Myocardial fat accumulation is independent of measures of insulin sensitivity
R Muniyappa, R Noureldin, R Ouwerkerk… - The Journal of …, 2015 - academic.oup.com
The Journal of Clinical Endocrinology & Metabolism, 2015•academic.oup.com
Background: Myocardial steatosis, an independent predictor of diastolic dysfunction, is
frequently present in type 2 diabetes mellitus. High free fatty acid flux, hyperglycemia, and
hyperinsulinemia may play a role in myocardial steatosis. There are no prior studies
examining the relationship between insulin sensitivity (antilipolytic and glucose disposal
actions of insulin) and cardiac steatosis. Objective: Using a cross-sectional study design of
individuals with and without metabolic syndrome (MetSyn), we examined the relationships …
frequently present in type 2 diabetes mellitus. High free fatty acid flux, hyperglycemia, and
hyperinsulinemia may play a role in myocardial steatosis. There are no prior studies
examining the relationship between insulin sensitivity (antilipolytic and glucose disposal
actions of insulin) and cardiac steatosis. Objective: Using a cross-sectional study design of
individuals with and without metabolic syndrome (MetSyn), we examined the relationships …
Background
Myocardial steatosis, an independent predictor of diastolic dysfunction, is frequently present in type 2 diabetes mellitus. High free fatty acid flux, hyperglycemia, and hyperinsulinemia may play a role in myocardial steatosis. There are no prior studies examining the relationship between insulin sensitivity (antilipolytic and glucose disposal actions of insulin) and cardiac steatosis.
Objective
Using a cross-sectional study design of individuals with and without metabolic syndrome (MetSyn), we examined the relationships between cardiac steatosis and the sensitivity of the antilipolytic and glucose disposal actions of insulin.
Methods
Pericardial fat (PF) volume, intramyocardial and hepatic fat (MF and HF) content, visceral fat (VF) and sc fat content were assessed by magnetic resonance imaging in 77 subjects (49 without MetSyn and 28 with MetSyn). In a subset of the larger cohort (n = 52), peripheral insulin sensitivity index (SI) and adipocyte insulin sensitivity (Adipo-SI) were determined from an insulin-modified frequently sampled iv glucose tolerance test. The Quantitative Insulin Sensitivity Check Index was used as a surrogate for hepatic insulin sensitivity.
Results
Individuals with the MetSyn had significantly higher body mass index, total body fat, and MF, PF, HF, and VF content. HF and VF, but not MF, were negatively correlated with the Quantitative Insulin Sensitivity Check Index, Adipo-SI, and SI. Stepwise regression revealed that waist circumference and serum triglyceride levels independently predicted MF and PF, respectively. Adipo-SI and serum triglyceride levels independently predict HF.
Conclusion
Myocardial steatosis is unrelated to hepatic, adipocyte, or peripheral insulin sensitivity. Although it is frequently observed in insulin-resistant subjects, further studies are necessary to identify and delineate pathogenic mechanisms that differentially affect cardiac and hepatic steatosis.
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