Body mass index and clinical outcomes in patients after ischaemic stroke in South Korea: a retrospective cohort study

The effect of body mass index on stroke prognosis: A systematic review and meta-analysis of 32 cohort studies with 330,353 patients

BACKGROUND

Many studies have explored the impact of body mass index (BMI) on stroke prognosis, yet findings remain inconsistent.

AIMS

The aims of this study were to conduct a systematic review and meta-analyses to summarize the existing evidence on BMI and stroke outcomes.

METHODS

PubMed, Web of Science, Embase, The Cochrane Library, CNKI, CBM, Wanfang Database, and VIP Database were systematically searched from inception to 1 January 2023. Cohort studies were included if they reported on a population of patients with stroke, evaluated BMI on stroke outcomes (mortality/recurrence/score of modified Rankin scale (mRs)), and reported original data. Data extraction and quality assessment were independently undertaken by two reviewers. Stata 16.0 software was used for meta-analysis.

RESULTS

Thirty-two studies involving 330,353 patients (5 Chinese language articles) were included in the analysis. The proportion of underweight, overweight, and obese patients was 1.85%, 18.2%, and 15.6%, respectively. Compared with normal weight, being underweight was associated with an increased risk of mortality (relative risk (RR) = 1.78, 95% confidence interval (CI) = 1.60-1.96), poor functional outcomes defined as modified Rankin scale ⩾ 3 (RR = 1.33, 95% CI = 1.22-1.45), and stroke recurrence (RR = 1.19, 95% CI = 1.04-1.37). Being overweight but not obese was associated with reduced mortality (RR = 0.81, 95% CI = 0.74-0.89) and better functional outcomes (RR = 0.92, 95% CI = 0.89-0.96), but did not alter the risk of stroke recurrence (RR = 1.03, 95% CI = 0.90-1.17). Obesity was associated with lower risk of mortality (RR = 0.76, 95% CI = 0.72-0.81) and better functional outcomes (RR = 0.89, 95% CI = 0.84-0.94).

CONCLUSIONS

Our findings indicate that in patients with stroke, being underweight is associated with an increased risk of mortality, poor functional outcomes, and stroke recurrence. In contrast, being overweight but not obese, or being obese, was associated with a decreased risk of mortality and better functional outcomes. This is consistent with the obesity paradox in stroke, whereby obesity increases stroke risk in the general population but is associated with improved outcome in patients suffering stroke.

Utility of the ACD-GENE-CLI Score in Asian Patients with Critical Limb Ischemia Undergoing Endovascular Interventions

AIMS

Critical limb ischemia (CLI) is an emerging public health threat and lacks a reliable score for predicting the outcomes. The Age, Body Mass Index, Chronic Kidney Disease, Diabetes, and Genotyping (ABCD-GENE) risk score helps identify patients with coronary artery disease who have cytochrome P450 2C19 (CYP2C19) polymorphism-related drug resistance and are at risk for cardiovascular adverse events. However, its application to CLI remains unknown. In this study, we aim to validate a modified ACD-GENE-CLI score to improve the prediction of major adverse limb events (MALEs) in patients with CLI receiving clopidogrel.

METHODS

Patients with CLI receiving clopidogrel post-endovascular intervention were enrolled prospectively in two medical centers. Amputation and revascularization as MALEs were regarded as the outcomes.

RESULTS

A total of 473 patients were recruited, with a mean follow-up duration of 25 months. Except for obesity, old age, diabetes, chronic kidney disease (CKD), and CYP2C19 polymorphisms were significantly associated with MALEs. Using bootstrap regression analysis, we established a modified risk score (ACD-GENE-CLI) that included old age (≥ 65 years), diabetes, CKD, and CYP2C19 polymorphisms. At a cutoff value of 8, the ACD-GENE-CLI score was superior to the CYP2C19 deficiency only, and the conventional ABCD-GENE score in predicting MALEs (area under the curve: 0.69 vs. 0.59 vs. 0.67, p=0.01). The diagnostic ability of the ACD-GENE-CLI score was consistent in the external validation. Also, Kaplan-Meier curves showed that in CYP2C19 deficiency, the ABCD-GENE and ACD-GENE-CLI scores could all differentiate patients with CLI who are free from MALEs.

CONCLUSIONS

The modified ACD-GENE-CLI score could differentiate patients with CLI receiving clopidogrel who are at risk of MALEs. Further studies are required to generalize the utility of the score.

The Impact of Modified Body Mass Index on Clinical Prognosis in the Elderly With Acute Ischemic Stroke

OBJECTIVES

The modified body mass index (mBMI) combines the body mass index and serum albumin, accurately reflecting the nutritional status. It remains uncertain whether modified body mass index influences neurological function and clinical prognosis in elderly patients with acute ischemic stroke.

METHODS

We divided the cohort into quartiles of mBMI (1 to 4). The primary outcome was analyzed using the percentage of patients with a 90-day modified Rankin scale (mRS) score of 0 to 1. There were 7 secondary outcomes, including the disability level at 90 days and the National Institute of Health Stroke Scale (NIHSS) score at 14 and 90 days.

RESULTS

mBMI was negatively associated with clinical prognosis at 90-day mRS score in the primary outcome (β=-0.167; 95% CI -0.311 to 0.023, P=0.023). Moreover, mBMI1 (<896.72) and primary outcomes (β=0.438; 95% CI: -0.018 to 0.894) were positively correlated with higher mBMI. Moreover, the number and percentage of patients completing all the duties and activities are also higher. Age-adjusted Charlson comorbidity index (aCCI) and posterior circulation lesion were positively associated with the clinical prognosis 90-day mRS score in the primary outcome (β=2.218; 95% CI: 1.144-4.300, β=2.771; 95% CI: 1.700-4.516). However, BMI and serum albumin were not associated the with clinical prognosis primary outcome. BMI negatively correlates with secondary outcomes (NIHSS at discharge, β=-0.023; 95% CI: -0.102 to 0.057).

CONCLUSIONS

Our study revealed that mBMI and not BMI could be a better primary outcome predictor in the elderly with acute ischemic stroke, and lower mBMI showed a worse prognosis.

Body mass index has a non-linear association with three-month outcomes in men with acute ischemic stroke: An analysis based on data from a prospective cohort study

Objective

Despite reports of a connection between body mass index (BMI) and stroke outcome, the findings remain debatable. In this investigation, we sought to determine whether BMI was associated with the probability of 3-month unfavorable outcomes in patients with acute ischemic stroke (AIS).

Methods

This is a second analysis based on a cohort study. 1,897 people with AIS who were treated at a hospital in South Korea from January 2010 to December 2016 were included in the study. The linear relationship between BMI and unfavorable outcomes for AIS patients was evaluated using a binary logistic regression model. The generalized additive model (GAM) and smoothed curve fitting (penalized spline approach) were employed to see if there was a non-linear association between BMI and unfavorable outcomes in patients with AIS.

Results

The binary logistic regression model did not detect any statistically significant correlation between BMI and unfavorable outcomes in AIS patients after controlling for variables. The association between them, however, was non-linear, with the BMI inflection point occurring at 23.07 kg/m2. Each 1 kg/m2 rise in BMI on the left side of the inflection point was linked to a 12% lower risk of unfavorable outcomes (OR= 0.88, 95% CI: 0.82 to 0.96, p = 0.003). We stratified the AIS patients by gender to further explore their relationship. The results showed a specific non-linear relationship and saturation effect of BMI (kg/m2) with 3-month unfavorable outcomes in male patients but not in female patients. The inflection point for BMI was 23.35 kg/m2. When BMI was below 23.35 kg/m2 in men with AIS, BMI was inversely associated with unfavorable outcomes (OR=0.89,95% CI:0.80-0.98).

Conclusion

A particular non-linear connection and saturation effect between BMI (kg/m2) and 3-month unfavorable outcomes were present in male patients with AIS but not in females. 23.35 kg/m2 was the BMI's inflection point. The probability of unfavorable outcomes was substantially and inversely associated with BMI in men with AIS when it was less than 23.35 kg/m2. Men with AIS should have a BMI of no less than 23.35 kg/m2 to reduce the probability of unfavorable outcomes following AIS.

Obesity and long-term outcomes after incident stroke: a prospective population-based cohort study

BACKGROUND

The association between obesity, major adverse cardiovascular events (MACE), and mortality in patients with incident stroke is not well established. We assessed the relationship between body mass index (BMI) and MACE in patients with incident stroke.

METHODS

The population-based cohort study identified 30 702 individuals from the Clinical Practice Research Datalink (CPRD GOLD) and Hospital Episode Statistics (HES) databases from the United Kingdom. Individuals were aged ≥18 years with incident stroke between 1-1-1998 and 31-12-2017, a BMI recorded within 24 months before incident stroke, and no prior history of MACE. BMI was categorized as underweight (<18.5 kg/m² ), normal (18.5-24.9 kg/m² ), overweight (25.0-29.9 kg/m² ), obesity class I (30.0-34.9 kg/m² ), class II (35.0-39.9 kg/m² ) and class III (≥40 kg/m2). MACE was defined as a composite of incident coronary heart disease, recurrent stroke, peripheral vascular disease (PVD), heart failure, and cardiovascular-related mortality. Multivariable Cox regression was used to assess differences in MACE risk between BMI categories.

RESULTS

At baseline, 1217 (4.0%) were underweight, 10 783 (35.1%) had a normal BMI, 10 979 (35.8%) had overweight, 5206 (17.0%) had obesity Class I, 1749 (5.7%) Class II, and 768 (2.5%) Class III. In multivariable analysis, higher BMI were associated with lower risk of subsequent MACE [overweight: HR 0.96, 95% CI 0.93-0.99)]; PVD [overweight: 0.65 (0.49-0.85); obesity Class III: 0.19 (0.50-0.77)]; cardiovascular-related death [overweight: 0.80 (0.74-0.86); obesity Class I: 0.79 (0.71-0.88); Class II: 0.80 (0.67-0.96)]; and all-cause mortality [overweight: 0.75 (0.71-0.79); obesity Class I: 0.75 (0.70-0.81); Class II: 0.77 (0.68-0.86)] when compared to those with normal BMI. The results were similar irrespective of sex, diabetes mellitus, smoking or cancer at time of incident stroke.

CONCLUSIONS

In patients with incident stroke, overweight or obesity were associated with a more favourable prognosis for subsequent MACE, PVD, and mortality, irrespective of sex, diabetes mellitus, smoking, or cancer at baseline. As with other cohort studies, our study demonstrates an association. Randomized control trials should be considered to robustly evaluate the impact of weight management recommendations on subsequent cardiovascular outcomes in stroke survivors.

Association between abnormal body weight and stroke outcome: A meta-analysis and systematic review

BACKGROUND AND PURPOSE

To test the hypothesis that "obesity paradox" exists in stroke patients, we conducted a meta-analysis and systematic review on the association between abnormal body weight (obesity, overweight, or underweight) and the outcome of different types of stroke.

METHODS

This meta-analysis and systematic review was performed in conformity to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines in Appendix S2. Studies investigating the association between abnormal body weight and the outcome of different types of stroke were searched for in the PubMed and Embase databases from their inception to 20 March 2021.

RESULTS

Thirty-three articles including 84,660 patients were included in this study. Obesity and overweight were associated with longer survival in mixed-stroke patients (acute ischemic stroke [AIS] combined with one or more other stroke subtypes) than was normal weight, whereas underweight was related to shorter survival; the pooled hazard ratios (HRs) of mortality were 0.77 (95% confidence interval [CI] = 0.71-0.83) for obesity, 0.76 (95% CI = 0.72-0.80) for overweight, and 1.71 (95% CI = 1.56-1.87) for underweight. However, only obesity was associated with longer survival in AIS patients compared with normal weight, and underweight was related to shorter survival; the pooled HR of mortality was 0.75 (95% CI = 0.64-0.88) for obesity and 1.53 (95% CI = 1.27-1.85) for underweight. After merging mixed-stroke and AIS patients, we obtained similar results as in mixed-stroke patients.

CONCLUSIONS

Our results suggested that in patients with mixed stroke or AIS, obesity was associated with a longer survival time than normal weight, whereas underweight was associated with a shorter survival time.

Obesity and mortality after the first ischemic stroke: Is obesity paradox real?

BACKGROUND AND PURPOSE

Obesity is an established risk factor for ischemic stroke but the association of increased body mass index (BMI) with survival after ischemic stroke remains controversial. Many studies have shown that increased BMI has a "protective" effect on survival after stroke while other studies have debunked the "obesity paradox". This study aimed at examining the relationship between BMI and all-cause mortality at one year in first-time ischemic stroke patients using a large dataset extracted from different resources including electronic health records.

METHODS

This was a retrospective cohort study of consecutive ischemic stroke patients captured in our Geisinger NeuroScience Ischemic Stroke (GNSIS) database. Survival in first-time ischemic stroke patients in different BMI categories was analyzed using Kaplan Meier survival curves. The predictors of mortality at one-year were assessed using a stratified Cox proportional hazards model.

RESULTS

Among 6,703 first-time ischemic stroke patients, overweight and obese patients were found to have statistically decreased hazard ratio (HR) compared to the non-overweight patients (overweight patients- HR = 0.61 [95% CI, 0.52-0.72]; obese patients- HR = 0.56 [95% CI, 0.48-0.67]). Predictors with a significant increase in the hazard ratio for one-year mortality were age at the ischemic stroke event, history of neoplasm, atrial fibrillation/flutter, diabetes, myocardial infarction and heart failure.

CONCLUSION

Our study results support the obesity paradox in ischemic stroke patients as shown by a significantly decreased hazard ratio for one-year mortality among overweight and obese patients in comparison to non-overweight patients.