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1.
Atherosclerosis ; 274: 41-46, 2018 07.
Article in English | MEDLINE | ID: mdl-29751283

ABSTRACT

BACKGROUND AND AIMS: Patients with familial hypercholesterolaemia (FH) have an elevated risk of coronary heart disease (CHD). Here we compare changes in CHD mortality in patients with heterozygous (FH) pre 1992, before lipid-lowering therapy with statins was used routinely, and in the periods 1992-2008 and 2008-2016. METHODS: 1903 Definite (DFH) and 1650 Possible (PFH) patients (51% women) aged 20-79 years, recruited from 21 lipid clinics in the United Kingdom and followed prospectively between 1980 and 2016 for 67,060 person-years. The CHD standardised mortality ratio (SMR) compared to the population in England and Wales was calculated (with 95% Confidence intervals). RESULTS: There were 585 deaths, including 252 from CHD. Overall, the observed 2.4-fold excess coronary mortality for treated DFH post-1991 was significantly higher than the 1.78 excess for PFH (35% 95% CI 3%-76%). In patients with DFH and established coronary disease, there was a significant excess coronary mortality in all time periods, but in men it was reduced from a 4.83-fold excess (2.32-8.89) pre-1992 to 4.66 (3.46-6.14) in 1992-2008 and 2.51 (1.01-5.17) post-2008, while in women the corresponding values were 7.23 (2.65-15.73), 4.42 (2.70-6.82) and 6.34 (2.06-14.81). Primary prevention in men with DFH resulted in a progressive reduction in coronary mortality over the three time-periods, with no excess mortality evident post-2008 (0.89 (0.29-2.08)), although in women the excess persisted (post-2008 3.65 (1.75-6.72)). CONCLUSIONS: The results confirm the benefit of statin treatment in reducing CHD mortality, but suggest that FH patients with pre-existing CHD and women with FH may not be treated adequately.


Subject(s)
Cholesterol/blood , Coronary Disease/mortality , Coronary Disease/prevention & control , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Hyperlipoproteinemia Type II/therapy , Primary Prevention/methods , Biomarkers/blood , Cause of Death , Coronary Disease/blood , Coronary Disease/diagnosis , Follow-Up Studies , Healthcare Disparities , Humans , Hyperlipoproteinemia Type II/blood , Hyperlipoproteinemia Type II/diagnosis , Hyperlipoproteinemia Type II/mortality , Prospective Studies , Protective Factors , Registries , Risk Assessment , Risk Factors , Sex Factors , Time Factors , Treatment Outcome , United Kingdom/epidemiology
2.
Atherosclerosis ; 240(1): 190-6, 2015 May.
Article in English | MEDLINE | ID: mdl-25797312

ABSTRACT

BACKGROUND/OBJECTIVE: Familial Hypercholesterolaemia (FH) is caused by mutations in genes of the Low Density Lipoprotein (LDL) receptor pathway. A definitive diagnosis of FH can be made by the demonstration of a pathogenic mutation. The Wales FH service has developed scoring criteria to guide selection of patients for DNA testing, for those referred to clinics with hypercholesterolaemia. The criteria are based on a modification of the Dutch Lipid Clinic scoring criteria and utilise a combination of lipid values, physical signs, personal and family history of premature cardiovascular disease. They are intended to provide clinical guidance and enable resources to be targeted in a cost effective manner. METHODS: 623 patients who presented to lipid clinics across Wales had DNA testing following application of these criteria. RESULTS: The proportion of patients with a pathogenic mutation ranged from 4% in those scoring 5 or less up to 85% in those scoring 15 or more. LDL-cholesterol was the strongest discriminatory factor. Scores gained from physical signs, family history, coronary heart disease, and triglycerides also showed a gradient in mutation pick-up rate according to the score. CONCLUSION: These criteria provide a useful tool to guide selection of patients for DNA testing when applied by health professionals who have clinical experience of FH.


Subject(s)
Apolipoprotein B-100/genetics , DNA Mutational Analysis , Genetic Testing/methods , Hyperlipidemia, Familial Combined/genetics , Hyperlipoproteinemia Type II/genetics , Mutation , Proprotein Convertases/genetics , Receptors, LDL/genetics , Serine Endopeptidases/genetics , Adult , Aged , Anticholesteremic Agents/therapeutic use , Biomarkers/blood , Cholesterol, LDL/blood , Female , Genetic Markers , Genetic Predisposition to Disease , Humans , Hyperlipidemia, Familial Combined/blood , Hyperlipidemia, Familial Combined/diagnosis , Hyperlipidemia, Familial Combined/drug therapy , Hyperlipidemia, Familial Combined/epidemiology , Hyperlipoproteinemia Type II/blood , Hyperlipoproteinemia Type II/diagnosis , Hyperlipoproteinemia Type II/drug therapy , Hyperlipoproteinemia Type II/epidemiology , Male , Middle Aged , Patient Selection , Pedigree , Phenotype , Predictive Value of Tests , Proprotein Convertase 9 , Risk Assessment , Risk Factors , Triglycerides/blood , Wales/epidemiology
3.
Health Educ Res ; 27(5): 767-79, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22907531

ABSTRACT

Family harmony, an important Confucian ideal in Chinese society is believed to determine family happiness and therefore health, but is this accurate? This is a qualitative study of 41 Hong Kong Chinese family members. Individual recorded interviews were thematically analysed describing perceived interactions between harmony, happiness and health. Family harmony comprised four components: communication, mutual respect, lack of conflict and family time [notably 'Gou tong' (in Cantonese )-opportunity and willingness to spend time together-requiring good interpersonal communication, emphasized by female respondents]. Lack of conflict was emphasized, while diverse values, parenting styles and financial difficulties were common causes of conflict. Respect required reciprocity. Family happiness comprised four elements: family harmony, an important pre-requisite; mutual caring and supportive orientation; sense of security emphasizing financial security in middle-class versus sense of togetherness in lower social class groups and contentment. Healthy families were harmonious; 'typical' (children/two-parent/two-grandparent); happy; caring and respectful, with individual health and healthy behaviours. Family harmony, happiness and health are interrelated and built on a communicative, respectful, caring and contented set of attitudes, in particular allowing for family time. Harmony is apparently a core element of good family functioning.


Subject(s)
Asian People/psychology , Family Health/ethnology , Family Relations , Happiness , Personal Satisfaction , Adolescent , Adult , Aged , Child , Female , Hong Kong , Humans , Male , Middle Aged , Qualitative Research , Young Adult
4.
Atherosclerosis ; 211(2): 618-23, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20356595

ABSTRACT

OBJECTIVE: To examine all-cause and cardiovascular mortality in patients with severe hypertriglyceridaemia. METHODS: 337 patients aged less than 80 years (47 with diabetes, 75 women) with a fasting triglyceride concentration on at least two occasions of >5.0mmol/l were registered by 21 lipid clinics in the United Kingdom and followed prospectively between 1980 and 2008 for 4353 person-years. The standardised mortality ratio (SMR) was calculated by comparison with the general population. RESULTS: The mean untreated total cholesterol concentration was 9.8 (SD 3.6)mmol/l for men and 11.9 (7.2)mmol/l for women and the corresponding geometric mean triglyceride concentration was 12.6 (inter-quartile range 7.3, 21.6) and 15.7 (8.2, 29.2)mmol/l. There were 70 deaths, including 35 from CHD and 7 from stroke. The SMR for CHD was raised at 327 (95% confidence intervals 228, 455; p<0.0001) and remained elevated after excluding patients with diabetes at registration (SMR=287, 95% CI 190, 419; p<0.0001), and after excluding patients with CHD at registration (SMR=259, 95% CI 158, 400; p=0.0003). The increased SMR was most marked in younger men aged 40-59 years (SMR=544, 95% CI 304, 897; p<0.0001). The SMR for stroke for patients aged 20-79 years was raised at 262 (95% CI 105, 540; p=0.04), as was all-cause mortality at 164 (95% CI 129, 208; p<0.001). CONCLUSION: Severe hypertriglyceridaemia is associated with a substantially increased mortality from cardiovascular disease, even in the absence of diabetes. In addition to lowering triglyceride concentrations to reduce the risk of pancreatitis, treatment should aim to reduce the overall cardiovascular risk.


Subject(s)
Cardiovascular Diseases/mortality , Hypertriglyceridemia/blood , Adult , Cardiovascular Diseases/epidemiology , Cohort Studies , Coronary Disease/blood , Female , Follow-Up Studies , Humans , Male , Middle Aged , Myocardial Infarction/pathology , Prospective Studies , Registries , Risk , Triglycerides/metabolism
5.
Int J STD AIDS ; 20(5): 346-50, 2009 May.
Article in English | MEDLINE | ID: mdl-19386973

ABSTRACT

Cambodia has one of the highest prevalence rates of HIV in Asia and is scaling up HIV testing. We conducted a cross-sectional survey with 358 health care providers in Phnom Penh, Cambodia to assess readiness for voluntary testing and counselling for HIV. We measured HIV knowledge and attitudes, and predictors of intentions to take a sexual history using the Theory of Planned Behaviour. Over 90% of health care providers correctly answered knowledge questions about HIV transmission, but their attitudes were often not positive towards people living with HIV. The Theory of Planned Behaviour constructs explained 56% of the variance in intention to take a sexual history: the control providers perceive they have over taking a sexual history was the strongest contributor (51%), while social pressure explained a further 3%. Attitudes about taking a sexual history did not contribute to intention. Interventions with Cambodian health care providers should focus on improving skills in sexual history-taking.


Subject(s)
Attitude of Health Personnel , Clinical Competence , HIV Infections/epidemiology , HIV Infections/prevention & control , Health Personnel/education , Safe Sex , Adult , Cambodia/epidemiology , Cross-Sectional Studies , Female , Health Personnel/standards , Humans , Male , Middle Aged , Surveys and Questionnaires
6.
Diabetes Obes Metab ; 10(4): 271-8, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18333887

ABSTRACT

LDL has been widely recognized as the major atherogenic lipoprotein and designated as the primary target for prevention of coronary heart disease (CHD); however, there is growing evidence that other triglyceride-rich lipoproteins, such as very low-density lipoprotein (VLDL) and intermediate density lipoprotein (IDL) carry atherogenic potential as well. This led to the designation of non-HDL cholesterol (HDL-C) (LDL + IDL + VLDL) as a secondary target of treatment for hyperlipidaemia. As each one of LDL, IDL and VLDL particles carries only one apolipoprotein B-100 (ApoB-100) molecule, the total ApoB value represents the total number of potentially atherogenic lipoproteins, whereas non-HDL-C provides the cholesterol content of these same lipoproteins. Recent data from epidemiological, observational and interventional studies suggest that non-HDL-C, apolipoproteins ApoA1 and ApoB may improve CHD risk assessment by identifying more high-risk individuals than the usual lipid profile alone. However, the targets for the optimal treatment of dyslipidaemia remain a subject of considerable debate. Further studies are needed to determine whether ApoB and ApoA1 are superior to conventional lipid parameters as predictors of cardiovascular disease or therapeutic targets of hyperlipidaemias. In this review, we summarize the current opinions on the use of ApoA1 and ApoB values as estimates of cardiovascular risk or as treatment goals in patients undergoing treatment for hyperlipidaemia.


Subject(s)
Apolipoprotein A-I/blood , Apolipoproteins B/blood , Cardiovascular Diseases/blood , Biomarkers/blood , Cholesterol/blood , Humans , Lipids/blood , Predictive Value of Tests , Risk Assessment/methods , Triglycerides/blood
7.
Eur J Clin Invest ; 36(12): 850-9, 2006 Dec.
Article in English | MEDLINE | ID: mdl-17087779

ABSTRACT

BACKGROUND: While folic acid (FA) reduces plasma homocysteine (Hcy), whether the simultaneous improvement in endothelial function is dependent on Hcy lowering per se is questionable. In the present study the relationship between FA dose, Hcy lowering and endothelial function in patients with coronary artery disease (CAD) was investigated. MATERIALS AND METHODS: Eighty-four patients with CAD received either 400 microg FA or 5 mg placebo daily for a 6-week treatment period. A further 44 patients with CAD received either 100 mg kg(-1) day(-1) of betaine or placebo for a 6-week treatment period. Flow-mediated dilatation (FMD), a measure of endothelial function, was assessed before and after the 6-week periods. Isometric tension and Western blotting were used to investigate the effect of FA on endothelial function and endothelial nitric oxide synthase (eNOS) dimerization in isolated rabbit aortic rings and cultured porcine aortic endothelial cells (PAEC), respectively. RESULTS: Both 400 micro g day(-1) and 5 mg day(-1) FA significantly increased plasma folate and decreased plasma Hcy. The FMD improved significantly after 6 weeks' treatment of 5 mg day(-1) FA but did not correlate with the reduction in Hcy. There was no change in FMD in either the 400 micro g FA or placebo group. In a subgroup analysis of 11 patients in the betaine group, despite a reduced Hcy, a significant impairment in FMD was observed. In the in vitro studies FA, but not betaine, reversed methionine-induced endothelial dysfunction. Moreover, the FA promoted eNOS dimerization in cultured PAEC. CONCLUSIONS: These data suggest that FA dose-dependently improves endothelial function in CAD via a mechanism independently of Hcy lowering. It may involve promotion of eNOS dimerization.


Subject(s)
Betaine/therapeutic use , Cardiotonic Agents/therapeutic use , Coronary Artery Disease/drug therapy , Endothelium, Vascular/drug effects , Folic Acid/administration & dosage , Hematinics/administration & dosage , Aged , Betaine/blood , Dose-Response Relationship, Drug , Double-Blind Method , Endothelium, Vascular/metabolism , Female , Folic Acid/blood , Hematinics/blood , Humans , Male , Middle Aged
8.
Ann Clin Biochem ; 42(Pt 5): 346-50, 2005 Sep.
Article in English | MEDLINE | ID: mdl-16168189

ABSTRACT

The effective use of cardiac-specific troponin estimations in the diagnosis of acute myocardial infarction (AMI) is clouded by the imprecise definition surrounding the decision limits. This has led to a wide variation of criteria for the diagnosis of myocardial infarction. A survey of troponin measurements in Welsh laboratories, undertaken in 2003 under the auspices of the All Wales Clinical Biochemistry Audit Group, revealed significant variations in laboratory and clinical practice. Extensive discussion and consultation led by a working group of clinical biochemists and cardiologists in Wales culminated in recommendations concerning the use of troponin assays to establish myocardial damage. The key recommendations are: Cardiac troponin (T or I) should be the first-line test for myocardial damage; Two samples should be collected, at admission and 12-24 h later. The first sample is used for 'rule in' purposes, but not to 'rule out' myocardial damage; Only one threshold (cut-off) value for troponin should be quoted on laboratory reports, values above which are indicative of myocardial damage. A study by the Wales External Quality Assurance Scheme (WEQAS) enabled the derivation of the recommended cut-off concentrations of troponin for defining myocardial damage, defined for each assay as the concentration that can be reliably distinguished, with a confidence interval of 99%, from the 99th percentile reference limit. These recommended standards provide a rationale for a uniform approach for troponin assays for patients with chest pain, working towards a standardized approach to the diagnosis and management of patients presenting with acute coronary syndromes.


Subject(s)
Biomarkers , Myocardial Infarction/physiopathology , Humans , Myocardial Infarction/pathology , Quality Control , Reproducibility of Results , Sensitivity and Specificity
9.
Ann Clin Biochem ; 42(Pt 5): 351-6, 2005 Sep.
Article in English | MEDLINE | ID: mdl-16168190

ABSTRACT

An audit of troponin measurement protocols in use in Wales showed significant variations in practice with no consensus on analytical methods, or in the selection of a decision limit for the diagnosis of myocardial damage. Peer review data on assay imprecision at concentrations approaching the analytical limit of detection are lacking. The objective of the study was to establish clinically relevant precision profiles for the troponin methods used throughout Wales, which could be used to develop a standardized approach to the selection of a decision limit. A series of five pools of human serum spiked with troponin I-T complex were prepared and stored at -70 degrees C until dispatch. Five sets of each pool were dispatched to all Welsh laboratories and stored at -20 degrees C until analysis. The analysis protocol consisted of two replicates of each pool per batch, and two batches per day for five days (n=20). All the laboratories performed all the measurements in the same week. The lowest concentration providing a 10% coefficient of variation (CV) was 0.02 microg/L for the Roche method and 0.11 microg/L for the Beckman AccuTnI. The lowest concentrations that could be distinguishable from the 99th percentile reference limit were 0.02 microg/L for the Roche method and 0.07 microg/L for the Beckman AccuTnI. Current methods do not achieve the 10% CV at the 99th percentile reference limit proposed by the European Society of Cardiology. Use of the lowest concentration that can be reliably distinguished from the 99th percentile reference limit offers a novel alternative decision limit, which provides a slightly lower concentration than at the 10% CV but maintaining confidence in the assay that false-positive rates will be minimized.


Subject(s)
Chemistry, Clinical/methods , Laboratories/standards , Troponin/blood , Chemistry, Clinical/standards , Humans , Reproducibility of Results , Sensitivity and Specificity , Wales
10.
Cochrane Database Syst Rev ; (3): CD004655, 2005 Jul 20.
Article in English | MEDLINE | ID: mdl-16034940

ABSTRACT

BACKGROUND: Vitamin B12 deficiency is common and rises with age. Most people with vitamin B12 deficiency are treated in primary care with intramuscular vitamin B12 which is a considerable source of work for health care professionals. Several case control and case series studies have reported equal efficacy of oral administration of vitamin B12 but it is rarely prescribed in this form, other than in Sweden and Canada. Doctors may not be prescribing oral formulations because they are unaware of this option or have concerns regarding effectiveness. OBJECTIVES: To assess the effectiveness of oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency. SEARCH STRATEGY: Searches were undertaken of The Cochrane Library, MEDLINE, EMBASE and Lilacs in early 2005. The bibliographies of all relevant papers identified using this strategy were searched. In addition we contacted authors of relevant identified studies and Vitamin B12 research and pharmaceutical companies to enquire about other published or unpublished studies and ongoing trials. SELECTION CRITERIA: Randomised controlled trials (RCTs) examining the use of oral or intramuscular vitamin B12 to treat vitamin B12 deficiency. DATA COLLECTION AND ANALYSIS: All abstracts or titles identified by the electronic searches were independently scrutinised by two reviewers. When a difference between reviewers arose, we obtained and reviewed a hard copy of the papers and made decisions by consensus. We obtained a copy of all pre-selected papers and two researchers independently extracted the data from these studies using piloted data extraction forms. The whole group checked whether inclusion and exclusion criteria were met, and disagreement was decided by consensus. The methodological quality of the included studies was independently assessed by two researchers and disagreements were brought back to the whole group and resolved by consensus. MAIN RESULTS: Two RCT's comparing oral with intramuscular administration of vitamin B12 met our inclusion criteria. The trials recruited a total of 108 participants and followed up 93 of these from 90 days to four months. High oral doses of B12 (1000 mcg and 2000 mcg) were as effective as intramuscular administration in achieving haematological and neurological responses. AUTHORS' CONCLUSIONS: The evidence derived from these limited studies suggests that 2000 mcg doses of oral vitamin B12 daily and 1000 mcg doses initially daily and thereafter weekly and then monthly may be as effective as intramuscular administration in obtaining short term haematological and neurological responses in vitamin B12 deficient patients.


Subject(s)
Vitamin B 12 Deficiency/drug therapy , Vitamin B 12/administration & dosage , Vitamin B Complex/administration & dosage , Administration, Oral , Aged , Humans , Injections, Intramuscular , Randomized Controlled Trials as Topic
12.
J Clin Pathol ; 57(5): 548-50, 2004 May.
Article in English | MEDLINE | ID: mdl-15113868

ABSTRACT

BACKGROUND: Induction of anaesthesia can precipitate catecholamine release from an undiscovered pheochromocytoma and induce a hypertensive crisis. However, it is assumed that catecholamine and metabolite values resulting from the effects of surgery per se in the early postoperative period would overlap with the values generated by a tumour, and it is not known how soon after biochemical investigations can be carried out. AIM: To study patterns of urinary catecholamine excretion and the feasibility of biochemical screening for phaeochromocytomas in the immediate postoperative period in otherwise healthy subjects undergoing a single type of major surgical procedure. METHODS: Catecholamines and metabolites were measured for each mole of creatinine in single voided urine on one preoperative and four postoperative days in five subjects who underwent elective coronary artery bypass graft surgery with an uncomplicated postoperative course. Reference ranges were established from 33 healthy normotensive volunteers. RESULTS: Excretion of adrenaline, noradrenaline, dopamine, vanillylmandelic acid, and metadrenaline was within normal limits. Normetadrenaline excretion was mildly raised in four patients, but did not exceed 1.5 times the upper reference limit, and returned to normality by the fourth postoperative day. CONCLUSION: It is feasible to perform simple urinary screening for possible phaeochromocytoma in the immediate postoperative period.


Subject(s)
Adrenal Gland Neoplasms/diagnosis , Catecholamines/urine , Pheochromocytoma/diagnosis , Adult , Aged , Biomarkers/urine , Coronary Artery Bypass , Feasibility Studies , Female , Humans , Male , Middle Aged , Postoperative Period , Reference Values
13.
Aging Ment Health ; 7(4): 259-70, 2003 Jul.
Article in English | MEDLINE | ID: mdl-12888437

ABSTRACT

The detection of mild cognitive impairment and dementia in high-functioning older adults can be difficult. It has also been observed that high-functioning persons show a lower prevalence of dementia than low-functioning persons. Three alternative explanations for this observation have been proposed in the literature: brain reserve capacity (BRC), cognitive reserve, and ascertainment bias. With data from a prospective, population-based study of incident dementia, the Canadian Study of Health and Aging (CSHA), we classified participants as being high- (HF) or low-functioning (LF) in three ways: educational and occupational attainment, and estimated premorbid IQ. We observed that fewer HF older adults were diagnosed with dementia after five years, which is in accordance with both the BRC and cognitive reserve models. Contrary to expectations, no difference on rate of memory deterioration was observed between those HF and LF persons who exhibited mild cognitive impairment at CSHA-1. However, HF persons who subsequently were diagnosed with dementia (CSHA-2) showed more rapid decline on five of the six memory measures over time than did LF persons diagnosed with dementia at CSHA-2. When performance on measures of memory functioning at CSHA-1 was examined for highly educated older adults, significantly more of those with dementia at CSHA-2 (n = 59) had scores falling within or below the average range in comparison to normative standards than those who continued to show no cognitive impairment (n = 145). Our findings suggest that the lower incidence of dementia for HF persons may be primarily the result of ascertainment bias, not underlying differences in brain or cognitive reserve.


Subject(s)
Activities of Daily Living/psychology , Cognition Disorders/physiopathology , Observer Variation , Aged , Aged, 80 and over , Canada , Female , Humans , Intelligence , Male , Neuropsychological Tests , Prospective Studies , Psychometrics
14.
Eur J Clin Nutr ; 57(3): 483-9, 2003 Mar.
Article in English | MEDLINE | ID: mdl-12627187

ABSTRACT

BACKGROUND: Various mechanisms have been proposed to explain the association between plasma total homocysteine (tHcy) and risk of cardiovascular disease, including oxidative activity of homocysteine. OBJECTIVE: To explore the putative role of reactive oxygen species in the association between plasma tHcy and risk of cardiovascular disease in healthy individuals. DESIGN: A double-blind, placebo-controlled crossover intervention to increase folate intake through diet (increased consumption of folate-rich foods) and supplement (400 micro g folic acid) was carried out in 126 healthy men and women. Measurements were made of antioxidant activity in red blood cells and plasma, and products of oxidant damage in plasma. RESULTS: Diet and supplement-based interventions led to an increase in measures of folate status and a reduction in plasma tHcy. This was not associated with any significant change in measures of antioxidant activity (plasma and red blood cell glutathione peroxidase activity and red blood cell superoxide dismutase activity) or oxidant damage (plasma malondialdehyde), although an improvement in plasma total antioxidant capacity just failed to reach significance. CONCLUSIONS: In healthy individuals lowering plasma tHcy does not have any functional implications regarding oxidative damage.


Subject(s)
Antioxidants/metabolism , Cardiovascular Diseases/blood , Folic Acid/administration & dosage , Homocysteine/blood , Adult , Aged , Cardiovascular Diseases/epidemiology , Cardiovascular Diseases/metabolism , Cross-Over Studies , Dietary Supplements , Double-Blind Method , Female , Folic Acid/blood , Folic Acid/metabolism , Glutathione Peroxidase/metabolism , Homocysteine/metabolism , Humans , Male , Malondialdehyde/metabolism , Middle Aged , Nutritional Status , Oxidation-Reduction , Reactive Oxygen Species , Risk Factors , Single-Blind Method , Superoxide Dismutase/metabolism
15.
Eur J Clin Nutr ; 57(2): 316-23, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12571666

ABSTRACT

OBJECTIVE: To assess and compare the effects of natural folate (100 micro g) with those of folic acid from fortified sources (100 micro g/day) on plasma folate and homocysteine. DESIGN: Randomized controlled trial (parallel groups). SETTING: Men and women living in South Wales, UK. SUBJECTS: A total of 135 healthy individuals recruited from the local workforce and blood donor sessions. All subjects possessed the 'wild-type' CC genotype for C677T polymorphism in methylenetetrahydrofolate reductase (MTHFR). INTERVENTIONS: Subjects underwent one of the following dietary interventions for 4 months: (1) fortified diet-usual diet plus 100 microg/day folic acid from fortified foods; (2) natural folate diet-usual diet plus 100 microg/day folate from natural sources; (3) control-usual diet. RESULTS: The fortified group increased reported intake of folic acid from fortified foods compared to other groups (P<0.001) achieving an extra 98 microg/day (95% CI 88-108). The natural folate group increased reported intake of natural source folates compared with the other two groups (P<0.001), but achieved a mean increase of only 50 microg/day (95% CI 34-66). Plasma folate increased (P<0.01) by a similar amount in both intervention groups compared to controls (fortified group 2.97, 95% CI 0.8-5.1; natural group 2.76, 95% CI 0.6-4.9. Plasma homocysteine, vitamins B(6) and B(12) were not significantly changed. CONCLUSIONS: Subjects achieved increases in folate intake using fortified foods more easily than by folate-rich foods, however both sources increased plasma folate by a similar amount. These levels of intake were insufficient to reduce homocysteine concentrations in MTHFR CC homozygotes, but may be more effective in other genotypes.


Subject(s)
Folic Acid/blood , Folic Acid/pharmacology , Food, Fortified , Fruit , Homocysteine/blood , Nutrition Policy , Vegetables , Adolescent , Adult , Aged , Diet Records , Female , Humans , Male , Middle Aged , Reference Values , United Kingdom
16.
J Inherit Metab Dis ; 25(2): 107-18, 2002 May.
Article in English | MEDLINE | ID: mdl-12118525

ABSTRACT

OBJECTIVES: We sought to investigate the effects of short- and long-term vitamin C therapy on endothelial dysfunction in patients with homocystinuria. BACKGROUND: Untreated homocystinuria due to cystathionine beta-synthase deficiency is associated with premature atherothrombotic disease; 25% of untreated patients suffer a vascular event by the age of 16 years and 50% by 29 years. Treatment directed at reducing homocysteine accumulation significantly reduces this risk. However, despite 'optimal' treatment and compliance, hyperhomocysteinaemia usually persists and individuals exhibit endothelial dysfunction indicative of an adverse cardiovascular prognosis. Additional intervention is therefore required to further reduce cardiovascular risk. METHODS: We investigated the endothelial effects of acute (2 g single dose) and chronic (1 g/day for 6 months) administration of oral vitamin C in 5 patients with homocystinuria (mean age 26 years, 1 male) and 5 age- and sex-matched controls. Brachial artery endothelium-dependent flow-mediated dilatation (FMD) and endothelium-independent responses to nitroglycerin (NTG) were measured using high-resolution ultrasonic vessel wall-tracking. RESULTS: Baseline: Plasma total homocysteine was 100.8 +/- 61.6 and 9.2 +/- 1.9 micromol/L in the patient and control groups, respectively (p < 0.001). FMD responses were impaired in the patient group (20 +/- 40 microm) compared with the controls (116 +/- 30 microm) (p < 0.001). Vitamin C administration: FMD responses in the patient group improved both acutely, 160 +/- 65 microm at 4 h (p < 0.001), and chronically, 170 +/- 70 microm at 2 weeks (p < 0.001) and 170 +/- 40 microm at 6 months (p < 0.001). FMD responses in the control group were unaltered (p = 0.526). Within both groups, neither the vascular response to NTG nor plasma homocysteine was altered (p > 0.4). CONCLUSIONS: Vitamin C ameliorates endothelial dysfunction in patients with homocystinuria, independent of changes in homocysteine concentration and should therefore be considered as an additional adjunct to therapy to reduce the potential long-term risk of atherothrombotic disease.


Subject(s)
Ascorbic Acid/therapeutic use , Endothelium, Vascular/physiopathology , Homocystinuria/drug therapy , Homocystinuria/physiopathology , Adult , Ascorbic Acid/administration & dosage , Blood Flow Velocity , Blood Pressure , Brachial Artery , Endothelium, Vascular/drug effects , Female , Heart Rate , Homocystine/blood , Humans , Male , Methionine/blood , Nitric Oxide/physiology , Nitroglycerin/pharmacology , Tetrahydrofolates/blood , Vasodilation
18.
J Am Coll Cardiol ; 38(7): 1799-805, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11738277

ABSTRACT

OBJECTIVES: We sought to study the effect of low-dose folic acid supplementation or optimization of dietary folate intake on plasma homocysteine and endothelial function in healthy adults. BACKGROUND: Elevated homocysteine is associated with cardiovascular disease, but it is not known whether this relationship is causal. Individuals homozygous (TT) for the C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene ( approximately 12% of the population) have increased homocysteine levels, particularly in association with suboptimal folate intake. METHODS: Healthy subjects (n = 126; 42 of each MTHFR genotype) were included in this cross-over study of three interventions of four months each: 1) placebo plus natural diet; 2) daily 400-microg folic acid supplement plus natural diet; and 3) increased dietary folate intake to 400 microg/day. RESULTS: At baseline, homocysteine was inversely related to plasma folate and was higher in TT homozygotes. For the whole group, plasma folate increased by 46% after dietary folate and by 79% after supplementation, with reductions of homocysteine of 14% and 16%, respectively. Within the genotype, TT homozygotes exhibited the most marked changes in these variables. Brachial artery endothelial function, as determined by a change in end-diastolic diameter in response to increased flow, was not changed by increased folate intake (98 +/- 73 microm at baseline, 110 +/- 69 microm after a high-folate diet, 114 +/- 59 microm after supplementation and 118 +/- 68 microm after placebo). Plasma von Willebrand factor antigen was unaltered. CONCLUSIONS: Optimization of dietary folate or low-dose folic acid supplementation reduces plasma homocysteine but does not enhance endothelial function, irrespective of the MTHFR (C667T) genotype.


Subject(s)
Endothelium, Vascular/drug effects , Folic Acid/administration & dosage , Genotype , Homocysteine/blood , Oxidoreductases Acting on CH-NH Group Donors/genetics , Adolescent , Adult , Aged , Dose-Response Relationship, Drug , Double-Blind Method , Female , Folic Acid/blood , Homozygote , Humans , Male , Methylenetetrahydrofolate Reductase (NADPH2) , Middle Aged , Nutritional Requirements , Reference Values , Vascular Resistance/genetics , Vascular Resistance/physiology
19.
Biomed Pharmacother ; 55(8): 425-33, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11686575

ABSTRACT

Elevated plasma homocysteine concentrations are associated with an increased risk of cardiovascular disease, but the relationship has not been proven to be causal. Folate is the strongest nutritional and pharmacological determinant of plasma homocysteine concentrations, which also interact with the genetic variation in methylenetetrahydrofolate reductase (MTHFR). Endothelial dysfunction due to reduced nitric oxide bioavailability is an early feature of vascular pathology. This can be assessed noninvasively by measurement of flow-mediated dilatation. Human studies on folic acid, homocysteine and endothelial function are reported. It is proposed that folic acid in high doses may have beneficial effects on endothelial function, which are independent of homocysteine lowering.


Subject(s)
Cardiovascular Diseases/etiology , Endothelium, Vascular/physiopathology , Folic Acid/physiology , Homocysteine/physiology , Cardiovascular Diseases/genetics , Clinical Trials as Topic , Folic Acid/blood , Homocysteine/adverse effects , Homocysteine/blood , Homocystinuria/etiology , Homocystinuria/therapy , Humans , Hyperhomocysteinemia/complications , Methylenetetrahydrofolate Reductase (NADPH2) , Nitric Oxide/metabolism , Oxidoreductases Acting on CH-NH Group Donors/genetics , Oxidoreductases Acting on CH-NH Group Donors/metabolism , Vitamins/therapeutic use
20.
Neurology ; 57(4): 714-6, 2001 Aug 28.
Article in English | MEDLINE | ID: mdl-11524488

ABSTRACT

Little is known about progression, short of dementia, in vascular cognitive impairment. In the Canadian Study of Health and Aging, 149 participants (79.3 +/- 6.7 years; 61% women) were found to have vascular cognitive impairment, no dementia (CIND). After 5 years, 77 participants (52%) had died and 58 (46%) had developed dementia. Women were at greater risk of dementia (OR 2.1, 1.0 to 4.5). Of 32 participants alive without dementia, cognition had deteriorated in seven and improved in four. Half of those with vascular CIND developed dementia within 5 years, suggesting a target for preventive interventions.


Subject(s)
Cerebrovascular Disorders/diagnosis , Cognition Disorders/diagnosis , Dementia, Vascular/diagnosis , Aged , Aged, 80 and over , Cerebrovascular Disorders/psychology , Cognition Disorders/psychology , Cohort Studies , Confidence Intervals , Dementia, Vascular/psychology , Disease Progression , Female , Humans , Logistic Models , Male , Neuropsychological Tests , Odds Ratio
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