Insulin
resistance is a condition in which the body's cells do not respond normally to
insulin, leading to elevated blood glucose levels and potentially to type 2 diabetes.
Insulin resistance is known to be associated with visceral fat accumulation.
As
described in the February 3, 2007 online edition of the Journal of Viral Hepatitis,
Japanese researchers conducted a study to test the hypothesis that HCV infection
itself may promote insulin resistance. Understanding the relationship between
HCV and insulin resistance "is of great clinical relevance," they noted,
because it can accelerate liver fibrosis
progression.
The
investigators prospectively evaluated 47 patients with chronic HCV infection who
underwent liver biopsy. Individuals
with obesity, pre-existing type 2 diabetes, or a history of heavy alcohol
consumption were excluded. In addition, 97 HCV negative non-diabetic subjects
served as controls.
Insulin
resistance was estimated using the modified homeostasis model of insulin resistance
(HOMA-IR) index. Abdominal fat distribution was determined using computed tomography.
Results
•
Fasting blood glucose levels were within the normal range for all patients.
•
A univariate analysis revealed a significant correlation between HCV RNA levels
and HOMA-IR scores (P = 0.0291).
•
There was no significant correlation between visceral adipose (fat) tissue area
and HOMA-IR score in patients with HCV (P = 0.496).
•
In contrast, a significant correlation between visceral adipose tissue and HOMA-IR
score was observed in HCV negative control subjects (P < 0.0001).
•
In a multiple regression analysis adjusting for age, sex, and visceral adipose
tissue area, there remained a significant correlation between HCV RNA levels and
HOMA-IR scores (P = 0.0446).
Conclusion
"HCV
is directly associated with insulin resistance in a dose-dependent manner, independent
of the visceral adipose tissue area," the investigators concluded.
They
claimed that, "This is the first report to demonstrate the direct involvement
of HCV and insulin resistance in patients with chronic HCV infection."
02/23/07
Reference M
Yoneda, S Saito, T Ikeda, and others. Hepatitis C virus directly associates with
insulin resistance independent of the visceral fat area in nonobese and nondiabetic
patients. Journal of Viral Hepatitis. January 3, 2007 [Epub ahead of print].
