Microplastics and the Endocrine–Metabolic Interface: Novel Diagnostic Tools Targeting Thyroid–Adipose Axis

Microplastics (MPs) have been identified as major environmental contaminants that can affect organisms directly and act as carriers of particles and chemical additives, thereby aggravating endocrine networks that coordinate metabolic homeostasis. However, evidence suggests that MPs and their chemical additives interfere with thyroid hormone signaling, adipocyte differentiation, and adipokine secretion. The mechanistic link across the thyroid-adipose axis remains poorly defined. This review delves into cutting-edge diagnostic technologies that are improving the identification, mapping, and understanding of MP-induced endocrine and metabolic issues. Quantum-dot nanosensors, single-cell multiomics, machine learning-assisted endocrine profiling, and microfluidic organ-on-chip systems offer high-resolution insights into how MPs interact with thyroid follicular cells and adipose tissues. These platforms, which combine environmental analysis and endocrine testing, enable the measurement of MP levels, the detection of hormone-receptor changes, and the modeling of endocrine system disruptions, facilitating the early identification of imbalances, novel treatments, and monitoring strategies. This review affirms the importance of studying thyroid toxicity with a focus on the adipose axis, emphasizing the importance of developing advanced diagnostic tools to assess metabolic risk in contaminated populations.