[A concept for normal range of serum cholesterol].

The normal range of serum cholesterol is not primarily defined. It largely depends on conditions of respective population such as age, sex and food uptake. Therefore, the reported normal range of respective laboratory differ each other. The upper limit of the normal range used in laboratories on Japan in recent decade is about 240-250 mg/dl, which were obtained statistically from normal persons. On the other hand, another normal range with 220 mg/dl upper limit was proposed after Framingham Study and other clinical studies. Many of clinical doctors are confusing with these two different normal ranges. We must clearly define the normal range whether it is obtained statistically or is used for preventive medicine, when it is presented to doctors.