Body mass index and all cause mortality in HUNT and UK Biobank studies: linear and non-linear mendelian randomisation analyses

Combined associations of body mass index and adherence to a Mediterranean-like diet with all-cause and cardiovascular mortality: A cohort study

BACKGROUND

It is unclear whether the effect on mortality of a higher body mass index (BMI) can be compensated for by adherence to a healthy diet and whether the effect on mortality by a low adherence to a healthy diet can be compensated for by a normal weight. We aimed to evaluate the associations of BMI combined with adherence to a Mediterranean-like diet on all-cause and cardiovascular disease (CVD) mortality.

METHODS AND FINDINGS

Our longitudinal cohort design included the Swedish Mammography Cohort (SMC) and the Cohort of Swedish Men (COSM) (1997-2017), with a total of 79,003 women (44%) and men (56%) and a mean baseline age of 61 years. BMI was categorized into normal weight (20-24.9 kg/m2), overweight (25-29.9 kg/m2), and obesity (30+ kg/m2). Adherence to a Mediterranean-like diet was assessed by means of the modified Mediterranean-like diet (mMED) score, ranging from 0 to 8; mMED was classified into 3 categories (0 to <4, 4 to <6, and 6-8 score points), forming a total of 9 BMI × mMED combinations. We identified mortality by use of national Swedish registers. Cox proportional hazard models with time-updated information on exposure and covariates were used to calculate the adjusted hazard ratios (HRs) of mortality with their 95% confidence intervals (CIs). Our HRs were adjusted for age, baseline educational level, marital status, leisure time physical exercise, walking/cycling, height, energy intake, smoking habits, baseline Charlson's weighted comorbidity index, and baseline diabetes mellitus. During up to 21 years of follow-up, 30,389 (38%) participants died, corresponding to 22 deaths per 1,000 person-years. We found the lowest HR of all-cause mortality among overweight individuals with high mMED (HR 0.94; 95% CI 0.90, 0.98) compared with those with normal weight and high mMED. Using the same reference, obese individuals with high mMED did not experience significantly higher all-cause mortality (HR 1.03; 95% CI 0.96-1.11). In contrast, compared with those with normal weight and high mMED, individuals with a low mMED had a high mortality despite a normal BMI (HR 1.60; 95% CI 1.48-1.74). We found similar estimates among women and men. For CVD mortality (12,064 deaths) the findings were broadly similar, though obese individuals with high mMED retained a modestly increased risk of CVD death (HR 1.29; 95% CI 1.16-1.44) compared with those with normal weight and high mMED. A main limitation of the present study is the observational design with self-reported lifestyle information with risk of residual or unmeasured confounding (e.g., genetic liability), and no causal inferences can be made based on this study alone.

CONCLUSIONS

These findings suggest that diet quality modifies the association between BMI and all-cause mortality in women and men. A healthy diet may, however, not completely counter higher CVD mortality related to obesity.

All-cause mortality in metabolically healthy individuals was not predicted by overweight and obesity

BACKGROUND

Metabolically healthy obesity (MHO) and metabolically healthy overweight (MH-OW) have been suggested to be important and emerging phenotypes with an increased risk of cardiovascular disease (CVD). However, whether MHO and MH-OW are associated with all-cause mortality remains inconsistent.

METHODS

The association of MHO and MH-OW and all-cause mortality was determined in a Chinese community-based prospective cohort study (the Kailuan study), including 93,272 adults at baseline. Data were analyzed from 2006 to 2017. Participants were categorized into 6 mutually exclusive groups, according to BMI and metabolic syndrome (MetS) status. The primary outcome was all-cause death, and accidental deaths were excluded.

RESULTS

During a median follow-up of 11.04 years (interquartile range, 10.74–11.22 years), 8977 deaths occurred. Compared with healthy participants with normal BMI (MH-NW), MH-OW participants had the lowest risk of all-cause mortality (multivariate-adjusted HR [aHR], 0.926; 95% CI, 0.861–0.997), whereas there was no increased or decreased risk for MHO (aHR, 1.009; 95% CI, 0.886–1.148). Stratified analyses and sensitivity analyses further validated that there was a nonsignificant association between MHO and all-cause mortality.

CONCLUSIONS

Overweight and obesity do not predict increased risk of all-cause mortality in metabolic healthy Chinese individuals.

FUNDING

National Natural Science Foundation of China (NSFC; 81673247, 81872682 and 81773527), the NSFC Joint Project, and the Australian National Health and Medical Research Council (NHMRC; NSFC 81561128020-NHMRC APP1112767).

Obesity does not predict increased risk of all-cause mortality in metabolic healthy Chinese individuals.

Bariatric surgery in the super-super morbidly obese: outcome analysis of patients with BMI >70 using the ACS-NSQIP database

BACKGROUND

Bariatric surgery offers patients short- and long-term benefits to their health and quality of life. Currently, we see more patients with superior body mass index (BMI) looking for these benefits. Evidence-based medicine is integral in the evaluation of risks versus benefit; however, data are lacking in this high-risk population.

OBJECTIVES

To assess the morbidity and mortality of patients with BMI ≥70 undergoing bariatric surgery.

SETTING

University Hospital, Bronx, New York, United States using national database.

METHODS

Using the American College of Surgeons-National Surgical Quality Improvement Project (ACS-NSQIP) database for years 2005 to 2016, we identified patients who underwent primary laparoscopic sleeve gastrectomy or laparoscopic Roux-en-Y gastric bypass. Patients with BMI ≥70 were assigned to the BMI >70 (BMI70+) cohort and less obese patients were assigned to the BMI <70 (U70) cohort. Length of stay and 30-day morbidity and mortality were compared.

RESULTS

A total of 163,413 patients underwent non-revisional bariatric surgery. Of those, 2322 had a BMI ≥70. BMI70+ was associated with increased mortality (.4% versus .1%, P = .0001), deep vein thrombosis (.6% versus .3%, P = .007), pulmonary (1.9% versus .5%, P = .0001), renal (.9% versus .2%, P = .0001), and infectious complications (1.1% versus .4%, P = .0001). BMI70+ patients had longer mean length of stay (2.6 versus 2.1 d, P = .0001) and operative time (126.1 versus 114.5 min, P = .0001). There was no statistically significant difference in the number of myocardial infarctions (.1% versus .1%, P = .319), pulmonary embolisms (.3% versus .2%, P = .596), and transfusion requirements (.1% versus .1%, P = .105) between groups.

CONCLUSIONS

Evaluation of risk and benefit is performed on a case-by-case basis, but evidence-based medicine is critical in empowering surgeons and patients to make informed decisions. The overall rate of morbidity and mortality for BMI70+ patients undergoing bariatric surgery was increased over U70 patients but was still relatively low. Our study will allow surgeons to incorporate objective data into their assessment of risk for super-obese patients pursuing bariatric surgery.

Non-random sampling leads to biased estimates of transcriptome association

Integration of independent data resources across -omics platforms offers transformative opportunity for novel clinical and biological discoveries. However, application of emerging analytic methods in the context of selection bias represents a noteworthy and pervasive challenge. We hypothesize that combining differentially selected samples for integrated transcriptome analysis will lead to bias in the estimated association between predicted expression and the trait. Our results are based on in silico investigations and a case example focused on body mass index across four well-described cohorts apparently derived from markedly different populations. Our findings suggest that integrative analysis can lead to substantial relative bias in the estimate of association between predicted expression and the trait. The average estimate of association ranged from 51.3% less than to 96.7% greater than the true value for the biased sampling scenarios considered, while the average error was - 2.7% for the unbiased scenario. The corresponding 95% confidence interval coverage rate ranged from 46.4% to 69.5% under biased sampling, and was equal to 75% for the unbiased scenario. Inverse probability weighting with observed and estimated weights is applied as one corrective measure and appears to reduce the bias and improve coverage. These results highlight a critical need to address selection bias in integrative analysis and to use caution in interpreting findings in the presence of different sampling mechanisms between groups.

Estimating expected life-years and risk factor associations with mortality in Finland: cohort study

OBJECTIVE

To develop a tool to inform individuals and general practitioners about benefits of lifestyle changes by providing estimates of the expected age of death (EAD) for different risk factor values, and for those who plan and decide on preventive activities and health services at population level, to calculate potential need for these.

DESIGN

Prospective cohort study to estimate EAD using a model with 27 established risk factors, categorised into four groups: (1) sociodemographic background and medical history, (2) lifestyles, (3) life satisfaction, and (4) biological risk factors. We apply a Poisson regression model on the survival data split into 1-year intervals.

PARTICIPANTS

Total of 38 549 participants aged 25-74 years at baseline of the National FINRISK Study between 1987 and 2007.

PRIMARY OUTCOME MEASURES

Register-based comprehensive mortality data from 1987 to 2014 with an average follow-up time of 16 years and 4310 deaths.

RESULTS

Almost all risk factors included in the model were statistically significantly associated with death. The largest influence on the EAD appeared to be a current heavy smoker versus a never smoker as the EAD for a 30-year-old man decreased from 86.8 years, which corresponds to the reference values of the risk factors, to 80.2 years. Diabetes decreased EAD by >6.6 years. Whole or full milk consumers had 3.4 years lower EAD compared with those consuming skimmed milk. Physically inactive men had 2.4 years lower EAD than those with high activity. Men who found their life almost unbearable due to stress had 2.8 years lower EAD.

CONCLUSIONS

The biological risk factors and lifestyles, and the factors connected with life satisfaction were clearly associated with EAD. Our model for estimating a person's EAD can be used to motivate lifestyle changes.

Characteristics of Chronic Cough in adults in Pakistani population: A cross sectional study

Background and Objective:

Data about causes of chronic cough are lacking in our part of world. The aim of our study was to look for spectrum of causes in our setup and to determine a correlation between causes of cough and baseline factors of age, gender, and BMI and compare it to other populations.

Methods:

Total 236 chronic cough patients who attended chest clinic at KRL Hospital Islamabad from January 2018 to June 2019 were included in this cross-sectional study. Chronic cough was defined as cough greater than eight weeks. Main causes of chronic cough taken were cough variant asthma, allergic rhinitis, interstitial lung disease, Gastro-esophageal reflux disease, bronchial hyper-reactivity, ACE-I induced cough and others’. Other demographic and clinical data were also recorded.

Results:

The mean age was 45.16± 16.50 years and BMI was 26.23 ± 4.68kg/m². Major cause of chronic cough was cough variant asthma in 111(47%). Age had significant positive correlations with ILD, ACE-I induced cough and CCF, while significant negative correlations with CVA and AR. On gender correlation, ILD and ACE-I cough were significantly found more in females. BMI had significant correlation with ACE-I cough only.

Conclusion:

Variability of epidemiology of cough variant asthma, allergic rhinitis and ACE-I induced cough is comparable to worldwide data while differences exist with epidemiology of interstitial lung disease. Further research is needed in the field to delineate the local trends in this regard and compare to other population groups.

Is austerity responsible for the recent change in mortality trends across high-income nations? A protocol for an observational study

INTRODUCTION

Mortality rates in many high-income countries have changed from their long-term trends since around 2011. This paper sets out a protocol for testing the extent to which economic austerity can explain the variance in recent mortality trends across high-income countries.

METHODS AND ANALYSIS

This is an ecological natural experiment study, which will use regression adjustment to account for differences in exposure, outcomes and confounding. All high-income countries with available data will be included in the sample. The timing of any changes in the trends for four measures of austerity (the Alesina-Ardagna Fiscal Index, real per capita government expenditure, public social spending and the cyclically adjusted primary balance) will be identified and the cumulative difference in exposure to these measures thereafter will be calculated. These will be regressed against the difference in the mean annual change in life expectancy, mortality rates and lifespan variation compared with the previous trends, with an initial lag of 2 years after the identified change point in the exposure measure. The role of underemployment and individual incomes as outcomes in their own right and as mediating any relationship between austerity and mortality will also be considered. Sensitivity analyses varying the lag period to 0 and 5 years, and adjusting for recession, will be undertaken.

ETHICS AND DISSEMINATION

All of the data used for this study are publicly available, aggregated datasets with no individuals identifiable. There is, therefore, no requirement for ethical committee approval for the study. The study will be lodged within the National Health Service research governance system. All results of the study will be published following sharing with partner agencies. No new datasets will be created as part of this work for deposition or curation.