focus on obesity, metabolism, and disease risk. obesity and disease risk copyright 2012, john wiley...

Focus OnOBESITY, METABOLISM, AND DISEASE RISK

Obesity and Disease Risk

Copyright 2012, John Wiley & Sons Canada, Ltd.

Obesity and Type 2 Diabetes A link exists between type 2 diabetes and

obesity. More than 85% of people with type 2

diabetes are overweight or obese. Insulin regulates both glucose and lipid

metabolism. Insulin resistant state individuals have more free fatty acids and glucose (gluconeogenesis) in their blood stream.


Obesity and Type 2 Diabetes Insulin resistance: When tissue (muscle and adipose) are less

responsive to insulin and do not take up glucose as readily. As a result, blood glucose levels remain high.

Beta-cells: Located in the pancreas and responsible for insulin secretion, beta-cells will increase insulin secretion to decrease circulating glucose.

Hyperinsulinemia: There are high levels of insulin in the blood to compensate for the high glucose levels due to insulin resistance.

Prediabetes: Increase insulin secretion and blood glucose levels remain high.

Hypoinsulinemia: Beta-cells are unable to produce enough insulin to lower blood sugars.

Type 2 diabetes: Insulin resistance persists and beta-cells fail. Lipidotoxic effect: Induces insulin resistance and contributes to beta-

cell failure.


Development of Type 2 Diabetes


Insulin Resistance


Obesity and Development of Type 2 Diabetes


Obesity and Cardiovascular Disease Obesity increases the risk of cardiovascular disease by altering the levels of

lipoproteins that circulate in the blood. The greater the adipose tissue mass, the greater the release of free fatty acids. An obese individual will have higher VLDLs (high serum TGs).

When VLDLs are high there is a typical transfer of cholesterol and triglycerides between VLDLs and other lipoproteins. Cholesterol from HDL is not taken up by the liver but transferred back to the VLDL, reducing the HDL cholesterol level. With the high level of VLDL there is a transfer of the triglycerides from VLDL to LDL. Hepatic Lipase removes the triglyceride component and leave an sd-LDL particle in the blood.

The small sd-LDL gets trapped in the blood vessel walls and the cholesterol in the particle is more readily oxidized, promoting atherosclerosis and cardiovascular disease.

Lipid Triad or Atherogenic Penotype: In the blood stream high triglycerides, low LDL and high levels sd-LDL.


Obesity and Cardiovascular Disease


Obesity and Cancer Risk


Obesity and Cancer Risk

Obesity is associated with several types of cancer. Obesity is linked to cancer because it promotes cell

proliferation and suppresses apoptosis by raising the levels of growth factors (insulin and estrogen) in the blood.

Research suggests it is insulin resistance and the resulting high blood glucose levels and hyperinsulinemia that promote the action of the two growth factors.

If cell proliferation is stimulated in vulnerable tissue, a tumour may develop.


Obesity, Insulin and Estrogen


Obesity and Gall Bladder Disease

Obesity is associated with an increase in gallstone formation. Gallstones are made mostly from cholesterol and may form a single large stone or many small ones.

The more obese a patient is, the greater the risk. Women who are obese have 3 to 7 times the risk of

developing gallstones as women at a healthy body weight.

Research shows that in obese people the liver produces too much cholesterol which is deposited in the gall bladder and from stones.


Obesity and Disease Sleep Apnea: Brief interruptions of breathing during

sleep, common in the obese because fatty tissue in the pharynx and neck compress the airway and block airflow.

Joint Disorder: Excess weight and fat increase the risk of developing osteoarthritis. The cartilage cushioning the joints breaks down, so the bones in the joint rub against each other resulting in pain and reduced movement.

Gout: High level of uric acid in the blood that increases uric acid synthesis with insulin resistance.


Copyright

Copyright © 2012 John Wiley & Sons Canada, Ltd.

All rights reserved. Reproduction or translation of this work beyond that permitted by Access Copyright (The Canadian Copyright Licensing Agency) is unlawful. Requests for further information should be addressed to the Permissions Department, John Wiley & Sons Canada, Ltd. The purchaser may make back-up copies for his or her own use only and not for distribution or resale. The author and the publisher assume no responsibility for errors, omissions, or damages caused by the use of these programs or from the use of the information contained herein.

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focus on obesity, metabolism, and disease risk. obesity and disease risk copyright 2012, john wiley...

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