Plasma Levels of Triglycerides and IL-6 Are Associated With Weight Regain and Fat Mass Expansion

CONTEXT: Long-term weight loss (WL) maintenance is the biggest challenge for overweight and obesity because of the almost unavoidable phenomenon of partial or even total weight regain (WR) after WL. OBJECTIVE: In the present study we investigated the relations of (the changes of) adipocyte size and other risk biomarkers with WR during the follow-up of the Yoyo dietary intervention. METHODS: In this randomized controlled study, 48 overweight/obese participants underwent a very-low-calorie diet to lose weight, followed by a weight-stable period of 4 weeks and a follow-up period of 9 months. Anthropometric measurements, adipocyte volume of abdominal subcutaneous adipose tissue, and plasma metabolic parameters (free fatty acids [FFAs], triglycerides [TGs], total cholesterol, glucose, insulin, homeostasis model assessment of insulin resistance [HOMA-IR], interleukin 6 [IL-6], angiotensin-converting enzyme [ACE] activity, retinol binding protein 4 [RBP4]) at the beginning and the end of follow-up were analyzed. RESULTS: Our results show that changes of TGs, IL-6, HOMA-IR, and ACE are significantly positively correlated with WR. Multiple linear regression analysis shows that only TG and IL-6 changes remained significantly correlated with WR and increased body fat mass. Moreover, the change in HOMA-IR was tightly correlated with the change in TGs. Surprisingly, change in adipocyte volume during follow-up was not correlated with WR nor with other factors, but positive correlations between adipocyte volume and HOMA-IR were found at the beginning and end of the follow-up. CONCLUSION: These results suggest that TGs and IL-6 are independently linked to WR via separate mechanisms, and that HOMA-IR and adipocyte volume may indirectly link to WR through the change of plasma TGs.