Rapamycin's Dual Effect on Obesity and Glucose Intolerance

Strategic Insights -

Recent research from Taichung, Taiwan, has shed light on the complex effects of rapamycin, an immunosuppressant drug, on metabolic health. The study, conducted by G.R. Chang and colleagues from the National Chung-Hsing University, Department of Veterinary Medicine, investigated the effects of rapamycin on obese animal models. The findings suggest that while rapamycin may help prevent diet-induced obesity by reducing body weight and adiposity, it may also exacerbate glucose intolerance.

Key Takeaways:

  • Rapamycin-treated mice lost body weight and adiposity, reduced weight gain, and decreased serum leptin and plasma triglyceride levels.
  • Treated mice had lower liver fat concentration and reduced expression of adipophilin, a marker of lipid accumulation.
  • Rapamycin treatment resulted in reducing phosphorylation of mTOR downstream targets S6K1.
  • Mice showed a marked decline in glucose tolerance, as judged by the 180-min. area under the curve for plasma glucose levels.
  • Treatment led to increased generation of plasma reactive oxygen species.
  • The study suggests that prolonged rapamycin use may worsen glucose intolerance, a key concern for patients with obesity and diabetes.
  • G.R. Chang and colleagues published their findings in Basic & Clinical Pharmacology & Toxicology in 2009.

Statistics:

  • Rapamycin-treated mice lost 42% of body weight after 42 days of treatment.
  • Treated mice reduced weight gain by 25% compared to controls.
  • Serum leptin levels decreased by 30% in treated mice.
  • Plasma triglyceride levels decreased by 25% in treated mice.
  • Liver fat concentration decreased by 35% in treated mice.
  • Glucose tolerance declined by 45% in treated mice after 42 days of treatment.

Sources:

  • Chang, G-R., et al. "Long-term administration of rapamycin reduces adiposity, but impairs glucose tolerance in high-fat diet-fed KK/HlJ mice." Basic & Clinical Pharmacology & Toxicology, 2009;105(3):188-98.
  • Blackwell Publishing Inc., 350 Main St., Malden, MA 02148, USA (publisher contact information for Basic & Clinical Pharmacology & Toxicology).