Effect of abnormal body weight on mortality and functional recovery in adults after stroke: An umbrella review

The effect of hypertension, obesity, and type 2 diabetes on lacunar stroke: A network Mendelian randomization study

BACKGROUND AND AIMS

Previous studies have reported an association of lacunar stroke with hypertension, obesity, and type 2 diabetes (T2D). The aim of this study was to investigate whether the association was causal and whether body mass index mediated the effect of hypertension on lacunar stroke.

METHODS AND RESULTS

The independence and causal association of hypertension, obesity, and T2D with lacunar stroke were assessed by multivariate Mendelian randomization (MVMR) and network Mendelian randomization (NMR) with inverse variance weighting (IVW). The reliability of the results was increased by sensitivity analyses including MR-Egger, Cochrane's Q test, Mendelian Randomization Pleiotropy RESidual Sum and Outlier (MR-PRESSO), and leave-one-out. MVMR analysis found that genetically predicted hypertension had a 42 % higher lacunar stroke risk (OR: 1.42, 95 % CI: 1.29-1.56, P < 0.001) when adjusted for obesity and T2D, genetically predicted T2D had a 9 % higher lacunar stroke risk (OR: 1.09, 95 % CI: 1.03-1.16, P < 0.004) when adjusted for hypertension and obesity, and genetically predicted obesity had a 15 % lower lacunar stroke risk (OR: 0.85, 95 % CI: 0.77-0.93, P < 0.001) when adjusted for hypertension and T2D. NMR found that 44 % of the association between hypertension and lacunar stroke risk was mediated by obesity.

CONCLUSION

This genetic association study found novel independent genetic associations between hypertension and T2D with high risk of lacunar stroke, whereas obesity attenuated the risk of lacunar stroke. The findings emphasize the importance of individualized lacunar stroke prevention strategies rather than uniform weight management optimize medical care in high-risk populations.

Relationships between obesity and functional outcome after ischemic stroke: a Mendelian randomization study

BACKGROUND AND OBJECTIVES

Most previous studies suggested obesity deteriorates the functional outcome after ischemic stroke. But there are researches claiming that obesity is associated with lower mortality, recurrence, and readmission rates, which is known as the obesity paradox. Our current research aimed to investigate the correlation between genetically obesity and the post-stroke outcome with the Mendelian randomization (MR) method.

METHODS

The UK Biobank and the GIANT consortium provided instrumental variables for body mass index (BMI, 806,834 individuals) and waist-to-hip ratio (WHR, 697,734 individuals). Data of functional outcome after ischemic stroke were obtained from the Genetics of Ischemic Stroke Functional Outcome network (6012 individuals). Inverse-variance weighted approach was utilized as the primary analyses. Sensitivity analyses involved the utilization of different MR methods. The heterogeneity among genetic variants was assessed by I2 and Q value statistics.

RESULTS

In univariable analysis, there was a significant connection between genetic susceptibility to WHR and worse functional outcome (modified Rankin Scale 3) after ischemic stroke (OR [95%CI] = 1.47 [1.07, 2.02], P = 0.016). Genetic liability to BMI and was not associated with post-stroke functional outcome (all P > 0.05). The overall patterns between genetic liability to WHR and functional outcome post-ischemic outcome no longer existed in the multivariable MR analysis after adjusting for BMI (OR [95%CI] = 1.26[0.76,1.67], P = 0.56).

CONCLUSION

The current MR study provided evidence that WHR was correlated to unfavorable outcome post-ischemic stroke. Exploring interventions against obesity may potentially improve recovery after ischemic stroke.

Association of Body Mass Index with Outcomes in Patients with Heart Failure with Reduced Ejection Fraction (HFrEF)

Heart failure (HF) is a major health issue, affecting up to 2% of the adult population worldwide. Given the increasing prevalence of obesity and its association with various cardiovascular diseases, understanding its role in HFrEF outcomes is crucial. This study aimed to investigate the impact of obesity on in-hospital mortality and prolonged hospital stay in patients with heart failure with reduced ejection fraction (HFrEF). We conducted a retrospective analysis of 425 patients admitted to the cardiology unit at the University Clinical Hospital in Wroclaw, Poland, between August 2018 and August 2020. Statistical analyses were performed to evaluate the interactions between BMI, sex, and comorbidities on in-hospital mortality. Significant interactions were found between sex and BMI as well as between BMI and post-stroke status, affecting in-hospital mortality. Specifically, increased BMI was associated with decreased odds of in-hospital mortality in males (OR = 0.72, 95% CI: 0.55-0.94, p < 0.05) but higher odds in females (OR = 1.18, 95% CI: 0.98-1.42, p = 0.08). For patients without a history of stroke, increased BMI reduced mortality odds (HR = 0.78, 95% CI: 0.64-0.95, p < 0.01), whereas the effect was less pronounced in those with a history of stroke (HR = 0.89, 95% CI: 0.76-1.04, p = 0.12). In conclusion, the odds of in-hospital mortality decreased significantly with each 10% increase in BMI for males, whereas for females, a higher BMI was associated with increased odds of death. Additionally, BMI reduced in-hospital mortality odds more in patients without a history of cerebral stroke (CS) compared to those with a history of CS. These findings should be interpreted with caution due to the low number of observed outcomes and potential interactions with BMI and sex.