Risks of low cholesterol highlighted
MedWire News: Low cholesterol may be a more important health indicator than high cholesterol in communities where vascular disease is uncommon, say Japanese researchers.
The team, led by Naoki Nago (Tokyo-kita Social Health Insurance Hospital), found that low cholesterol was strongly associated with mortality from hemorrhagic stroke, heart failure, and cancer.
"Although the dangers of a high cholesterol level are widely known, they are less important in regions - such as rural Japan - where cardiovascular disease is less common," the researchers comment in the Journal of Epidemiology.
"It may therefore be necessary to highlight the risks of low cholesterol."
The study included 11,869 healthy adults aged between 40 and 69 years who lived in 12 rural areas of Japan. During 11.9 years of follow-up, 635 men and 423 women died.
Cancer was the leading cause of mortality in this cohort, accounting for 36.0% of deaths, while stroke accounted for 14.4% and heart disease for 14.2% of deaths.
Overall, men with low total cholesterol levels (<4.14 mmol/l; 160.2 mg/dl) were 49% more likely to die than those with moderate cholesterol levels (4.14-5.17 mmol/l; 160.2-200.0 mg/dl). Women were 50% more likely to die if they had low, rather than moderate, levels of cholesterol.
In contrast, men and women with cholesterol levels of 6.21 mmol/l (240.3 mg/dl) or higher were not at increased mortality risk relative to those with moderate levels.
The increased mortality risk related to low cholesterol was driven by an increased risk for cancer mortality in men and for hemorrhagic stroke and heart failure mortality in women.
Nago et al note that the effect of low cholesterol on cancer mortality persisted after excluding patients with liver disease.
"This suggests a need for screening of cancers other than liver cancer in individuals with low cholesterol levels," they say.
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By Eleanor McDermid