Smoking Affects the Patterns of Metabolic Disorders and Metabolic Syndrome in Patients With First-Episode Drug-Naive Schizophrenia: A Large Sample Study Based on the Chinese Han Population

Objective Although metabolic disorders and smoking are common in schizophrenia, few studies have investigated the effects of smoking on metabolic disorders or metabolic syndrome (MetS) in schizophrenia patients, especially in first-episode drug-naive (FEDN) patients. We sought to investigate the differences in metabolic disorders and MetS between smoking and nonsmoking FEDN schizophrenia patients. Methods A total of 428 FEDN schizophrenia patients and 435 controls were recruited. Blood pressure, waist circumference, body mass index (BMI), lipid profiles, and glucose metabolism were measured. The psychopathology was evaluated by Positive and Negative Syndrome Scale. Results FEDN schizophrenia patients had a higher smoking rate than controls (23.8% vs 14.0%, P<.001). After adjusting for confounding variables, the prevalence of MetS, overweight, hypertension, hypertriglyceridemia, elevated insulin, and insulin resistance in smoking patients was higher than those in nonsmoking patients, while overweight and hypertension were higher in the smoking controls than in nonsmoking controls (all P<.05). In smoking patients, triglyceridemia, high-density lipoprotein cholesterol, and fasting blood glucose were the main contributing components to MetS, while in nonsmoking patients, waist circumference, systolic blood pressure, triglyceridemia, high-density lipoprotein cholesterol, and fasting blood glucose were the main contributing components to MetS. In smoking patients, BMI and homeostatic model assessment for insulin resistance were associated factors of MetS (both P<.05). In nonsmoking patients, sex, BMI, insulin, and homeostatic model assessment for insulin resistance were associated factors of MetS (all P<.05). Conclusions Our study indicates that smoking schizophrenia patients have a higher prevalence of MetS and metabolic disorders than nonsmoking patients. Moreover, smoking and nonsmoking patients have different contributing components and associated factors for MetS.