I want to know exactely if the medecin for reduce the LDL level is a temporary medecin or a chronic one.
Your LDL level is considered high, that means that there is high risk for problems (including heart events).
Keep in mind that doctors do advise the patients some TLC (therapeutic lifestyle changes) at the beginning. And I think this is even for your case. So, quit "bad" habits, shift to healthy life (exercise, better dietary strategy) and you’ll see that your numbers will come down.
Also, keep in mind that if TLC fails, then and only then you must shift to drugs (usually prescribed are statins). This kind of drugs are never given for lifetime. If during the drug-therapy, your numbers come down, then your doctor will prescribe lower doses till (if the numbers are ok and steady) you will not take them anymore.
But if after a while, your numbers will be high, and you cannot decrease them by TLC, then you have to start again the drugs.
Remember: TLC is lifetime, lowering-cholesterol drugs (if well-managed) are not!
For lowering-cholesterol drugs info visit http://www.cholesterol-hdl-ldl.com/high-cholesterol-medication.html