Metabolic obesity phenotypes and thyroid cancer risk: A systematic exploration of the evidence

Obesity is recognized as a risk factor for various cancers, including thyroid cancer. However, the association between different metabolic obesity phenotypes and thyroid cancer risk remains unclear. This systematic review aimed to comprehensively evaluate the existing literature to elucidate the association between metabolic obesity phenotypes and thyroid cancer risk.

This systematic review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed, Scopus, EMBASE, Web of Science, and Google Scholar were searched for relevant studies until April 2024. Studies examining the link between metabolic obesity phenotypes and thyroid cancer risk were included.

Five cohort studies involving 831,510 participants met the inclusion criteria. Metabolically unhealthy obesity was consistently associated with an increased risk of thyroid cancer in both men and women. Central adiposity emerged as a significant predictor of thyroid cancer risk. Mechanistically, chronic inflammation, dysregulated adipokine secretion, hormonal imbalances, and altered signaling pathways may contribute to thyroid carcinogenesis. There is an ongoing debate regarding the risk associated with metabolically healthy obesity, with some suggesting potential protective effects due to favorable metabolic profiles.

This systematic review highlights the complex relationship between metabolic obesity phenotypes and thyroid cancer risk. The findings highlighted the importance of considering metabolic status alongside obesity in thyroid cancer risk assessment and intervention strategies.