Relationship between Serum Homocysteine and Metabolic Syndrome among Patients with Schizophrenia and Bipolar Disorder: A Cross Sectional Study

Abstract

Objective: This study aimed to compare the prevalence of metabolic syndrome and hyperhomocysteinemia and to specify predictors of the metabolic syndrome among patients with schizophrenia and bipolar disorder.
 Method: This cross sectional study was conducted on 100 patients with schizophrenia and 100 patients with bipolar disorder. The participants' metabolic syndrome was determined according to the criteria set by Third Report of the National Cholesterol Education Program–Adult Treatment Panel III. Hyperhomocysteinemia was considered as homocysteine levels higher than 15 µmol/L. Chi-square test, Fisher's exact test, student t test, Mann-Whitney test, and logistic regression were used for data analysis.
 Results: The prevalence of metabolic syndrome was not significantly different (P = 0.07) between patients with schizophrenia (27%) and bipolar disorder (39%). No statistically significant difference (P = 0.17) was observed between patients with schizophrenia (82%) and bipolar disorder (74%) in the prevalence of hyperhomocysteinemia. The results of multivariable logistic regression model showed a significant association of smoking and BMI with metabolic syndrome in patients with schizophrenia (OR = 3.69, 95% CI: 1.13-12.05, and OR = 1.38, 95% CI: 1.20-1.60, respectively). In patients with bipolar disorder, BMI was a significant predictor of developing metabolic syndrome (OR = 1.29, 95% CI: 1.14-1.47). Metabolic syndrome was more prevalent in women than in men in both diagnostic groups (P < 0.05). No significant difference was observed in hyperhomocysteinemia prevalence between male and female patients with schizophrenia (P = 1.00). However, hyperhomocysteinemia was more prevalent in males than in females among patients with bipolar disorder (P = 0.001).
 Conclusion: Findings showed a high prevalence of metabolic syndrome and hyperhomocysteinemia among patients with schizophrenia and bipolar disorder. To deal with this problem, regular monitoring and conducting early interventions are recommended to determine the metabolic risk profile and to prevent the cardiovascular diseases.

Homocysteine levels in first-episode patients with psychiatric disorders

“…Sandwich enzyme-linked immunosorbent assay kit (catalog no: EIA-2925, DRG Instruments GmbH, Marburg, Germany) was used to measure the Hcy levels of the participants. Hcy concentrations of > 15 μmol/L were defined as Hhcy ( 8 ).…”

“…Elevated Hcy levels of > 15 mmol/L are defined as hyperhomocysteinemia (Hhcy) ( 4 ). Both elevated Hcy and Hhcy levels are associated with several neurological and psychiatric disorders, such as stroke ( 5 ), major cognitive disorders ( 6 ), schizophrenia (SZ) ( 7 ), bipolar disorder (BD) ( 4 ), and major depression ( 8 ). These factors contribute to the pathogenesis of these disorders through multiple pathways ( 3 ).…”

“…Previous studies have mostly compared Hcy levels in SZ, BD, or depression separately ( 8 , 11 , 12 , 16 ). Few studies have simultaneously compared the Hcy levels between two of these diseases, and the homogeneity of patients was not considered.…”

“…Therefore, simultaneously investigating multiple diseases is crucial, and symptoms and disease status should be considered. In addition, the confounding effects of age, medication, race, and chronic illness also need to be controlled because these biological factors could influence Hcy levels ( 8 , 16 ). For example, Hcy levels decreased after antipsychotic therapy, and the severity of psychotic symptoms was associated with higher Hcy levels ( 17 ).…”

“…For example, Hcy levels decreased after antipsychotic therapy, and the severity of psychotic symptoms was associated with higher Hcy levels ( 17 ). Hcy is also associated with age ( 8 ). However, while different diagnostic tools have a crucial impact on the study results, whether confounding factors were controlled could also have significantly impacted the results of these studies ( 13 ).…”