a1 National Public Health Institute, Department for Mental Health and Alcohol Research, Mannerheimintie 166, 00300 Helsinki, Finland
a2 Department of Public Health, University of Helsinki, University of Helsinki, Helsinki, Finland
a3 UKK Institute for Health Promotion Research, Tampere, Finland
a4 Research Unit, Pirkanmaa Hospital District, Tampere, Finland
a5 Department of Psychiatry, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
Background The literature suggests an association between obesity and schizophrenia but fat mass and fat-free mass, which have been shown to be more predictive of all-cause mortality than only waist circumference and obesity [body mass index (BMI) ≥30 kg/m2], have not been reported in psychotic disorders. We examined the detailed body composition of people with different psychotic disorders in a large population-based sample.
Method We used a nationally representative sample of 8082 adult Finns aged ≥30 years with measured anthropometrics (height, weight, waist circumference, fat percentage, fat-free mass and segmental muscle mass). Psychiatric diagnoses were based on a consensus procedure utilizing the Structured Clinical Interview for DSM-IV (SCID)-interview, case-notes and comprehensive register data.
Results Schizophrenia (including schizo-affective disorder) was associated with obesity [odds ratio (OR) 2.3, 95% confidence interval (CI) 1.5–3.6], abdominal obesity (waist circumference ≥88 cm for women, ≥102 cm for men) (OR 2.2, 95% CI 1.3–3.6) and with higher fat percentage (mean difference 3.8%, 95% CI 2.0–5.7%), adjusted for age and gender, than in the remaining sample. The associations between schizophrenia and low fat-free mass and decreased muscle mass on trunk and upper limbs became statistically significant after adjusting for BMI. After further adjusting for current antipsychotic medication, education, diet and smoking, schizophrenia remained associated with obesity (OR 1.9, 95% CI 1.1–3.6) and abdominal obesity (OR 3.8, 95% CI 1.5–9.4). Participants with affective psychoses did not differ from the general population.
Conclusions Individuals with schizophrenia have metabolically unfavorable body composition, comprising abdominal obesity, high fat percentage and low muscle mass. This leads to increased risk of metabolic and cardiovascular diseases.
(Received November 14 2007)
(Revised July 04 2008)
(Accepted July 04 2008)
(Online publication July 08 2008)