Is there any concern of insulin resistance and metabolic dysfunctions with antiseizure medications? A prospective comparative study of valproate vs. levetiracetam.

PURPOSE

To evaluate the incidence of insulin resistance and its association with change in serum anti-seizure medication (ASM) level and their pharmacokinetic, body composition and metabolic hormones after six months of levetiracetam (LEV) exposure in persons with epilepsy (PWE) in comparison to valproate (VPA).

METHODS

This prospective-longitudinal study included clinically diagnosed PWE on VPA or LEV monotherapy (for<3 months). At enrolment, body weight/composition, BMI were measured and blood samples were collected for assessing metabolic dysfunctions by estimation of serum insulin, insulin resistance [in terms of Homeostatic Model Assessment of Insulin Resistance (HOMA-IR)], leptin, adiponectin, lipid profile along with ASMs level. Subjects were followed up for six months and all the above parameters were reassessed.

RESULTS

A total of 150 PWE were screened based on inclusion and exclusion criteria, and 105 number of subjects were enrolled (n = 35 in VPA and n = 70 in LEV group). Out of them, 92 subjects (n = 32 in VPA; n = 60 in LEV) completed six months follow-up. After six months, serum insulin level increased significantly in VPA group compared to baseline p < 0.001). Insulin resistance (HOMA-IR>2.5) was observed in 14.28 % of PWE in VPA group. Significantly higher percentage-change in body-weight (p = 0.003), leptin and decreased adiponectin were found in VPA-group compared to baseline ((p = 0.003, 0.02, 0.001, <0.001, respectively). These changes were independent of serum level or pharmacokinetic of VPA. On the other hand, no such changes were observed in LEV-group despite increased serum LEV level and altered pharmacokinetic parameters after six months.

CONCLUSION

Six months treatment with VPA resulted in insulin resistance and metabolic dysfunctions in PWE. These alterations were not correlated with change in VPA serum level. These changes were not observed in LEV therapy suggesting its better safety profile. This may be considered while prescribing the ASM like VPA and LEV in adult patients with obesity or insulin resistance and diabetes.