Association of hemoglobin-to-red blood cell distribution width ratio (HRR) and sleep duration with stroke: A cross-sectional study from NHANES 2008-2018.
Both HRR and sleep duration are independently and interactively associated with stroke prevalence, with nonlinear thresholds identified for both variables, highlighting HRR as a hematological indicator associated with stroke prevalence and underscoring the association of balanced sleep duration with lower stroke prevalence.
Key Findings
Results
Higher HRR values were associated with stroke prevalence, particularly when HRR exceeded a threshold of 3.04.
HRR was calculated as the ratio of hemoglobin to red blood cell distribution width (RDW) concentration.
Restricted cubic splines (RCS) were used to examine the nonlinear relationship between HRR and stroke prevalence.
The nonlinear threshold of 3.04 was identified as the inflection point above which higher HRR was associated with stroke.
Multivariable logistic regression models were employed, adjusting for demographic and health-related covariates.
The analysis was based on data from 22,956 participants from NHANES 2008–2018.
Results
Both short and long sleep durations were associated with higher stroke prevalence, while moderate sleep duration (6.40–7.01 hours) appeared to show a protective association.
Short sleep was defined as less than 6.40 hours per night and long sleep as greater than 7.01 hours per night.
Sleep duration was based on self-reported hours of sleep per night.
Restricted cubic splines revealed a nonlinear (U-shaped) relationship between sleep duration and stroke prevalence.
The moderate sleep range of 6.40–7.01 hours was identified as the range associated with lower stroke prevalence.
Results
Subgroup analyses indicated stronger associations between HRR/sleep duration and stroke in females, individuals younger than 50 years, African Americans, and those with hypertension or hyperlipidemia.
Subgroup analyses were conducted across demographic categories including sex, age, race, and comorbid conditions.
Females, individuals younger than 50 years, African Americans, and those with hypertension or hyperlipidemia showed stronger associations.
These subgroup findings suggest potential effect modification by demographic and clinical characteristics.
Results
The association between HRR and stroke prevalence was modified by age, poverty index ratio, and hypertension status.
Interaction analysis was performed to identify variables that modified the HRR–stroke association.
Age, poverty index ratio, and hypertension were identified as significant effect modifiers.
These interaction effects suggest that the relationship between HRR and stroke is not uniform across all population subgroups.
Methods
The study used a cross-sectional design with data from 22,956 NHANES participants collected between 2008 and 2018.
Data were drawn from the National Health and Nutrition Examination Survey (NHANES) cycles spanning 2008 to 2018.
Stroke was defined as a self-reported history of stroke.
HRR and sleep duration were treated as the primary independent variables.
Multivariable logistic regression and restricted cubic splines were the primary analytic methods.
The cross-sectional design precludes causal inference between HRR, sleep duration, and stroke.
What This Means
This research suggests that two measurable factors — a blood marker called the hemoglobin-to-red blood cell distribution width ratio (HRR) and how long a person sleeps each night — are both linked to whether someone has had a stroke. The study analyzed health data from nearly 23,000 American adults collected between 2008 and 2018. It found that people with HRR values above a certain threshold (3.04) and people who slept either too little (under about 6.4 hours) or too much (over about 7 hours) per night had a higher likelihood of reporting a history of stroke. A moderate sleep range of roughly 6.4 to 7 hours appeared to be associated with lower stroke prevalence.
The study also found that these associations were not the same for everyone. Stronger links between these factors and stroke were observed in women, people under age 50, African Americans, and those with high blood pressure or high cholesterol. Additionally, the relationship between the blood marker HRR and stroke was influenced by a person's age, income level (measured by a poverty index), and whether they had hypertension.
This research is important because it highlights a relatively simple blood test ratio (HRR) as a potential marker worth monitoring in relation to stroke risk, and it reinforces the idea that both insufficient and excessive sleep may be associated with worse cerebrovascular health. However, because this was a cross-sectional study — meaning it looked at one point in time rather than following people over years — it cannot prove that HRR or sleep duration directly cause stroke. Further research is needed to understand the underlying biological mechanisms and to determine whether interventions targeting these factors could help reduce stroke risk.
Xue H, Zhao Y, Xu H, Si X, Song K, Jia M. (2026). Association of hemoglobin-to-red blood cell distribution width ratio (HRR) and sleep duration with stroke: A cross-sectional study from NHANES 2008-2018.. Medicine. https://doi.org/10.1097/MD.0000000000049243