Hyperhomocysteinaemia And Vitamin B12 Deficiency In Ischaemic Strokes In India

Abstract

Hyperhomocysteinemia is a recognised risk factor for stroke and ischemic heart disease (HID). Vit B12 Folate and pyridoxine deficiency are important causes of raised serum homocysteine. As a vegetarian diet is very poor in Vit B12 we sought to study the incidence of hyperhomocysteinaemia in our stroke populating and to measure Vit B12 and folate in these cases. Consecutive cases of ischaemic stroke, either arterial or venous, admitted over a period of 2 1/2 years were studied. Embolic strokes and those on vitamin supplements were excluded. cases were divided into vegetarian (including those taking milk and / Or eggs), those who took non-vegetarian 4 or less times a month, and frequent non-vegetarians taking 5 or more times a month. Serum total homocysteine, serum B12 and folate levels were studied along with all other routine parameters. For comparison we examined 101 controls without HID, stroke, peripheral vascular disease, rental failure or recent vitamin intake. With the international norm for homocysteine given as 5-15 umol/litre (1)we called serum homocysteine 16 umol/litre or more as raised. There were 147 cases of ischcmic stroke :119 arterial and 28 venous infarcts. In the arterial strokes 99 of 119 cases (83.19%) had raised serum Homocysteine including 25 of 27 (92.5%) of those with arterial stroke before age 45. Of 28 cases with venous infarct 21 (75%) had raised homocysteine (HCY). Hyperhomocysteinemia was the commonest risk factor for stroke in our populations. Out of the total 147 cases the exact dietary intake was not known for ten cases., 58 were vegetarians, 54 were occasional non vegetarians (NV) and 25 were frequent NV. In the 58 vegetarians, 55 had serum HCY> 16 umol/1 (94.8%) and of those vegetarians with HCY> 16, serum B12 <200pg/ml was seen in 44 (75.8%) and between 200-300 pg/ml in five (8.6%). Of the 54 occasional NV, 46 had HCY>16umo/1 (85.2%) Of those with HCY >16, serum B12 level of <200 pg/ ml was seen in 28 (51.85% occ. NV) and the level was 200-300 pg/ml in 12 patients (22.2%) . Of the 25 frequent NV 11 had increased HCY (44%), none had serum B12 <200 pg/ml and six had serum B12 between 200-300 pg/ml (24%). MCV (means corpuscular volume) was greater than 95fL in 51% of vegetarians, 4606% of occasional non- vegetarians and 6% of frequent NV. Low serum folate (<3 mg/ml) was uncommon and found in3 vegetarians, 3 occasional NV and 2 frequent NV and each time with B12 deficiency. In 101 controls homocysteine was raised in 52 (51.5%) including 86.6% of vegetarians and 17.1% frequent NV. Serum B12 <200 pg/ml was present in39 (38.6%). This included 56.6% of vegetarians and 5.7% of frequent NV. Raised serum homocysteine is common in India and is a major risk factor for strokes and this is mainly due to Vit B12 deficiency. The important predisposing factor is a vegetarians diet. A regular supplement, or fortification of food with vit. B12 (with or without folate) could be a very worthwhile preventive measure in this country.