HOMOCYSTEINE AND RISK OF DEGENERATIVE DISEASES

1. PRESENTED BY:
Kavita Kachhawa

2. Homocysteine
• Homocysteine, a endogenous sulfur containing non proteinous
amino acid that occupies a central location in the metabolic
pathways of thiol compounds.
• Homocysteine (Hcy), an intermediate formed during the
catabolism of the essential dietary amino acid methionine
(Castro et al 2006)

3. • Multiple forms of homocysteine circulate in blood
• Because of the many forms of homocysteine, tHcy was often
termed “Homocyst(e)ine” to account for these multiple forms.
• Storage of plasma or serum causes redistribution of these forms
with an increase in the protein-bound fraction
• Plasma Hcy is a good marker of Hcy level in body rather than
tHcy.
Klee et al 2000
Protein linked Hcy
(65%)
Oxidized Hcy
(~30% )
Free reduced form
(~1.5–4% )

4. Production of Homocysteine
It is a key branch-point intermediate in the ubiquitous methionine cycle, the function
of which is to generate one-carbon methyl groups for transmethylation reactions that
are essential for several biological processes.
HOMOCYSTEINE
S-adenosyl
homocysteine (SAH)
S- Adenosyl
Methionine (SAM)
Methionine

5. Examples of transmethylation reactions:
Groups Transmethyaltion reactions
DNA DNA-cytosine / gene expression
regulation, inactivation, imprinting
RNA mRNA-guanine / capping of mRNA
tRNA-cytosine, -guanine, -adenine /
alteration of tRNA flexibilty
Proteins carboxyl groups L-isoaspartate (D-aspartate) in protein
repair
Proteins amino acid residues lysine in histones
arginine, e.g. in basic myelin protein
Lipids Phosphatidylethanolamine / synthesis
of phosphatidylcholine
N-methyltransferases Guanidinoacetic acid / creatine
synthesis
O-methyltransferases Catechols e.g norepinephrine,
epinephrine, dopamine / inactivation

6. Homocystine Metabolism
In body, Homocysteine is removed by two pathways
or
There are two separate remethylation reactions, catalyzed by
• homocysteine methyltransferase
• Methionine synthase
Transsulfuration pathway
(irreversible conversion of Hcy to cysteine )
Remethylation pathway
(reversible conversion of Hcy to methionine)
Ramon 2000

7. Homocysteine is an amino acid that can be deadly if it is not properly
metabolized.
Gullium 2004

8. Blood levels of Hcy
Sex Age Hcy level
(µmol / litre)
Therapeutic target Elevated
Male 12–19
years
3.3 7.2 < 6.3 μmol/L
> 10.4 μmol/L
>60 years 4.9- 11.6
Female 12–19
years
4.3-9.9 < 6.3 μmol/L
> 11.4 μmol/L
>60 years 5.9-15.3
The Doctor's Doctor: Homocysteine

9. Homocysteine Analysis
• Hcy diagnostic methods are classified as (Gates 2000)
1. Chromatography
GC-MS
HPLC
IEC
2. Electrophoretic Methods
Capillary electrophoresis (CZE)
gel electrophoresis (SDS-PAGE)
3. Immunochemical-Based Assays
ELISA
4. Spectrochemical Techniques
Indirect methods
1.Plasma Hcy measurement
2.Folic acid measurement
3.Hydroxycobalamin measurement
4.Plasma Hcy measurement after
methionine load
Direct methods

10. Factors affecting Hcy level
Plasma Hcy levels are maintained by a complex interaction of
acquired and genetic factors. These includes
Genetic factors
Nutritional status
Age and Sex
Drugs
 Life style factors
Pregnancy

11. GENETIC FACTORS
• Still 135 genes were identified in human body that either modulate the
levels of Hcy or modulated by elevated levels of Hcy
• These genes are mainly invoved in regulation of lipid and methionine
metabolism, transport of lipid, apoptosis and cell signaling
• Defects in these Genes, primarily due to single nucleotide
polymorphism (SNP) leads to elevate the levels of Hcy.
• Harmful effects of increased Hcy is its ability to modulate the
expression of certain genes that may either directly or indirectly lead to
several pathological conditions
Sharma et al 2006

12. Homocystinuria
• Genetic defect of cystathionine synthetase which occurs in
approximately 1 in 200000 live births and is associated with fasting
plasma Hcy concentrations of up to 200 μmol/L.
• Unable to synthesise cysteine from methionine
• Urinary excretion of Hcy, leads to significant loss of cysteine from body
• Clinical manifestations include
Mental retardation Thromboembolism
Seizures Premature atherosclerosis
Skeletal deformities Ectopia

13. Treatment
• ~ 50% of patients respond to supplements
Vitamin B6 50 – 200 mg /day should be given.
• For others, dietary control,
Minimal methionine to meet requirements and
Supplements of cysteine
Dwivedi et al 2011

14. Polymorphism in MTHFR genes
• Homozygous deficiency of MTHFR is rare and results in severe
hyperhomocysteinemia and early death
• This polymorphism is common, and the prevalence of homozygotes is
5% to 10%
• A much more common mutation in the MTHFR gene is a C-to-T
transition at codon 677 that substitutes a valine for an alanine
• Patients homozygous for the C677T mutation have slight elevations in
Hcy levels and are at increased risk for premature vascular disease
• Patients with the V/V MTHFR genotype have higher folate requirements
than individuals with a normal genotype. Botto 2000

15. Nutrition and
Homocystine

16. Hcy and B-vitamin connection
Cysteine –β-
synthtase
• pyridoxal
phosphate
(B6)
methionine
synthase
• Cobalamine
(B12)
• Folic acid(B9)
methyl group
donation
• Betaine
Conversion of Hcy
into cysteine
amino acid
Conversion of Hcy into methionine amino
acid
Brosnan et al 2004

17. Vitamin B2
• The cosubstrate for methionine synthase, 5-methyltetrahydrofolate, is
regenerated via the folate cycle and the MTHFR enzyme, which requires
FAD as a prosthetic group
• In addition, riboflavin in another active form (FMN) is required for the
generation of pyridoxal phosphate, which serves as a cofactor of
cystathionine b-synthase and other enzymes of the trans-sulfuration
pathway

18. Particulars Requirement (mg/day)
Male 1.4-1.9
Female 1.1-1.5
Pregnency +0.2
RDA (ICMR 2010)

19. Vitamin B6
• Dietary vitamin B6 ratio of 0.02-mg/g protein has been reported to
ensure normal biochemical status with regard to most parameters
• Vitamin B6 deficiency is an increase in Hcy plasma concentration and
is associated to an increment in cardiovascular diseases (Tottes et al
2001）

20. Particular Requirement (mg/day)
Male 2.0
Female 2.0
Pregnancy 2.5
RDA (ICMR 2010)

21. Vitamin B12
• Vitamin B 12 deficiency is rare due to dietary deficiency (except in
Vegetarians )
• If deficiency occur it may be most commonly due to failure of
absorption which is an increasing problem with aging
Achlorhydria – failure to secrete gastric acid and intrinsic factor
(required for vitamin B12 release from proteins and absorption) due
to Loss of gastric parietal cells or gastric atrophy

22. Particular Requirement
(µg/day)
Male 1.0
Female 1.0
Pregnanacy 1.2
RDA (ICMR 2010)

23. Folic Acid
• Plasma homocysteine can be reliably lowered 25 to 30 percent with a
daily dose of at least 500 μg of folic acid in combination with vitamin
B 12 and pyridoxine (Seshadri and Robinson 2000)
• Increase intake of folate to at least 400 μg per day to prevent chronic
disease, particularly cancer and CVD

24. RDA (ICMR 2010)
Particulars Requirement
(µg/day)
Male 200
Female 200
Pregnancy 500

25. Patients with
Subjects
(n =
Dose
[Folate
Treatment]
Results
[Folate
treatment
significantly]
Unstable Angina
Angioplasty of a
bypassed vessel
with a patent graft
Disease of the left
main artery
Myocardial
infarction
Renal dysfunction
Folic acid (1 mg)
Pyridoxine (10 mg)
Vitamin B 12
(400 μg)
Lowered plasma
Hcy (11.1 to 7.2
μmol per liter)
Increased minimal
luminal diameter
(1.72 vs. 1.45 mm)
Reduces degree of
stenosis
(39.9% vs. 48.2%)
Lowered restenosis
(19.6 % vs. 37.6 %)
Schnyder et al
2001

26. Subjects
20
hypercholesterolemic
adults taking
Lovastatin® + 20
control
Doses
folate supplement
(5 mg) for 8 weeks
Results
The folate-
supplemented group
experienced
decreased blood
levels of
homocysteine
Shidfar 2009

27. Subject
36 stable renal transplant
recipients with
hyperhomocysteinemia
Results
homocysteine
significantly decreased in
the B-vitamin treatment
group compared with
baseline (12.6 vs. 20.1
µmol/l)
Vasodilatation responses
were significantly
improved in the
treatment group
compared to controls.
5 mg folic acid, 50 mg
vitamin B6
1,000 mg vitamin B12
Doses
Xu et al (2008)

28. SUBJECTS
5522 patients
(55 years of age or
older) who had
vascular disease or
diabetes
DOSE
2.5 mg of folic acid
50 mg of vitamin B6
1 mg of vitamin B12
or with placebo for an average of five
years.
RESULTS
Mean plasma homocysteine levels decreased by 2.4 micromol per
liter (0.3 mg per liter) in the active-treatment group and increased
by 0.8 micromol per liter (0.1 mg per liter) in the placebo group.
Supplements combining folic acid and vitamins B6 and B12 did
not reduce the risk of major cardiovascular events in patients with
vascular disease
Lonn et al 2006

29. Betaine [Tri methyl glycine (TMG) ]
• TMG is considered a "methylation enhancing compound“ which helps
Hcy convert to methionine (Lv 2009)
• Betaine is used as therapy to lower plasma Hcy in hyperhomocysteinemic
patients with genetic defects in their Hcy metabolism who are
unresponsive to pyridoxine, folic acid, and vitamin B12 (Wilcken et al
1983)
• Betaine occurs naturally in the diet, or it can be produced endogenously
through oxidation of choline (Smolin et al 1981)

30. • Dietary intake of betaine is estimated at 0.5–2 g/d generally, and major
food sources are wheat products (e.g. bread), beets, and spinach
• Choline, the precursor of betaine, also occurs naturally in foods, mainly
as phosphatidylcholine. Daily intake of choline is generally estimated to
be 0.3–1 g
Subjects Doses Results

31. Methionine
All Hcy in the body is biosynthesized from methionine of diet
• Rich sources : meats, seafood, dairy products, and eggs
• Fair sources: Vegetables, sesame seeds and Brazil nuts
• Poor sources : proteinrich legumes as beans, peas, and lentils contain
relatively small amounts of methionine

32. FATS
• Marine lipids, rich in omega-3 polyunsaturated fatty acids (PUFAs),
reveals that omega-3 rich fish oil supplementation can reduce elevated
Hcy levels
• Other Ω-3 fatty acid rich food sources : Milk and meat products, fats and
oils and nuts and oilseeds
Subjects
81 patients with type
2 diabetes
Doses
three capsules of
omega-3 fatty acids
(3g) or a placebo
every day for a period
of 2 months
Results
Hcy levels in the
treatment group
declined as much as
3.10 µmol/L
Glycolsylated Hb
(HbA1C) a measure
of long-term sugar
levels in the blood)
decreased in the
treatment group and
increased in the
control group
Pooya 2010

33. Taurine
• Taurine promoted cysteine synthesis in body
• Amino acid taurine can block methionine absorption from the diet,
thereby reducing available substrate for homocysteine synthesis
• Taurine can normalized hyperhomocysteinemia and reduced
atherosclerosis by 64% over control animals and reduced endothelial
cell apoptosis by 30% due to a favorable effect on plasma total
homocysteine and apoptosis (Zulli 2009)

34. Subjects
22 healthy middle-
aged women
(33 to 54 years)
Doses
Taurine
supplementation
(3g per day for 4
weeks)
Results
Plasma Hcy levels
exhibited a
significant decline,
from 8.5 µmol/L to
7.6 µmol/L
Sufficient taurine
supplementation
might effectively
prevent CVD
(Ahn 2009)

35. • Daily doses of 250 mg of vitamin B6, 5 mg of folic acid, and 6 gm of
betaine by themselves or in combination normalized the majority of
high homocysteine levels in patients administered high doses of
methionine (Boers 1994)
• Supplementation of folic acid at least 800 μg or more per day of to
achieve a meaningful decrease in homocysteine (Wald 2001)
• 120 mg of vitamin B6 had similar homocysteine-lowering effects as 300
μg of folic acid (17% vs 20%, 32% when combined) in apparently
healthy subjects (Mansoor et al 1999)

36. AGE and SEX
• Old age is closely associated with elevated Hcy levels (Jacques et al 1999)
• Homocysteine levels are relatively stable through the first 4 decades of
life and then rise sharply, particularly after age 70 (Nygard et al 1995,
Selhub et al 1993)
• Prior to puberty, both sexes enjoy optimally healthy levels (about 6
µmol/L)
• During puberty, levels rise, more in males than females (Must 2003,
Jacques 1999), reaching, on average, almost 10 µmol/L in men and more
than 8 µmol/L in women (Ganji 2006)
• Male sex is associated with higher Hcy levels at all ages except in the very
old age

37. DRUGS
• Some antiepileptic drugs (phenobarbitol, valproate, phenytoin etc)
• Diuretic therapy
• Methotrexate
• Nitrous oxide
• Cholestyramine
• Fibric acid derivatives (fenofibrate)
• Estrogen-containing oral contraceptives
• Metformin
• Theophylline
• Sulfasalazine Carmel and Jecobson (2001)
Increases Hcy in
blood

38. Life style factors
• smoking cigarettes is linked with elevated levels of Hcy (Bazzano et al
2003)
• High coffee consumption (>4 cups/day) linked with moderate elevations
in Hcy , although this effect can apparently be countered by
supplementing with 200 μg/day of folic acid (Verhoef et al 2002)
• Moderate alcohol consumption may raise Hcy levels (Bleich etal 2001)
Moderate beer consumption may actually lower Hcy levels ( Mennen et
al 2003)
• Sedentary life style enhances the blood Hcy levels

39. PREGNANCY
• Total serum Hcy was found to be significantly decreased in the first
trimester of pregnancy, became maximal in the second trimester (about
50% compared with non-pregnant women) where after the concentration
remained stable throughout the remainder of pregnancy.
• A return to normal concentrations was seen within 2—4 days post
partum. Possible reasons for the decrease of serum Hcy in pregnancy
could be
1. Haemodilution 2. Increased remethylation of homocysteine
3. Increased secreation of female sex hormones i.e oestrogens &
progestogens.
Andersson et al 1992

40. Kidney diseases
• Only free (unbound) Hcy is filtered and metabolized by the normal
kidney. Conversion of bound Hcy to free Hcy for removal may be to
stimulated by normal kidneys (Guilliams et al 2004)
• In kidney disease, Hcy levels in the blood increase because the kidneys
do not properly filter Hcy
• Elevated levels of Hcy are commonly seen in renal patients, sometimes
three or four times higher than normal levels (Suliman et al. 2001)
• Hcy is consistently elevated to very high levels in patients who require
dialysis . Plasma Hcy concentrations often decrease after dialysis (Levin
et al. 2002)

42. Hyperhomocysteinemia
• Individuals with vitamin B deficiencies or congenital metabolic defects
are often incapable of maintain normal Hcy levels.
• Consequently, intracellular Hcy levels rapidly increase until the cell is
forced to excrete Hcy into the bloodstream Resulting in elevated serum
Hcy levels
Increased levels of homocysteine are classified as
Moderate levels 15-30 µ moles/liter
Intermediate levels 30 to 100 µ moles/liter
high levels ≥ 100 µ moles/liter

43. Homocysteine and Risk of Degenerative
Disease

44. CARDIOVASCULAR DISEASES
• Hcy act as independent biomarkar of CVD can also promote various
causative factors of CVD
• High Hcy in normal persons (age 29-89) 24.4% Hcy and in
atherosclerosis cases 70.9% blood Hcy was found (Rahman et al 2006)
• Every 5-µM increase in tHcy plasma levels followed by increased risk of
coronary heart disease of 60% for men and 80% for women (Boushey et
al 1995)
• Hyperhomocysteinemia is believed to directly affect cardiovascular
proteins. Excess Hcy may alter the biochemical properties of arterial
surfaces, thereby inducing lesions and the onset of atherosclerosis
(McCully 1969)

45. Hcy is an independent risk factor of CVD
1. Procoagulant
Inhibits or downregulates anticoagulants
Activates procoagulants
 Prostacyclin synthesis
Activation of protein C
Thrombomodulin expression
 Heparan sulphate expression
Fibrinolysis
Factor V
Tissue clotting factor

46. 2. Desquamation of endothelium and impairs regeneration
Hcy induce the expression and secretion of chemokines in vascular
endothelial cells (such as (MCP1) and interlukin 8 (IL-8)
Attract monocytes and neutrophils to sites of vascular injury
Transform into macrophages, engulf oxidized LDL, and become foam cells
Foam cells are a source of reactive oxygen species which can play a role in
other sequences of events that promote atherosclerosis
( Hajjar 1998, Poddar 2001).

47. 3. proliferation of vascular smooth muscle
4. Increases platelet coagulability
5. Connective tissue abnormalities
impaired cross-linking of collagen and elastin
6. Homocysteine chelates copper and inhibits lysyl oxidase
• In the presence of Hcy, fibroblasts produce excessively sulphated
proteoglycans
• Product is granular rather than fibrillar excessively sulphated
proteoglycans attract and bind ε-amino groups of lysine in lipoproteins

48. Subjects
100 Iranian patients
with CAD and 100
normal controls
Total plasma Hcy
with using
homocysteine
measuring kit by Elisa
method.
Results
1. Plasma Hcy was
significantly raised in
Iranian CAD cases
compared to the
normal control (15.56
versus 11.51, p<0.05).
2. An increase in
plasma Hcy can be
considered a major
risk factor for CAD in
selected Iranian
population.
Ghaedi et al 2007

49. Design (Meta analysis study)
(a) 72 studies in which the
prevalence of a
mutation in the MTHFR gene (n=16
849)
(b) 20 prospective studies (
n=3820) of serum homocysteine
and disease risk.
Results
1. lowering Hcy concentrations by 3
µmol/l from current levels
(achievable by increasing folic acid
intake) would reduce the
risk of ischaemic heart disease by
16% (11% to 20%),
deep vein thrombosis by 25% (8% to
38%) and
stroke by 24%
2. Odds ratios of the three
diseases (ischaemic heart
disease, deep vein thrombosis and
stroke) for a 5 ìmol/l increase in
serum Hcy
Wald 2002

50. Subjects
2,127 men and 2,639 women
for over 4 years
Material and methodology
The population was divided into quintiles
based on initial plasma tHcy (5.1–-8.9, 9.0–
11.9, 12.0–14.9, 15.0–19.9, >20 μmol/L) and
followed for survival
Results
 After adjusting other CVD risk factors , a 5 μmol/L increase in tHcy
increased all-cause mortality by 49%, cardiovascular mortality 50%, cancer
mortality 26%, and non-cancer, non-cardiovascular mortality 104%.
Relative risk surpasses 1 when tHcy is 6.5 μmol/L, and continues to
increase in a near linear fashion until plasma levels reach 20 μmol/L or more.
Vollset et al 2000

51. Hypoxia
• Hyperhomocysteinemia has also been reported to be associated albeit
indirectly with hypoxic conditions.
• Eleveted Hcy increases expression of Cap43 [that codes for a 43 kDa
protein associated with hypoxia in endothelial cells EC)] in cells treated
with homocysteine.
• Hypoxia in alveoli leads to
damage of capillary wall,
decrease in the MAT1A transcription
decrease mRNA stability in cultured hepatocytes
Avila et al1998

52. Hypertension
• Elevated tHcy is an independent risk factor for primary hypertension as
well as primary pulmonary hypertension (Rodrigo et al 2003)
• Hypertensive patients typically have higher homocysteine than
normotensive patients
• Each 5 μmol/L increase in plasma Hcy was associated with an increase
in systolic and diastolic blood pressure of 0.7/0.5 mmHg in men and
1.2/0.7 mmHg in women, which was independent of renal function and
B vitamin status but also of other factors (Lim and Cassano, 2002)

53. NO is endothelium-derived relaxation factor)
Which leads to Loss of vasodilatation action of •NO and generation of
superoxide
Hcy + •NO S-nitrosohomocysteine Hcy+ NO3 •O2
Mechanisms (Stehouwer et al 2005)
Hcy-induced arteriolar constriction
Renal dysfunction
Increased arterial stiffness.

54. Hyperhomocysteinamia
Activity of
antioxidant
enzymes
Oxidative stresss
Endothelial
dysfunction
Bioavailability
of No•
Elastin and
collagen activity
Elastin collagen
ratio
Hypertension
Rodrigo et al2003

55. 100 hypertensive patients
Interview
Pre and post BP measured by sphygmomanometer.
Serum samples analyzed for Hcy by FPIA
 80 out of the 100 subjects had elevated homocysteine level
SBP (150.25 mmHg)
DBP (104.75 mmHg)
Homocysteine (18.77µmol/l)

56. • 78 patients with EH,
• 100 patients with CAD
•100 healthy subjects
serum folate, B12 and Hcy on MTHFR
C677T genotype (CC,TT and CT) of
subjects by PCR
 The TT genotype of the MTHFR polymorphism is associated with EH
and CAD
 TT genotypes had higher plasma Hcy levels in CAD patients
compared with CC and CT genotypes
 MTHFR gene polymorphism is an independent risk factor for EH but
not for CAD
Ilhan et al 2008

57. DASH Diet
• Dietary Approaches to Stop Hypertension (DASH) diet, recommended
to hypertensive patients, is beneficial for lowering blood pressure as
well as homocysteine
• This diet is high in fruit and vegetable consumption and recommends
low dairy and meat fat intake
(Craddick et al 2003)

58. Diabetes
• For each 5 μmol/L increase in serum tHcy, the risk of 5-year mortality
rose by 17% in non-diabetics and 60% in diabetic subjects (Hoogeveen
et al 2000)

59. NEUROGENERATIVE DISEASES
• Hcy as a potential biomarker in age-related neurodegenerative
diseases.
• In deficiency of B vitamin Hcy act as neurotoxic medulloblastoma cells
of the brain (Parsons 1998). Hcy and its metabolite homocysteic acid
are potent agonists forN-methyl-D-aspartate receptors and are
neurotoxic to neurons at concentrations that are likely reached in the
central nervous system after breakdown of the blood-brain barrier.
• Oxidation products of homocysteine are excitatory sulfur amino acids
and may act as excitatory neurotransmitters (Kumar et al 1994)

60. Epilapsy
• A high dose of homocysteine (usually 50-200 μmol/L) produce
convulsive seizures (epilapsy
• 20% of patients with homozygous CBS deficiency have seizures
Subjects
Doses
Results

61. Parkinson's disease
Subjects
Doses
Results

62. Alzheimer Disease (AD)
• S-adenosyl homocysteine (SAH) is a better marker of AD development
than homocysteine
• Elevated SAH concentrations antagonistically reduce the SAM-
dependent methylation capacity, impairing cell functions, increase DNA
damage and prerturb Myelin synthesis in brain
• With higher plasma Hcy, Alzheimer patients also have higher levels of
asymmetric dimethylarginine and decreased concentrations of nitric
oxide, two risk factors for cardiovascular disease related to the oxidative
affects of homocysteine and perhaps emerging risk factors for dementia
(Salley et al 2003)

63. Subjects
1092
subjects
without
dementia
(667 women
and 425
men; mean
age, 76
years)for 8
years
Method includes
Annual neurological
and
neuropsychological
assessment
Results
During follow-up period,
dementia developed in
111 subjects, including
83 given a diagnosis of
Alzheimer’s disease.
With a plasma Hcy level
greater than 14 μmol per
liter, the risk of
Alzheimer’s
disease nearly doubled
An increased plasma
homocysteine
level is a strong,
independent risk factor
for the development
of dementia and
Alzheimer’s disease
Sheshadri et al
2002

64. Subjects
92 Alzheimer disease
(AD) patients
WMHs (by MRI)
Neuropsychological tests including cognitive ability screening
instrument, mini-mental state examination
Followup period
6 months
Hcy levels did not differ
between AD patients and
controls, and Hcy levels did
not correlate with cognitive
scores
Plasma Hcy levels were
associated with rapid
cognitive decline as abstract
thinking
Higher WMH in the trigone
area on brain magnetic
resonance
imaging (MRI).
Tu et al (2010)

65. OSTEOPOROSIS
Subjects
Doses
Results

66. PREGNANCY RELATED COMPLICATIONS
• In hyperhomocysieinemia, ovarian follicular fluid contains detectable
amounts of Hcy along with B12, B6, and folate.
• Follicular fluid provides nourishment to the oocyte by facilitating
transport from plasma
• The ovum may be exposed to high Hcy or low methionine
concentrations or both, as well as a lack of vitamins.
• The vitamins fed to the ovum through this route, as well as the
balance of homocysteine to methionine, may be important to
fertilization and early embryogenesis.
Steegers et al 1993

67. • Increased tHcy has been associated with
Abruptio
placenta
Preeclamsia
Or
Gestational
hypertension
Stillbirth
and
miscarriage
intrauterine
growth
restriction

68. METHODS OF STUDY SELECTION:
Serum Hcy analysis before and after
onset of preeclampsia
Meta-analytic techniques were used
Hcy could lead
preeclampsia
• Hcy levels are slightly increased in normotensive pregnancies that
later develop preeclampsia (weighted mean difference 3.36 μmol/L
versus 0.68 μmol/L)
•The mechanisms underlying hyperhomocysteinemia (folate and
vitamin B12 deficiency and genetic polymorphisms) were not found to
be plausible
•There was no dose-response relationship between homocysteine
concentration and severity of preeclampsia.
•Oxidative stress and endothelial dysfunction were higher in
hyperhomocysteinemia.
Mignini et al 2005

69. 2119 Pregnant women
After 20 weeks of gestation period,
blood sample analysis of tHcy and serum folate levels.
Detailed pregnancy information questionnaire and medical record review
103 (4.9% ) pregnancy loss, 115 (5.7% ) gestational hypertension, 65 (3.2%) preeclampsia and
129 (6.4%) small-for-gestational age cases were reported
Increased risk of pregnancy loss or preeclampsia was reported in subjects with high tHcy but
increased tHcy concentration was not associated with increased risk of developing GH or
having an SGA infant
High tHcy in early pregnancy as a risk factor for pregnancy loss and preeclampsia is consistent
with a hypothesis that increased tHcy results in abnormalities of the placental vasculature.
Subjects
Materials and Methodology
Results
Conclusion
Dodds et
al2008

70. CONCLUSION
Hcy is a
natural
product of
metabolism
Elevation in
Hcy leads to
risk of
diseases
Prevention
is better
than cure
healthy life
style and
balanced
diet

72. THANKS