| Background and purposeEpilepsy is a type of common disease of nervous system. There are nearly 50,000,000 epileptic worldwide, and 6,000,000 to 7,000,000 in China. Epilepsy can be seen in all of the age grades. Different age grade has different pathogen. The peak incidence is in childhood, about 2/3 of epilepsy occur in childhood, and a part of is refractory epilepsy, such as West Syndrome,Lennox-Gastaut Syndrome. Up to now, long-term antiepileptic drug (AED) therapy was the main method, especially some refractory epilepsy which needed lifetime medication and drug combination. Indubitably, most of the AEDs have side effects in varying degree. It is the critical period of body's growth and development, and bone mineralization in childhood. Since 1960s, someone in abroad have reported AEDs caused decreased bone mass of children. More and more scholars began to pay attention to antiepileptic drugs on bone health of children. A growing body of literature indicates that patients taking AEDs are at increased risk for low bone mineral density and metabolic bone disease. Not only the influence of bone mineral density(BMD), but also the potential mechanism which mainly affected the catabolism of vitamin D and secondary hyperparathyroidism and stimulating osteoclast activity and augments osteocalstic bone resorption. So far,more researches had been on conventional AEDs, involving phenytoin, phenobarbital, carbamazepine and valproic acid. Plenty of the researches had found long-term AEDs using induce osteopenia, bone mineral denstity decrease, bone metabolism disorder and increase the risk of rickets, osteomalacia, osteoporosis, fracture and increase the incidence of fracture by 2 to 6 times. Nevertheless, many clinicians lack the general awareness of this aspect at present. The monitoring of BMD and bone metabolism related index during the therapy of epilepsy is not enough. In addition, many new AEDs whose research data of influence on children's bone metabolism was in deficiency and the conclusion was different had been in clinical use. Based on the current research, further research should be the affection of bone metabolism of AEDs, the potential mechanism and the related factors,especially the research of new AEDs for children needing long-term drugs use. It has very important practical meaning to offer guidelines for prevention and intervention, give primary and secondary prevention to osteoporosis, reduce the damage to the bone, ensure healthy growth and development and improve the quality of life in children with epilepsy.MethodSelect 50 cases of epilepsy outpatients at the age 6～14 that come to our hospital during June 2009 to March 2010, including 26 boys,24 girls, and accept a regular and single drug (VPA, TPM) treatment more than 6 month. We divide the patients into two groups by the drugs they use:TPM and VPA, meanwhile we collect 25 cases (14 boys and 11 girls) at the age 6-14 that have been newly diagnosed as epilepsy and have not taken drugs for therapy. We measure up the bone mineral density and the T score of the L2 to L4 vertebra and the femoral neck of the left thighbone, along with bio-chemical index (including serum calcium, phosphorus, alkaline phosphatase and parathyroid hormone). We make statistical analysis of these results by using the SPSS13.0, compare the differences between VPA group and the control group, TPM group and the control group,respectively.And analyse the correlations among the body mass index(BMI), the drug-taken time, the bone mineral density and the bio-chemical index.ResultThe bone density of patients that take VPA has declined significantly compared with the patients take no drugs (P<0.05), and there are no significant differences between TPM group and the control group. For the bio-chemical index, compared with the control group, the serum phosphorus has declined and the PTH has ascended in the teenage group who take the VPA (P<0.05). But between the group TPM and the control group, there are no significant differences in the numerical values of serum calcium, phosphorus, ALP and PTH. The analysis of two variable correlation indicate that in the patients who take the VPA, the bone mineral density presents a negative correlation with the drug-taken time (r=-0.46, P<0.05), it also presents a positive correlation with serum calcium (r=0.466, P<0.05), but has no correlation with illness time, BMI, serum phosphorus and serum PTH.Conclusion1 Long term of VPA taking leads to a descending of bone mineral density in lumbar vertebra, and results in a disorder of the bone metabolism. A change happens in the hormone and serum bio-chemical index concern with the bone density, which leads to a descending of phosphorus and an ascending of PTH, but the serum calcium is in normal range. Valproic acid may interfere with phosphorus metabolism through a mechanism, promoting bone resorption.The descending of bone mineral density in lumbar vertebra presents a negative correlation with the drug-taken time.2 The patients who take TPM for therapy, the drug has no influence on the bone metabolism. Long term of TPM taking is safe to bone health for children with epilepsy. |
