Cross-sectional association between metabolic parameters and psychotic-like experiences in a population-based sample of middle-aged and elderly individuals

Background: Metabolic alterations are often found in patients with clinical psychosis early in the course of the disorder. Psychotic-like experiences are observed in the general population, but it is unclear whether these are associated with markers of metabolism. Methods: A population-based cohort of 1890 individuals (mean age 58.0 years; 56.3% women) was included. Metabolic parameters were measured by body-mass index (BMI), concentrations of low-density and high-density lipoprotein cholesterol (LDL-C and HDL-C), total cholesterol, triglycerides, and fasting glucose and insulin in blood. Frequency and distress ratings of psychotic-like experiences from the positive symptom dimension of the Community Assessment of Psychic Experience questionnaire were assessed. Cross-sectional associations were analysed using linear regression analyses. Results: Higher BMI was associated with higher frequency of psychotic-like experiences (adjusted mean difference: 0.04, 95% CI 0.02–0.06) and more distress (adjusted mean difference: 0.02, 95% CI 0.01–0.03). Lower LDL-C was associated with more psychotic-like experiences (adjusted mean difference: −0.23, 95% CI −0.40 to −0.06). When restricting the sample to those not using lipid-lowering medication, the results of BMI and LDL-C remained and an association between lower HDL-C and higher frequency of psychotic-like experiences was found (adjusted mean difference: −0.37, 95% CI −0.69 to −0.05). We observed no significant associations between cholesterol, triglycerides, glucose, insulin or homeostatic model assessment and psychotic-like experiences. Conclusions: In a population-based sample of middle-aged and elderly individuals, higher BMI and lower LDL-C were associated with psychotic-like experiences. This suggests that metabolic markers are associated with psychotic-like experiences across the vulnerability spectrum.