Obesity and changes in cholesterol (HDL and LDL)

Obesity has a deleterious effect on the lipid profile.

• any primary hyperlipidaemia will be exacerbated by obesity:
  • in general obesity will lead to increased triglyceride levels (usually type IV hyperlipidaemia); in susceptible individuals however, there will also be hypercholesterolaemia (e.g. due to increased LDL in type IIb hyperlipidaemia)
    
    
• the likelihood of hypertriglyceridaemia is higher with android obesity (male-pattern) than with gynoid obesity (female-pattern)
  
  
• the mechanism for hypertriglyceridaemia in obesity is a result of increased hepatic triglyceride synthesis and consequent increased hepatic VLDL production. This occurs because of increased levels of non-estirified fatty acid (from adipocytes) which are metabolised by the liver. Occasionally there is an increased level of lipoprotein lipase activity associated with obesity so that there is not necessarily an associated hypertriglyceridaemia; there is also an increased level of cholesterol synthesis associated with obesity
  
• HDL levels are often reduced in obesity

There is evidence that for every kilogramme of weight lost (1):

• LDL-cholesterol decreases by 0.02 mmol/L
• HDL-cholesterol increases by 0.009 mmol/L

Reference:

• 1) Dattilo, AM, Kris-Etherton, PM et al. (1992). Effects of weight reduction on blood lipids and lipoproteins: a meta-analysis. Am. J. Clin. Nutr. 56, 320-8.