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Penelope M.S. Clark

Bio: Penelope M.S. Clark is an academic researcher from University of Cambridge. The author has contributed to research in topics: Insulin & Impaired glucose tolerance. The author has an hindex of 26, co-authored 57 publications receiving 8713 citations. Previous affiliations of Penelope M.S. Clark include Queen Elizabeth Hospital Birmingham.


Papers
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Journal ArticleDOI
26 Oct 1991-BMJ
TL;DR: Reduced growth in early life is strongly linked with impaired glucose tolerance and non-insulin dependent diabetes and reduced early growth is also related to a raised plasma concentration of 32-33 split proinsulin, which is interpreted as a sign of beta cell dysfunction.
Abstract: OBJECTIVE--To discover whether reduced fetal and infant growth is associated with non-insulin dependent diabetes and impaired glucose tolerance in adult life. DESIGN--Follow up study of men born during 1920-30 whose birth weights and weights at 1 year were known. SETTING--Hertfordshire, England. SUBJECTS--468 men born in east Hertfordshire and still living there. MAIN OUTCOME MEASURES--Fasting plasma glucose, insulin, proinsulin, and 32-33 split pro-insulin concentrations and plasma glucose and insulin concentrations 30 and 120 minutes after a 75 g glucose drink. RESULTS--93 men had impaired glucose tolerance or hitherto undiagnosed diabetes. They had had a lower mean birth weight and a lower weight at 1 year. The proportion of men with impaired glucose tolerance fell progressively from 26% (6/23) among those who had weighted 18 lb (8.16 kg) or less at 1 year to 13% (3/24) among those who had weighed 27 lb (12.25 kg) or more. Corresponding figures for diabetes were 17% (4/23) and nil (0/24). Plasma glucose concentrations at 30 and 120 minutes fell with increasing birth weight and weight at 1 year. Plasma 32-33 split proinsulin concentration fell with increasing weight at 1 year. All these trends were significant and independent of current body mass. Blood pressure was inversely related to birth weight and strongly related to plasma glucose and 32-33 split proinsulin concentrations. CONCLUSIONS--Reduced growth in early life is strongly linked with impaired glucose tolerance and non-insulin dependent diabetes. Reduced early growth is also related to a raised plasma concentration of 32-33 split proinsulin, which is interpreted as a sign of beta cell dysfunction. Reduced intrauterine growth is linked with high blood pressure, which may explain the association between hypertension and impaired glucose tolerance.

2,687 citations

Journal ArticleDOI
TL;DR: It is concluded that Type 2 diabetes and hypertension have a common origin in sub-optimal development in utero, and that syndrome X should perhaps be re-named “the small-baby syndrome”.
Abstract: Two follow-up studies were carried out to determine whether lower birthweight is related to the occurrence of syndrome X-Type 2 (non-insulin-dependent) diabetes mellitus, hypertension and hyperlipidaemia. The first study included 407 men born in Hertfordshire, England between 1920 and 1930 whose weights at birth and at 1 year of age had been recorded by health visitors. The second study included 266 men and women born in Preston, UK, between 1935 and 1943 whose size at birth had been measured in detail. The prevalence of syndrome X fell progressively in both men and women, from those who had the lowest to those who had the highest birthweights. Of 64-year-old men whose birthweights were 2.95 kg (6.5 pounds) or less, 22% had syndrome X. Their risk of developing syndrome X was more than 10 times greater than that of men whose birthweights were more than 4.31 kg (9.5 pounds). The association between syndrome X and low birthweight was independent of duration of gestation and of possible confounding variables including cigarette smoking, alcohol consumption and social class currently or at birth. In addition to low birthweight, subjects with syndrome X had small head circumference and low ponderal index at birth, and low weight and below-average dental eruption at 1 year of age. It is concluded that Type 2 diabetes and hypertension have a common origin in sub-optimal development in utero, and that syndrome X should perhaps be re-named "the small-baby syndrome".

2,423 citations

Journal ArticleDOI
TL;DR: It is concluded that the oral glucose tolerance test can be used to derive estimates of the relative roles of insulin secretion and insulin resistance in population studies of glucose tolerance.
Abstract: The extent to which the oral glucose tolerance test can be used to estimate insulin secretion and insulin resistance has been evaluated by comparing glucose and insulin concentrations during an oral glucose tolerance test with specific measurements of insulin secretion and insulin resistance in 85 normoglycaemic subjects and 23 subjects with impaired glucose tolerance (IGT). Insulin secretion was measured by the first phase insulin response to intravenous glucose and insulin resistance by the insulin tolerance test which measures the decline of plasma glucose after the injection of a bolus of insulin. The best measure of insulin secretion was the ratio of the 30 min increment in insulin concentration to the 30 min increment in glucose concentration following oral glucose loading. This correlated with the first phase insulin release following intravenous glucose (r=0.61, p 0.05). Insulin resistance could be estimated by the fasting insulin, proinsulin, or split proinsulin concentrations. However, fasting split proinsulin appeared to discriminate best between insulin resistance (r = −0.53, p 0.05). Relative insulin resistance estimated by homeostasis model assessment (HOMA) also correlated well with insulin resistance (r= −0.57, p 0.05). We conclude that the oral glucose tolerance test can be used to derive estimates of the relative roles of insulin secretion and insulin resistance in population studies of glucose tolerance.

624 citations

Journal ArticleDOI
TL;DR: The association between impaired glucose tolerance in adult life and low birthweight previously reported in Hertfordshire (UK) is confirmed and demonstrated in women as well as men, suggesting that the association reflects the long-term effects of reduced growth of the endocrine pancreas and other tissues in utero.
Abstract: A follow-up study was carried out to determine whether reduced fetal growth is associated with the development of impaired glucose tolerance in men and women aged 50 years. Standard oral glucose tolerance tests were carried out on 140 men and 126 women born in Preston (Lancashire, UK) between 1935 and 1943, whose size at birth had been measured in detail. Those subjects found to have impaired glucose tolerance or non-insulin-dependent diabetes mellitus had lower birthweight, a smaller head circumference and were thinner at birth. They also had a higher ratio of placental weight to birthweight. The prevalence of impaired glucose tolerance or diabetes fell from 27% in subjects who weighed 2.50 kg (5.5 pounds) or less at birth to 6% in those who weighed more than 3.41 kg (7.5 pounds) (p < 0.002 after adjusting for body mass index). Plasma glucose concentrations taken at 2-h in the glucose tolerance test fell progressively as birthweight increased (p < 0.004), as did 2-h plasma insulin concentrations (p < 0.001). The trends with birthweight were independent of duration of gestation and must therefore be related to reduced rates of fetal growth. These findings confirm the association between impaired glucose tolerance in adult life and low birthweight previously reported in Hertfordshire (UK), and demonstrate it in women as well as men. It is suggested that the association reflects the long-term effects of reduced growth of the endocrine pancreas and other tissues in utero. This may be a consequence of maternal undernutrition.

487 citations

Journal ArticleDOI
18 Feb 1995-BMJ
TL;DR: In women, as in men, reduced fetal growth leads to insulin resistance and the associated disorders: raised blood pressure and high serum triglyceride and low serum high density lipoprotein cholesterol concentrations.
Abstract: Objective: To examine whether cardiovascular risk factors in women are related to fetal and infant growth. Design: Follow up study of women born 1923-30 whose birth weights and weights at one year were recorded. Setting: Hertfordshire. Subjects: 297 women born and still living in East Hertfordshire. Main outcome measures: Plasma glucose and insulin concentrations during a standard oral glucose tolerance test; fasting plasma proinsulin and 32-33 split proinsulin concentrations; blood pressure; fasting serum total, low density lipoprotein and high density lipoprotein cholesterol, triglyceride, and apolipoprotein A I and B concentrations; and plasma fibrinogen and factor VII concentrations. Results: Fasting plasma concentrations of glucose, insulin, and 32-33 split proinsulin fell with increasing birth weight (P=0.04, P=0.002, and P=0.0002 respectively, when current body mass index was allowed for). Glucose and insulin concentrations 120 minutes after an oral glucose load showed similar trends (P=0.03 and P=0.02). Systolic blood pressure, waist:hip ratio, and serum triglyceride concentrations also fell with increasing birth weight (P=0.08, P=0.07, and P=0.07 respectively), while serum high density lipoprotein cholesterol concentrations rose (P=0.04). At each birth weight women who currently had a higher body mass index had higher levels of risk factors. Conclusion: In women, as in men, reduced fetal growth leads to insulin resistance and the associated disorders: raised blood pressure and high serum triglyceride and low serum high density lipoprotein cholesterol concentrations. The highest values of these coronary risk factors occur in people who were small at birth and become obese. In contrast with men, low rates of infant growth did not predict levels of risk factors in women. Key messages Key messages They have increased levels of cardiovascular risk factors associated with insulin resistance The highest levels of these risk factors are in people who were small at birth and obese as adults Unlike in men, low rates of growth in infancy are not linked to coronary heart disease in women

474 citations


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Journal ArticleDOI
06 Apr 2000-Nature
TL;DR: The global epidemic of obesity results from a combination of genetic susceptibility, increased availability of high-energy foods and decreased requirement for physical activity in modern society, and should be regarded as an epidemic that threatens global well being.
Abstract: Obesity is now so common within the world's population that it is beginning to replace undernutrition and infectious diseases as the most significant contributor to ill health. In particular, obesity is associated with diabetes mellitus, coronary heart disease, certain forms of cancer, and sleep-breathing disorders. Obesity is defined by a body-mass index (weight divided by square of the height) of 30 kg m(-2) or greater, but this does not take into account the morbidity and mortality associated with more modest degrees of overweight, nor the detrimental effect of intra-abdominal fat. The global epidemic of obesity results from a combination of genetic susceptibility, increased availability of high-energy foods and decreased requirement for physical activity in modern society. Obesity should no longer be regarded simply as a cosmetic problem affecting certain individuals, but an epidemic that threatens global well being.

4,697 citations

Journal ArticleDOI
TL;DR: The present report has been written to focus attention on the issue and to urge policy-makers to consider taking action before it is too late.
Abstract: Ten per cent of the world’s school-aged children are estimated to be carrying excess body fat (Fig. 1), with an increased risk for developing chronic disease. Of these overweight children, a quarter are obese, with a significant likelihood of some having multiple risk factors for type 2 diabetes, heart disease and a variety of other co-morbidities before or during early adulthood. The prevalence of overweight is dramatically higher in economically developed regions, but is rising significantly in most parts of the world. In many countries the problem of childhood obesity is worsening at a dramatic rate. Surveys during the 1990s show that in Brazil and the USA, an additional 0.5% of the entire child population became overweight each year. In Canada, Australia and parts of Europe the rates were higher, with an additional 1% of all children becoming overweight each year. The burden upon the health services cannot yet be estimated. Although childhood obesity brings a number of additional problems in its train – hyperinsulinaemia, poor glucose tolerance and a raised risk of type 2 diabetes, hypertension, sleep apnoea, social exclusion and depression – the greatest health problems will be seen in the next generation of adults as the present childhood obesity epidemic passes through to adulthood. Greatly increased rates of heart disease, diabetes, certain cancers, gall bladder disease, osteoarthritis, endocrine disorders and other obesityrelated conditions will be found in young adult populations, and their need for medical treatment may last for their remaining life-times. The costs to the health services, the losses to society and the burdens carried by the individuals involved will be great. The present report has been written to focus attention on the issue and to urge policy-makers to consider taking action before it is too late. Specifically, the report:

3,953 citations

Journal ArticleDOI
15 Jul 1995-BMJ
TL;DR: The fetal origins hypothesis states that fetal undernutrition in middle to late gestation, which leads to disproportionate fetal growth, programmes later coronary heart disease.
Abstract: The fetal origins hypothesis states that fetal undernutrition in middle to late gestation, which leads to disproportionate fetal growth, programmes later coronary heart disease. Animal studies have shown that undernutrition before birth programmes persisting changes in a range of metabolic, physiological, and structural parameters. Studies in humans have shown that men and women whose birth weights were at the lower end of the normal range, who were thin or short at birth, or who were small in relation to placental size have increased rates of coronary heart disease. We are beginning to understand something of the mechanisms underlying these associations. The programming of blood pressure, insulin responses to glucose, cholesterol metabolism, blood coagulation, and hormonal settings are all areas of active research.

3,228 citations

Journal ArticleDOI
TL;DR: It is proposed that one of the major long-term consequences of inadequate early nutrition is impaired development of the endocrine pancreas and a greatly increased susceptibility to the development of Type 2 diabetes.
Abstract: In this contribution we put forward a novel hypothesis concerning the aetiology of Type 2 (non-insulin dependent) diabetes mellitus. The concept underlying our hypothesis is that poor foetal and early post-natal nutrition imposes mechanisms of nutritional thrift upon the growing individual. We propose that one of the major long-term consequences of inadequate early nutrition is impaired development of the endocrine pancreas and a greatly increased susceptibility to the development of Type 2 diabetes. In the first section we outline our research which has led to this hypothesis. We will then review the relevant literature. Finally we show that the hypothesis suggests a reinterpretation of some findings and an explanation of others which are at present not easy to understand.

3,107 citations

Journal ArticleDOI
TL;DR: Prevention will be the most cost-effective and feasible approach for many countries and should involve three mutually reinforcing strategies throughout life, starting in the antenatal period.
Abstract: Objective: To briefly review the current understanding of the aetiology and prevention of chronic diseases using a life course approach, demonstrating the lifelong influences on the development of disease. Design: A computer search of the relevant literature was done using Medline-‘life cycle’ and ‘nutrition’ and reviewing the articles for relevance in addressing the above objective. Articles from references dated before 1990 were followed up separately. A subsequent search using Clio updated the search and extended it by using ‘life cycle’, ‘nutrition’ and ‘noncommunicable disease’ (NCD), and ‘life course’. Several published and unpublished WHO reports were key in developing the background and arguments. Setting: International and national public health and nutrition policy development in light of the global epidemic in chronic diseases, and the continuing nutrition, demographic and epidemiological transitions happening in an increasingly globalized world. Results of review: There is a global epidemic of increasing obesity, diabetes and other chronic NCDs, especially in developing and transitional economies, and in the less affluent within these, and in the developed countries. At the same time, there has been an increase in communities and households that have coincident under- and over-nutrition. Conclusions: The epidemic will continue to increase and is due to a lifetime of exposures and influences. Genetic predisposition plays an unspecified role, and with programming during fetal life for adult disease contributing to an unknown degree. A global rise in obesity levels is contributing to a particular epidemic of type 2 diabetes as well as other NCDs. Prevention will be the most cost-effective and feasible approach for many countries and should involve three mutually reinforcing strategies throughout life, starting in the antenatal period.

2,984 citations