scholarly journals Non-fasting reference intervals for the Abbott IMxTM homocysteine and AxSYMTM plasma folate assays: influence of the methylenetetrahydrofolate reductase 677 C→T mutation on homocysteine

2000 ◽  
Vol 37 (3) ◽  
pp. 390-398 ◽  
Author(s):  
James G Donnelly ◽  
Phillip A Isotalo
Keyword(s):  
Methylenetetrahydrofolate Reductase ◽  
Mthfr C677t ◽  
Hospital Staff ◽  
Reference Intervals ◽  
Mean Value ◽  
Plasma Homocysteine ◽  
Healthy Individuals ◽  
Plasma Folate ◽  
The Mean ◽  
677T Allele

Plasma homocysteine comes under both genetic and nutritional control. B vitamins and particularly folate are important factors in homocysteine metabolism. We have obtained reference intervals for total plasma homocysteine and plasma folate. We have also determined the influence of methylenetetrahydrofolate reductase (MTHFR) genotype on plasma homocysteine concentrations in healthy individuals. Reference intervals for Abbott IMxTM homocysteine and AxSYMTM plasma folate assays were established using 116 volunteers recruited from hospital staff. Exclusion criteria included cardiac, hepatic or renal disorders, and use of over-the-counter prescription medications. An exception was the inclusion of three women using oral contraceptives and one woman receiving post-menopausal oestrogen supplementation. Methylenetetrahydrofolate reductase 677C-T genotyping was performed on 101 of the volunteers to determine whether the MTHFR 677T allele influences homocysteine concentrations in healthy individuals. Reference intervals for homocysteine and folate were determined using the mean±2 standard deviations of the data. Folate/homocysteine ratios were sorted by MTHFR C677T genotype. Homocysteine correlated negatively with plasma folate. Mean male homocysteine concentrations were significantly higher (9· μmol/L; P<0·05) than the mean value (7·1 μmol/L) obtained for females. Mean homocysteine values were significantly higher in subjects who were homozygous for the MTHFR 677T allele when compared with the 677CC genotype ( P<0·05). Ratios of folate/homocysteine were 20% and 7·44% lower in the male and female 677TT group than in the 677CC group, respectively. The mean homocysteine value of 43 volunteers who were taking multivitamins was not significantly different from that of 73 who were not vitamin supplemented. Conversely, the mean folate value was slightly greater, and statistically significant, in the group taking vitamin supplements. The mean folate values and reference intervals were not significantly different when grouped by sex or age. MTHFR 677C T mutations influenced homocysteine values observed in our study of healthy volunteers, even though we did not observe outright folate-deficient individuals. Our random homocysteine values were similar to the fasting homocysteine values obtained in other studies.

scholarly journals Intra- and interindividual variability of carbohydrate-deficient transferrin, γ-glutamyltransferase, and mean corpuscular volume in teetotalers

1998 ◽  
Vol 44 (10) ◽  
pp. 2120-2125 ◽  
Author(s):  
Anders Helander ◽  
Erling Vabö ◽  
Klas Levin ◽  
Stefan Borg
Keyword(s):  
Mean Corpuscular Volume ◽  
Iron Concentration ◽  
Reference Interval ◽  
Reference Intervals ◽  
Mean Value ◽  
Corpuscular Volume ◽  
Mean Values ◽  
Reference Limit ◽  
Carbohydrate Deficient Transferrin ◽  
The Mean

Abstract Blood samples for determination of the biochemical alcohol markers carbohydrate-deficient transferrin (CDT) in serum, γ-glutamyltransferase (GGT) in serum, and erythrocyte mean corpuscular volume (MCV) were collected once every 1–2 weeks over ∼5 months from 10 female and 4 male teetotalers. Mean values for serum CDT (using the CDTectTM assay) ranged from 9.9 to 29.4 units/L (median, 14.2 units/L), and the highest results were obtained in the women. The mean values for serum GGT ranged from 0.15 to 0.49 μkat/L (median, 0.30 μkat/L, or 18 U/L) except for one woman with a very high mean of 3.07 μkat/L. For MCV, the mean values ranged from 79.5 to 91.5 fL. Two women showed several CDT results above the upper reference limit (mean values, 27.6 and 29.4 units/L, respectively); however, their GGT and MCV values fell within the reference intervals. One of these women exhibited an increased total transferrin concentration (mean value, 5.38 g/L), which was possibly related to the use of oral contraceptives and/or a low serum iron concentration. When the CDTect value was expressed relative to total transferrin, a ratio within the reference interval was observed for this woman but not for the other woman with increased CDTect values. The present study demonstrates a considerable variation between individuals in CDT, GGT, and MCV without drinking any alcohol. The results also show that these baseline values are fairly constant over time within the same individual.

scholarly journals Nutritional advice to increase soluble fibre intake does not change plasma folate or homocysteine in men with angina: a randomised controlled trial

2002 ◽  
Vol 5 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Pauline AL Ashfield-Watt ◽  
Zoë E Clark ◽  
Pat Breay ◽  
Paul C Zotos ◽  
Sara B Cale ◽  
...  
Keyword(s):  
Methylenetetrahydrofolate Reductase ◽  
Randomised Trial ◽  
Intervention Group ◽  
Plasma Homocysteine ◽  
Fruit And Vegetables ◽  
Dietary Advice ◽  
Soluble Fibre ◽  
Fibre Intake ◽  
Plasma Folate

AbstractObjective:To study the effect of advice to increase dietary soluble fibre, including fruit and vegetables, on plasma folate and homocysteine in men with angina.Design:Data were collected on a subset of subjects from the Diet and Angina Randomised Trial (DART II). In a randomised (2 × 2) factorial design, subjects received advice on either, neither or both interventions to: (1) increase soluble fibre intake to 8.0 g day−1(fruit, vegetables and oats); (2) increase oily fish intake to 2 portions week−1. Those who received soluble fibre advice were compared with those who did not. Subjects were genotyped for C677T variant 5,10-methylenetetrahydrofolate reductase (MTHFR).Setting/subjects:Seven hundred and fifty-three male angina patients were recruited from general practice.Results:Plasma homocysteine concentrations were at the upper end of the normal range (median 11.5, 25% 9.4, 75% 14.0 μmol l−1). Baseline intake of fruit and vegetables was positively correlated with plasma folate (rs= 0.29,P< 0.01). Smokers had lower intakes of fruit and vegetables, lower plasma folate and higher homocysteine (allP< 0.01). Homozygotes for variant MTHFR had higher homocysteine concentrations at low plasma folate (P< 0.01). Reported intakes of fruit and vegetables and estimated dietary folate increased in the intervention group (ca.+75 g day−1,P< 0.01 andca.+20 g day−1,P< 0.05, respectively). However, neither plasma folate (baseline/follow-up 4.5 vs. 4.4 μg l−1,P= 0.40) nor homocysteine (baseline/follow-up 11.7 vs. 11.7 μmol l−1,P= 0.31) changed.Conclusions:Plasma homocysteine, a cardiovascular risk factor, is influenced by MTHFR genotype, plasma folate and smoking status. Dietary advice successfully led to changes in fruit and vegetable intake, but not to changes in plasma folate or homocysteine, possibly because the fruits and vegetables that were chosen were not those richest in folate.

Lack of carotid stiffening associated with MTHFR 677TT genotype in cardiorespiratory fit adults

2010 ◽  
Vol 42 (2) ◽  
pp. 259-265 ◽  
Author(s):  
Motoyuki Iemitsu ◽  
Haruka Murakami ◽  
Kiyoshi Sanada ◽  
Kenta Yamamoto ◽  
Hiroshi Kawano ◽  
...  
Keyword(s):  
Arterial Stiffness ◽  
Cardiorespiratory Fitness ◽  
Methylenetetrahydrofolate Reductase ◽  
Homocysteine Level ◽  
Mthfr C677t ◽  
Plasma Homocysteine ◽  
C677t Polymorphism ◽  
Significant Interaction Effect ◽  
Mthfr C677t Polymorphism ◽  
Fitness Level

The TT genotype of C677T polymorphism in 5,10-methylenetetrahydrofolate reductase (MTHFR) induces elevation of homocysteine level and leads to atherosclerosis and arterial stiffening. Furthermore, cardiorespiratory fitness level is also associated with arterial stiffness. In the present study, a cross-sectional investigation of 763 Japanese men and women (18–70 yr old) was performed to clarify the effects of cardiorespiratory fitness on the relationship between arterial stiffness and MTHFR C677T gene polymorphism. Arterial stiffness was assessed by carotid β-stiffness with ultrasonography and tonometry. The study subjects were divided into high-cardiorespiratory fitness (High-Fit) and low-cardiorespiratory fitness (Low-Fit) groups based on the median value of peak oxygen uptake in each sex and decade. The plasma homocysteine level was higher in the TT genotype of MTHFR C677T polymorphism compared with CC and CT genotype individuals. MTHFR C677T polymorphism showed no effect on carotid β-stiffness, but there was a significant interaction effect between fitness and MTHFR C677T polymorphism on carotid β-stiffness ( P = 0.0017). In the Low-Fit subjects, carotid β-stiffness was significantly higher in individuals with the TT genotype than the CC and CT genotypes. However, there were no such differences in High-Fit subjects. In addition, β-stiffness and plasma homocysteine levels were positively correlated in Low-Fit subjects with the TT genotype ( r = 0.71, P < 0.0001), but no such correlations were observed in High-Fit subjects. In CC and CT genotype individuals, there were also no such correlations in either fitness level. These results suggest that the higher cardiorespiratory fitness may attenuate central artery stiffening associated with MTHFR C677T polymorphism.

Phase I Clinical and Pharmacogenetic Trial of Irinotecan and Raltitrexed Administered Every 21 Days to Patients With Cancer

2001 ◽  
Vol 19 (20) ◽  
pp. 4081-4087 ◽  
Author(s):  
James P. Stevenson ◽  
Maryann Redlinger ◽  
Leo A.J. Kluijtmans ◽  
Weijing Sun ◽  
Kenneth Algazy ◽  
...  
Keyword(s):  
Methylenetetrahydrofolate Reductase ◽  
Clinical Investigation ◽  
Performance Status ◽  
Mthfr C677t ◽  
Mthfr Gene ◽  
Plasma Homocysteine ◽  
Gastrointestinal Malignancies ◽  
Patients With Cancer ◽  
Functional Polymorphisms

PURPOSE: Irinotecan and raltitrexed display schedule-dependent synergy in vitro, which supports the clinical investigation of the combination. Functional polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) gene result in intracellular redistribution of folate derivatives, which may affect raltitrexed-associated cytotoxicity.PATIENTS AND METHODS: Patients with a range of solid cancers and good performance status received irinotecan as a 90-minute infusion on day 1 and raltitrexed as a 15-minute infusion on day 2, repeated every 21 days. Samples were collected for MTHFR C677T genotyping and fasting plasma homocysteine during the first cycle.RESULTS: Thirty-nine assessable patients received 127 cycles of therapy. Irinotecan doses ranged from 100 to 350 mg/m2, and raltitrexed, 1.0 to 4.0 mg/m2. Raltitrexed doses of more than 3.0 mg/m2were not tolerated and were associated with dose-limiting asthenia, diarrhea, and AST/ALT elevation. Irinotecan/raltitrexed doses of 350/3.0 mg/m2were well-tolerated; principal toxicities included neutropenia, diarrhea, and fatigue. Two partial responses were observed in patients with pretreated gastroesophageal cancers. Homozygotes with the MTHFR 677 TT polymorphism incurred significantly less raltitrexed-associated toxicity than those with either wild-type or heterozygous genotypes (P = .05). No significant differences were noted in plasma homocysteine values between the genotypic subtypes, and plasma homocysteine levels did not predict the risk of toxicity.CONCLUSION: Irinotecan and raltitrexed doses of 350 and 3.0 mg/m2are recommended for further study on a day 1, 2 schedule every 21 days. Efficacy results suggest that trials in upper and lower gastrointestinal malignancies are warranted. MTHFR C677T genotypes may be predictive of clinical raltitrexed toxicity.

Reference values for fructosamine concentrations in children's sera: influence of protein concentration, age, and sex.

1988 ◽  
Vol 34 (12) ◽  
pp. 2444-2447 ◽  
Author(s):  
J De Schepper ◽  
M P Derde ◽  
P Goubert ◽  
F Gorus
Keyword(s):  
Reference Values ◽  
Protein Concentration ◽  
Reference Intervals ◽  
Mean Value ◽  
Age Dependency ◽  
Serum Total Protein ◽  
Normal Children ◽  
Glycated Protein ◽  
The Mean ◽  
Mean Concentration

Abstract Fructosamine and protein (total and fractionated) were measured in the serum of 170 normal children, ages two weeks to 15 years. The mean fructosamine concentration was 2.12 mmol/L, 5% lower than the mean value observed for adults. We observed no sex-related difference in fructosamine values, but saw a pronounced age dependency of reference values. For children younger than three years, the mean concentration of fructosamine was 15% lower than in adults, but glycated protein concentrations increased with age, reaching essentially adult values by age six years. Expressing fructosamine concentrations per gram of serum total protein or of albumin weakened the influence of age, but did not eliminate it completely. We report reference intervals for fructosamine concentrations in children's sera.

scholarly journals The Allele Frequencies of Three Polymorphisms in Genes Involved in Homocysteine Metabolism in a Group of Unrelated Healthy Singaporeans

2010 ◽  
Vol 29 (2) ◽  
pp. 111-119 ◽  
Author(s):  
Chuanfei Chen ◽  
Yik-Yuen Gan
Keyword(s):  
Genetic Risk ◽  
Total Population ◽  
Methylenetetrahydrofolate Reductase ◽  
Mthfr C677t ◽  
Allele Frequencies ◽  
Methionine Synthase ◽  
Asian Populations ◽  
Insertion Allele ◽  
677T Allele ◽  
Ms A2756g

The cystathionineβ-synthase (CBS) 844ins68 polymorphism, methionine synthase (MS) A2756G SNP, and 5,10-methylenetetrahydrofolate reductase (MTHFR) C677T SNP are associated with homocysteine (Hcy) level in humans. Elevated Hcy level is considered a risk factor for atherosclerotic diseases among Asian populations. Therefore, the three polymorphisms may vary the risk for developing such diseases in Singaporeans. In this study, the three polymorphisms were determined in a group of unrelated healthy Singaporeans (273 Chinese, 127 Indians, and 156 Malays). Regarding allele frequencies, Indians had the highest frequencies of the CBS insertion allele (2.0%) and the MS 2756G allele (26.4%), while Chinese had the highestMTHFR677T allele frequency (27.5%). In addition, theMTHFR677T allele was found significantly lower in Chinese males than in their female counterparts. As the CBS insertion allele was suggested to be associated with lower Hcy level, whereas the MS 2756G allele and theMTHFRT/T genotype were related to higher Hcy level, the MS A/G or G/G genotype and theMTHFRT/T genotype were considered double genetic risk factors for elevated Hcy level. The frequency of such double genetic risk was 0.7% (4 subjects) in the total population consisting of 3 Chinese (1.1%) and 1 Malays (0.6%). NoMTHFRT/T genotype was found in Indians. Such results suggested that Chinese could have higher Hcy levels than Malays while the situation for Indians was complicated. Since human Hcy levels are also affected by environmental factors, further studies are required to better evaluate the association between these three polymorphisms and Hcy levels and/or disease susceptibilities in Singaporeans.

scholarly journals Methylenetetrahydrofolate reductase gene polymorphism and its association with coronary artery disease

2007 ◽  
Vol 125 (1) ◽  
pp. 4-8 ◽  
Author(s):  
Alexandre Rodrigues Guerzoni ◽  
Érika Cristina Pavarino-Bertelli ◽  
Moacir Fernandes de Godoy ◽  
Carla Renata Graça ◽  
Patrícia Matos Biselli ◽  
...  
Keyword(s):  
Risk Factors ◽  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Methylenetetrahydrofolate Reductase ◽  
Mthfr C677t ◽  
Plasma Homocysteine ◽  
C677t Polymorphism ◽  
Specific Patient ◽  
Mthfr C677t Polymorphism ◽  
Artery Disease

CONTEXT AND OBJECTIVE: Obstructive coronary artery disease (CAD) is characterized by the deposition of atherosclerotic plaque on the coronary artery wall. Its manifestations depend on interactions between environmental and genetic risk factors. The aim of this work was to analyze the frequency of methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism in patients with CAD and its association with plasma homocysteine levels. Risk factors for CAD were also evaluated. DESIGN AND SETTING: Retrospective with blind quantitative analysis, at Hospital de Base, Faculdade de Medicina de São José do Rio Preto. METHODS: One hundred and twenty-seven individuals were studied. All completed a questionnaire to analyze risk factors for CAD. MTHFR polymorphism was investigated by restriction fragment length analysis and correlated with the number of affected arteries and degree of arterial obstruction determined by coronary cineangiography, and with plasma homocysteine levels measured by liquid chromatography/sequential mass spectrometry. RESULTS: Smoking (p = 0.02) and high-density lipoprotein cholesterol (p = 0.01) were associated with CAD. The C allele was the most prevalent in patients (0.61) and controls (0.66). There was no correlation between MTHFR/C677T polymorphism and plasma homocysteine levels. However, in patients with the TT genotype there was a correlation with the prevalence of coronary obstruction greater than 95% (p = 0.02) and the presence of two affected arteries (p = 0.04). CONCLUSIONS: The TT genotype is associated with coronary artery obstruction greater than 95% and the presence of two affected arteries. This confirms the relationship between genetic variants in specific patient subgroups and cardiovascular diseases.

scholarly journals HOMA-IR Mean Values in Healthy Individuals: A Population Based Study in Iranian Subjects

2021 ◽  
Author(s):  
Seyed Mohammad Masoodian ◽  
Abolfazl Omidifar ◽  
Sepideh Moradkhani ◽  
Majid Asiabanha ◽  
Majid Khoshmirsafa
Keyword(s):  
Large Population ◽  
Population Based ◽  
Mean Value ◽  
Medical Laboratory ◽  
Healthy Population ◽  
Large Sample Size ◽  
Healthy Individuals ◽  
Population Based Study ◽  
Mean Values ◽  
The Mean

Abstract Aims HOMA-IR considers as the valid index for estimation of insulin sensitivity (IS) and insulin resistance (IR) in different pathological conditions. Few studies have evaluated the relation of IR with a broad group of health related-outcomes in population-based human subjects. In this population-based investigation, we sought to report the mean value of HOMA-IR in different subgroups of a large population-based database in Iranian healthy subjects. Methods This population-based study recruited adult healthy individuals between the ages of 18 to 70 years old who referred to Massoud Medical Laboratory, Tehran, Iran. Fasting insulin was measured by using the Electro chemiluminescence method using Roche Cobas 6000 e601/602 instrument. Results The mean value of HOMA-IR of the entire population was 2.11 ± 0.99. It was observed that the HOMA-IR index tended to be higher in age subgroups of 18–25 (839 individuals), 40–45 (642 individuals) and 35–40 (1179 individuals), HOMA-IR values of 2.17 ± 0.98, 2.19 ± 1.01, and 2.16 ± 1.01 respectively. Conclusion Our findings showed the mean value of 2.11 ± 0.99 HOMA-IR in the Iranian healthy population. Considering the large sample size in our study, more clinical investigations in terms of ethnicity should be done to provide a precise standardized HOMA-IR index in the Iranian population.

scholarly journals Serum Interleukin 4 and 6 Levels Measured Using the ELISA Method in Patients with Acquired Bronchiectasis Compared to Healthy Subjects. An anti-inflammatory and pro-inflammatory relation

2019 ◽  
Vol 70 (7) ◽  
pp. 2410-2414 ◽  
Author(s):  
Andrei Lesan ◽  
Milena Adina Man ◽  
Roxana Maria Nemes ◽  
Tudor Harsovescu ◽  
Ioan Sorin Tudorache ◽  
...  
Keyword(s):  
Serum Levels ◽  
Mean Value ◽  
Point Of View ◽  
Interleukin 4 ◽  
Future Research ◽  
Healthy Individuals ◽  
Elisa Method ◽  
Statistical Point ◽  
Immunodeficiency Disorder ◽  
The Mean

Evaluation of the inflammatory response based on the Interleukin 4 and Interleukin 6 levels in patients with acquired bronchiectasis (non-cystic fibrosis) and healthy controls. The study was conducted on a group of 77 subjects, divided into 2 lots: the first lot consisting of 57 patients with acquired bronchiectasis objectified by Computed Tomography and 20 healthy individuals. The serum Interleukins 4 and 6 levels were measured using the ELISA biochemical spectrophotometry test. The results are significant from a statistical point of view, especially when it comes to the mean value of Interleukin 4 that was much higher in the control lot. Interleukin 4 is a proinflammatory cytokine and therefore we can draw the conclusion that to some extent bronchiectasis can be associated with an immunodeficiency disorder prior to the pathology itself or it can be caused by the pathology. Future research is open in this field for the analysis of interleukin levels in bronchioloalveolar lavage compared to serum levels.

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