Low Serum Cholesterol May Be Associated With Suicide Attempt History

Objective: This case-control study used both healthy blood donors and psychiatric inpatients as controls and controlled for gender, age, low body mass index, alcohol and nicotine use, and aggressive and impulsive behaviors to examine the association between low serum cholesterol levels and suicide attempts.

Method: At a Spanish general hospital, the recruitment included 417 patients with suicide attempt history (138 men and 279 women), 155 psychiatric inpatient controls without suicide history (68 men and 87 women), and 358 healthy controls (220 men and 138 women). All participants were aged 18 years or older. To study the association between low serum cholesterol levels (fasting < 160 mg/dL) and suicide attempts, odds ratios (ORs) and 95% confidence intervals (CIs) were calculated in univariate analyses. Logistic regression models adjusted ORs for confounding variables in male, female, and total samples. The study was conducted from January 1996 to December 1997.

Results: The ORs in the total sample (for psychiatric and healthy controls respectively) were 1.8 (95% CI = 1.2 to 2.9, p = .007) and 1.9 (95% CI = 1.4 to 2.6, p < .001) for the univariate analyses, and 1.6 (95% CI = 0.95 to 2.6, p = .08) and 1.6 (95% CI = 1.0 to 2.4, p = .04) after variable adjustment. In women, the adjusted OR was 1.8 (95% CI = 0.90 to 3.5, p = .09) for psychiatric controls. In men, the adjusted OR was 2.0 (95% CI = 0.99 to 4.1, p = .05) for healthy controls. All ORs were in the hypothesized direction but some subsamples appeared too small to reach significance.

Conclusion: This study, somewhat limited by the small sample size, suggests that low cholesterol may be associated with suicide attempts. Low cholesterol level in suicide attempts may be more important from a pathophysiologic than from a diagnostic point of view.