Objective: To investigate whether low serum cholesterol concentration or changing serum cholesterol concentration is associated with risk of suicide in men.
Design: Cohort study with annual repeat measurements of serum cholesterol concentration (for up to four years).
Setting: Paris, France.
Subjects: 6393 working men, aged 43-52 in 1967-72, who had at least three measurements of serum cholesterol concentration.
Main outcome measures: Individual change over time in serum cholesterol concentration (estimated using within person linear regression method); death from suicide during average of 17 years' follow up after last examination.
Results: 32 men committed suicide during follow up. After adjustment for age and other factors, relative risk of suicide for men with low average serum cholesterol concentration (< 4.78 mmol/l) compared with those with average serum cholesterol concentration of 4.78-6.21 mmol/l was 3.16 (95% confidence interval 1.38 to 7.22, P = 0.007). Men whose serum cholesterol concentration decreased by more than 0.13 mmol/l a year had multivariate adjusted relative risk of 2.17 (0.97 to 4.84, P = 0.056) compared with those whose cholesterol remained stable (change of < or = 0.13 mmol/l a year).
Conclusion: Both low serum cholesterol concentration and declining cholesterol concentration were associated with increased risk of death from suicide in men. Although there is some evidence in favour of a concomitant rather than a causal effect for interpreting these associations, long term surveillance of subjects included in trials of lipid lowering treatments seems warranted.