National trends in total cholesterol obscure heterogeneous changes in HDL and non-HDL cholesterol and total-to-HDL cholesterol ratio : a pooled analysis of 458 population-based studies in Asian and Western countries

Background: Although high-density lipoprotein (HDL) and non-HDL cholesterol have opposite associations with coronary heart disease, multi-country reports of lipid trends only use total cholesterol (TC). Our aim was to compare trends in total, HDL and nonHDL cholesterol and the total-to-HDL cholesterol ratio in Asian and Western countries. Methods: We pooled 458 population-based studies with 82.1 million participants in 23 Asian and Western countries. We estimated changes in mean total, HDL and non-HDL cholesterol and mean total-to-HDL cholesterol ratio by country, sex and age group. Results: Since similar to 1980, mean TC increased in Asian countries. In Japan and South Korea, the TC rise was due to rising HDL cholesterol, which increased by up to 0.17 mmol/L per decade in Japanese women; in China, it was due to rising non-HDL cholesterol. TC declined in Western countries, except in Polish men. The decline was largest in Finland and Norway, at similar to 0.4 mmol/L per decade. The decline in TC in most Western countries was the net effect of an increase in HDL cholesterol and a decline in non-HDL cholesterol, with the HDL cholesterol increase largest in New Zealand and Switzerland. Mean total-to-HDL cholesterol ratio declined in Japan, South Korea and most Western countries, by as much as similar to 0.7 per decade in Swiss men (equivalent to similar to 26% decline in coronary heart disease risk per decade). The ratio increased in China. Conclusions: HDL cholesterol has risen and the total-to-HDL cholesterol ratio has declined in many Western countries, Japan and South Korea, with only a weak correlation with changes in TC or non-HDL cholesterol.Peer reviewe

Contributions of mean and shape of blood pressure distribution to worldwide trends and variations in raised blood pressure: A pooled analysis of 1018 population-based measurement studies with 88.6 million participants

© The Author(s) 2018. Background: Change in the prevalence of raised blood pressure could be due to both shifts in the entire distribution of blood pressure (representing the combined effects of public health interventions and secular trends) and changes in its high-blood-pressure tail (representing successful clinical interventions to control blood pressure in the hypertensive population). Our aim was to quantify the contributions of these two phenomena to the worldwide trends in the prevalence of raised blood pressure. Methods: We pooled 1018 population-based studies with blood pressure measurements on 88.6 million participants from 1985 to 2016. We first calculated mean systolic blood pressure (SBP), mean diastolic blood pressure (DBP) and prevalence of raised blood pressure by sex and 10-year age group from 20-29 years to 70-79 years in each study, taking into account complex survey design and survey sample weights, where relevant. We used a linear mixed effect model to quantify the association between (probittransformed) prevalence of raised blood pressure and age-group- and sex-specific mean blood pressure. We calculated the contributions of change in mean SBP and DBP, and of change in the prevalence-mean association, to the change in prevalence of raised blood pressure. Results: In 2005-16, at the same level of population mean SBP and DBP, men and women in South Asia and in Central Asia, the Middle East and North Africa would have the highest prevalence of raised blood pressure, and men and women in the highincome Asia Pacific and high-income Western regions would have the lowest. In most region-sex-age groups where the prevalence of raised blood pressure declined, one half or more of the decline was due to the decline in mean blood pressure. Where prevalence of raised blood pressure has increased, the change was entirely driven by increasing mean blood pressure, offset partly by the change in the prevalence-mean association. Conclusions: Change in mean blood pressure is the main driver of the worldwide change in the prevalence of raised blood pressure, but change in the high-blood-pressure tail of the distribution has also contributed to the change in prevalence, especially in older age groups

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(.)(1,2) This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity(3-6). 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.Peer reviewe

P in the right place : Revisiting the evidential value of P-values

P-values are often calculated when testing hypotheses in quantitative settings, and low P-values are typically used as evidential measures to support research findings in published medical research. This article reviews old and new arguments questioning the evidential value of P-values. Critiques of the P-value include that it is confounded, fickle, and overestimates the evidence against the null. P-values may turn out falsely low in studies due to random or systematic errors. Even correctly low P-values do not logically provide support to any hypothesis. Recent studies show low replication rates of significant findings, questioning the dependability of published low P-values. P-values are poor indicators in support of scientific propositions. P-values must be inferred by a thorough understanding of the study's question, design, and conduct. Null hypothesis significance testing will likely remain an important method in quantitative analysis but may be complemented with other statistical techniques that more straightforwardly address the size and precision of an effect or the plausibility that a hypothesis is true

Power of the Pill : Views about Cardiovascular Risk and the Risk-reducing Effect of Statins

Medical treatments with statins are prescribed to patients with increased risk of cardiovascular events. The benefits from statin treatment are well documented in clinical trials, but long-term adherence in patients is low, indicating that patients have an uncertainty about the necessity and benefits of treatment. The aims of this thesis were to investigate how patients and doctors view different aspects of statin treatment. Further aims were to investigate if the cardiovascular risk level in patients affects their views about different aspects of statin treatment. Yet further aims were to compare health behaviours and views about risk factors in patients using statins to a non-treated population. Data was obtained from patients (n = 829), doctors (n = 330) and a population sample (n = 720) using postal questionnaires. Views about the effect of statin treatment were assessed in different ways for patients and doctors. Patients based their assessments on their own situation, and doctors’ treatment decisions and assessments of anticipated effect of treatment were based on two hypothetical patient cases. The results indicate that patients greatly overestimate the general effect of statins, compared to efficacy results reported from clinical trials. Patients’ previous coronary heart disease or high overall risk were factors not associated with their views and expectations of treatment effect. Statin users with an internally perceived health control and patients satisfied with their doctor’s treatment explanation reported higher beliefs in treatment necessity and benefits. Statin users reported having better health behaviours and generally rated risk factors as more important than the non-treated population. Doctors had suboptimal understanding of the number of patients expected to benefit following five years of statin treatment and had a varying understanding of statins’ ability to prolong life. Overall the results illustrate that patients and doctors have different perspectives and views of the benefits from statin treatment which puts emphasis on how statin treatment is discussed in the clinical setting

Power of the Pill : Views about Cardiovascular Risk and the Risk-reducing Effect of Statins

Medical treatments with statins are prescribed to patients with increased risk of cardiovascular events. The benefits from statin treatment are well documented in clinical trials, but long-term adherence in patients is low, indicating that patients have an uncertainty about the necessity and benefits of treatment. The aims of this thesis were to investigate how patients and doctors view different aspects of statin treatment. Further aims were to investigate if the cardiovascular risk level in patients affects their views about different aspects of statin treatment. Yet further aims were to compare health behaviours and views about risk factors in patients using statins to a non-treated population. Data was obtained from patients (n = 829), doctors (n = 330) and a population sample (n = 720) using postal questionnaires. Views about the effect of statin treatment were assessed in different ways for patients and doctors. Patients based their assessments on their own situation, and doctors’ treatment decisions and assessments of anticipated effect of treatment were based on two hypothetical patient cases. The results indicate that patients greatly overestimate the general effect of statins, compared to efficacy results reported from clinical trials. Patients’ previous coronary heart disease or high overall risk were factors not associated with their views and expectations of treatment effect. Statin users with an internally perceived health control and patients satisfied with their doctor’s treatment explanation reported higher beliefs in treatment necessity and benefits. Statin users reported having better health behaviours and generally rated risk factors as more important than the non-treated population. Doctors had suboptimal understanding of the number of patients expected to benefit following five years of statin treatment and had a varying understanding of statins’ ability to prolong life. Overall the results illustrate that patients and doctors have different perspectives and views of the benefits from statin treatment which puts emphasis on how statin treatment is discussed in the clinical setting

Health and wellbeing in informal caregivers and non-caregivers : a comparative cross-sectional study of the Swedish a general population

Background: Informal caregiving by relatives is a great resource for individuals as well as for society, but the caregiving role is associated with health problems for the caregiver. This study aimed to compare caregivers' self-rated health, number of recent days with poor health and psychological wellbeing with that of non-caregivers in a general Swedish population. Methods: From 2004 to 2013, 90,845 Swedish people completed a postal questionnaire about their health, number of recent days with poor health during last month, psychological wellbeing and if they were performing caregiving or not. Descriptive statistics, chi-square analysis, ANOVA, logistic regressions and negative binomial regression models were used to investigate associations between being a caregiver or not and health and wellbeing. Negative binomial regression was used to assess the relation between caregiver status and recent days with poor health or functioning. Results: Eleven percent reported having a caregiving role. Caregivers reported poorer self-rated health compered to non-caregivers, also in adjusted models; odds ratio (OR): 1.07 with a 95 % confidence interval (CI): 1.01-1.13. Caregivers also reported lower psychological wellbeing compared to non-caregivers; OR: 1.22, CI: 1.15-1.30. Caregiving status was associated with more recent days with poor physical health and more recent days with poor mental health. Conclusions: This study suggests that caregivers have worse perceptions in self-rated health and psychological wellbeing compared with non-caregivers, indicating that the role of caregiver is adversely associated with health. This association also appears in terms of reporting days of poor health in the last month. The underlying mechanism of these associations, including the potential detrimental health effects of being a caregiver, needs to be investigated in longitudinal studies