Syndrome X

Endocrine and metabolicconsequences of obesity

What is obesity?

n BMI greater than 30 kg/m2

n Incidence greater than 30% of populationand growing in size

Obesity as a consequence of

n Excessive foodintake

n Inappropriatefood choices

Obesity as a consequence of

n Inadequatephysicalactivity

n Hormonaleffects

n Bioenergeticeffects

Health risks of obesity in men

n Arthritisn Diabetesn Hypertensionn Gall stones

Health risks of obesity in women

n Arthritisn Diabetesn Hypertensionn Cancern Gall stones

Inactivity and CHD risk

Health risks of obesity

n depend on fatpatterning

n android (“apple”) hashigher risks

n gynoid (“pear”) haslower risks

Android pattern of obesity

Gynoid pattern of obesity

Android obesity and insulinresistance

n Reducedglucosetolerance

Android obesity and insulinresistance

n Insulinoversecretion

Android obesity and insulinresistance

n Reducedglucoseutilization

Android obesity and insulinresistance

n Reducedglucoseutilization

Android obesity and insulinresistance

n Reducedglucosemetabolism

Android obesity and insulinresistance

n Reducedcapacity ofinsulin tosuppresshepaticglucoseproduction

Android obesity and insulindefectsn Insulin

oversecretion isa function ofobesityindependentlyof its pattern

Android obesity and insulindefectsn Insulin

clearance isreduced

Insulin oversecretion and resistancein aging

n Aging is oftenasociated with obesity

n Reduced insulin-induced glucoseuptake is seen both inaged and obese

n This is due to reducedperipheral sensitivityto insulin, principallyin the muscle

Insulin oversecretion andresistance in aging

n Aging is oftenasociated with obesity

n Oversecretion ofinsulin is seen in bothaged and obese

n High fasting plasmainsulin

Insulin defect acts on portalvascular bedn Insulin

concentration ishigh in theportalcirculation dueto insulinoversecretion

Insulin defect acts on portalvascular bedn High insulin acts on

the visceral adiposetissue causingincreased visceraladiposity

Insulin resistance of androidobesen Resides in skeletal musclen Muscle is insensitive to insulin

Insulin resistance of muscles inthe android obesen Deficient

glucoseuptake

n Deficientglycogensynthesis

Insulin resistance affects lipidmetabolismn Adipose LPL

hypoactivebecauseadiposetissue isinsulinresistant

n Lower LDLreceptorbinding

Development of syndrome X

n Peripheralinsulinresistance

n Insulinoversecretion

n More insulinresistance

Role of androgens in androidobesityn Reduced levels of

SHBG, the high-affinity bindingprotein for androgens

Role of androgens in androidobesityn Reduced levels of

SHBG, the high-affinity bindingprotein for androgens

n Increased freeandrogen titers

Exercise counteracts syndrome x

n Fat lossn Increased insulin sensitivityn Reduced blood pressuren Reduced plasma lipids

Exercise and increased insulinsensitivityn Acute increase in

sensitivityn Associated with

glycogendepletion,increased GLUT-4and glucose uptake

Exercise and reduced plasmalipids

Android obesity and muscle fibertypesn Higher

proportionsof fastanaerobicfibers

n Trainingincreasesconversionto red fibers

Endurance training counteracts

n obesity

Endurance training counteracts

n hyper-tension

Endurance training counteracts

n plasmalipids

Endurance training counteracts

n glucoseintolerance

Endurance training improves

n glucosedisposal

Obesity

n Major health problemn Results from inappropriate life-style choicesn Can be reduced and its risks attentuated

with aerobic exercise and better dietarychoices