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Biomedical subjects

P C Adams

Publications and source records attributed to P C Adams.

At least 37 records · Page 2Linked to original sources

Attaining United States and European guideline LDL-cholesterol levels with simvastatin in patients with coronary heart disease (the GOALLS study).

The effectiveness and safety of simvastatin in reducing low-density lipoprotein cholesterol (LDL-C) to target levels in patients with coronary heart disease (CHD) were evaluated in the GOALLS (Getting to Appropriate LDL-C Levels with Simvastatin) study. This multinational, multicentre, prospective, open-label, study consisted of a six-week diet washout period followed by a 14-week titrate-to-goal treatment period with simvastatin. One hundred and ninety-eight men and women with documented CHD and a fasting LDL-C level between 115 mg/dl (3.0 mmol/l) and 180 mg/dl (4.7 mmol/l) and triglycerides (TGs) < or = 400 mg/dl (4.5 mmol/l) were enrolled. The patients were started on 20 mg simvastatin with dose titration up to 80 mg if the LDL-C remained above 100 mg/dl at weeks 6 and 10. The key efficacy parameters were the percentage of patients achieving US and European LDL-C goals [< or = 100 mg/dl (2.6 mmol/l) and < or = 115 mg/dl (3.0 mmol/l), respectively]. Safety was evaluated by monitoring laboratory tests and recording adverse events. After 14 weeks of simvastatin (20-80 mg) treatment, approximately 90% of the patients achieved LDL-C goals according to US (87%) and European (94%) guidelines. Most patients (72-93%) achieved target LDL-C levels on 20 mg simvastatin. An estimated 14% of the patients required titration to the 80 mg dose. Treatment with simvastatin (20-80 mg) produced statistically significant improvements in all measured lipid variables by the end of the study. The mean reductions in total cholesterol and LDL-C, and the median reduction in TG, were 28%, 41% and 16%, respectively. The increase in high-density lipoprotein cholesterol and apolipoprotein A-1 were 5% and 4%, respectively. Simvastatin was well tolerated across the dosage range. In conclusion, simvastatin, 20-80 mg/day, was safe and highly effective at reducing LDL-C levels. The recommended US and European LDL-C treatment goals were achieved in approximately 90% of the patients. These goals were similarly achieved for a variety of high-risk sub-groups (hypertensives, diabetics and elderly patients).

Aged↗

Prevalence of the C282Y mutation of the hemochromatosis gene in liver transplant recipients and donors.

Hemochromatosis heterozygotes may be predisposed to end-stage liver disease from other causes. The aims of this study were to determine the prevalence of the hemochromatosis mutation, C282Y, in end-stage liver disease and to determine if transplantation of C282Y heterozygous livers adversely affected survival. The C282Y status of patients who underwent hepatic transplantation and, whenever possible, their donors, was determined and correlated with hepatic iron status. Survival was compared in patients who received livers from heterozygotes and normals. Prevalence of C282Y in recipients was compared with 5,211 voluntary blood donors. Twenty-six C282Y heterozygotes were detected among 304 transplant recipients (8.6%) compared with a prevalence of 8.4% in blood donors. Six of 26 heterozygous recipients (23%) had >/=2+ iron staining in their explanted livers compared with 40 of 277 wild-type livers (14%) (P = ns). There was no significant difference in mean hepatic iron concentration between C282Y heterozygotes and wild-type explanted livers with >/=2+ iron staining. Seven of 31 patients (23%) with alcoholic liver disease were C282Y heterozygotes. Twenty-four heterozygotes were detected in 141 donors (17.0%). Survival did not differ between recipients who received heterozygous or normal livers. The prevalence of C282Y heterozygotes in patients requiring liver transplantation does not differ significantly from the general population. Heterozygotes are not at increased risk of developing end-stage liver disease. Transplantation of C282Y heterozygous livers is a safe, effective practice.

Adolescent↗

Alternate splicing produces a soluble form of the hereditary hemochromatosis protein HFE.

HFE is a non-typical MHC class 1-type protein that is mutated in hereditary hemochromatosis. The purpose of this study was to identify possible splice variants of HFE mRNA and investigate the regulation of these isoforms in duodenum and liver of patients with normal and altered iron stores. RT-PCR was performed using HFE specific primers and duodenal RNA obtained from patients with hemochromatosis, iron deficiency, secondary iron overload and normal controls. The reaction products were visualized by Southern blot and identified by DNA sequence analysis. Additional studies were performed on RNA isolated from liver and a range of human tissues. A truncated (soluble) form of HFE protein was identified that lacks the transmembrane domain and occurs as a result of alternative splicing. Soluble HFE was found predominantly in the duodenum, spleen, breast, skin and testicle. In hereditary hemochromatosis full length HFE was the predominant isoform present in the duodenum similar to iron deficiency. Alternate splicing produces soluble HFE that may have a unique function to regulate cellular iron transport.

Alternative Splicing↗

A survey of 2,851 patients with hemochromatosis: symptoms and response to treatment.

PURPOSE: Hemochromatosis is a genetic disorder of iron absorption that affects 5 per 1,000 persons and is associated with reduced health and quality of life. We sought to determine the type and frequency of symptoms that patients experienced before the diagnosis and the treatments that they received. METHODS: We mailed a questionnaire to 3,562 patients with hemochromatosis who were located using patient advocacy groups, physicians, blood centers, newsletters, and the Internet. RESULTS: Of the 2,851 respondents, 99% were white and 62% were men. Circumstances that led to diagnosis of hemochromatosis included symptoms (35%), an abnormal laboratory test (45%), and diagnosis of a family member with hemochromatosis (20%). The mean (+/- SD) age of symptom onset was 41 +/- 14 years. Symptoms had been present for an average of 10 +/- 10 years before the diagnosis was made. Among the 58% of patients with symptoms, 65% had physician-diagnosed arthritis and 52% had liver disease. The most common and troublesome symptoms were extreme fatigue (46%), arthralgia (44%), and loss of libido (26%). Physician instructions to patients included treatment with phlebotomy (90%), testing family members (75%), and avoiding iron supplements (65%). CONCLUSIONS: The diagnosis of hemochromatosis in most patients was delayed. Physician education is needed to increase the detection of patients with the disease and to improve its management.

Adolescent↗

A survey of phlebotomy among persons with hemochromatosis.

BACKGROUND: One in 10 whites in the United States is a carrier for hemochromatosis and an estimated 1 in 200 is clinically affected. Early treatment with therapeutic phlebotomy to remove excess iron can prevent associated chronic diseases. However, little information is available on the amount of blood withdrawn or the rates of withdrawal from hemochromatosis patients. The patterns of therapeutic phlebotomy and the magnitude of charges in persons with hemochromatosis were surveyed. STUDY DESIGN AND METHODS: Surveys were mailed to persons with hemochromatosis identified by health care providers, blood centers, patient advocacy groups, and the Internet. There were 2362 respondents to the survey from the United States. RESULTS: Thirty-seven percent of respondents reported being voluntary blood donors prior to diagnosis. The mean rate of therapeutic phlebotomy for iron depletion was 2.6 units per month (mean duration, 13 months). The mean rate of maintenance phlebotomy was 0.5 units per month. Therapeutic phlebotomy rates varied by sex, age, reason for diagnosis, and severity of symptoms. Seventy-six percent of respondents reported full or partial insurance coverage of therapeutic phlebotomy charges. Seventy-six percent received therapeutic phlebotomy services in a hospital or physician's office and 30 percent in a blood center. Charges for therapeutic phlebotomy varied by site, with a mean cost of $90 in hospitals and $52 in blood centers. Fifty-four percent of respondents attempted to donate blood after their diagnosis but were excluded. CONCLUSION: The amount of blood withdrawn from persons with hemochromatosis is substantial. The location where patients received phlebotomy services appears to be influenced by charges and time since diagnosis.

Adult↗

Patient-related outcomes five years after coronary artery bypass graft surgery.

For five years, we prospectively studied 353 consecutive patients undergoing first-time coronary artery bypass graft surgery (CABG) for stable angina in the North of England. Angina was present before surgery in nearly all patients, in 20% 3 months after surgery, and in 48% after 60 months. The Nottingham Health Profile, showed a significant improvement in perceived health status (PHS) 12 and 60 months after surgery compared with preoperation. However, PHS at 60 months was worse than at 12 months in the dimensions 'pain' and 'physical mobility' in part 1, and in 'looking after the home' and 'taking holidays' in part 2. Employment rates were 36%, 34% and 21%, before, and 12 and 60 months after surgery, respectively. Working at 12 and 60 months was associated with age below retirement age, work preoperation and absence of angina, and at 12 months also with male gender and waiting time < 6 months. This study describes everyday clinical practice. The significant improvement in angina symptoms and PHS after CABG persists for at least 5 years. However, only one third of patients in this geographical area return to work, and this is not solely dependent on clinical symptoms.

Aged↗

Screening blood donors for hereditary hemochromatosis: decision analysis model comparing genotyping to phenotyping.

OBJECTIVE: The identification of a gene for hereditary hemochromatosis in 69-100% of typical hemochromatosis patients has resulted in a genotypic test to identify persons with the typical missense mutation. Population screening by genotyping has the potential to reduce screening costs because of a high specificity of the genetic test. METHODS: Decision analysis techniques are used to compare the outcome, utility, and incremental cost savings of a plan to screen voluntary blood donors and their siblings for hemochromatosis using a genotypic test (C282Y mutation) with phenotypic tests (transferrin saturation, serum ferritin). RESULTS: Genotypic screening is less expensive than phenotypic screening only if the cost of the initial genetic test is less than $20. The screening program saves money (dominant strategy) if the cost of the initial genetic test is less than $28. Incremental cost saving declines as the cost of the gene test increases. At a gene test cost of $173, it costs $109,358 to identify a homozygote with potential life-threatening illness. Incremental cost saving also declines as the penetrance of the hemochromatosis gene in the population screened decreases. Phenotypic screening with confirmatory genetic testing results in a cost of $2,711 per homozygote with life-threatening complications. CONCLUSIONS: Population screening programs for hemochromatosis have the potential to save money. Optimal strategies for screening include initial testing for iron overload (phenotyping) with confirmatory genetic testing, or initial genetic testing if the test is less than $28.

Blood Donors↗

High apolipoprotein AI concentrations are associated with lower mortality and myocardial infarction five years after coronary artery bypass graft surgery.

OBJECTIVE: To examine mortality and myocardial infarction five years after coronary artery bypass graft (CABG) surgery and the association with different lipid fractions and haemostatic, glycaemic, and demographic risk factors. SETTING: A regional cardiothoracic centre, Freeman Hospital, and the University Clinical Investigation Unit, Royal Victoria Infirmary, Newcastle upon Tyne, UK. DESIGN: 353 consecutive patients (297 male, mean age 57.2 years) undergoing first time CABG for stable angina were recruited to a prospective cohort study and studied to five years. MAIN OUTCOME MEASURES: All cause mortality, late cardiac mortality (beyond 30 days) alone and in combination with non-fatal myocardial infarction. Risk factor assessments before operation and 3, 6, 12, 24, and 60 months after surgery. For each laboratory variable a weighted mean for the period of exposure was calculated from the concentration at each time interval and the time between measurements. The distribution was divided into tertiles. RESULTS: 41 patients died (16 late cardiac deaths) and eight had a myocardial infarct. An adverse outcome occurred more frequently in the lower tertile of weighted apolipoprotein AI compared with the upper tertile. An adverse outcome was also more common in patients in the upper tertile of weighted total white blood cell count and less consistently so in patients in the upper tertile of the haemostatic covariates, factor VIIc and factor VIIIc. There was no association with other lipid fractions except for total mortality and apolipoprotein B (owing to low levels in five patients with carcinoma). CONCLUSIONS: Low apolipoprotein AI concentrations, but no other markers of an adverse lipid profile, were associated with mortality and myocardial infarction five years after CABG. Apolipoprotein AI is associated with paraoxonase, an enzyme located on high density lipoprotein, which may limit the oxidation of low density lipoprotein. An association between outcome and other covariates such as white cell count provides a credible pointer to inflammation mediating a component of cardiovascular risk.

Apolipoprotein A-I↗

Management of hemochromatosis. Hemochromatosis Management Working Group.

The complications of iron overload in hemochromatosis can be avoided by early diagnosis and appropriate management. Therapeutic phlebotomy is used to remove excess iron and maintain low normal body iron stores, and it should be initiated in men with serum ferritin levels of 300 microg/L or more and in women with serum ferritin levels of 200 microg/L or more, regardless of the presence or absence of symptoms. Typically, therapeutic phlebotomy consists of 1) removal of 1 unit (450 to 500 mL) of blood weekly until the serum ferritin level is 10 to 20 microg/L and 2) maintenance of the serum ferritin level at 50 microg/L or less thereafter by periodic removal of blood. Hyperferritinemia attributable to iron overload is resolved by therapeutic phlebotomy. When applied before iron overload becomes severe, this treatment also prevents complications of iron overload, including hepatic cirrhosis, primary liver cancer, diabetes mellitus, hypogonadotrophic hypogonadism, joint disease, and cardiomyopathy. In patients with established iron overload disease, weakness, fatigue, increased hepatic enzyme concentrations, right upper quadrant pain, and hyperpigmentation are often substantially alleviated by therapeutic phlebotomy. Patients with liver disease, joint disease, diabetes mellitus and other endocrinopathic abnormalities, and cardiac abnormalities often require additional, specific management. Dietary management of hemochromatosis includes avoidance of medicinal iron, mineral supplements, excess vitamin C, and uncooked seafoods. This can reduce the rate of iron reaccumulation; reduce retention of nonferrous metals; and help reduce complications of liver disease, diabetes mellitus, and Vibrio infection. This comprehensive approach to the management of hemochromatosis can decrease the frequency and severity of iron overload, improve quality of life, and increase longevity.

Diet↗

Hereditary hemochromatosis: gene discovery and its implications for population-based screening.

OBJECTIVE: To evaluate the role of genetic testing in screening for hereditary hemochromatosis to help guide clinicians, policymakers, and researchers. PARTICIPANTS: An expert panel was convened on March 3, 1997, by the Centers for Disease Control and Prevention (CDC) and the National Human Genome Research Institute (NHGRI), with expertise in epidemiology, genetics, hepatology, iron overload disorders, molecular biology, public health, and the ethical, legal, and social implications surrounding the discovery and use of genetic information. EVIDENCE: The group reviewed evidence regarding the clinical presentation, natural history, and genetics of hemochromatosis, including current data on the candidate gene for hemochromatosis (HFE) and on the ethical and health policy implications of genetic testing for this disorder. CONSENSUS PROCESS: Consensus was achieved by group discussion confirmed by a voice vote. A draft of the consensus statement was prepared by a writing committee and subsequently reviewed and revised by all members of the expert group over a 1-year period. CONCLUSIONS: Genetic testing is not recommended at this time in population-based screening for hereditary hemochromatosis, due to uncertainties about prevalence and penetrance of HFE mutations and the optimal care of asymptomatic people carrying HFE mutations. In addition, use of a genetic screening test raises concerns regarding possible stigmatization and discrimination. Tests for HFE mutations may play a role in confirming the diagnosis of hereditary hemochromatosis in persons with elevated serum iron measures, but even this use is limited by uncertainty about genotype-phenotype correlations. To address these questions, the expert group accorded high priority to population-based research to define the prevalence of HFE mutations, age and sex-related penetrance of different HFE genotypes, interactions between HFE genotypes and environmental modifiers, and psychosocial outcomes of genetic screening for hemochromatosis.

Female↗

Factors affecting the rate of iron mobilization during venesection therapy for genetic hemochromatosis.

Although progressive iron accumulation is a characteristic feature of genetic hemochromatosis, the factors affecting the rate of iron mobilization by venesection have not been established. Venesection records were analyzed in 77 hemochromatosis homozygotes to study the factors affecting the rate of iron mobilization by venesection. The rate of iron mobilization was the iron removed divided by the time required to deplete iron stores (serum ferritin < 50 microg/L). Mean duration of venesection therapy was 1.4 years (range 0.44-3.6 years). All patients completed the therapy and there were no significant adverse effects. Rate of iron mobilization was higher in cirrhotics compared to non-cirrhotic patients (P = 0.04). Iron mobilization was inversely related to intestinal radioiron absorption (r = -0.45, P = .01). There was no significant relationship between iron mobilization and patient age, gender, serum ferritin, and hepatic iron concentration. Iron mobilization is increased in cirrhotics and patients with lower intestinal iron absorption. Venesection therapy is safe and well tolerated in all age groups.

Adult↗