S. Holland1, S. Browning1, S. Kuys2, I. Wellwood1
1Australian Catholic University, School of Allied Health, Faculty of Health Sciences, Ballarat, Victoria, Australia, 2Australian Catholic University, School of Allied Health, Faculty of Health Sciences, Brisbane, Australia
Background: Stroke is the second leading cause of disability and death worldwide.Obesity or being overweight is an established risk factor for stroke and has tripled globally over the past 50 years.Recently, a phenomenon, the “obesity paradox”, has been documented in the scientific stroke literature. This counterintuitively indicates that stroke survivors who are overweight have better mortality and functional outcomes following stroke, compared to people of normal weight. In addition to this phenomenon, underweight people appear to be consistently worse off after stroke, in terms of these same outcomes, compared to people of normal weight after stroke. Several systematic reviews on the impact of abnormal body weight (i.e. being underweight, overweight or obese) on post-stroke mortality and functional recovery have reached conflicting conclusions, and findings remains unclear.
Purpose: We aimed to systematically review and synthesise knowledge on the effects of abnormal body weight on stroke outcomes, to better understand the prognosis for stroke survivors with abnormal body weight, and facilitate evidence-based, person-centred care. Our review question was: What is the effect of abnormal body weight (underweight, overweight, or obesity) on mortality and functional recovery in adults after stroke?
Methods: We conducted an umbrella review (systematic review of systematic reviews) using Joanna Briggs Institute (JBI) methodology and standard reporting guidelines. We includedonlysystematic reviews and meta-analyses that included adults (> 18 years) with stroke, in all settings and all stages after stroke, categorised by body weight (Body Mass Index (BMI)) that recorded all-cause mortality and/or functional recovery at any time point following stroke.
Eight databases were searched up to Mar 2022. Key words related to stroke, body weight, functional recovery and survival. Studies were independently screened and managed in Covidence software. Reference lists were searched manually. We used JBI critical appraisal checklist for systematic reviews and research syntheses to evaluate risk of bias and methodological quality. Outcomes were tabulated and collated with a narrated synthesis.
Eight databases were searched up to Mar 2022. Key words related to stroke, body weight, functional recovery and survival. Studies were independently screened and managed in Covidence software. Reference lists were searched manually. We used JBI critical appraisal checklist for systematic reviews and research syntheses to evaluate risk of bias and methodological quality. Outcomes were tabulated and collated with a narrated synthesis.
Results: Six systematic reviews (980,680 participants; range 2-14 studies) were included. Five reported on post stroke mortality; four reported post stroke functional recovery. Most had a low to moderate risk of bias.Heterogeneity of studies varied or was not reported. Excess body weight (being overweight (BMI 25 – 29.9 kg/m2) or obese (BMI >30 kg/m2)) appears to reduce mortality. Risk of mortality increases with being underweight (BMI < 18.5 kg/m2). The impact of abnormal body weight on functional recovery is less clear; data from studies of excess body weight are inconclusive, while those on underweight appear to be associated with poor functional outcomes.
Conclusions: Abnormal body weight effects post stroke outcomes and should be considered in clinical decision-making, prognostic research, and clinical trials of rehabilitation interventions. The “obesity paradox” seen in several diseases is evident after stroke, and excess body weight is associated with increased survival time compared to normal body weight.
Implications: Body weight should be routinely recorded for stroke patients. Further research including well designed cohort studies is needed to further investigate the impact of body weight and distribution on post stroke outcomes.
Funding acknowledgements: This unfunded study was supported by Australian Catholic University's Bachelor of Physiotherapy Hons programme. Authors declare no conflicts of interest
Keywords:
Stroke
Abnormal body weight
Functional recovery
Stroke
Abnormal body weight
Functional recovery
Topics:
Neurology: stroke
Disability & rehabilitation
Non-communicable diseases (NCDs) & risk factors
Neurology: stroke
Disability & rehabilitation
Non-communicable diseases (NCDs) & risk factors
Did this work require ethics approval? No
Reason: This study is a systematic review which uses publicly available data and approval was not required by Australian Catholic University’s HREC.
All authors, affiliations and abstracts have been published as submitted.
