Magnesium deficiency enhances oxidative stress which contributes to early development of cataract formation, and also the progression in type 2 diabetes mellitus patients remains unclear. The present study was designed to evaluate the serum levels of magnesium, oxidative stress marker and antioxidant status and to find out if there is any association between them in the pathogenesis of diabetic cataract compared with non-diabetic senile cataract, diabetes without cataract and normal healthy subjects. This comparative study includes 90 type 2 diabetes mellitus patients with cataract, 90 non-diabetic senile cataract patients, 90 type 2 diabetes mellitus without cataract and 90 normal healthy individual subjects without cataract in the age group between 40 and 75 years of both genders. Serum magnesium was estimated by using a fully automated analyser. Serum malondialdehyde (MDA), an indicator of oxidative stress biomarker, was determined by spectrophotometry, and the antioxidant status such as serum reduced glutathione (GSH) and glutathione peroxidase-3(GPX-3) levels was estimated by ELISA method. The present study shows significantly decreased levels of magnesium, GSH, GPX-3 and increased level of MDA in type 2 diabetes mellitus patients with cataract when compared with non-diabetic senile cataract patients, type 2 DM without cataract and normal healthy individuals. A significant negative correlation of serum magnesium with MDA and positive correlation with GPX-3 were observed. The present findings indicate that hypomagnesaemia is a significant pathogenic factor which causes increased oxidative stress which may trigger earlier cataractogenesis in patients with type 2 diabetes mellitus.
Keywords: Cataract; Hypomagnesaemia; Oxidative stress; Type 2 diabetes mellitus.