The relationship between body mass index, the use of second-generation antipsychotics, and dental caries among hospitalized patients with schizophrenia

Objective: Weight gain is common in schizophrenia due to use of the second-generation antipsychotic medicines (SGAs). Studies have also shown that body mass index (BMI) and the side effect of SGAs, such as anticholinergic activity, are related to the risk of dental caries. This study aims to investigate the relationship between BMI, the use of the SGAs, and the decayed, missing, and filled tooth index (DMFT) among hospitalized patients with schizophrenia. Methods: A cross-sectional survey of oral health was conducted in a psychiatric long-term care hospital in Taiwan in 2006. A total of 878 schizophrenic inpatients participated in this survey. The DMFT index was used to assess dental caries, the use of SGAs of subjects were recorded, and the BMI classification was done in accordance with Asian standard scales. Multiple regression models were used to measure the effects of SGAs or BMI on the DMFT index in each subject. Results: Among the subjects with schizophrenia, DMFT is significantly related to independent variables such as age, length of stay, BMI, education, marital status, and grade of disability. Consequent multiple linear regression showed that being underweight (β = 0.07, p = 0.041) and age were the most significant factors that influence the DMFT score. Conclusions: We found that the use of SGAs was not significantly associated with the DMFT index. After adjusting for age, being underweight is a significant factor associated with the increased risk of dental caries in hospitalized patients with schizophrenia. Psychologists and dentists should pay more attention to the relation between BMI and dental caries in this population.