How does insulin reduce triglycerides

Treatment with the lipid-lowering drug pravastatin reduces the risk of type 2 diabetes by 30 percent

(29.08.2001) The results of a retrospective data analysis of the Study on the Prevention of Heart Disease in West Scotland (WOSCOPS) were recently published. Treatment with the lipid-lowering drug pravastatin showed a 30 percent reduction in the risk of developing type 2 diabetes.

The study evaluated data collected over a period of 3.5 to 6.1 years from almost 6000 men between the ages of 45 and 64 with regard to their influence on the development of type 2 diabetes mellitus. Among other things, all study participants who already had diabetes mellitus or increased fasting blood sugar levels at the start of the study were excluded from the evaluation. During the survey period, 139 men developed diabetes mellitus. Body mass index (BMI), triglyceride values, blood sugar value and treatment with the blood lipid lowering drug pravastatin were found as independent predictor factors for the development of diabetes mellitus.

The body mass index (BMI) and the triglyceride values ​​are already known, independent of other facts, risk factors for the development of so-called insulin resistance. Since type 2 diabetes mellitus develops out of insulin resistance, this supports the connection found. Treatment with the drug pravastatin, which lowers total cholesterol, LDL cholesterol (so-called "bad" cholesterol) and triglycerides, and increases HDL cholesterol (so-called "good cholesterol"), showed a risk reduction for the development of diabetes mellitus type 2 of 30 percent. The authors give three possible causes for this:

  1. It is known that elevated blood lipid levels favor the development of type 2 diabetes. Pravastatin lowers blood lipid levels (e.g. plasma triglycerides) and should therefore have a positive effect on the risk of diabetes. However, since other drugs, which lower blood lipid levels (especially triglycerides) more than pravastatin, do not influence the development of type 2 diabetes mellitus, blood fat reduction does not in itself explain the beneficial effects of pravastatin.
  2. Pravastatin lowers inflammatory substances in the body that are responsible for the development of insulin resistance when people are overweight. These anti-inflammatory properties of pravastatin could be decisive in reducing the risk of diabetes, especially since recent studies have shown that increased markers for inflammation in the body (e.g. CRP) are associated with an increased risk of diabetes.
  3. Positive effects of pravastatin on the tissue that lines the inside of the vessels (endothelium) could positively influence the blood sugar metabolism through an increase in blood flow with an improvement in the transport of insulin and glucose, so that type 2 diabetes mellitus is less likely to develop.

Another rationale for reducing the risk of diabetes could be the following: Lowering blood lipids with pravastatin leads to a reduction in cardiovascular disease, as has been shown in other studies. As a result, fewer cardiovascular drugs (e.g. thiazides, beta blockers) are required, which have been shown to lead to a deteriorated blood sugar metabolism, which would more often lead to type 2 diabetes mellitus.

Although previous studies had not shown any clear results regarding the reduction of the risk of diabetes through treatment with pravastatin, the authors of this study assume conclusive results, since this study is a long-term evaluation with participants who did not have elevated blood sugar levels at the start of the study.

The authors themselves emphasize, however, that the results of this subsequent study evaluation should be seen as hypotheses that must be confirmed in further studies with the lipid-lowering drug atorvastatin.

Dr. med. Melanie Stapperfend, Prof. Dr. med. Werner Scherbaum

Source: Circulation. 2001; 103: 357-362