Low cholesterol and noncardiovascular mortality

Recent clinical trial data have suggested that low cholesterol might cause increased mortality from noncardiovascular conditions. Several randomized trials have suggested an increase in noncoronary deaths at low levels of total cholesterol. When subcategories for causes of death were investigated, it was noted that hemorrhagic stroke risk was inversely related to total cholesterol, whereas nonhemorrhagic stroke risk was positively related to total cholesterol. Certain cancers were shown to be more common at low total cholesterol levels, namely lung, liver, lymphatic, and hematopoietic cancer. Another issue to consider is whether increased mortality rates are seen in individuals with "naturally" occurring low cholesterol or whether they are seen in individuals whose cholesterol has been deliberately lowered through dietary or drug intervention, or in both. If an association between low cholesterol and noncardiovascular mortality is present, there is continuing uncertainty regarding the mechanism by which it occurs.