ANOTHER FLAWED CHOLESTEROL STUDY -- 2/21/07

Read about a new study below. They knock out a gene and find that the mice have high cholesterol and diabetes. They then seem to suggest that the high cholesterol "caused" the diabetes. That conclusion certainly would not be justified. Particularly if they can't come up with a reasonable theory of how high cholesterol can "cause" diabetes.

Wouldn't it be more logical to assume the missing gene caused BOTH the high cholesterol and the diabetes? Or the missing gene caused the diabetes and the body reacted by increasing the cholesterol to repair damage to the cell membranes by the diabetes?

This study might be an interesting and worthwhile experiment -- but on its own -- I see no proof of anything. -- MRC
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Scientists have conducted a study, the first of its kind to link cholesterol with Type 2 Diabetes. The experiment was performed on mice, yet scientists say the findings may be applicable to humans too.

The cause for Type 2 diabetes is still unknown. There are varied theories on this. Yet one of the features of this disease is the reduction in production of insulin, by the beta cells of the pancreas.

The Canadian Diabetes Association estimates that more than 2 million Canadians have diabetes, of which 1.8 million have type 2. And the figures are rising.

In 2000 the World Health Organization (WHO) estimated that over 177 million people had diabetes worldwide and they say by 2025 the figure will be 300 million.

The scientists based at Canada’s Vancouver Child and Family Research Institute, in the online edition of Nature Medicine reveal study results that, when cholesterol levels in the pancreas go up, diabetes might be the outcome. This refers to the cholesterol in the pancreas.

Few might be aware that cholesterol is found in all cells and a normal amount is beneficial to the body as it aids in cell membrane function, meaning it regulates the materials entering and leaving a cell.

The presence of cholesterol in the pancreas and its high expression was brought to the lead author’s notice by one of his students, Dr. Liam Brunham .In response to that the researcher Dr. Michael Hayden, decided to experiment with the gene ABCA1.

Previous studies showed that the gene called ABCA1, was responsible for regulating cholesterol levels in cells. When the scientists used genetically modified mice to switch off these genes, it was seen that obviously, the cholesterol levels in these cells began to get upset. They increased significantly and strangely, the rats began to show symptoms of diabetes like reduced levels of insulin and glucose intolerance. They went on to become fully diabetic.

On testing the pancreas cells of the mice in vitro they found high levels of cholesterol arising due to disturbance in cholesterol homeostasis.

The scientists,excited with this possible link between cholesterol and insulin secretion, now plan to extend these studies to humans too, hoping it may pave the way for a better understanding and prevention of Type 2 diabetes.

Source-Medindia
ANN