KINESIOL 1Y03 Chapter Notes - Chapter 11: Oxidative Stress, Hyperglycemia, Beta Cell
22 Jun 2018
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Diet and the metabolic syndrome
Insulin responsiveness = the maximal effect of insulin
Insulin sensitivity = insulin concentration required for half-maximal response
Insulin resistance = decrease in insulin responsiveness and/or insulin sensitivity required for
glucose disposal and/or suppression of hepatic glucose output
Measurement
Insulin sensitivity is measured by ‘euglycaemic hyperinsulinaemic glucose dispersal’
using a euglycaemic hyperinsulinaemic glucose clamp, which MEASURES insulin
sensitivity from which insulin responsiveness is DERIVED.
This is the gold standard
After an overnight fast, insulin is infused IV at a constant rate whilst dextrose is
infused IV at a variable rate to “clamp” blood glucose in the normal range
After few hours steady state for plasma insulin, blood glucose and glucose infusion
rate (GIR) is attained
GIR is equal to glucose disposal rate (M), assuming HGO is inhibited
This can be used to generate an estimate of insulin sensitivity
Metabolic syndrome = clustering of three or more of:
1) hypertension
2) hypertriglyceridaemia
3) low HDL-cholesterol
4) impaired glucose handling
5) centripetal obesity
6) microalbuminaemia
Overall definitions of the metabolic syndrome have been simplistic: whilst it used to be
thought that insulin resistance caused the plethora of metabolic syndrome characteristics, it
is now clear that INTRA-ABDOMINAL ADIPOCYTE SIZE is the important causative factor:
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Insulin responsiveness = the maximal effect of insulin. Insulin sensitivity = insulin concentration required for half-maximal response. Insulin resistance = decrease in insulin responsiveness and/or insulin sensitivity required for glucose disposal and/or suppression of hepatic glucose output. Insulin sensitivity is measured by euglycaemic hyperinsulinaemic glucose dispersal" using a euglycaemic hyperinsulinaemic glucose clamp, which measures insulin sensitivity from which insulin responsiveness is derived. After an overnight fast, insulin is infused iv at a constant rate whilst dextrose is infused iv at a variable rate to clamp blood glucose in the normal range. After few hours steady state for plasma insulin, blood glucose and glucose infusion rate (gir) is attained. Gir is equal to glucose disposal rate (m), assuming hgo is inhibited. This can be used to generate an estimate of insulin sensitivity. Metabolic syndrome = clustering of three or more of: hypertension, hypertriglyceridaemia, low hdl-cholesterol, impaired glucose handling, centripetal obesity, microalbuminaemia.
