STUDY OF METHYLENE TETRAHYDROFOLATE REDUCTASE VARIANTS IN THE ELDERLY IN RELATION TO PLASMA HOMOCYSTEINE AND SERUM FOLATE

Abstract

Cardiovascular disease is the leading cause of mortality around the world. Over the past few years, homocysteine has taken its place among other major risk factors such as cholesterol, smoking , obesity, hypertention and diabetes .

Now, it is widely accepted that increased total plasma homocysteine is an independent risk factor for cardiovascular disease.

Human plasma contains both reduced and oxidized species of homocysteine. The oxidized forms usually comprise 98-99% of total plasma homocysteine in human plasma.

The determinants of total plasma homocysteine are complex and involve genetic and acquired factors. Genetic factors include impaired enzyme function as a result of genetic mutation which may involve the enzyme responsible for the remethylation of homocysteine to methionine which is MTHFR enzyme. Acquired factors include nutrition, age, gender and life style.

Dietary insufficency or malabsorption of folate, vitamin 812 or vitamin 86 will lead to hyperhomocysteinemia and an increased risk of CVD. Mildly increased homocysteine causes dysfunction of the vascular endothelium. Homocysteine appears to alter the anticoagulant properties of endothelial cells to a procoagulant phenotype.

It was shown that folic acid and vit-812 supplementation are very effective to reduce total homocysteine concentration.

The aim of this study is to evaluate homocysteine in healthy elderly people and in those with coronary heart disease in a trial to explain whether homocysteinemia whenever present is due to the presence of MTHFR variants or due to folate and vitamin 812 deficiency and to assess the impact ofhomocysteinemia in the clinical status.

Seventy five male subjects were included in the study and they were divided as follows :

Group 1: Control group: 25 young apparently healthy volunteers, their age ranging from 35-50 years. Group II: 50 old subjects, their age ranging from 60-75 years and they were further subdivided into: Group II a which comprises 25 healthy old subjects without CHD . Group II b which comprises 25 patients with CHD.

For all the studied subjects the following was done:

+ Thorough history taking and full clinical examination were done and a battery of investigations were done including, + Electrocardiogram. + Laboratory investigations included complete urine analysis.