Aging & Longevity

Association of high-sensitivity C-reactive protein-to-hemoglobin ratio with stroke risk: A study based on the China Health and Retirement Longitudinal Study and English Longitudinal Study of Ageing cohorts.

TL;DR

C-reactive protein-to-hemoglobin ratio levels are significantly and positively associated with stroke risk in middle-aged and older adults across two independent cohorts.

Key Findings

Higher C-reactive protein-to-hemoglobin (CRP/Hb) ratio quartiles were significantly associated with increased stroke risk compared to the lowest quartile.

  • Participants in Q2 had a hazard ratio of 2.23 (95% CI: 1.35–3.69, P < 0.01)
  • Participants in Q3 had a hazard ratio of 2.24 (95% CI: 1.36–3.71, P < 0.01)
  • Participants in Q4 had a hazard ratio of 3.14 (95% CI: 1.93–5.12, P < 0.01)
  • Q1 served as the reference group; all comparisons were statistically significant at P < 0.01
  • Adjustments were made for sex, age, lifestyle factors, and multiple clinical biochemical indicators

Dose-response analysis revealed an approximately linear positive association between CRP-to-hemoglobin ratio and stroke risk.

  • The relationship was characterized as 'approximately linear' rather than a threshold or J-shaped effect
  • This suggests that increasing CRP/Hb ratio incrementally corresponds to increasing stroke risk
  • The dose-response analysis was conducted alongside Cox proportional hazards regression modeling

The study was conducted using two independent prospective cohorts of middle-aged and older adults from China and England.

  • The China Health and Retirement Longitudinal Study (CHARLS) contributed 5,368 participants
  • The English Longitudinal Study of Ageing (ELSA) contributed 1,422 participants
  • Only participants without a history of stroke at baseline were included
  • Cox proportional hazards regression models were used to analyze associations
  • Subgroup interaction testing was also performed

What This Means

This research suggests that a simple ratio calculated from two common blood test values — C-reactive protein (a marker of inflammation) divided by hemoglobin (a measure of red blood cell health) — may help predict stroke risk in middle-aged and older adults. The study followed over 6,700 people from China and England who had no history of stroke at the start, and found that those with higher CRP-to-hemoglobin ratios were significantly more likely to experience a stroke during follow-up. Specifically, people in the highest quarter of this ratio were about three times more likely to have a stroke compared to those in the lowest quarter. The relationship between the ratio and stroke risk appeared to be roughly linear, meaning that as the ratio increased, stroke risk steadily increased as well, rather than only jumping at a certain threshold. This pattern was consistent after accounting for many other factors such as age, sex, lifestyle habits, and other clinical measurements. The finding held across two culturally and geographically distinct populations, lending additional credibility to the association. This research suggests that combining inflammation and anemia-related information into a single ratio could be a useful, low-cost tool for identifying older adults at elevated stroke risk. Since both C-reactive protein and hemoglobin are routinely measured in standard blood tests, this ratio could potentially be calculated without any additional testing. However, further research would be needed to determine how this measure might be applied in clinical practice and whether addressing the underlying contributors to a high ratio reduces stroke risk.

Have a question about this study?

Citation

Ding M, Qin B. (2026). Association of high-sensitivity C-reactive protein-to-hemoglobin ratio with stroke risk: A study based on the China Health and Retirement Longitudinal Study and English Longitudinal Study of Ageing cohorts.. The Journal of international medical research. https://doi.org/10.1177/03000605261459294