Background: Recent studies noted that circulating growth differentiation factor 15 (GDF15) were closely related to metabolic states. The study aimed to explore the changes of GDF15 levels and their influencing factors after 4 weeks of lifestyle intervention (LI) or LI combined with breakfast meal replacement (LI+MR) in newly diagnosed type 2 diabetes patients.
Methods: A total of 84 patients with available serum samples at both baseline and Week 4 were enrolled in this biomarker substudy. All subjects underwent a 2-hour 75g oral glucose tolerance test at baseline and Week 4. Serum GDF15 levels were determined by a sandwich enzyme-linked immunosorbent assay.
Results: After 4-weeks of LI, GDF15 levels overall significantly decreased compared with baseline (P<0.05). ∆GDF15 levels were significantly and negatively associated with baseline GDF15 levels (r=–0.450, P<0.001). The optimal cut-off point of baseline GDF15 levels for predicting a GDF15 decrease after 4-weeks of LI was 904.57 pg/ml, with an area under curve of 0.699. Based on the cut-off point of 900 pg/ml, patients with baseline GDF15 ≥900 pg/ml had significantly decreased GDF15 levels after LI, while those <900 pg/ml had no significant changes. Regression models showed that baseline GDF15 level was an independent positive factor for the improvement of fasting plasma glucose and homeostasis model assessment for insulin resistance only in patients with baseline GDF15 levels ≥900 pg/ml.
Conclusions: LI led to significantly decreased GDF15 levels among patients with newly diagnosed type 2 diabetes and its effect was more significant among patients with baseline GDF15 levels ≥900 pg/ml.
Trial registration: ClinicalTrials.gov, NCT02248714. Registered 25 September 2014 - Retrospectively registered, https://www.clinicaltrials.gov/ct2/show/NCT02248714?term=NCT02248714&draw=2&rank=1