Issue 131 Item 3 Visceral Fat Linked To Peripheral And Hepatic Insulin Resistanc

Visceral adiposity is associated with both peripheral and hepatic insulin resistance, independent of gender, in the type 2 diabetic patients Visceral fat is associated with peripheral and hepatic insulin resistance in both male and female patients with type 2 diabetes. However, deep subcutaneous fat appears to be associated with insulin resistance only in male diabetics.

Yoshinori Miyazaki and colleagues at the Diabetes Division of the University of Texas Health Science Center, in San Antonio, Texas, United States, investigated how insulin resistance may be related to deep subcutaneous fat, superficial subcutaneous fat, and intra-abdominal visceral fat among men and women with type 2 diabetes.

The study included 62 type 2 diabetics, 36 men and 26 women, whose median age was 55 years and who had a mean body mass index of 30 ± 1 kg per square meter. All patients underwent a two-step euglycemic insulin clamp with 3-(3)H-glucose and magnetic resonance imaging to quantify the total amount of fat in each of the three areas.

The investigators found that basal endogenous glucose production and the product of basal endogenous glucose production and fasting plasma insulin concentration -an index of hepatic insulin resistance) were similar in male and female patients. So, too, were total body glucose disposal during the first and second insulin clamp steps.

Intra-abdominal visceral fat area and deep subcutaneous fat area were not significantly different in male and female subjects. However, fat in the superficial subcutaneous area was significantly greater among female compared with male patients, despite their similar body mass index and similar total body fat mass, the researchers reported.

In female subjects, first total body glucose disposal during the first clamp step and the hepatic insulin resistance index were correlated with the amount of their intra-abdominal visceral fat, but not with the amount of deep subcutaneous fat, superficial subcutaneous fat or total subcutaneous fat.

Among male subjects, total body glucose disposal and hepatic insulin resistance were correlated with the amount of fat in all three measured areas.

"We conclude that visceral adiposity is associated with both peripheral and hepatic insulin resistance, independent of gender, in the type 2 diabetic patients," the researchers wrote. "In male, but not in female, type 2 diabetic subjects deep subcutaneous adipose tissue also is associated with peripheral and hepatic insulin resistance." Am J Physiol Endocrinol Metab 2002; 13