Correlation between homocysteine and Vitamin B12 levels: A post-hoc analysis from North-West India

Sunil Kumar Raina; Jagjit Singh Chahal; Navjot Kaur

doi:10.4103/2278-344X.154915

SHORT COMMUNICATION

Year : 2015 | Volume : 4 | Issue : 2 | Page : 115-118

Correlation between homocysteine and Vitamin B12 levels: A post-hoc analysis from North-West India

Sunil Kumar Raina¹, Jagjit Singh Chahal², Navjot Kaur³
¹ Department of Community Medicine, Dr. RP Government Medical College, Tanda, Himachal Pradesh, India
² Department of Biochemistry, Dr. RP Government Medical College, Tanda, Himachal Pradesh, India
³ Department of Pathology, Dr. RP Government Medical College, Tanda, Himachal Pradesh, India

Date of Web Publication

10-Apr-2015

Correspondence Address:
Sunil Kumar Raina
Department of Community Medicine, Dr. RP Government Medical College, Tanda, Himachal Pradesh
India

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/2278-344X.154915

Abstract

Background: Homocysteine has been shown to be a risk factor for cardiovascular disease and is a degradation product of sulfur containing amino acids. The aim of this post-hoc analysis was aimed at arriving at homocysteine levels among voluntarily consenting healthy adults in the context of other hematological parameters. Methods: The data for this post-hoc analysis were derived from an observational study carried out at a medical college in rural North-west India. Results: About 77.42% of those participants enrolled in this study having serum homocysteine level more than 30 μmol/L were seen to possess suboptimal serum Vitamin B ₁₂ (<200 pg/ml). On subjecting data to regression analysis, serum homocysteine was observed to possess an inverse correlation with serum level of Vitamin B _12, in general. Conclusions: Hyperhomocysteinemia observed in our study was sufficiently common and wholly ascribable to low Vitamin B ₁₂ concentration as we did not find any case of subnormal serum folic acid level.

Keywords: Correlation, homocysteine, Vitamin B12

How to cite this article:
Raina SK, Chahal JS, Kaur N. Correlation between homocysteine and Vitamin B12 levels: A post-hoc analysis from North-West India. Int J Health Allied Sci 2015;4:115-8

How to cite this URL:
Raina SK, Chahal JS, Kaur N. Correlation between homocysteine and Vitamin B12 levels: A post-hoc analysis from North-West India. Int J Health Allied Sci [serial online] 2015 [cited 2023 Oct 1];4:115-8. Available from: https://www.ijhas.in/text.asp?2015/4/2/115/154915

Introduction

Homocysteine has been shown to be a risk factor for cardiovascular disease and is a degradation product of sulfur containing amino acids. ^[1],[2] It gets converted into an essential amino acid methionine after undergoing "methylation" in the presence of Vitamin B ₁₂ . This is the step in its metabolism, where Vitamin B ₁₂ and folic acid are intricately involved. ^[3] Elevated serum homocysteine has also been implicated in the vascular changes compatible with atherosclerosis and endothelial dysfunction similar to the vascular changes of the placenta in preeclampsia. Homocysteine levels are too elevated significantly in patients with preeclampsia in the absence of Vitamin B ₁₂ deficiency. ^[4]

Most of the analytical systems measure total homocysteine content after pretreatment with a reductant. Storage of whole blood at room temperature causes significant increases in the concentration of total homocysteine in serum of plasma.

The aim of this post-hoc analysis was aimed at arriving at homocysteine levels among voluntarily consenting healthy adults in the context of other hematological parameters.

Methods

The data for this post-hoc analysis were derived from an observational study carried out at a medical college in rural North-West India. A brief description of the original study is presented here.

A total of 153 study units voluntarily willing students and employees were picked by stratified random sampling method from the sampling frame that comprised of all students and employees of the medical college. The participants were subjected to general physical examination after having been interviewed using a structured questionnaire. Anthropometric measurements were taken on 1 ^st day of contact only. Height was measured to the nearest 1.0 cm, without shoes, with feet together, in Frankfurt's plane with measuring tape. ^[5] Weight was measured in light indoor clothes barefooted on adult weighing machine. Body mass index was calculated as weight in kilogram divided by height in meter square.

Blood sample was collected by following standardized procedure for the collection of blood sample, when the enrolled subject (with empty stomach after overnight fasting) came to the Department of Biochemistry next day after having got their clinical variables recorded the previous day.

Inclusion criteria

Any voluntarily consenting adult subject (both male and female) aged from 18 to 62 years, student or employee of the medical college.

Exclusion criteria

Subject's refusal
Subjects who were taking methylcobalamin or Vitamin B ₁₂ or folic acid or iron, folic acid or have taken the same for more than 15 days during last 3 months
Subjects who had received Vitamin B ₁₂ or iron formulations as injectables during last 1-year
Subjects on medication for hypertension or diabetes or on lipid-lowering drugs
Those with chronic illness like tuberculosis, cancer or immunocompromised subjects
Pregnant or lactating mothers
Anyone who had either donated or received blood in last 3 months.

Results

A total of 153 subjects comprising 69 employees (group I) along with 84 students (group II) of the medical college were analyzed in this post-hoc study. Hyperhomocysteinemia (serum Hcy (t) >12 μmol/L), is found prevalent to the tune of 73.9% among participants of study population, and 20.3% of participants had serum homocysteine level even more than 30 μmol/L. Proportion of females with severe hyperhomocysteinemia (who had serum Hcy (t) more than 30 μmol/L) is less than that of males (17.9% vs. 22.61%) [Table 1]. An analysis [Table 2] of intergroup distribution of hematological and hematopoietic variables along with their deficiency markers among participants of study population reveals the relation between homocysteine levels, Vitamin B12 levels, and folic acid levels.

Table 1: Tertile distribution of serum total homocysteine (n=153)

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Table 2: Intergroup distribution of hematological and hematopoietic variables along with their deficiency markers among participants of study population (n=153)

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About 77.42% of those participants enrolled in this study having serum homocysteine level more than 30 μmol/L were seen to possess suboptimal serum Vitamin B ₁₂ (<200 pg/ml). On subjecting data to regression analysis, serum homocysteine was observed to possess an inverse correlation with serum level of Vitamin B _12, in general. This inverse correlation (P = 0.005, r² = 0.052) between serum level of Vitamin B ₁₂ and serum level of homocysteine was statistically significant. We also found even stronger inverse correlation (P = 0.001, r² = 0.187) between serum Vitamin B ₁₂ and methylmalonic acid [Figure 1].

Figure 1: Correlation between homocysteine and Vitamin B12

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Discussion

Vitamin B ₁₂ and folic acid, essential cofactors in homocysteine metabolism are known determinants of serum Hcy (t) concentrations. Deficiency of either Vitamin B ₁₂ or folic acid can cause elevated levels of Hcy (t). ^[6],[7] Determination of total homocysteine in serum has now become an important diagnostic procedure in clinical chemistry on account of accumulating evidence that a slightly increased concentration of Hcy (t) is a significant independent risk factor for atherosclerotic diseases. We found hyperhomocysteinemia (>12 μmol/L) prevalent to the tune of 73.9% among enrolled subjects and it was very much in agreement with similar high prevalence of 76% as reported by Refsum et al. from South India. ^[8] However, our finding of hyperhomocysteinemia was much higher than that reported by Pandey et al. who reported its prevalence to be 24.2% in their study population comprising exclusively of females. ^[7]

We had a particular finding to take note of; an inverse association existed between serum level of Vitamin B ₁₂ and homocysteine. This correlation was more pronounced when participants had suboptimal vitamin B ₁₂ because 77.42% of those subjects who had serum Hcy (t) more than 30 μmol/L, were having suboptimal serum Vitamin B ₁₂ (<200 pg/ml) in our study. Results from our study confirmed the observed associations between Hcy (t), Vitamin B _12, and folic acid concentrations in a large population-based studies from India and abroad. ^[7],[16]

The occurrence of hyperhomocysteinemia has been very much discussed in recent literature, and we noted the mean level of serum total homocysteine in the instant study (21.53 ± 12.20 μmol/L) to be among the higher levels recorded in India. This observation of higher Hcy (t) was comparable to the highest reported level of homocysteine from India by Misra et al. who found a level of 23.2 ± 8.4 μmol/L among subjects in slums. ^[14] Reports of hyperhomocysteinemia were also released by many workers during the same period from different parts of the world as well as from country. ^{[11],[12],[15]} Gheye et al. compared the prevalence of hyperhomocysteinemia between original Bangladeshis migrated to United Kingdom and Caucasians and found it to higher among South Asians migrated to England. ^[11] Misra et al. mentioned poor economic condition of their subjects residing in slums as a coincidental factor, but this was contrasted by Chambers et al. as they enrolled a significant proportion of cases and controls from "nonmanual" class as was the case of our study, therefore hyperhomocysteinemia was not correlated to economic class of enrolled subjects. ^[12],[14] Deepa et al. did not observe a significant difference between serum levels of Hcy (t) between cases and controls recruited for their study. ^[15] A difference in findings from different studies has been summarized in [Table 3].

Table 3: Inter - ethnic data of serum or plasma levels of Hcy (t)

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Conclusion

Hyperhomocysteinemia observed in our study was sufficiently common and wholly ascribable to low Vitamin B ₁₂ concentration as we did not find any case of subnormal serum folic acid level.

References

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