF1 level is an independent prognostic factor for the progression and survival of HCC patients.

The Association Between IGF-1 Levels and the Histologic Severity of Nonalcoholic Fatty Liver Disease.

Objectives:The mechanisms responsible for the development of nonalcoholic fatty liver disease (NAFLD) and progression to nonalcoholic steatohepatitis (NASH) are incompletely understood. Growing evidence suggests that growth hormone (GH) and insulin-like growth factor-1 (IGF-1) may have roles in the development and progression of NAFLD. We hypothesized that lower serum IGF-1 levels would be associated with increased liver fat accumulation, inflammation, and fibrosis in a group of meticulously phenotyped obese subjects with liver biopsies.Methods:A retrospective, cross-sectional study was performed at Massachusetts General Hospital, Boston, MA, USA and St. Mary's Hospital, Richmond, VA, USA. Liver biopsies were performed in 142 subjects during NAFLD work-up or bariatric surgery and were graded by a single, blinded pathologist. Main outcome measures included liver histology and serum IGF-1.Results:Mean age was 52±10 years and body mass index (BMI) was 43±9 kg/m2. Mean serum IGF-1 was lower in subjects with lobular inflammation (112±47 vs. 136±57 ng/ml, P=0.01), hepatocyte ballooning (115±48 vs. 135±57 ng/ml, P=0.05), higher fibrosis stage (stage 2–4 vs. 0–1; 96±40 vs. 125±51 ng/ml, P=0.005), and NASH (109±45 vs. 136±57 ng/ml, P=0.002). All results remained significant after controlling for age, BMI, and a diagnosis of diabetes, and all but hepatocyte ballooning (trend, P=0.06) remained significant after excluding individuals with cirrhosis. Steatosis was not significantly associated with mean serum IGF-1 levels.Conclusions:Low serum IGF-1 levels are associated with increased histologic severity of NAFLD when rigorously controlled for age, BMI, the presence of diabetes, and after the exclusion of subjects with cirrhosis. Further investigation is warranted to determine the differential effects of GH and IGF-1 on the development and progression of NAFLD, which could further elucidate pathophysiology and identify therapeutic targets.

Lower prevalence of proliferative diabetic retinopathy in elderly onset patients with diabetes.

To assess diabetic retinopathy (DR) prevalence between elderly onset and younger onset diabetes with similar diabetes duration and evaluate the association between DR prevalence and serum insulin-like growth factor 1 (IGF-1) levels. A total of 1787 patients with diabetes were enrolled between January 2010 and November 2015. Fundoscopy examination was performed. Patients were divided into three groups by age of diagnosis (<45, 45-64, and ⩾65years) for the analysis of the prevalence of DR. Among them, 150 patients underwent serum IGF-1 measurement. The serum IGF-1 level was compared between patients <65years and ⩾65years. Among 1787 patients, 779 (43.6%) had DR, in which proliferative DR (PDR) 229 (12.8%) patients. For similar diabetes duration, DR prevalence was lower in elderly onset patients. Patients ⩾65years at diagnosis had significantly lowest PDR prevalence of the three groups for similar diabetes duration. IGF-1 levels were lower in patients ⩾65years than in patients <65years (104.89±49.91ng/mL vs. 141.73±62.04ng/mL, P<0.001). Elderly onset patients with diabetes have lower prevalence of PDR than those younger onset patients for similar diabetes duration, which may relate with lower serum IGF-1 levels in older patients. Thus, less stringent glycemic control in older onset patients with diabetes may not increase the prevalence of PDR.

Prognostic significance of serum insulin-like growth factor-1 in patients with hepatocellular carcinoma following transarterial chemoembolization.

Insulin-like growth factor-1 (IGF-1) is an effective survival factor that is involved in the development and progression of various tumors. The aim of the present study was to investigate whether baseline serum IGF-1 levels are associated with time to progression (TTP) and overall survival (OS) in patients with hepatocellular carcinoma (HCC) who have undergone transarterial chemoembolization (TACE). A total of 145 patients with HCC who underwent TACE as an initial treatment were enrolled in the study. Baseline serum IGF-1 levels were detected using enzyme-linked immunosorbent assay (ELISA) kits. The patients were followed up for a median follow-up period of 47 months (range, 10.6-69.3 months). During the follow-up, 98 patients (76.6%) experienced disease progression and 59 patients (46.1%) succumbed. The serum IGF-1 level was found to be significantly associated with hepatitis infection status, Child-Pugh class, bilirubin level, tumor size and nodularity, vascular invasion and the Barcelona Clinic Liver Cancer (BCLC) stage. Multivariate analysis was conducted, which indicated that BCLC stage, vascular invasion and serum IGF-1 were independent risk factors for disease progression. When clinical factors were examined as potential independent risk factors for OS, only advanced BCLC stage and low serum IGF-1 levels were found to be significantly associated with poorer OS. These results suggest that serum IGF-1 may serve as a predictor of the prognosis of patients with HCC undergoing TACE.

Effects of exercise and poor indoor air quality on learning, memory and blood IGF-1 in adolescent mice

It is known that regular aerobic exercise enhances cognitive functions and increases blood insulin-like growth factor 1 (IGF-1) levels. People living in urban areas spend most of their time indoors and indoor air quality can affect health. We investigated the effects of aerobic exercise in poor and good air quality environments on hippocampus and prefrontal cortex (PFC) neurons, anxiety, and spatial learning and memory in adolescent mice. Poor air quality impaired spatial learning and memory; exercise did not affect learning or memory impairment. Exercise in a good air quality environment improved spatial learning and memory. Poor air quality increased apoptosis in the hippocampus and PFC. Both exercised and sedentary groups living in a poor air quality environment had lower serum IGF-1 levels than those living in a good air quality environment. Living in a poor air quality environment has negative effects on the hippocampus, PFC and blood IGF-1 levels in adolescent mice, but exercise did not alter the negative effects of poor air quality.

Serum insulin-like growth factor-1 (IGF-1) during CF pulmonary exacerbation: Trends and biomarker correlations

Cystic fibrosis (CF) is characterized by low circulating levels of insulin-like growth factor-1 (IGF-1), a hormone produced by the liver that governs anabolism and influences immune cell function. Because treatment of CF pulmonary exacerbation (CFPE) often improves body weight and lung function, we questioned whether serum IGF-1 trends were emblematic of these responses. Initially, we compared serum levels between healthy adults with CF and controls of similar age. We then measured serum IGF-1 throughout the CFPE cycle. We also investigated correlations among IGF-1 and other serum biomarkers during CFPE. Anthopometric, spirometric, and demographic data were collected. Serum IGF-1 concentrations were measured by ELISA. CF subjects in their usual state of health had lower serum IGF-1 levels than controls. Serum IGF-1 concentrations fell significantly from baseline at the beginning of CFPE. Treatment with intravenous antibiotics was associated with significant improvement in serum IGF-1 levels, body mass index (BMI), and percent-predicted forced expiratory volume in 1 sec (FEV1 %). At early and late CFPE, serum IGF-1 was directly correlated with FEV1 %, serum iron, hemoglobin concentration, and transferrin saturation (TSAT) and indirectly correlated with alpha-1-antitrypsin. This study not only supports the paradigm that CF is characterized by IGF-1 deficiency but also that trends in lung function, nutritional status, and serum IGF-1 are related. Improvements in all three parameters after antibiotics for CFPE likely highlight the connection between lung function and nutritional status in CF. Close correlations among IGF-1 and iron-related hematologic parameters suggest that IGF-1 may participate in CF iron homeostasis, another process that is known to be influenced by CFPE.

Insulin‐like growth factor‐1 predicts cognitive functions at 2‐year follow‐up in early, drug‐naïve Parkinson's disease

Cognitive impairment is common in Parkinson's disease (PD), even in the early stages. We aimed to assess the relationship between insulin-like growth factor-1 (IGF-1) and cognitive functions in early, drug-naïve patients with PD. Serum IGF-1 was measured in 65 early, drug-naïve patients with PD that underwent a complete neuropsychological battery at baseline and after 2 years. Linear regression analysis was used to evaluate the relationships between neuropsychological scores and IGF-1. Repeated-measures anova was applied to assess changes in neuropsychological variables over time. At baseline, IGF-1 levels were related to phonological fluency. At follow-up, IGF-1 levels were associated with the Rey auditory verbal learning test (RAVLT) - immediate and delayed recall, Frontal Assessment Battery, verbal span and Benton judgement of the line orientation test. Patients with low IGF-1 levels at baseline showed a significantly faster decline of performances than patients with high IGF-1 levels on immediate and delayed recall of the RAVLT and interference task of the Stroop test. Low serum IGF-1 levels are related to poor performance on executive tasks in early, drug-naïve patients with PD, and may predict poor performance on attention/executive and verbal memory tasks after a 2-year follow-up.