Lower Serum Cholesterol Level is Associated with More Serious Injury in Psychiatric Patients with Suicide Attempt

자살을 시도한 정신과 환자에서 낮은 혈청 콜레스테롤 농도와 심각한 자살 수행과의 연관성

An association of low total cholesterol in blood with psychiatric diseases and suicidal behavior has been suggested. As part of an attempt to further explore this relationship, we examine first, whether serum cholesterol levels in psychiatric patients with suicidal attempt would be lower than in non-suicidal psychiatric inpatients or normal controls, second, whether such significant difference of cholesterol levels would be present when the diagnostic groups are analyzed separately, third, whether low cholesterol level would be associated with a history of serious suicidal attempts, and finally, whether low cholesterol level in suicide attempters is a state or a trait marker. We determined the serum cholesterol levels in 231 patients admitted to an emergency room following an suicidal attempt, in the same numbers of age-, sex- and diagnosis- matched non-suicidal psychiatric controls, and in the same numbers of age-, sex matched normal controls. The seriousness of an attempt was divided into 5 grades according to the degree of the resulting medical injury. Total cholesterol levels in suicide attempters were significantly lower compared with both psychiatric and normal controls, when sex, age, and nutritional status (i.e., body mass index) were controlled for. This significant relationship was observed in major depressive disorders and personality disorders, but not in schizophrenia and bipolar type I disorders. The severity of suicide by a lowering of blood cholesterol was related to the magnitude of the cholesterol reduction. After treatment of their psychiatric ailments, the cholesterol levels in suicide attempters were significantly increased. This result suggests that low cholesterol level in psychiatric patients might be a potential biological marker of suicide risk. It is hypothesized that low cholesterol levels is associated with the suicide by modifying the serotonin metabolism, the production of interleukin-2 and melatonin metabolism in psychiatric patients.

자살 시도군 231명, 환자 대조군 231명, 정상대조군 231명을 대상으로 혈청 콜레스테롤 농도를 측정하여 다음의 결과를 얻었다. 1) 자살 시도군이 환자대조군 혹은 정상대조군보다 혈청 콜레스테롤 농도의 유의한 저하를 보였다. 2) 진단별로는 우울증과 인격장애에서 자살 시도군이 환자대조군보다 콜레스테롤 농도의 유의한 저하를 보였으나, 정신분열병과 양극성 정동장애 조증형에선 차이가 없었다. 3) 자살 시도군의 남녀별로 비교시, 남자가 여자보다 콜레스테롤 농도의 유의한 저하를 보였으며, 진단별로는 우울증에서만 유의한 차이를 보였다. 4) 자살 시도군에서 낮은 콜레스테롤 농도는 심각한 자살 수행과 연관성이 있었다. 5) 자살 시도군에서 치료전에 비해 치료후 혈청 콜레스테롤 농도의 유의한 증가를 보였다. 본 연구의 결과는 자살 시도의 예측인자로서 혈청 콜레스테롤이 이용될 수 있음을 시사한다. 향후 콜레스테롤 농도에 미치는 변인들을 통제한 전향적 방법을 통해 원인적 측면에서 혈청 콜레스테롤 농도와 세로토닌, 인터루킨-2, 멜라토닌 간의 연관성에 관한 연구가 이루어져야 하겠다.