Effect of liver fat on insulin clearance

2007 ◽  
Vol 293 (6) ◽  
pp. E1709-E1715 ◽  
Author(s):  
Anna Kotronen ◽  
Satu Vehkavaara ◽  
Anneli Seppälä-Lindroos ◽  
Robert Bergholm ◽  
Hannele Yki-Järvinen

A fatty liver is associated with fasting hyperinsulinemia, which could reflect either impaired insulin clearance or hepatic insulin action. We determined the effect of liver fat on insulin clearance and hepatic insulin sensitivity in 80 nondiabetic subjects [age 43 ± 1 yr, body mass index (BMI) 26.3 ± 0.5 kg/m2]. Insulin clearance and hepatic insulin resistance were measured by the euglycemic hyperinsulinemic (insulin infusion rate 0.3 mU·kg−1·min−1for 240 min) clamp technique combined with the infusion of [3-3H]glucose and liver fat by proton magnetic resonance spectroscopy. During hyperinsulinemia, both serum insulin concentrations and increments above basal remained ∼40% higher ( P < 0.0001) in the high (15.0 ± 1.5%) compared with the low (1.8 ± 0.2%) liver fat group, independent of age, sex, and BMI. Insulin clearance (ml·kg fat free mass−1·min−1) was inversely related to liver fat content ( r = −0.52, P < 0.0001), independent of age, sex, and BMI ( r = −0.37, P = 0.001). The variation in insulin clearance due to that in liver fat (range 0–41%) explained on the average 27% of the variation in fasting serum (fS)-insulin concentrations. The contribution of impaired insulin clearance to fS-insulin concentrations increased as a function of liver fat. This implies that indirect indexes of insulin sensitivity, such as homeostatic model assessment, overestimate insulin resistance in subjects with high liver fat content. Liver fat content correlated significantly with fS-insulin concentrations adjusted for insulin clearance ( r = 0.43, P < 0.0001) and with directly measured hepatic insulin sensitivity ( r = −0.40, P = 0.0002). We conclude that increased liver fat is associated with both impaired insulin clearance and hepatic insulin resistance. Hepatic insulin sensitivity associates with liver fat content, independent of insulin clearance.

2009 ◽  
Vol 94 (1) ◽  
pp. 50-55 ◽  
Author(s):  
Antti P. M. Viljanen ◽  
Patricia Iozzo ◽  
Ronald Borra ◽  
Mikko Kankaanpää ◽  
Anna Karmi ◽  
...  

Abstract Objective: Weight loss has been shown to decrease liver fat content and whole-body insulin resistance. The current study was conducted to investigate the simultaneous effects of rapid weight reduction with a very-low-calorie diet on liver glucose and fatty acid metabolism and liver adiposity. Hypothesis: We hypothesized that liver insulin resistance and free fatty acid uptake would decrease after weight loss and that they are associated with reduction of liver fat content. Design: Thirty-four healthy obese subjects (body mass index, 33.7 ± 8.0 kg/m2) were studied before and after a very-low-calorie diet for 6 wk. Hepatic glucose uptake and endogenous glucose production were measured with [18F]fluorodeoxyglucose during hyperinsulinemic euglycemia and fasting hepatic fatty acid uptake with [18F]fluoro-6-thia-heptadecanoic acid and positron emission tomography. Liver volume and fat content were measured using magnetic resonance imaging and spectroscopy. Results: Subjects lost weight (11.2 ± 2.9 kg; P &lt; 0.0001). Liver volume decreased by 11% (P &lt; 0.002), which was partly explained by decreased liver fat content (P &lt; 0.0001). Liver free fatty acid uptake was 26% lower after weight loss (P &lt; 0.003) and correlated with the decrement in liver fat content (r = 0.54; P &lt; 0.03). Hepatic glucose uptake during insulin stimulation was unchanged, but the endogenous glucose production decreased by 40% (P &lt; 0.04), and hepatic insulin resistance by 40% (P &lt; 0.05). Conclusions: The liver responds to a 6-wk period of calorie restriction with a parallel reduction in lipid uptake and storage, accompanied by enhancement of hepatic insulin sensitivity and clearance.


2015 ◽  
Vol 100 (2) ◽  
pp. 607-616 ◽  
Author(s):  
Gemma Llauradó ◽  
Ksenia Sevastianova ◽  
Sanja Sädevirta ◽  
Antti Hakkarainen ◽  
Nina Lundbom ◽  
...  

2007 ◽  
Vol 292 (3) ◽  
pp. E829-E835 ◽  
Author(s):  
Leena Juurinen ◽  
Mirja Tiikkainen ◽  
Anna-Maija Häkkinen ◽  
Antti Hakkarainen ◽  
Hannele Yki-Järvinen

We determined whether insulin therapy changes liver fat content (LFAT) or hepatic insulin sensitivity in type 2 diabetes. Fourteen patients with type 2 diabetes (age 51 ± 2 yr, body mass index 33.1 ± 1.4 kg/m2) treated with metformin alone received additional basal insulin for 7 mo. Liver fat (proton magnetic resonance spectroscopy), fat distribution (MRI), fat-free and fat mass, and whole body and hepatic insulin sensitivity (6-h euglycemic hyperinsulinemic clamp combined with infusion of [3-3H]glucose) were measured. The insulin dose averaged 75 ± 10 IU/day (0.69 ± 0.08 IU/kg, range 24–132 IU/day). Glycosylated hemoglobin A1c (Hb A1c) decreased from 8.9 ± 0.3 to 7.4 ± 0.2% ( P < 0.001). Whole body insulin sensitivity increased from 2.21 ± 0.38 to 3.08 ± 0.40 mg/kg fat-free mass (FFM)·min ( P < 0.05). This improvement could be attributed to enhanced suppression of hepatic glucose production (HGP) by insulin (HGP 1.04 ± 0.28 vs. 0.21 ± 0.19 mg/kg FFM·min, P < 0.01). The percent suppression of HGP by insulin increased from 72 ± 8 to 105 ± 11% ( P < 0.01). LFAT decreased from 17 ± 3 to 14 ± 3% ( P < 0.05). The change in LFAT was significantly correlated with that in hepatic insulin sensitivity ( r = 0.56, P < 0.05). Body weight increased by 3.0 ± 1.1 kg ( P < 0.05). Of this, 83% was due to an increase in fat-free mass ( P < 0.01). Fat distribution and serum adiponectin concentrations remained unchanged while serum free fatty acids decreased significantly. Conclusions: insulin therapy improves hepatic insulin sensitivity and slightly but significantly reduces liver fat content, independent of serum adiponectin.


2008 ◽  
Vol 93 (12) ◽  
pp. 4867-4872 ◽  
Author(s):  
Anna Kotronen ◽  
Moira Lewitt ◽  
Kerstin Hall ◽  
Kerstin Brismar ◽  
Hannele Yki-Järvinen

Background and Aims: The liver is the main source and insulin the main regulator of IGF binding protein 1 (IGFBP-1) in humans. Here we examined how serum IGFBP-1 concentrations are related to directly measured hepatic insulin sensitivity and liver fat content in humans. Methods: We measured fasting serum (fS) IGFBP-1 concentrations and liver fat content by proton magnetic resonance spectroscopy in 113 nondiabetic subjects. In addition, hepatic insulin sensitivity was measured using the euglycemic hyperinsulinemic clamp (insulin 0.3 mU/kg·min) technique in combination with the infusion of [3-(3)H]glucose in 78 subjects. Results: fS-IGFBP-1 concentrations were inversely related to liver fat content (r = −0.38, P &lt; 0.0001). Of circulating parameters, fS-IGFBP-1 was better correlated to hepatic insulin sensitivity (r = 0.48, P &lt; 0.0001) than fS-insulin (r = −0.42, P = 0.0001), fS-C-peptide (r = −0.41, P = 0.0002), fS-triglyceride (r = −0.33, P = 0.003), or fS-high-density lipoprotein cholesterol (r = 0.30, P = 0.007). In multiple linear regression analyses, body mass index (P &lt; 0.0001) and fS-IGFBP-1 (P = 0.008), but neither age nor gender, were independently associated with hepatic insulin sensitivity (P &lt; 0.0001 for ANOVA). Neither fS-insulin nor fS-C-peptide were independent determinants of hepatic insulin sensitivity after adjusting for age, gender, and body mass index. Conclusions: fS-IGFBP-1 is inversely correlated with liver fat and is an obesity-independent and liver-specific circulating marker of hepatic insulin sensitivity.


2006 ◽  
Vol 291 (2) ◽  
pp. E282-E290 ◽  
Author(s):  
Riikka Lautamäki ◽  
Ronald Borra ◽  
Patricia Iozzo ◽  
Markku Komu ◽  
Terho Lehtimäki ◽  
...  

Nonalcoholic fatty liver (NAFL) is a common comorbidity in patients with type 2 diabetes and links to the risk of coronary syndromes. The aim was to determine the manifestations of metabolic syndrome in different organs in patients with liver steatosis. We studied 55 type 2 diabetic patients with coronary artery disease using positron emission tomography. Myocardial perfusion was measured with [15O]H2O and myocardial and skeletal muscle glucose uptake with 2-deoxy-2-[18F]fluoro-d-glucose during hyperinsulinemic euglycemia. Liver fat content was determined by magnetic resonance proton spectroscopy. Patients were divided on the basis of their median (8%) into two groups with low (4.6 ± 2.0%) and high (17.4 ± 8.0%) liver fat content. The groups were well matched for age, BMI, and fasting plasma glucose. In addition to insulin resistance at the whole body level ( P = 0.012) and muscle ( P = 0.002), the high liver fat group had lower insulin-stimulated myocardial glucose uptake ( P = 0.040) and glucose extraction rate ( P = 0.0006) compared with the low liver fat group. In multiple regression analysis, liver fat content was the most significant explanatory variable for myocardial insulin resistance. In addition, the high liver fat group had increased concentrations of high sensitivity C-reactive protein, soluble forms of E-selectin, vascular adhesion protein-1, and intercellular adhesion molecule-1 ( P < 0.05) and lower coronary flow reserve ( P = 0.02) compared with the low liver fat group. In conclusion, in patients with type 2 diabetes and coronary artery disease, liver fat content is a novel independent indicator of myocardial insulin resistance and reduced coronary functional capacity. Further studies will reveal the effect of hepatic fat reduction on myocardial metabolism and coronary function.


2020 ◽  
Vol 244 (2) ◽  
pp. 353-367 ◽  
Author(s):  
Jiali Liu ◽  
Yue Li ◽  
Xiaoyan Zhou ◽  
Xi Zhang ◽  
Hao Meng ◽  
...  

High-fat diet (HFD) not only induces insulin resistance in liver, but also causes autophagic imbalance and metabolic disorders, increases chronic inflammatory response and induces mitochondrial dysfunction. Calcium/calmodulin-dependent protein kinase IV (CaMKIV) has recently emerged as an important regulator of glucose metabolism and skeletal muscle insulin action. Its activation has been involved in the improvement of hepatic and adipose insulin action. But the underlying mechanism is not fully understood. In the present study, we aimed to address the direct effects of CaMKIV in vivo and to evaluate the potential interaction of impaired insulin sensitivity and autophagic disorders in hepatic insulin resistance. Our results indicated obese mice receiving CaMKIV showed decreased blood glucose and serum insulin and improved insulin sensitivity as well as increased glucose tolerance compared with vehicle injection. Meanwhile, defective hepatic autophagy activity, impaired insulin signaling, increased inflammatory response and mitochondrial dysfunction in liver tissues which are induced by high-fat diet were also effectively alleviated by injection of CaMKIV. Consistent with these results, the addition of CaMKIV to the culture medium of BNL cl.2 hepatocytes markedly restored palmitate-induced hepatic insulin resistance and autophagic imbalance. These effects were nullified by blockade of cyclic AMP response element-binding protein (CREB), indicating the causative role of CREB in action of CaMKIV. Our findings suggested that CaMKIV restores hepatic autophagic imbalance and improves impaired insulin sensitivity via phosphorylated CREB signaling pathway, which may offer novel opportunities for treatment of obesity and diabetes.


2020 ◽  
Vol 52 (11) ◽  
pp. 809-814
Author(s):  
Sabrina Reif ◽  
Sarah Moschko ◽  
Christina Gar ◽  
Uta Ferrari ◽  
Nina Hesse ◽  
...  

AbstractAnimal data link high circulating fetuin-A to low insulin sensitivity and observational studies identify the hepatokine as a marker of future incident type 2 diabetes mellitus in humans. However, a recent, well-powered Mendelian randomization study finds no causal role. We therefore tested in a deeply-phenotyped human cohort if circulating fetuin-A correlates independently with insulin sensitivity and how it relates to the metabolic syndrome and ectopic fat deposition. We analyzed data from 290 young women with and without recent gestational diabetes mellitus. We found that circulating fetuin-A correlates inversely with insulin sensitivity in univariate analyses, but that this correlation is lost after adjustment for markers of the metabolic syndrome and of fatty liver. Additionally, we investigated which fat compartment associates most strongly with circulating fetuin-A. In whole body MRI data from a subcohort of 152 women, this was liver fat content. We conclude that high circulating fetuin-A occurs as part of the metabolic syndrome in young women and associates most strongly with liver fat content. Its close link to the metabolic syndrome may also cause the inverse correlation of circulating fetuin-A with insulin sensitivity as we found no independent association.


2008 ◽  
Vol 93 (6) ◽  
pp. 2122-2128 ◽  
Author(s):  
Claudio Maffeis ◽  
Riccardo Manfredi ◽  
Maddalena Trombetta ◽  
Silvia Sordelli ◽  
Monica Storti ◽  
...  

Abstract Aim: Our aim was to explore the relationship between insulin sensitivity, body fat distribution, ectopic (liver and skeletal muscle) fat deposition, adipokines (leptin and adiponectin), and inflammation markers (highly sensitive C-reactive protein, IL-6, IL-10, and TNF-α) in prepubertal children. Subjects and Methods: Thirty overweight and obese children (16 males and 14 females with body mass index z-score range of 1.1–3.2) were recruited. Body fat distribution and fat accumulation in liver and skeletal muscle were measured using magnetic resonance imaging. Insulin sensitivity was assessed by iv glucose tolerance test. Results: Insulin sensitivity was associated with sc abdominal adipose tissue (SAT) (r = −0.52; P &lt; 0.01) and liver fat content (r = −0.44; P &lt; 0.02) but not with visceral abdominal adipose tissue (VAT) (r = −0.193; P value not significant) and fat accumulation in skeletal muscle (r = −0.210; P value not significant). Adipokines, but not inflammation markers, were significantly correlated to insulin sensitivity. VAT correlated with C-reactive protein (r = 0.55; P &lt; 0.01) as well as adiponectin (r = −0.53; P &lt;0.01). Multiple regression analysis showed that only SAT and liver fat content were independently correlated to insulin sensitivity (P &lt; 0.01; 20 and 16% of explained variance, respectively). Conclusions: In overweight and moderately obese prepubertal children, insulin sensitivity was negatively correlated with SAT and liver fat content. Furthermore, contrary to adults, VAT and inflammation markers were not correlated with insulin sensitivity in children.


2015 ◽  
Vol 29 (4) ◽  
pp. 528-541 ◽  
Author(s):  
Jiali Liu ◽  
Huixia Li ◽  
Bo Zhou ◽  
Lin Xu ◽  
Xiaomin Kang ◽  
...  

Abstract Progranulin (PGRN) has recently emerged as an important regulator for glucose metabolism and insulin sensitivity. However, the underlying mechanisms of PGRN in the regulation of insulin sensitivity and autophagy remain elusive. In this study, we aimed to address the direct effects of PGRN in vivo and to evaluate the potential interaction of impaired insulin sensitivity and autophagic disorders in hepatic insulin resistance. We found that mice treated with PGRN for 21 days exhibited the impaired glucose tolerance and insulin tolerance and hepatic autophagy imbalance as well as defective insulin signaling. Furthermore, treatment of mice with TNF receptor (TNFR)-1 blocking peptide-Fc, a TNFR1 blocking peptide-Fc fusion protein to competitively block the interaction of PGRN and TNFR1, resulted in the restoration of systemic insulin sensitivity and the recovery of autophagy and insulin signaling in liver. Consistent with these findings in vivo, we also observed that PGRN treatment induced defective autophagy and impaired insulin signaling in hepatocytes, with such effects being drastically nullified by the addition of TNFR1 blocking peptide -Fc or TNFR1-small interference RNA via the TNFR1-nuclear factor-κB-dependent manner, indicating the causative role of PGRN in hepatic insulin resistance. In conclusion, our findings supported the notion that PGRN is a key regulator of hepatic insulin resistance and that PGRN may mediate its effects, at least in part, by inducing defective autophagy via TNFR1/nuclear factor-κB.


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