Subclinical hypothyroidism is known to be associated with increased serum cholesterol. Since thyroid-stimulating hormone (TSH) exerts an inductor effect on cholesterol biosynthesis, we aimed to investigate the relationship between TSH mRNA and cholesterol metabolism in human adipose tissue (AT). Cross-sectionally, AT TSH-β () mRNA was evaluated in 4 independent cohorts in association with serum total and LDL cholesterol, and AT lipidomics. Longitudinally, the effects of statins and of diet and exercise on AT mRNA were also examined. The bidirectional relationship between cholesterol and were studied in isolated human adipocytes. mRNA was consistently detected in AT from euthyroid subjects, and positively associated with serum total- and LDL-cholesterol, and with AT-specific cholesterol metabolism-associated lipids [arachidonoyl cholesteryl ester, C8-dihydroceramide,-stearoyl-d-sphingosine, and GlcCer(18:0, 24:1)]. Reduction of cholesterol with statins and with diet and exercise interventions led to decreased mRNA in human AT, whereas excess cholesterol up-regulated mRNA in human adipocytes. In addition, recombinant human TSH α/β administration resulted in increased mRNA levels in human adipocytes. In mice, subcutaneous AT expression levels correlated directly with circulating cholesterol levels. In summary, current results provide novel evidence of as a paracrine factor that is modulated in parallel with cholesterol metabolism in human AT.-Moreno-Navarrete, J. M., Moreno, M., Ortega, F., Xifra, G., Hong, S., Asara, J. M., Serrano, J. C. E., Jové, M., Pissios, P., Blüher, M., Ricart, W., Portero-Otin, M., Fernández-Real, J. M. mRNA is linked to cholesterol metabolism in adipose tissue.