Plasma IL-6 and CRP concentrations are increased and plasma adiponectin and IL-10
concentrations are decreased in obese and insulin resistant individuals. The goal
of this study was to determine whether the relation between IL-6, IL-10, CRP, adiponectin
and insulin resistance and obesity is independent of the status of glycemic control.
We evaluated the IL-6, IL-10, CRP, and adiponectin plasma concentrations in three
different groups, which were matched for body-mass-index (BMI) and underwent euglycemic
hyperinsulinemic clamps: Group NGT (control group): 28 healthy volunteers with normal
glucose tolerance, Group IGT: 24 individuals with insulin resistance, normal fasting
glucose but impaired glucose tolerance (IGT), Group T2D: 32 patients with diabetes
type 2, insulin resistance and chronic hyperglycemia.
Plasma IL-6 and CRP concentrations were significantly lower (P<0.01) and plasma adiponectin
and IL-10 concentrations were significantly higher (P<0.05) in the control group (NGT)
as compared to the other groups. In addition, IL-6 and CRP concentrations were significantly
elevated in patients with type 2 diabetes (T2D) compared to individuals with IGT (IGT).
The IL-6 and CRP plasma concentrations correlate with fasting plasma glucose, 2-h
OGTT plasma glucose, HbA1c value, fasting insulin concentration and whole body glucose
uptake in the clamp, whereas circulating adiponectin and IL-10 showed a negative correlation
only with the fasting insulin concentration and whole body glucose uptake in the clamp.
In conclusion, our data suggest that independently of obesity elevated IL-6 and CRP
plasma concentrations are associated with the glycemic status and insulin resistance,
whereas plasma adiponectin and IL-10 concentrations showed only a relationship to
insulin resistance in obese patients with insulin resistance and IGT or type 2 diabetes.
