Hepatic insulin extraction in NAFLD is related to insulin resistance rather than liver fat content

KM Utzschneider, SE Kahn… - The Journal of Clinical …, 2019 - academic.oup.com
KM Utzschneider, SE Kahn, DC Polidori
The Journal of Clinical Endocrinology & Metabolism, 2019academic.oup.com
Context Total insulin clearance is decreased in nonalcoholic fatty liver disease (NAFLD), but
the relationship between liver fat and hepatic insulin extraction (HIE) is unknown. Objective
This cross-sectional study addresses the hypothesis that HIE is reduced in NAFLD and
investigates metabolic and/or anthropometric characteristics most closely associated with
insulin clearance. Participants Nondiabetic subjects with NAFLD (n= 13) and age-and body
mass index (BMI)-matched controls with normal liver enzymes (n= 15) underwent abdominal …
Context
Total insulin clearance is decreased in nonalcoholic fatty liver disease (NAFLD), but the relationship between liver fat and hepatic insulin extraction (HIE) is unknown.
Objective
This cross-sectional study addresses the hypothesis that HIE is reduced in NAFLD and investigates metabolic and/or anthropometric characteristics most closely associated with insulin clearance.
Participants
Nondiabetic subjects with NAFLD (n = 13) and age- and body mass index (BMI)-matched controls with normal liver enzymes (n = 15) underwent abdominal CT, dual-energy X-ray absorptiometry, oral glucose tolerance test (OGTT), and labeled two-step hyperinsulinemic-euglycemic clamps.
Outcome Measurements
Liver fat was estimated by the CT liver/spleen ratio. Hepatic and extrahepatic insulin clearances were modeled using clamp and OGTT data.
Results
Extrahepatic insulin clearance and HIE were not different between NAFLD and controls and did not correlate with liver fat. HIE was positively correlated with insulin sensitivity [rate of glucose disposal (Rd; low r = +0.7, P < 0.001; high r = +0.6, P = 0.001), adiponectin (r = +0.55, P = 0.004), and insulin-mediated suppression of clamp nonesterified free fatty acid (NEFA; r = +0.67, P < 0.001)] but was not associated with fasting NEFA, insulin-mediated suppression of glucose production, or measures of adiposity. Extrahepatic insulin clearance was positively associated with percent body fat (r = +0.44, P = 0.02) and subcutaneous fat (r = +0.42, P = 0.03) but not BMI, intra-abdominal fat, liver fat, Rd, adiponectin, or NEFA.
Conclusions
HIE is not directly associated with hepatic steatosis but is associated with muscle and adipose tissue insulin resistance. The data suggest differential regulation of insulin clearance with extrahepatic insulin clearance being associated with body fat and not insulin sensitivity.
Oxford University Press