National, regional, and global trends in systolic blood pressure since 1980: systematic analysis of health examination surveys and epidemiological studies with 786 country-years and 5·4 million participants

Common genetic variants in the endothelial system predict blood pressure response to sodium intake: the GenSalt study

BACKGROUND We examined the association between 14 endothelial system genes and salt-sensitivity of blood pressure (BP). METHODS After a 3-day baseline examination, during which time the usual diet was consumed, 1,906 Chinese participants received a 7-day low-sodium diet (51.3 mmol of sodium/day) followed by a 7-day high-sodium diet (307.8 mmol of sodium/day). BP measurements were obtained at baseline and at the end of each intervention using a random-zero sphygmomanometer. RESULTS The DDAH1 rs11161637 variant was associated with reduced BP salt sensitivity, conferring attenuated systolic BP (SBP) and mean arterial pressure (MAP) decreases from baseline to the low-sodium intervention (both P = 2×10(-4)). Examination of genotype-sex interactions revealed that this relation was driven by the strong associations observed in men (P for interactions = 1.10×10(-4) and 0.008, respectively). When switching from the low- to high-sodium intervention, increases in diastolic BP (DBP) and MAP were attenuated by the COL18A1 rs2838944 minor A allele (P = 1.41×10(-4) and 1.55×10(-4), respectively). Conversely, the VWF rs2239153 C variant was associated with increased salt sensitivity, conferring larger DBP and MAP reductions during low-sodium intervention (P = 1.22×10(-4) and 4.44×10(-5), respectively). Ten variants from 3 independent SELE loci displayed significant genotype-sex interactions on DBP and MAP responses to low-sodium (P for interaction = 1.56×10(-3) to 1.00×10(-4)). Among men, minor alleles of 4 correlated markers attenuated BP responses to low-sodium intake, whereas minor alleles of another 4 correlated markers increased BP responses. No associations were observed in women for these variants. Further, qualitative interactions were shown for 2 correlated SELE markers. CONCLUSIONS These data support a role for the endothelial system genes in salt sensitivity.

Whole grains and health: from theory to practice--highlights of The Grains for Health Foundation's Whole Grains Summit 2012

The Grains for Health Foundation's Whole Grains Summit, held May 19-22, 2012 in Minneapolis, was the first meeting of its kind to convene >300 scientists, educators, food technologists, grain breeders, food manufacturers, marketers, health professionals, and regulators from around the world. Its goals were to identify potential avenues for collaborative efforts and formulate new approaches to whole-grains research and health communications that support global public health and business. This paper summarizes some of the challenges and opportunities that researchers and nutrition educators face in expanding the knowledge base on whole grains and health and in translating and disseminating that knowledge to consumers. The consensus of the summit was that effective, long-term, public-private partnerships are needed to reach across the globe and galvanize the whole-grains community to collaborate effectively in translating whole-grains science into strategies that increase the availability and affordability of more healthful, grain-based food products. A prerequisite of that is the need to build trust among diverse multidisciplinary professionals involved in the growing, producing, marketing, and regulating of whole-grain products and between the grain and public health communities.

Independent and combined effects of physical activity and sedentary behavior on blood pressure in adolescents: gender differences in two cross-sectional studies

Objectives

To examine the independent and combined association of physical activity (PA) and sedentary behavior (SB) on both systolic (SBP) and diastolic blood pressure (DBP) in adolescents from two observational studies.

Methods

Participants from two cross-sectional studies, one conducted in Europe (n = 3,308; HELENA study) and the other in Brazil (n = 991; BRACAH study), were selected by complex sampling. Systolic and diastolic blood pressure (outcomes), PA and SB, both independently and combined, and potential confounders were analyzed. Associations were examined by multilevel linear regression.

Results

Performing the recommended amount of PA (≥60 min/d) attenuated the effect of SB on DBP in BRACAH study girls and in boys from both studies. In contrast, PA did not attenuate the effects of SB on the SBP of girls in the HELENA study. The combination of less than recommended levels of PA with 2–4 h/d of sedentary behavior was found to be associated with increased SBP in boys from both studies.

Conclusions

Meeting current PA recommendations could mediate the association between SB and DBP in both sexes. In boys, the joint effect of low levels of PA and excessive sedentary activity increases SBP levels. Longitudinal studies are required to confirm these findings.

Clinical correlates of change in inflammatory biomarkers: The Framingham Heart Study

OBJECTIVES

Traditional clinical risk factors are associated with inflammation cross-sectionally, but associations of longitudinal variation in inflammatory biomarkers with corresponding changes in clinical risk factors are incompletely described. We sought to analyze clinical factors associated with change in inflammation in the community.

METHODS

We studied 3013 Framingham Offspring (n = 2735) and Omni Cohort (n = 278) participants (mean age 59 years, 55% women, 9% ethnic/racial minority) who attended two consecutive examination cycles (mean 6.7 years apart). We selected ten inflammatory biomarkers representing distinctive biological functions: C-reactive protein (CRP), intercellular adhesion molecule-1, interleukin-6, isoprostanes, lipoprotein-associated phospholipase-2 (Lp-PLA2) activity, Lp-PLA2-mass, monocyte chemoattractant protein-1, osteoprotegerin, P-selectin, and tumor necrosis factor receptor II (TNFRII). We constructed multivariable-adjusted regression models to assess the relations of baseline, follow-up and change in clinical risk factors with change in biomarker concentrations over time.

RESULTS

Baseline, follow-up and change in clinical risk factors explain a moderate amount of the variation in biomarker concentrations across 2 consecutive examinations (ranging from r(2) = 0.28 [TNFRII] up to 0.52 [Lp-PLA2-mass]). In multivariable models, increasing body-mass index, smoking initiation, worsening lipid profile, and increasing waist size were associated with increasing concentrations of several biomarkers. Conversely, hypercholesterolemia therapy and hormone replacement cessation were associated with decreasing concentrations of biomarkers such as CRP, Lp-PLA2-mass and activity.

CONCLUSION

Cardiovascular risk factors have different patterns of association with longitudinal change in inflammatory biomarkers and explain modest amounts of variability in biomarker concentrations. Nevertheless, a substantial proportion of longitudinal change in inflammatory markers is not explained by traditional risk factors.

Non-communicable disease: a welcome and long needed addition to the WHO's 2012 World Heath Statistics

The World Health Organization's annual report World Health Statistics 2012 was recently published. In addition to annually published indicators of health, this year's report contains a highlighted new section on non-communicable diseases and their impact on world health. The section gives particular attention to hypertension and obesity. Interestingly, despite worldwide increases in obesity and metabolic syndrome, hypertension rates have actually improved in wealthy nations since 1980, while rates have greatly increased in developing regions and particularly in Africa. Potential contributors to these disparities likely include access to screening and treatment, and the rise of high sodium and low potassium processed foods in poorer nations. It will be imperative in years to come to identify and employ the success seen in wealthy nations worldwide to improve outcomes and productivity in the developing world.

Dairy and blood pressure: a fresh look at the evidence

The Dietary Guidelines for Americans, 2010 indicated there is moderate evidence for an association between the consumption of dairy foods and lower blood pressure in adults; however, it also stated that more evidence was needed, especially in clinical trials, to fully delineate a causal relationship. The purpose of this review is to provide background by examining the historical literature and the evidence reviewed by the 2010 Dietary Guidelines Advisory Committee, to examine the gaps in knowledge indicated by that committee, and to determine if recently published evidence is sufficient to elucidate or dismiss an association between dairy foods and blood pressure maintenance. Examination of the newly published literature, together with evaluation of the evidence as a whole, shows that the preponderance of evidence indicates dairy foods are beneficially associated with blood pressure; however, additional research is necessary to identify the mechanism of action of dairy foods. New evidence should come from carefully designed clinical trials that examine not only blood pressure outcomes but also the ability of dairy foods to affect the vasculature.

The global cardiovascular risk transition: associations of four metabolic risk factors with national income, urbanization, and Western diet in 1980 and 2008

BACKGROUND

It is commonly assumed that cardiovascular disease risk factors are associated with affluence and Westernization. We investigated the associations of body mass index (BMI), fasting plasma glucose, systolic blood pressure, and serum total cholesterol with national income, Western diet, and, for BMI, urbanization in 1980 and 2008.

METHODS AND RESULTS

Country-level risk factor estimates for 199 countries between 1980 and 2008 were from a previous systematic analysis of population-based data. We analyzed the associations between risk factors and per capita national income, a measure of Western diet, and, for BMI, the percentage of the population living in urban areas. In 1980, there was a positive association between national income and population mean BMI, systolic blood pressure, and total cholesterol. By 2008, the slope of the association between national income and systolic blood pressure became negative for women and zero for men. Total cholesterol was associated with national income and Western diet in both 1980 and 2008. In 1980, BMI rose with national income and then flattened at ≈Int$7000; by 2008, the relationship resembled an inverted U for women, peaking at middle-income levels. BMI had a positive relationship with the percentage of urban population in both 1980 and 2008. Fasting plasma glucose had weaker associations with these country macro characteristics, but it was positively associated with BMI.

CONCLUSIONS

The changing associations of metabolic risk factors with macroeconomic variables indicate that there will be a global pandemic of hyperglycemia and diabetes mellitus, together with high blood pressure in low-income countries, unless effective lifestyle and pharmacological interventions are implemented.

The rising burden of diabetes and hypertension in southeast asian and african regions: need for effective strategies for prevention and control in primary health care settings

Aim. To review the available literature on burden of diabetes mellitus (DM) and hypertension (HTN) and its coexistence in Southeast Asian (SEA) and the African (AFR) regions and to suggest strategies to improve DM and HTN prevention and control in primary health care (PHC) in the two regions. Methods. A systematic review of the papers published on DM, HTN, and prevention/control of chronic diseases in SEA and AFR regions between 1980 and December 2012 was included. Results. In the year 2011, SEA region had the second largest number of people with DM (71.4 million), while the AFR region had the smallest number (14.7 million). Screening studies identified high proportions (>50%) of individuals with previously undiagnosed HTN and DM in both of the SEA and AFR regions. Studies from both regions have shown that DM and HTN coexist in type 2 DM ranging from 20.6% in India to 78.4% in Thailand in the SEA region and ranging from 9.7% in Nigeria to 70.4% in Morocco in the AFR region. There is evidence that by lifestyle modification both DM and HTN can be prevented. Conclusion. To meet the twin challenge of DM and HTN in developing countries, PHCs will have to be strengthened with a concerted and multipronged effort to provide promotive, preventive, curative, and rehabilitative services.

Innovations in medical care and mortality trends from four circulatory diseases between 1970 and 2005

BACKGROUND

Governments have identified innovation in pharmaceuticals and medical technology as a priority for health policy. Although the contribution of medical care to health has been studied extensively in clinical settings, much less is known about its contribution to population health. We examine how innovations in the management of four circulatory disorders have influenced trends in cause-specific mortality at the population level.

METHODS

Based on literature reviews, we selected six medical innovations with proven effectiveness against hypertension, ischaemic heart disease, heart failure and cerebrovascular disease. We combined data on the timing of these innovations and cause-specific mortality trends (1970-2005) from seven European countries. We sought to identify associations between the introduction of innovations and favourable changes in mortality, using Joinpoint-models based on linear spline regression.

RESULTS

For both ischaemic heart disease and cerebrovascular disease, the timing of medical innovations was associated with improved mortality in four out of five countries and five out of seven countries, respectively, depending on the innovation. This suggests that innovation has impacted positively on mortality at the population level. For hypertension and heart failure, such associations could not be identified.

CONCLUSION

Although improvements in cause-specific mortality coincide with the introduction of some innovations, this is not invariably true. This is likely to reflect the incremental effects of many interventions, the time taken for them to be adopted fully and the presence of contemporaneous changes in disease incidence. Research on the impact of medical innovations on population health is limited by unreliable data on their introduction.

High blood pressure in a semi-urban community in south-south Nigeria: a community-based study

BACKGROUND

Non communicable diseases (NCDs) are taking their toll in most low and middle income countries; incidentally, in the same populations that are struggling to deal with communicable diseases, hence presenting a picture of "double tragedy". Most of the researches conducted on NCDs are facility-based; often in urban locations.

OBJECTIVE

To determine the prevalence of high BP in a semi-urban community in Nigeria.

METHODS

It was a cross-sectional study, where all the adult residents of the community were enrolled. Data was collected using a multi-section questionnaire, including anthropometric measurements. Data entry and analysis was done using SPSS 17.0 for windows and STATA 10.

RESULTS

The results showed that 47.0% of the study population had a raised BP ≥140/90mmHg. At a univariate level, age, sex, higher income, more people in the household, daily cigarette smoking, daily alcohol intake and BMI, showed increased risk for high BP. However, sleeping for at least 8 hours a day showed protective influence against raised BP among the participants. In the adjusted model, only age, sex and BMI remained statistically significant with Odds Ratio (OR) of 1.04 (95%CI; 1.00, 1.08), 0.45 (95%CI; 0.22, 0.90) and 1.08(95%CI; 1.03, 1.13) respectively. The model had an area under curve of 71.9%.

CONCLUSION

It was concluded that there is a high prevalence of raised BP in this semi-urban community, thus the need for intervention and preventive services to curb the looming epidemic of hypertension in this community in particular, and Nigeria as a whole, cannot be overemphasized.

Education, household wealth and blood pressure in Albania, Armenia, Azerbaijan and Ukraine: findings from the Demographic Health Surveys, 2005-2009

BACKGROUND

While socioeconomic gradients in cardiovascular disease have been well established in high-income countries, this relationship is not well understood in middle-income countries.

METHODS

Data from Demographic Health Surveys collected in Albania (2008-09), Armenia (2005), Azerbaijan (2006) and Ukraine (2007) were used to estimate age-adjusted differences in systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), hypertension (HTN), elevated blood pressure, and optimal blood pressure across a standardized wealth index, level of educational attainment, and urban versus rural residence.

RESULTS

The wealthiest Albanian females had lower average SBP, DBP, PP (all p<0.01) and HTN status (odds ratio [OR]=0.3, CI: 0.2-0.5, p<0.001) compared to the poorest; similar education gradients were also found. Such disparities also existed for Albanian men. Among Armenian women, urban (OR=1.4, 1.1-1.8, p<0.01), more educated (OR=0.7, CI: 0.6-0.9, p<0.01), and wealthier (OR=1.8, 1.4-2.4, p<0.001) women were more likely to have optimal blood pressure. Urban Armenian men were also more likely to have optimal blood pressure (OR=1.8, 1.2-2.9, p<0.01). Wealthier and urban Azerbaijani had lower risk of elevated blood pressure and Azerbaijani women displayed strong wealth gradients with higher quintiles of wealth associated with lower continuous blood pressure measures. There were no socioeconomic gradients for Ukrainian males or females.

CONCLUSIONS

There is compelling evidence that wealth and education gradients affect the probability of HTN for women in Albania, Armenia, and Azerbaijan, and for men in Albania.

High energy diets-induced metabolic and prediabetic painful polyneuropathy in rats

To establish the role of the metabolic state in the pathogenesis of polyneuropathy, an age- and sex-matched, longitudinal study in rats fed high-fat and high-sucrose diets (HFSD) or high-fat, high-sucrose and high-salt diets (HFSSD) relative to controls was performed. Time courses of body weight, systolic blood pressure, fasting plasma glucose (FPG), insulin, free fatty acids (FFA), homeostasis model assessment-insulin resistance index (HOMA-IR), thermal and mechanical sensitivity and motor coordination were measured in parallel. Finally, large and small myelinated fibers (LMF, SMF) as well as unmyelinated fibers (UMF) in the sciatic nerves and ascending fibers in the spinal dorsal column were quantitatively assessed under electron microscopy. The results showed that early metabolic syndrome (hyperinsulinemia, dyslipidemia, and hypertension) and prediabetic conditions (impaired fasting glucose) could be induced by high energy diet, and these animals later developed painful polyneuropathy characterized by myelin breakdown and LMF loss in both peripheral and central nervous system. In contrast SMF and UMF in the sciatic nerves were changed little, in the same animals. Therefore the phenomenon that high energy diets induce bilateral mechanical, but not thermal, pain hypersensitivity is reflected by severe damage to LMF, but mild damage to SMF and UMF. Moreover, dietary sodium (high-salt) deteriorates the neuropathic pathological process induced by high energy diets, but paradoxically high salt consumption, may reduce, at least temporarily, chronic pain perception in these animals.

Effect of a fixed combination of Perindopril and Amlodipine on blood pressure control in 6256 patients with not-at-goal hypertension: the AVANT'AGE study

In clinical practice, general practitioners are likely to face hypertensives with uncontrolled blood pressure (BP), whose antihypertensive treatment need to be modified. In the present study, 710 general practitioners have each included the first 10 patients with not-at-goal hypertension, for whom they decided to modify their antihypertensive treatment with addition of a fixed combination of Perindopril and Amlodipine at either of its four dosages: 5/5, 5/10, 10/5, or 10/10 mg. In total, 6256 patients were included, with BP measured both at baseline and after 3 months. At the end of follow-up, a mean reduction of 20.3 ± 12.4 mm Hg in systolic BP and 11.3 ± 9.6 mm Hg in diastolic BP were observed, and 62.3% achieved successful BP control. Body mass index and waist circumference were significant determinants of both systolic and diastolic BP reductions (P ≤ .04). Moreover, in addition to baseline BP level, body mass index was the only significant determinant of BP control of systolic, diastolic BP, and of both (P ≤ .04). Addition of a fixed combination of Perindopril and Amlodipine to BP regimen was efficient, in terms of BP control, for 62.3% of those patients with not-at-goal hypertension. Furthermore, baseline BP level and obesity were important influential factors of BP control.

Inequalities in non-communicable diseases and effective responses

In most countries, people who have a low socioeconomic status and those who live in poor or marginalised communities have a higher risk of dying from non-communicable diseases (NCDs) than do more advantaged groups and communities. Smoking rates, blood pressure, and several other NCD risk factors are often higher in groups with low socioeconomic status than in those with high socioeconomic status; the social gradient also depends on the country's stage of economic development, cultural factors, and social and health policies. Social inequalities in risk factors account for more than half of inequalities in major NCDs, especially for cardiovascular diseases and lung cancer. People in low-income countries and those with low socioeconomic status also have worse access to health care for timely diagnosis and treatment of NCDs than do those in high-income countries or those with higher socioeconomic status. Reduction of NCDs in disadvantaged groups is necessary to achieve substantial decreases in the total NCD burden, making them mutually reinforcing priorities. Effective actions to reduce NCD inequalities include equitable early childhood development programmes and education; removal of barriers to secure employment in disadvantaged groups; comprehensive strategies for tobacco and alcohol control and for dietary salt reduction that target low socioeconomic status groups; universal, financially and physically accessible, high-quality primary care for delivery of preventive interventions and for early detection and treatment of NCDs; and universal insurance and other mechanisms to remove financial barriers to health care.

The prevalence and mechanisms of metabolic syndrome in schizophrenia: a review

Metabolic syndrome (MetS), a constellation of central obesity, hypertension, dyslipidaemia and glucose intolerance, is highly prevalent in individuals with schizophrenia and conveys significant cardiovascular risk and mortality. Associated risk factors are female sex, some ethnic groups, advanced age, long duration of illness, smoking and exposure to antipsychotic agents. The prevalence of MetS varies across countries and psychiatric populations, and its development can be very rapid. Regular monitoring of all features of MetS is the cornerstone of its early detection and management. Future research needs to focus more on genetic determinants of MetS in the context of schizophrenic illness. This review aims to update the reader with the latest knowledge about the prevalence of MetS in schizophrenia and what might be the underlying pathophysiological mechanisms.

Analysis of sex hormone genes reveals gender differences in the genetic etiology of blood pressure salt sensitivity: the GenSalt study

BACKGROUND

We examined the association between 799 single-nucleotide polymorphisms in 39 sex hormone genes and blood pressure (BP) responses to a dietary-sodium intervention.

METHODS

A 7-day low-sodium feeding study (51.3 mmol sodium/day) followed by a 7-day high-sodium feeding study (307.8 mmol sodium/day) was conducted among 1,906 Han Chinese participants. Nine BP measurements were obtained at baseline and the end of each intervention period using a random-zero sphygmomanometer.

RESULTS

Among men, absolute BP responses to sodium interventions decreased with the number of minor alleles of estrogen receptor 1 (ESR1) markers rs9340844, rs9397453, rs9371562, rs9397459, and rs9383951. For example, mean diastolic blood pressure (DBP) responses to low-sodium intervention (95% confidence interval) were -2.67 (-3.13, -2.22) mm Hg among those with the rs9397453 C/C genotype, -1.23 (-1.98, -0.48) mm Hg among those with the C/T genotype, and 0.08 (-2.31, 2.47) mm Hg among those with the T/T genotype (P = 1×10(-4); false discovery rate (FDR)-q = 0.04). Mean DBP responses to high sodium according to the rs9397453 genotypes were 1.46 (1.03, 1.89) mm Hg among those with C/C, 0.19 (-0.54, 0.91) mm Hg among those with C/T, and -1.10 (-2.82, 0.61) mm Hg among those with T/T (P = 2×10(-4); FDR-q = 0.04). Similar trends were noted for the association between these ESR1 variants and SBP responses to the dietary intervention. There were no significant associations between sex hormone gene variants and salt sensitivity in women, with genotype-gender interactions noted for the ESR1 markers that achieved significance in men.

CONCLUSIONS

We identified strong, consistent associations between ESR1 gene variants and salt sensitivity in men. Our results support a gender-specific role for ESR1 in the etiology of this complex trait.

Tackling non-communicable diseases in low- and middle-income countries: is the evidence from high-income countries all we need?

Shah Ebrahim and colleagues argue that more research on non-communicable diseases (NCDs) in both high-income countries and low- and middle-income countries can result in mutual benefits and will help better address the growing burden of NCDs.

Normotension, prehypertension, and hypertension in urban middle-class subjects in India: prevalence, awareness, treatment, and control

OBJECTIVE

We conducted a multisite study to determine the prevalence and determinants of normotension, prehypertension, and hypertension, and awareness, treatment, and control of hypertension among urban middle-class subjects in India.

METHODS

We evaluated 6,106 middle-class urban subjects (men 3,371; women, 2,735; response rate, 62%) in 11 cities for sociodemographic and biological factors. The subjects were classified as having normotension (BP < 120/80), prehypertension (BP 120-139/80-89), and hypertension (documented or BP ≥ 140/90). The prevalence of other cardiovascular risk factors was determined and associations evaluated through logistic regression analysis.

RESULTS

The age-adjusted prevalences in men and women of normotension were 26.7% and 39.1%, of prehypertension 40.2% and 30.1%, and of hypertension 32.5% and 30.4%, respectively. The prevalence of normotension declined with age whereas that of hypertension increased (P-trend < 0.01). A significant association of normotension was found with younger age, low dietary fat intake, lower use of tobacco, and low obesity (P < 0.05). The prevalence of hypercholesterolemia, diabetes, and metabolic syndrome was higher in the groups with prehypertension and hypertension than in the group with normotension (age-adjusted odds ratios (ORs) 2.0-5.0, P < 0.001). The prevalences in men and women, respectively, of two or more risk factors were 11.1% and 6.4% in the group with normotension, 25.1% and 23.3% in the group with prehypertension, and 38.3% and 39.1% in the group with hypertension (P < 0.01). Awareness of hypertension in the study population was in 55.3%; 36.5% of the hypertensive group were receiving treatment for hypertension, and 28.2% of this group had a controlled BP (< 140/90 mm Hg).

CONCLUSIONS

The study found a low prevalence of normotension and high prevalence of hypertension in middle-class urban Asian Indians. Significant associations of hypertension were found with age, dietary fat, consumption of fruits and vegetables, smoking, and obesity. Normotensive individuals had a lower prevalence of cardiometabolic risk factors than did members of the prehypertensive or hypertensive groups. Half of the hypertensive group were aware of having hypertension, a third were receiving treatment for it, and quarter had a controlled BP.

Predicting Changes in Cardiovascular Risk Factors in Type 2 Diabetes in the Post-UKPDS Era: Longitudinal Analysis of the Swedish National Diabetes Register

The aim of the current study was to provide updated time-path equations for risk factors of type-2-diabetes-related cardiovascular complications for application in risk calculators and health economic models. Observational data from the Swedish National Diabetes Register were analysed using Generalized Method of Moments estimation for dynamic panel models (N = 5,043, aged 25-70 years at diagnosis in 2001-2004). Validation was performed using persons diagnosed in 2005 (n = 414). Results were compared with the UKPDS outcome model. The value of the risk factor in the previous year was the main predictor of the current value of the risk factor. People with high (low) values of risk factor in the year of diagnosis experienced a decreasing (increasing) trend over time. BMI was associated with elevations in all risk factors, while older age at diagnosis and being female generally corresponded to lower levels of risk factors. Updated time-path equations predicted risk factors more precisely than UKPDS outcome model equations in a Swedish population. Findings indicate new time paths for cardiovascular risk factors in the post-UKPDS era. The validation analysis confirmed the importance of updating the equations as new data become available; otherwise, the results of health economic analyses may be biased.

Obesity and diabetic kidney disease

Obesity and diabetes are major causes of CKD and ESRD, and are thus enormous health concerns worldwide. Both obesity and diabetes, along with other elements of the metabolic syndrome including hypertension, are highly interrelated and contribute to the development and progression of renal disease. Studies show that multiple factors act in concert to initially cause renal vasodilation, glomerular hyperfiltration, and albuminuria, leading to the development of glomerulopathy. The coexistence of hypertension contributes to the disease progression, which, if not treated, may lead to ESRD. Although early intervention and management of body weight, hyperglycemia, and hypertension are imperative, novel therapeutic approaches are also necessary to reduce the high morbidity and mortality associated with both obesity-related and diabetes-related renal disease.

Change in the body mass index distribution for women: analysis of surveys from 37 low- and middle-income countries

BACKGROUND

There are well-documented global increases in mean body mass index (BMI) and prevalence of overweight (BMI ≥ 25.0 kg/m(2)) and obese (BMI ≥ 30.0 kg/m(2)). Previous analyses, however, have failed to report whether this weight gain is shared equally across the population. We examined the change in BMI across all segments of the BMI distribution in a wide range of countries, and assessed whether the BMI distribution is changing between cross-sectional surveys conducted at different time points.

METHODS AND FINDINGS

We used nationally representative surveys of women between 1991-2008, in 37 low- and middle-income countries from the Demographic Health Surveys ([DHS] n = 732,784). There were a total of 96 country-survey cycles, and the number of survey cycles per country varied between two (21/37) and five (1/37). Using multilevel regression models, between countries and within countries over survey cycles, the change in mean BMI was used to predict the standard deviation of BMI, the prevalence of underweight, overweight, and obese. Changes in median BMI were used to predict the 5th and 95th percentile of the BMI distribution. Quantile-quantile plots were used to examine the change in the BMI distribution between surveys conducted at different times within countries. At the population level, increasing mean BMI is related to increasing standard deviation of BMI, with the BMI at the 95th percentile rising at approximately 2.5 times the rate of the 5th percentile. Similarly, there is an approximately 60% excess increase in prevalence of overweight and 40% excess in obese, relative to the decline in prevalence of underweight. Quantile-quantile plots demonstrate a consistent pattern of unequal weight gain across percentiles of the BMI distribution as mean BMI increases, with increased weight gain at high percentiles of the BMI distribution and little change at low percentiles. Major limitations of these results are that repeated population surveys cannot examine weight gain within an individual over time, most of the countries only had data from two surveys and the study sample only contains women in low- and middle-income countries, potentially limiting generalizability of findings.

CONCLUSIONS

Mean changes in BMI, or in single parameters such as percent overweight, do not capture the divergence in the degree of weight gain occurring between BMI at low and high percentiles. Population weight gain is occurring disproportionately among groups with already high baseline BMI levels. Studies that characterize population change should examine patterns of change across the entire distribution and not just average trends or single parameters.

Trends in blood pressure in 9 to 11-year-old children in the United Kingdom 1980-2008: the impact of obesity

OBJECTIVES

High blood pressure (BP) is a major public health issue, both in the United Kingdom and worldwide. Although BP levels in UK adults are declining, there is little published information on BP trends in children, a particular concern in the context of the rising levels of childhood adiposity. Our aims are to determine whether BP in children has changed over time and whether the change reflected trends in adiposity.

METHODS

We collated data from seven population-based BP studies conducted in the United Kingdom between 1980 and 2008. Children of white European origin were included (9-11 years, mean 10.3 years). Adjustments were made to account for differences in mean ages, BP devices and cuff sizes used in different studies.

RESULTS

Mean SBP increased over time both in boys and girls: annual increases were 0.45 mmHg (95% CI: 0.43, 0.48) for boys; 0.51 mmHg (0.49, 0.53) for girls. Mean BMI increased by 0.064 kg/m(2) (0.060, 0.068) per year for boys; 0.070 kg/m(2) (0.065, 0.074) for girls; the prevalence of overweight/obesity increased from 5.7 to 21.1% and from 9.7 to 24.1%, respectively. The SBP trends occurred both in children with low and high BMI, but were more marked in low BMI group; BMI explained only 15.3% (15.1%, 15.6%) of increases in SBP for boys and 14.9% (14.6%, 15.1%) for girls. The BMI/SBP association appeared to become weaker over time (P < 0.001 for negative interaction from 1984). There was only a modest annual increase in DBP (<0.1 mmHg).

CONCLUSIONS

SBP levels have increased with time, but the increase is not explained by increased BMI. Further research is needed to identify the factors responsible.

Changes in prevalence, awareness, treatment and control of hypertension in Thai population, 2004-2009: Thai National Health Examination Survey III-IV

OBJECTIVE

To determine the changes in prevalence, awareness, treatment and control of hypertension and their metabolic risk factors in Thai population between 2004 and 2009.

METHODS

The Thai National Health Examination Survey (NHES) in 2004 and 2009 data were used. Blood pressure and anthropometric measurements were performed. Prevalence, awareness, treatment and control of hypertension of Thai population aged at least 15 years were calculated. Analyses were weighted to the probability of sampling.

RESULTS

The prevalence of hypertension in 2004 and 2009 were relatively stable at approximately 21.0%. There was improvement in awareness of hypertension, from 18.2% for men and 33.0% for women in 2004 to 39.5 and 59.4% in 2009, respectively. The high blood pressure control rates improved from 4.8 to 14.4% for men and from 10.8 to 27.2% for women, respectively (all P < 0.05). The improvement in awareness, treatment and control of hypertension was also observed in individuals with diabetes, obesity and hypercholesterolemia. However, among hypertensive individuals, there were increases in proportions of obesity (BMI ≥ 25 kg/m(2)) between two surveys: from 39.1 to 47.5% in men and from 54.6 to 62.9% in women, respectively (all P < 0.05).

CONCLUSION

Despite improvement in awareness and control of hypertension in Thai population, a large proportion of hypertensive individuals remained suboptimally controlled. Strengthening measures to control high blood pressure and metabolic risk factors, especially obesity and hypercholesterolemia, in individuals with hypertension are needed.

A comparative risk assessment of burden of disease and injury attributable to 67 risk factors and risk factor clusters in 21 regions, 1990-2010: a systematic analysis for the Global Burden of Disease Study 2010

BACKGROUND

Quantification of the disease burden caused by different risks informs prevention by providing an account of health loss different to that provided by a disease-by-disease analysis. No complete revision of global disease burden caused by risk factors has been done since a comparative risk assessment in 2000, and no previous analysis has assessed changes in burden attributable to risk factors over time.

METHODS

We estimated deaths and disability-adjusted life years (DALYs; sum of years lived with disability [YLD] and years of life lost [YLL]) attributable to the independent effects of 67 risk factors and clusters of risk factors for 21 regions in 1990 and 2010. We estimated exposure distributions for each year, region, sex, and age group, and relative risks per unit of exposure by systematically reviewing and synthesising published and unpublished data. We used these estimates, together with estimates of cause-specific deaths and DALYs from the Global Burden of Disease Study 2010, to calculate the burden attributable to each risk factor exposure compared with the theoretical-minimum-risk exposure. We incorporated uncertainty in disease burden, relative risks, and exposures into our estimates of attributable burden.

FINDINGS

In 2010, the three leading risk factors for global disease burden were high blood pressure (7·0% [95% uncertainty interval 6·2-7·7] of global DALYs), tobacco smoking including second-hand smoke (6·3% [5·5-7·0]), and alcohol use (5·5% [5·0-5·9]). In 1990, the leading risks were childhood underweight (7·9% [6·8-9·4]), household air pollution from solid fuels (HAP; 7·0% [5·6-8·3]), and tobacco smoking including second-hand smoke (6·1% [5·4-6·8]). Dietary risk factors and physical inactivity collectively accounted for 10·0% (95% UI 9·2-10·8) of global DALYs in 2010, with the most prominent dietary risks being diets low in fruits and those high in sodium. Several risks that primarily affect childhood communicable diseases, including unimproved water and sanitation and childhood micronutrient deficiencies, fell in rank between 1990 and 2010, with unimproved water and sanitation accounting for 0·9% (0·4-1·6) of global DALYs in 2010. However, in most of sub-Saharan Africa childhood underweight, HAP, and non-exclusive and discontinued breastfeeding were the leading risks in 2010, while HAP was the leading risk in south Asia. The leading risk factor in Eastern Europe, most of Latin America, and southern sub-Saharan Africa in 2010 was alcohol use; in most of Asia, North Africa and Middle East, and central Europe it was high blood pressure. Despite declines, tobacco smoking including second-hand smoke remained the leading risk in high-income north America and western Europe. High body-mass index has increased globally and it is the leading risk in Australasia and southern Latin America, and also ranks high in other high-income regions, North Africa and Middle East, and Oceania.

INTERPRETATION

Worldwide, the contribution of different risk factors to disease burden has changed substantially, with a shift away from risks for communicable diseases in children towards those for non-communicable diseases in adults. These changes are related to the ageing population, decreased mortality among children younger than 5 years, changes in cause-of-death composition, and changes in risk factor exposures. New evidence has led to changes in the magnitude of key risks including unimproved water and sanitation, vitamin A and zinc deficiencies, and ambient particulate matter pollution. The extent to which the epidemiological shift has occurred and what the leading risks currently are varies greatly across regions. In much of sub-Saharan Africa, the leading risks are still those associated with poverty and those that affect children.

FUNDING

Bill & Melinda Gates Foundation.

Spatial parasite ecology and epidemiology: a review of methods and applications

The distributions of parasitic diseases are determined by complex factors, including many that are distributed in space. A variety of statistical methods are now readily accessible to researchers providing opportunities for describing and ultimately understanding and predicting spatial distributions. This review provides an overview of the spatial statistical methods available to parasitologists, ecologists and epidemiologists and discusses how such methods have yielded new insights into the ecology and epidemiology of infection and disease. The review is structured according to the three major branches of spatial statistics: continuous spatial variation; discrete spatial variation; and spatial point processes.

Use of alternative time scales in Cox proportional hazard models: implications for time-varying environmental exposures

Issues surrounding choice of time scales in Cox proportional hazard regression models have received limited attention in the literature. Although the choice between time on study and 'attained' age time scales has been examined, the calendar time scale may be of interest when modeling health effects of environmental exposures with noteworthy secular trends such as ambient particulate matter air pollution in large epidemiological cohort studies. The authors use simulation studies to examine performance (bias, mean squared error, coverage probabilities, and power) of models using all three time scales when the primary exposure of interest depends on calendar time. Results show that performance of models fit to the calendar time scale varies inversely with the strength of the linear association between the time-varying primary exposure and calendar time. Although models fit to attained age and time on study that do not adjust for calendar time were relatively robust, the authors conclude that care should be exercised when using time scales that are highly correlated with exposures of interest.

Incidence of hypertension in a prospective cohort study of adults from Porto, Portugal

Background

During the past 30 years, Portugal has been described as one of the countries with highest median blood pressure levels in Europe, but the incidence of hypertension is unknown. The aim of this study was to estimate the incidence of hypertension, according to socio-demographic characteristics and lifestyles.

Methods

A population-based cohort of randomly selected dwellers from Porto, Portugal, aged ≥18 years, was assembled in 1999–2003 (EPIPorto study) and 796 hypertension-free individuals (62.6% women) were reassessed after a median of 3.8 years. Hypertension was defined as blood pressure ≥140/90 mmHg and/or antihypertensive drug therapy. Incidence rate ratios (IRR) were estimated using Poisson regression.

Results

The overall incidence rate was 47.3 [95% confidence interval (95% CI): 40.5-55.5] per 1000 person-years. Among women, the incidence was 43.4 (35.6-53.1) and among men 52.7 (41.3-68.0) per 1000 person-years. The incidence was lower in women up to 60 years and much higher among women above 60 (110.0 vs. 64.4 per 1000 person-years among men, p for age-sex interaction=0.032). Participants with higher education had a lower risk of becoming hypertensive (≥13 years vs. ≤4 years: RR=0.70, 95% CI, 0.46-1.08, p for linear trend <0.001), independently of age and sex. Overweight and obesity were associated with a 1.67-fold and 2.44-fold increased risk of hypertension, respectively, independently of age, sex and education.

Conclusions

In this urban Portuguese population the incidence rate of hypertension was high, with new cases occurring predominantly among older subjects, the less educated and those with overweight-obesity. Despite recent progresses in blood pressure related outcomes, the risk of hypertension remains higher in Portugal than in other developed countries.

National, regional, and global trends in adult overweight and obesity prevalences

BACKGROUND

Overweight and obesity prevalence are commonly used for public and policy communication of the extent of the obesity epidemic, yet comparable estimates of trends in overweight and obesity prevalence by country are not available.

METHODS

We estimated trends between 1980 and 2008 in overweight and obesity prevalence and their uncertainty for adults 20 years of age and older in 199 countries and territories. Data were from a previous study, which used a Bayesian hierarchical model to estimate mean body mass index (BMI) based on published and unpublished health examination surveys and epidemiologic studies. Here, we used the estimated mean BMIs in a regression model to predict overweight and obesity prevalence by age, country, year, and sex. The uncertainty of the estimates included both those of the Bayesian hierarchical model and the uncertainty due to cross-walking from mean BMI to overweight and obesity prevalence.

RESULTS

The global age-standardized prevalence of obesity nearly doubled from 6.4% (95% uncertainty interval 5.7-7.2%) in 1980 to 12.0% (11.5-12.5%) in 2008. Half of this rise occurred in the 20 years between 1980 and 2000, and half occurred in the 8 years between 2000 and 2008. The age-standardized prevalence of overweight increased from 24.6% (22.7-26.7%) to 34.4% (33.2-35.5%) during the same 28-year period. In 2008, female obesity prevalence ranged from 1.4% (0.7-2.2%) in Bangladesh and 1.5% (0.9-2.4%) in Madagascar to 70.4% (61.9-78.9%) in Tonga and 74.8% (66.7-82.1%) in Nauru. Male obesity was below 1% in Bangladesh, Democratic Republic of the Congo, and Ethiopia, and was highest in Cook Islands (60.1%, 52.6-67.6%) and Nauru (67.9%, 60.5-75.0%).

CONCLUSIONS

Globally, the prevalence of overweight and obesity has increased since 1980, and the increase has accelerated. Although obesity increased in most countries, levels and trends varied substantially. These data on trends in overweight and obesity may be used to set targets for obesity prevalence as requested at the United Nations high-level meeting on Prevention and Control of NCDs.

Is the health burden associated with obesity changing?

Prioritization of obesity prevention and management policy is based on one's understanding of the health risks associated with increasing body weight. However, there is evidence that the magnitude of these health risks may be changing over time. Here, the authors analyze the theoretical drivers of these changes and then examine whether there is empirical evidence to support the theory. They conclude that, although the mortality risks associated with increasing body weight may be decreasing over time, the overall health burden appears likely to increase.

Beta-blockers for hypertension

BACKGROUND

This review is an update of the Cochrane Review published in 2007, which assessed the role of beta-blockade as first-line therapy for hypertension.

OBJECTIVES

To quantify the effectiveness and safety of beta-blockers on morbidity and mortality endpoints in adults with hypertension.

SEARCH METHODS

In December 2011 we searched the Cochrane Central Register of Controlled Trials, Medline, Embase, and reference lists of previous reviews; for eligible studies published since the previous search we conducted in May 2006.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of at least one year duration, which assessed the effects of beta-blockers compared to placebo or other drugs, as first-line therapy for hypertension, on mortality and morbidity in adults.

DATA COLLECTION AND ANALYSIS

We selected studies and extracted data in duplicate. We expressed study results as risk ratios (RR) with 95% confidence intervals (CI) and combined them using the fixed-effects or random-effects method, as appropriate.

MAIN RESULTS

We included 13 RCTs which compared beta-blockers to placebo (4 trials, N=23,613), diuretics (5 trials, N=18,241), calcium-channel blockers (CCBs: 4 trials, N=44,825), and renin-angiotensin system (RAS) inhibitors (3 trials, N=10,828). Three-quarters of the 40,245 participants on beta-blockers used atenolol. Most studies had a high risk of bias; resulting from various limitations in study design, conduct, and data analysis.Total mortality was not significantly different between beta-blockers and placebo (RR 0.99, 95%CI 0.88 to 1.11; I(2)=0%), diuretics or RAS inhibitors, but was higher for beta-blockers compared to CCBs (RR 1.07, 95%CI 1.00 to 1.14; I(2)=2%). Total cardiovascular disease (CVD) was lower for beta-blockers compared to placebo (RR 0.88, 95%CI 0.79 to 0.97; I(2)=21%). This is primarily a reflection of the significant decrease in stroke (RR 0.80, 95%CI 0.66 to 0.96; I(2)=0%), since there was no significant difference in coronary heart disease (CHD) between beta-blockers and placebo. There was no significant difference in withdrawals from assigned treatment due to adverse events between beta-blockers and placebo (RR 1.12, 95%CI 0.82 to 1.54; I(2)=66%).The effect of beta-blockers on CVD was significantly worse than that of CCBs (RR 1.18, 95%CI 1.08-1.29; I(2)=0%), but was not different from that of diuretics or RAS inhibitors. In addition, there was an increase in stroke in beta-blockers compared to CCBs (RR 1.24, 95%CI 1.11-1.40; I(2)=0%) and RAS inhibitors (RR 1.30, 95%CI 1.11 to 1.53; I(2)=29%). However, CHD was not significantly different between beta-blockers and diuretics, CCBs or RAS inhibitors. Participants on beta-blockers were more likely to discontinue treatment due to adverse events than those on RAS inhibitors (RR 1.41, 95% CI 1.29 to 1.54; I(2)=12%), but there was no significant difference with diuretics or CCBs.

AUTHORS' CONCLUSIONS

Initiating treatment of hypertension with beta-blockers leads to modest reductions in cardiovascular disease and no significant effects on mortality. These effects of beta-blockers are inferior to those of other antihypertensive drugs. The GRADE quality of this evidence is low, implying that the true effect of beta-blockers may be substantially different from the estimate of effects found in this review. Further research should be of high quality and should explore whether there are differences between different sub-types of beta-blockers or whether beta-blockers have differential effects on younger and elderly patients.

Trends in estimated kidney function: the FINRISK surveys

We evaluated the temporary trend in estimated glomerular filtration rate (eGFR) of subjects aged from 25 to 74 years between two cross-sectional population surveys in 2002 and in 2007. The mean eGFR across age-groups, the prevalences of eGFR categories, and the prevalence of chronic kidney disease (CKD) stage 3–5 defined by eGFR\60 mL/min/1.73 m2 were defined in sex- and age-specific groups using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) Study equation. The eGFR decreased from year 2002 to 2007 across the age-groups in both genders. The prevalence of CKD stage 3–5 (eGFR\60 mL/min/1.73) increased in women from 1.8 to 3.1% (P=0.017), but not in men. In the combined analysis of both genders, CKD stage 3–5 was markedly more common in 2007 compared to 2002, with odds ratio (OR) 1.59 (95% confidence interval (CI) 1.22–2.08) remaining significant after adjusting the model for age, gender, study area, hypertension, obesity, prior cardiovascular disease, and diabetes mellitus, and being at lowest when only age, gender and waist circumference were included in the model (OR 1.34; 95% CI 1.02–1.76). To conclude, the mean eGFR decreased significantly during 2002–2007 in both sexes, and CKD stage 3–5 increased in women. This trend was concurrent with increases in mean waist circumference and in the prevalence of diabetes mellitus.

Exome sequencing of only seven Qataris identifies potentially deleterious variants in the Qatari population

The Qatari population, located at the Arabian migration crossroads of African and Eurasia, is comprised of Bedouin, Persian and African genetic subgroups. By deep exome sequencing of only 7 Qataris, including individuals in each subgroup, we identified 2,750 nonsynonymous SNPs predicted to be deleterious, many of which are linked to human health, or are in genes linked to human health. Many of these SNPs were at significantly elevated deleterious allele frequency in Qataris compared to other populations worldwide. Despite the small sample size, SNP allele frequency was highly correlated with a larger Qatari sample. Together, the data demonstrate that exome sequencing of only a small number of individuals can reveal genetic variations with potential health consequences in understudied populations.

Early life iron deficiency impairs spatial cognition in neonatal piglets

Iron deficiency is common throughout the world and has been linked to cognitive impairments. Using neonatal piglets to model human infants, we assessed the impact of iron deficiency on spatial learning and memory. Artificially reared piglets were fed 1 of 3 liquid diets with varying concentrations of iron: control (CON), mildly deficient (MID), or severely deficient (SID; 100, 25.0, or 10.0 mg iron/kg milk solids, respectively) for 4 wk. Relative to CON, SID and MID piglets had reduced hemoglobin (P < 0.05) as well as magenta skin color (P < 0.001), which correlated with hematocrit (R(2) = 0.76; P < 0.001). SID and MID hemoglobin differed at wk 3 and 4 (P < 0.05). In a hippocampal-dependent, spatial, T-maze task, SID piglets were unable to acquire the task (post hoc contrast: first vs. last day of acquisition), while MID piglets demonstrated deficits in reversal learning (P = 0.032). Iron concentrations in the liver (P < 0.001), serum (P = 0.003), and hippocampus (P = 0.004), but not prefrontal cortex, were lower in MID and SID compared with CON piglets. The level of the transferrin receptor mRNA (TFR) was greater in the prefrontal cortex of CON piglets than in MID and SID piglets (P = 0.001) but not the hippocampus. Gene expression of several neurotrophic factors and proinflammatory cytokines, as well as whole-brain and hippocampal volume, were not affected by dietary treatment. In conclusion, neonatal iron deficiency leads to cognitive impairment, which may be due in part to a reduced iron concentration in the hippocampus.

Trends in prevalence of hypertension in Brazil: a systematic review with meta-analysis

Background

The prevalence of hypertension in emerging nations was scarcely described to date. In Brazil, many population-based surveys evaluated the prevalence in cities throughout the country. However, there is no population-based nationwide study of prevalence of hypertension. In this study, we estimated the prevalence of hypertension for the country and analyzed the trends for the last three decades.

Methods

Cross-sectional and cohort studies conducted from 1980 to 2010 were independently identified by two reviewers, without language restriction, in the PubMed, Embase, LILACS, and Scielo electronic databases. Unpublished studies were identified in the Brazilian electronic database of theses and in annals of Cardiology congresses and meetings. In total, 40 studies were selected, comprising 122,018 individuals.

Results

Summary estimates of prevalence by the former WHO criteria (BP≥160/95 mmHg) in the 1980’s and 1990’s were 23.6% (95% CI 17.3–31.4%) and 19.6% (16.4–23.3%) respectively. The prevalence of hypertension by the JNC criteria (BP≥140/90 mmHg) in the 1980’s, 1990’s and 2000’s were 36.1% (95% CI 28.7–44.2%), 32.9% (29.9–36.0%), and 28.7% (26.2–31.4%), respectively (P<0.001). In the 2000’s, the pooled prevalence estimates of self-reported hypertension on telephone inquiries was 20.6% (19.0–22.4%), and of self-reported hypertension in home surveys was 25.2% (23.3–27.2%).

Conclusions

The prevalence of hypertension in Brazil seems to have diminished 6% in the last three decades, but it still is approximately 30%. Nationwide surveys by self-reporting by telephone interviews underestimate the real prevalence. Rates of blood pressure control decreased in the same period, corresponding currently to only one quarter of individuals with hypertension.