Hidden Risks: Relationship among VAT, IL-18, and Adiponectin in the Development of Type 2 Diabetes in Filipino Americans

Abstract

Background and Aims: Filipino Americans (FAs) are at high risk for developing type 2 diabetes however little research exists as to why this occurs. There is some evidence that pro-inflammatory Interleukin-18 (IL-18) and anti-inflammatory (adiponectin) markers associated with visceral adipose tissue (VAT) may explain this risk but have not been examined in FAs without diabetes, with pre-diabetes and with type 2 diabetes. In these groups the aims were to 1) Quantify VAT, IL-18, and adiponectin and describe the values in relation to known reference ranges (RR) 2) Determine the relationships of VAT, IL-18, and adiponectin within the three groups 3) Determine if VAT, IL-18, and adiponectin were significantly different among the three groups. Methods: FAs were recruited from healthcare and community centers in Solano County, California. VAT was measured using the InBody 570 © body impedance analyzer. Blood was obtained for HgA1c and plasma was used to quantify IL-18 and adiponectin with ELISA. Correlation coefficients were conducted to determine the association among VAT, IL-18 and adiponectin in the three groups. One-way ANOVAs were conducted for each variable to assess if there was significance among groups. Results: Seventy-five participants were recruited (N=25 per group); 68% were female; mean age of 42 years. 57% of women but only 27 % of men had VAT values above the RR. The percentage of participants with an IL-18 above the RR used for this study was greater in the pre-diabetes (68%) and diabetes groups (64%) vs. the non-diabetes group (40%). Interestingly, 90-100% of the adiponectin values in both men and women were well above the RR. There was no correlation among the biomarkers within any group. VAT and IL-18 were not significantly different among groups; however, adiponectin was significantly lower in the diabetes group vs. the non-diabetes group (p<0.05). Significance: This is the first time VAT, IL-18 and adiponectin have been examined in FAs without diabetes, with pre-diabetes and with diabetes. While a young, active and mostly female sample may have confounded the biomarker findings, the results point toward the need for further study of the mechanisms of diabetes development and progression in FAs.