mTOR Dysregulation, Insulin Resistance, And Hypertension

Research Summary

A narrative review of the signalling route that connects mTOR overactivation to insulin resistance and high blood pressure. It follows mTOR from nutrient, cytokine and salt signals through the PI3K/AKT pathway to reduced nitric oxide production and vasoconstriction, and then reviews the drugs that block it.

Who Or What Was Studied?

A review of published research rather than a new study: cell and animal experiments, clinical and epidemiological reports on diabetes, metabolic syndrome and hypertension, and studies of mTOR inhibitors and metformin in animals and people.

What Did The Research Show?

• The authors propose that mTOR hyperactivation is driven by hypercaloric diets, pro-inflammatory cytokines and branched-chain amino acids, and is found alongside insulin resistance, cancer and cardiovascular disease.
• In their account, mTORC1 activation of p70S6K1 blocks insulin receptor signalling, keeping glucose transporters inside the cell and raising blood glucose.
• Increased salt intake is described as activating the renin-angiotensin-aldosterone system and then PI3K/AKT/mTOR, lowering nitric oxide production and contributing to hypertension.
• Animal work cited in the review reports that metformin and rapamycin reduced inflammation, hyperlipidaemia and hyperglycaemia, and induced autophagy by blocking mTOR.
• Everolimus, temsirolimus and SGLT2 inhibitors are reported to block mTORC1, with improved glucose sensitivity in animal studies.

Limitations And Interpretation

• It is a narrative review, not a trial: no new experiments and no patient outcomes are reported.
• The authors themselves flag contradictory findings – rapamycin has been reported both to improve insulin sensitivity and, in human adipocytes, to reduce glucose uptake and contribute to insulin resistance.
• Most of the drug and metabolic effects described come from animal or cell studies; the review does not establish that mTOR inhibitors improve metabolic outcomes in people.
• It offers no dosing or treatment recommendation.