Serum interleukin 8 concentrations in obese subjects with and without impaired glucose tolerance

ABSTRACT

Interleukin 8 [IL-8] is a cytokine with atherogenic properties. Studies revealed that it is produced and secreted by human adipocytes. The aim of the present study is to evaluate serum IL-8 concentrations in obese subjects with normal glucose tolerance [NGT] and in obese subjects with impaired glucose tolerance [IGT] in fasting state and after oral glucose tolerance test [OGTT] and to find any relation between serum IL-8 and BMI, WHR and glucose level. A total of 60 subjects with marked overweight or obesity [BMI >27.8kg/m[2]], without previously diagnosed disturbances of glucose tolerance, were included in the present study. They were divided into two groups. Group I included 30 subjects with NGT [13 men and 17 women] and group 2 included 30 subjects with IGT [11 men and 19 women]. 25 sex and age-matched healthy lean volunteers were included as control group. In the fasting state, there was no significant difference in fasting serum IL- 8 concentrations between group I and group II. However, fasting serum IL-8 level was significantly higher in both groups in relation to control lean group [p<0.05 and <0.05 respectively]. After OGTT, serum IL-8 level showed no significant differences in lean group [p>0.05] and a highly significant increase in-group I and II [p<0.001]. There was a highly significant increase in serum level of IL-8 after OGTT in-group I and II in relation to control group [p< 0. 01 and <0.001 respectively]. There was also a highly significant increase in serum level of IL-8 in-group II when compared with group I [p<0.01]. In both groups fasting serum IL-8 was related to BMI [group I, r=0.919, p<0.00l; group 2, r=0.843, p<0.001], and also to WHR [group I, r=0.758, p<0.01; group II, r=0.641, p<0.05]. There were no significant correlations between fasting serum IL-8 and plasma glucose level in studied groups. Serum IL-8 concentrations after OGTT were positively related to post load glucose level [r= 0.83, p< 0.001], in group II, but not in group I. We conclude that fasting serum IL-8 levels are increased in obese subjects with normal and impaired glucose tolerance, and are related to BMI and WHR after OGTT, serum IL-8 levels are related to glucose level in obese subjects with IGT. It is possible that an increase in circulating serum IL-8 level might be one of the factors linking obesity and prediabetic stage with greater cardiovascular risk