Possible association between moderate intellectual disability and weight gain in valproic acid-treated patients with epilepsy.

BACKGROUND: Although patients with moderate intellectual disability (ID) are known to have higher rates of being overweight and obese than those without ID, there are no current data regarding the relationship between ID and weight gain in epilepsy patients treated with valproic acid (VPA). PATIENTS AND METHODS: The possible association between moderate ID and an overweight status at the time of initiation of VPA therapy (baseline) was investigated using a logistic regression analysis in 143 patients with epilepsy. Among the 119 nonoverweight patients at baseline, the longitudinal association between moderate ID and the weight status during VPA therapy was retrospectively examined using a Cox hazards regression analysis and the generalized estimating equations approach, while also paying careful attention to associations with other patient characteristics. RESULTS: The proportion of patients with moderate ID was 52.4% among the 143 study subjects. The presence of moderate ID was not associated with an overweight status at baseline (P=0.762). Among the nonoverweight patients at baseline, 16 subjects were newly diagnosed as being overweight during treatment with VPA (3.6±2.1 years). The presence of moderate ID was significantly associated with the incidence of an overweight status after starting VPA therapy (adjusted hazard ratio =6.72, P=0.007). The patient age at baseline and treatment with co-administered carbamazepine, clobazam, and zonisamide significantly influenced the degree of weight fluctuation during VPA therapy among the patients with moderate ID (P<0.001, P<0.001, P=0.002, and P=0.028, respectively), whereas only patient age at baseline affected this parameter among the patients without moderate ID (P=0.022). CONCLUSION: The present findings suggest that the weight status should be carefully monitored in VPA-treated patients with moderate ID, especially those receiving other co-administered antiepileptic drugs that facilitate weight gain, such as carbamazepine.

Impact of the superoxide dismutase 2 Val16Ala polymorphism on the relationship between valproic acid exposure and elevation of γ-glutamyltransferase in patients with epilepsy: a population pharmacokinetic-pharmacodynamic analysis.

BACKGROUND: There has been accumulating evidence that there are associations among γ-glutamyltransferase (γ-GT) elevation and all-cause mortality, cardiovascular diseases and metabolic diseases, including nonalcoholic fatty liver disease. The primary objective of this study was to evaluate the impact of the most common and potentially functional polymorphisms of antioxidant enzyme genes, i.e. superoxide dismutase 2 (SOD2), glutathione S-transferase M1 and glutathione S-transferase T1, on the γ-GT elevation during valproic acid (VPA) therapy. METHODS AND FINDINGS: This retrospective study included 237 and 169 VPA-treated Japanese patients with epilepsy for population pharmacokinetic and pharmacokinetic-pharmacodynamic analyses, respectively. A nonlinear mixed-effect model represented the pharmacokinetics of VPA and the relationships between VPA exposure and γ-GT elevation. A one-compartment model of the pharmacokinetic parameters of VPA adequately described the data; while the model for the probability of the γ-GT elevation was fitted using a logistic regression model, in which the logit function of the probability was a linear function of VPA exposure. The SOD2 Val16Ala polymorphism and complication with intellectual disability were found to be significant covariates influencing the intercept of the logit function for the probability of an elevated γ-GT level. The predicted mean percentages of the subjects with γ-GT elevation were about 2- to 3-fold, 3- to 4-fold and 4- to 8-fold greater in patients with the SOD2 Val/Val genotype but without any intellectual disability, those with the SOD2 Val/Ala or Ala/Ala genotype and intellectual disability and those with the SOD2 Val/Val genotype and intellectual disability, respectively, compared to those with the SOD2 Val/Ala or Ala/Ala genotype without intellectual disability. CONCLUSION: Our results showed that the SOD2 Val16Ala polymorphism has an impact on the relationship between VPA exposure and γ-GT elevation in patients with epilepsy. These results suggest that determining the SOD2 genotype could be helpful for preventing the VPA-induced γ-GT elevation.

Possible associations between antioxidant enzyme polymorphisms and metabolic abnormalities in patients with schizophrenia.

BACKGROUND: This study investigated the possible association between common and potentially functional polymorphisms of antioxidant enzymes and metabolic abnormalities in patients with schizophrenia. METHODS: The possible associations of the glutathione S-transferase (GST) M1 null and GSTT1 null genotypes, and the superoxide dismutase 2 (SOD2) Val16Ala polymorphism with the risks of being overweight and having metabolic syndrome were examined using a logistic regression analysis in 154 schizophrenic Japanese patients and 203 controls. RESULTS: Among smokers with schizophrenia, the risks of being overweight and having decreased high-density lipoprotein cholesterol were significantly higher in those with the GSTM1 null genotype than in those with the present genotype (odds ratio 3.20 and 3.15, P=0.03 and P=0.04, respectively), while among nonsmokers with schizophrenia, the risk of an abnormal waist circumference was lower in those with the GSTM1 null genotype (odds ratio 0.34, P=0.04). The risk of a decreased high-density lipoprotein cholesterol level was significantly higher in patients with the combined GSTM1 null and GSTT1 present genotypes than in those with the present genotypes of both genes (odds ratio 3.60, P<0.01). The SOD2 Val16Ala polymorphism was not associated with risk of metabolic abnormalities in either group. CONCLUSION: The present study suggests that the GSTM1 null genotype, in combination with smoking status or GSTT1 genotype, might be associated with the metabolic abnormalities in patients with schizophrenia.

Sex differences in the effect of cytochrome P450 2C19 polymorphisms on the risk of diabetic retinopathy: a retrospective longitudinal study in Japanese patients with type 2 diabetes.

Cytochrome P450 2C19 (CYP2C19) is expressed in human endothelial cells and catalyzes the biosynthesis of vasoprotective epoxyeicosatrienoic acids and 19-hydroxyeicosatetraenoic acid from arachidonic acid. This study investigated the association between CYP2C19 polymorphisms and an increased risk of diabetic retinopathy (DR). A clinic-based retrospective longitudinal analysis was carried out that included 383 Japanese patients with type 2 diabetes mellitus. Compared with male extensive metabolizers, female intermediate metabolizers [adjusted odds ratio (OR), 2.43; 95% confidence interval (95% CI), 1.17-5.06] and poor metabolizers (OR, 7.49; 95% CI, 2.64-21.26) were at a significantly higher risk of developing DR. Furthermore, the CYP2C19 poor metabolizer genotype was found to be an independent risk factor for DR only in women when patients were stratified by sex (OR, 4.18; 95% CI, 1.42-12.26). This is the first report showing the interactive effect of sex and CYP2C19 polymorphisms on microvascular disease in humans, although further investigations are needed to verify these findings.

Superoxide dismutase 2 Val16Ala polymorphism is a risk factor for the valproic acid-related elevation of serum aminotransferases.

The association between the superoxide dismutase 2 (SOD2) Val16Ala polymorphism and the serum aminotransferase levels was retrospectively investigated in 207 valproic acid-treated patients with epilepsy. The Val/Val genotype tended to show elevated alanine aminotransferase levels (odds ratio=3.5; P=0.056). In addition, an elevated γ-glutamyltransferase level was associated with the Val/Val genotype (odds ratio=3.1; P=0.022). The SOD2 Val/Val genotype may therefore contribute to a valproic acid-induced elevation in the serum aminotransferase levels.