Metabolic Syndrome Flashcards
definition
- a class of closely related metabolic disorders
- increasing the risk of developing DM2 and CVD
example
HTN, dyslipidemia, high abdominal adipiosity, insulin resistence, high fasting blood glucose (IFG)
criteria of diagnosis
meet three: 1 + 2 out of 4
- [Ethnicity specific] central obesity: wast circumference ( M>102 cm ; F>88 cm, CA & US, Caucasians)
- Plasma TG no less than 1.7 M OR with drug Tx
- Plasma HDJ-C <1.0 (M)/<1.3 (F) OR with drug Tx
- BP: no less than 130 sys / no less 85 Dia OR with drug Tx
- Fasting Glucose no less than 5.6M or previously diagnosed diabetes OR with drug Tx
Tell the story: how does excess NRG intake cause the MetS?
usually contributed by fat and sugar:
abnormal visceral adipose tissue due to systemic low-grade inflammation—> decreased Glucose uptake + excess lipid intake–> exhaust insulin response increase the lipolysis to the blood –> insulin decrease the activity of adipose leptin (GLP) –> decrease the insulin sensitivity–> increase hepatic output –> elevated VLDL in blood–> TG are trapped in the liver–> fatty liver –> systemic glucotoxicicity and lipotoxicity–> chronic diabetes
proposed mechanisms (3)
- insulin resistance usually is the central to MetS abnormalities, but it probably is not the sole cause
- Direct venous drainage of visceral fat in hepatic portal vein –> increase hepatic FFA delivery–> fatty liver
- adipose tissue macrophages release inflammatory cytokines acting on surrounding adipocytes–> impaired insulin action (GLP decreases, so decrease the sensitivity of insulin) and promoting release of FFA
what is the “overflow hypothesis”
excess body fat and spillover cause lipid accumulation in hepatocytes, visceral adipocytes and heart, instead of subcutaneous tissue
what is the outcome of “overflow”? (2)
in hepatocyte: elevate VLDL (dyslipidemia) +/or fatty liver or NAFLD
in muscle:
fat infiltration in muscle +/or insulin resistance
