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Biomedical subjects

C N Martyn

Publications and source records attributed to C N Martyn.

At least 37 records · Page 2Linked to original sources
PubMed1999

Outcomes of undernutrition in patients in the community with cancer or cardiovascular disease.

Public health concern has tended to focus on the dangers of obesity, but there is evidence that undernutrition may also pose a risk to physical and mental well-being, particularly in those who are already ill. Using the General Practice Research Database (see office for Population Censuses and Surveys, 1995), we followed up 10,128 men and women aged 18 years and over who had been diagnosed with cancer or cardiovascular disease to examine whether nutritional status, as indicated by BMI, affected rates of use of health care resources and mortality. In both diagnostic groups, patients with a BMI below 20 kg/m2 had higher rates of consultation with GP, higher rates of prescription and higher death rates during the follow-up period compared with those with a BMI of 20-< 25 kg/m2. In men and women with cardiovascular disease, poor nutritional status was associated with a sharply increased risk of hospital admission. Patients whose BMI was 30-< 40 kg/m2 also tended to have increased rates of GP consultation and prescription, and if they were under the age of 65 years, they had an increased risk of death. The results of the present study suggest that in men and women with cancer or cardiovascular disease, even minor degrees of undernutrition are associated with a marked increase in morbidity and mortality.

Adult↗
PubMed1998

Impaired fetal growth and atherosclerosis of carotid and peripheral arteries.

BACKGROUND: Although epidemiological studies suggest that people with low birthweight are at higher risk of coronary heart disease and stroke in adult life than those of higher birthweight, the mechanisms underlying this relation are unclear. We investigated whether impaired fetal growth leads to an increased risk of atherosclerosis by assessment of the carotid and lower-limb arteries in a group of people aged around 70 years for whom birthweight data were available. METHODS: 2232 singleton babies were born to married mothers at a maternity hospital in Sheffield, UK, between 1922 and 1926, and had complete birth records. We traced 829 survivors and invited 395 who still lived in Sheffield to take part in this study. 322 agreed; they were interviewed at home and 181 underwent duplex ultrasonographic examination of the extracranial parts of the carotid arteries. Atherosclerosis in the arteries of the lower limb was assessed in 186 people by the ankle-brachial-pressure index (ABPI). FINDINGS: The prevalence and severity of carotid atherosclerosis was greatest in those with the lowest recorded birthweight. The risk of carotid stenosis was greater for people who had weighed 6.5 lb or less at birth than for those who weighed over 7.5 lb (odds ratio 5.3 [95% CI 2.0-14.0]), after adjustment for cardiovascular risk factors and gestational age at birth. The odds ratio for atherosclerotic disease in the lower limbs (low ABPI) was highest in people with the lowest recorded birthweight, but this relation was not significant (odds ratio 2.3 [1.0-5.6]). INTERPRETATION: Increased atherogenesis may be one mechanism mediating the observed epidemiological link between impaired fetal growth and cardiovascular disease. Adaptations made by the fetus in response to influences that retard its growth may have long-term consequences for the structure and metabolism of the vascular system.

Aged↗
PubMed1998

Effect on the quality of peer review of blinding reviewers and asking them to sign their reports: a randomized controlled trial.

CONTEXT: Anxiety about bias, lack of accountability, and poor quality of peer review has led to questions about the imbalance in anonymity between reviewers and authors. OBJECTIVE: To evaluate the effect on the quality of peer review of blinding reviewers to the authors' identities and requiring reviewers to sign their reports. DESIGN: Randomized controlled trial. SETTING: A general medical journal. PARTICIPANTS: A total of 420 reviewers from the journal's database. INTERVENTION: We modified a paper accepted for publication introducing 8 areas of weakness. Reviewers were randomly allocated to 5 groups. Groups 1 and 2 received manuscripts from which the authors' names and affiliations had been removed, while groups 3 and 4 were aware of the authors' identities. Groups 1 and 3 were asked to sign their reports, while groups 2 and 4 were asked to return their reports unsigned. The fifth group was sent the paper in the usual manner of the journal, with authors' identities revealed and a request to comment anonymously. Group 5 differed from group 4 only in that its members were unaware that they were taking part in a study. MAIN OUTCOME MEASURE: The number of weaknesses in the paper that were commented on by the reviewers. RESULTS: Reports were received from 221 reviewers (53%). The mean number of weaknesses commented on was 2 (1.7, 2.1, 1.8, and 1.9 for groups 1, 2, 3, and 4 and 5 combined, respectively). There were no statistically significant differences between groups in their performance. Reviewers who were blinded to authors' dentities were less likely to recommend rejection than those who were aware of the authors' identities (odds ratio, 0.5; 95% confidence interval, 0.3-1.0). CONCLUSIONS: Neither blinding reviewers to the authors and origin of the paper nor requiring them to sign their reports had any effect on rate of detection of errors. Such measures are unlikely to improve the quality of peer review reports.

Authorship↗
PubMed1998

Fetal growth and hyperinsulinaemia in adult life.

To explore the relation between reduced fetal growth and impaired glucose tolerance in adult life, an oral glucose tolerance test (75 g glucose) was carried out on 218 men and women, now aged around 50 years, who had been measured in detail at birth. Measurements of plasma concentrations of glucose and insulin were made at 0, 30, and 120 min. Fasting plasma concentrations of proinsulin and 32-33 split proinsulin were also measured. People in the highest category of birthweight tended to have the lowest plasma concentrations of insulin as adults at both 0 and 120 min, though both these relations were weak. Plasma insulin concentrations in adult life were more strongly related to abdominal circumference at birth than to birthweight. After adjusting for sex and body mass index, mean insulin concentrations at 0 min fell from 50 pmol l-1 to 46 pmol l-1 (p = 0.04) and at 120 min from 235 pmol l-1 to 144 pmol l-1 (p = 0.003) between people whose abdominal circumference at birth had been less than 11.5 in and those who abdominal circumference had been greater than 13 in. Plasma glucose concentrations at 120 min also fell with increasing abdominal circumference at birth. Because abdominal circumference at birth is an indicator of the growth of the liver in fetal life, one interpretation of these findings is that the sensitivity of the liver to insulin is permanently reduced if the intrauterine development of this organ is impaired.

Adult↗
PubMed1998

Effect of nutritional status on use of health care resources by patients with chronic disease living in the community.

The prevalence of malnutrition in patients with chronic disease living in the community in the UK is around 8%. Whether such patients experience greater morbidity and mortality or make increased use of health care resources is unknown. The aim of this study was to investigate how the use of health care resources by patients with chronic disorders of the respiratory, gastrointestinal and neurological systems varied by nutritional status. We used longitudinal data, collected since 1987, which formed part of the General Practice Research Database in the UK. Subjects were 11 357 men and women aged 18 years or over. Main outcomes were consultation rates in general practice, prescription rates, hospital referral rates, hospital admission rates and mortality. Consultation and prescription rates were lowest amongst patients whose body mass index (BMI) was between 20 and 25. Rates were higher in patients whose BMI was below 20, or 25 and above. There was no statistically significant relation between rate of hospital outpatient referral and nutritional status, but both hospital admission rate and mortality were greatest in those people whose BMIs were below 20 and declined as BMIs increased. In patients with differential use of health care resources in both primary care and hospital practice, and with differences in mortality.

Adolescent↗
PubMed1997

Impaired synthesis of elastin in walls of aorta and large conduit arteries during early development as an initiating event in pathogenesis of systemic hypertension.

There is much evidence that people who had low birthweight tend to have higher blood pressure in later life. However, the mechanisms that mediate this relation are unknown. We argue that, in fetuses whose growth is impaired, synthesis of elastin in the walls of the aorta and large arteries may be deficient, and that this deficiency would lead to permanent changes in the mechanical properties of these vessels. Over a lifetime, such changes could predispose an individual to higher blood pressure, increased left-ventricular mass, and cardiovascular disease.

Aging↗
PubMed1997

Infection in childhood and neurological diseases in adult life.

Other chapters in this issue discuss the evidence that implicates infection during infancy and childhood in the etiology of respiratory disease. Here I argue that experience of infection in early life may also be involved in the aetiology of some diseases of the adult nervous system. The descriptive epidemiology of three neurological diseases is compatible with the hypothesis that they are delayed consequences of childhood infection. It is not difficult to imagine that the effects of an infection which results in loss of cells from an organ system, like the central nervous system, whose cell populations have lost the capacity to replace themselves by mitotic division could remain hidden until unmasked by ageing. Such a mechanism may be important in the aetiology of motor neuron disease and Parkinson's disease. Age-related differences in host response, which may be partly related to a maturing immune system, are known to influence both short- and long-term outcome for several infections. Perhaps the immune response to infection with Epstein-Barr virus, or another common micro-organism with similar epidemiology, in adolescence or early adult life is sometimes directed at antigens that are also present in the central nervous system. At present, the evidence that supports these hypotheses is largely circumstantial. But it may be possible to devise ways of testing them both epidemiologically and in the laboratory.

Adolescent↗
PubMed1997

Aluminum concentrations in drinking water and risk of Alzheimer's disease.

To investigate the relation of aluminum and silicon in drinking water to risk of Alzheimer's disease, we carried out a case-control study in eight regions of England and Wales. Subjects were identified from the records of neuroradiology centers, and diagnoses were confirmed by a review of hospital case-notes. Exposure to aluminum and silicon in drinking water was estimated from residential histories of 106 men with Alzheimer's disease, 99 men with other dementing illnesses, 226 men with brain cancer, and 441 men with other diseases of the nervous system. All subjects in the study were between 42 and 75 years of age. There was little association between Alzheimer's disease and higher aluminum or lower silicon concentrations in drinking water when cases were compared with any of the control groups. The results indicate that any risk of Alzheimer's disease from aluminum in drinking water at concentrations below 0.2 mg per liter is small, and they give no support for a protective role of silicon.

Adult↗