Worldwide trends in body-mass index, underweight, overweight, and obesity from 1975 to 2016: a pooled analysis of 2416 population-based measurement studies in 128·9 million children, adolescents, and adults.

BACKGROUND: Underweight, overweight, and obesity in childhood and adolescence are associated with adverse health consequences throughout the life-course. Our aim was to estimate worldwide trends in mean body-mass index (BMI) and a comprehensive set of BMI categories that cover underweight to obesity in children and adolescents, and to compare trends with those of adults. METHODS: We pooled 2416 population-based studies with measurements of height and weight on 128·9 million participants aged 5 years and older, including 31·5 million aged 5-19 years. We used a Bayesian hierarchical model to estimate trends from 1975 to 2016 in 200 countries for mean BMI and for prevalence of BMI in the following categories for children and adolescents aged 5-19 years: more than 2 SD below the median of the WHO growth reference for children and adolescents (referred to as moderate and severe underweight hereafter), 2 SD to more than 1 SD below the median (mild underweight), 1 SD below the median to 1 SD above the median (healthy weight), more than 1 SD to 2 SD above the median (overweight but not obese), and more than 2 SD above the median (obesity). FINDINGS: Regional change in age-standardised mean BMI in girls from 1975 to 2016 ranged from virtually no change (-0·01 kg/m2 per decade; 95% credible interval -0·42 to 0·39, posterior probability [PP] of the observed decrease being a true decrease=0·5098) in eastern Europe to an increase of 1·00 kg/m2 per decade (0·69-1·35, PP>0·9999) in central Latin America and an increase of 0·95 kg/m2 per decade (0·64-1·25, PP>0·9999) in Polynesia and Micronesia. The range for boys was from a non-significant increase of 0·09 kg/m2 per decade (-0·33 to 0·49, PP=0·6926) in eastern Europe to an increase of 0·77 kg/m2 per decade (0·50-1·06, PP>0·9999) in Polynesia and Micronesia. Trends in mean BMI have recently flattened in northwestern Europe and the high-income English-speaking and Asia-Pacific regions for both sexes, southwestern Europe for boys, and central and Andean Latin America for girls. By contrast, the rise in BMI has accelerated in east and south Asia for both sexes, and southeast Asia for boys. Global age-standardised prevalence of obesity increased from 0·7% (0·4-1·2) in 1975 to 5·6% (4·8-6·5) in 2016 in girls, and from 0·9% (0·5-1·3) in 1975 to 7·8% (6·7-9·1) in 2016 in boys; the prevalence of moderate and severe underweight decreased from 9·2% (6·0-12·9) in 1975 to 8·4% (6·8-10·1) in 2016 in girls and from 14·8% (10·4-19·5) in 1975 to 12·4% (10·3-14·5) in 2016 in boys. Prevalence of moderate and severe underweight was highest in India, at 22·7% (16·7-29·6) among girls and 30·7% (23·5-38·0) among boys. Prevalence of obesity was more than 30% in girls in Nauru, the Cook Islands, and Palau; and boys in the Cook Islands, Nauru, Palau, Niue, and American Samoa in 2016. Prevalence of obesity was about 20% or more in several countries in Polynesia and Micronesia, the Middle East and north Africa, the Caribbean, and the USA. In 2016, 75 (44-117) million girls and 117 (70-178) million boys worldwide were moderately or severely underweight. In the same year, 50 (24-89) million girls and 74 (39-125) million boys worldwide were obese. INTERPRETATION: The rising trends in children's and adolescents' BMI have plateaued in many high-income countries, albeit at high levels, but have accelerated in parts of Asia, with trends no longer correlated with those of adults. FUNDING: Wellcome Trust, AstraZeneca Young Health Programme

Rising rural body-mass index is the main driver of the global obesity epidemic in adults

Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities. This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity. Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55% of the global rise in mean BMI from 1985 to 2017—and more than 80% in some low- and middle-income regions—was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing—and in some countries reversal—of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories

Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults

Background Underweight and obesity are associated with adverse health outcomes throughout the life course. We estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from 1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories. Methods We used data from 3663 population-based studies with 222 million participants that measured height and weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children and adolescents (age 5–19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the individual and combined prevalence of underweight (BMI 2 SD above the median). Findings From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in 11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and 140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%) with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and 42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents, the increases in double burden were driven by increases in obesity, and decreases in double burden by declining underweight or thinness. Interpretation The combined burden of underweight and obesity has increased in most countries, driven by an increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of underweight while curbing and reversing the increase in obesity. Funding UK Medical Research Council, UK Research and Innovation (Research England), UK Research and Innovation (Innovate UK), and European Union

Diminishing benefits of urban living for children and adolescents’ growth and development

AbstractOptimal growth and development in childhood and adolescence is crucial for lifelong health and well-being1–6. Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5–19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few high-income countries. By 2020, the urban height advantage became smaller in most countries, and in many high-income western countries it reversed into a small urban-based disadvantage. The exception was for boys in most countries in sub-Saharan Africa and in some countries in Oceania, south Asia and the region of central Asia, Middle East and north Africa. In these countries, successive cohorts of boys from rural places either did not gain height or possibly became shorter, and hence fell further behind their urban peers. The difference between the age-standardized mean BMI of children in urban and rural areas was &lt;1.1 kg m–2 in the vast majority of countries. Within this small range, BMI increased slightly more in cities than in rural areas, except in south Asia, sub-Saharan Africa and some countries in central and eastern Europe. Our results show that in much of the world, the growth and developmental advantages of living in cities have diminished in the twenty-first century, whereas in much of sub-Saharan Africa they have amplified.</jats:p

Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults

Background Underweight and obesity are associated with adverse health outcomes throughout the life course. We estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from 1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories. Methods We used data from 3663 population-based studies with 222 million participants that measured height and weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children and adolescents (age 5–19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the individual and combined prevalence of underweight (BMI 2 SD above the median). Findings From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in 11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and 140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%) with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and 42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents, the increases in double burden were driven by increases in obesity, and decreases in double burden by declining https://researchonline.ljmu.ac.uk/images/research_banner_face_lab_290.jpgunderweight or thinness. Interpretation The combined burden of underweight and obesity has increased in most countries, driven by an increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of underweight while curbing and reversing the increase in obesity

Consensus Conference. Italian Society of Cardiovascular Echography (SIEC) Consensus Conference on the state of the art of contrast echocardiography

Part 1: Technical and methodological issues. Contrast echocardiography is based on the use of gas microbubbles. The size, gas composition and shell structure of the microbubbles modify their stability, resistance to pressure and scattering behavior. A proposed classification of contrast agents is based on the modalities of production of microbubbles (galenic or industrial); the industrial agents are divided into three generations depending on their characteristics. Following venous administration, the industrial microbubbles behave as intravascular free-flowing tracers and this is fundamental for their use in perfusion studies. When insonated at a low acoustic pressure, microbubbles show a linear behavior and can be used for signal amplification. At intermediate acoustic pressures microbubbles resonate and produce a harmonic signal that is detectable by new scanners. Higher acoustic pressures cause microbubble disruption with emission of a transient acoustic signal. The available contrast agents behave differently in an ultrasound field. Part 2: Safety of contrast echocardiography. Galenic contrast agents were tested in many studies for intracoronary and intravenous injection and no clinically relevant side effects were detected. The intravenous injection of industrial contrast agents is safe in all conditions, even in acute coronary syndromes. The interaction between ultrasound and microbubbles produces energy with potential effects on tissue for inertial cavitation and acoustic current production. These effects seem particularly interesting for the therapeutic applications of contrast echocardiography, but they do not appear to have clinically relevant effects. Part 3: Experimental studies. Experimental studies in contrast echocardiography are designed to induce, in animal models, acute myocardial infarction and coronary artery stenosis and to evaluate the differences in blood flow. The risk area and infarct area are well visualized with serial contrast agent infusion. No-reflow after coronary occlusion is a well-known phenomenon and is detectable at contrast echocardiography. Different degrees of induced coronary stenosis cause differences in the regional flow rate. The results of contrast echocardiographic studies are comparable with those of other invasive flow measurements. Caution must be used to transfer the knowledge acquired from animal studies to the clinical arena, owing to both methodological and anatomical differences. Part 4: Enhancement of Doppler signal and coronary flow study. The anterior descending coronary artery flow is detectable in almost all patients, and the posterior descending coronary artery in about 70%. The coronary flow reserve can be measured by injection of a vasodilator agent (dipyridamole or preferably adenosine) with a success rate of almost 100 % for the anterior descending but only 50 % for the posterior descending coronary artery. Data from transthoracic studies are comparable with those of Doppler flow wire. The fields of application presently include the evaluation of acute myocardial infarction, the short- and long-term results of percutaneous coronary interventions and coronary grafts, and the study of the microcirculation in several clinical conditions where the coronary flow reserve may be reduced, such as in syndrome X, hypertension, hypercholesterolemia or diabetes. Part 5: Endocardial border enhancement. Opacification of the left ventricle is the main indication to contrast echocardiography that, in this setting, is principally used to improve endocardial border delineation. This allows accurate evaluation of left ventricular volumes and function, increasing the role of echocardiography for the quantitative study of the left ventricle. Other indications for left ventricular opacification are the identification of intraventricular thrombosis, non-compaction of the left ventricle and heart rupture. In this respect, industrial second-generation contrast agents are more useful. The most appropriate patients for contrast echocardiography are those with a poor or suboptimal acoustic window, in whom a predictable diagnostic and prognostic usefulness of the procedure is expected. If appropriately used, contrast echocardiography is a cost-effective technique, although lack of reimbursement presently limits its use. Part 6: Use of contrast agents during stress echocardiography. Contrast agents during stress echocardiography may be used to improve the diagnostic accuracy of the test and to study myocardial perfusion. The diagnosis of ischemia in stress echo relies on the operator's visual assessment of changes in contractility during stress. Contrast agents must be considered an important tool that improve image quality especially in patients with an intermediate or poor acoustic window and their use has been reported to be cost-effective in the few studies designed to this end. The evaluation of myocardial perfusion during stress is certainly one of the most important goals of contrast echocardiography. Preliminary data are interesting but there is still a number of methodological problems that currently hamper clinical application. Part 7: Myocardial perfusion. Echocardiography has the potential of visualizing microbubbles in the microcirculation by detecting stimulated acoustic emission, produced by high-energy applied ultrasound, or by detecting the harmonic signal produced by resonance of the microbubbles in a low-energy ultrasound field. In the first case images are triggered at increasing end-systolic intervals (intermittent imaging), whereas in the second case entire cardiac cycles are analyzed (real-time imaging). Continuous infusion is the preferred method of maintaining a large and constant microbubble concentration inside the microcirculation. Analysis of the perfusion signal may be made in the qualitative, semi-quantitative or quantitative mode. Quantitative analysis is based on the construction of videointensity-time curves to study the refilling phase after complete microbubble destruction. There are not enough data in the literature showing the additional role of quantitative analysis for clinical purposes. Thus, at present, quantitative softwares should be considered as research tools. Conversely, there is a general consensus based on experimental and clinical studies on the use of myocardial contrast echo in patients with acute myocardial infarction by means of qualitative or semi-quantitative analysis. Important information on the infarct area extension, on the efficacy of reperfusion therapy, on the presence and extension of the no-reflow phenomenon and on the extent of residual tissue viability may be derived from the routine use of myocardial contrast echo. The reference technique still remains myocardial scintigraphy even though many theoretical problems are being discussed. Part 8: Implementing ultrasound contrast in the echocardiography laboratory. Contrast echocardiography should be considered an extension of the existing echocardiographic examination. Standard laboratory equipment is sufficient to run a contrast echocardiography program. However, cultural and technological upgrading is mandatory to obtain good results in contrast echocardiography. Intravenous infusion is easier during stress echocardiography than during rest study, because the time and cost for the venous line are comprised. In this setting, the cost-effectiveness for the addition of contrast agent is optimal, but patient selection is a critical point. The economic issue (contrast agent and personnel costs, and time needed) of contrast echocardiography determines the fact that without adequate reimbursement there is no incentive to perform the procedure

Oncological Applications of Positron Emission Tomography with Fluorine-18 Fluorodeoxyglucose

Positron emission tomography (PET) is now primarily used in oncological indication owing to the successful application of fluorine-18 fluorodeoxyglucose (FDG) in an increasing number of clinical indications at different stages of diagnosis, and for staging and follow-up. This review first considers the biological characteristics of FDG and then discusses methodological considerations regarding its use. Clinical indications are considered, and the results achieved in respect of various organs and tumour types are reviewed in depth. The review concludes with a brief consideration of the ways in which clinical PET might be improved