Different risk factors for stroke subtypes and depending on age
Age‐Specific Vascular Risk Factor Profiles According to Stroke Subtype
The main stroke subtypes are ischemic stroke (IS), spontaneous intracerebral hemorrhage (sICH), and aneurysmal subarachnoid hemorrhage (aSAH). IS and sICH are increasingly considered heterogeneous disease with distinct subtypes, etiologies and epidemiology. Vascular risk profiles may differ according to stroke subtype and age. Limited information exists, however, about the variation in distribution of vascular risk factors according to age in stroke subtypes [1-5].
In this prospective, multi-center, hospital-based cohort in The Netherlands with 4033 patients, the age-specific prevalence of vascular risk factors in patients with IS and its subtypes, sICH, and aSAH was investigated. Patients with cerebral ischemia (including IS and transient ischemic attack [TIA], both referred to as IS, n=3311), sICH (n=sICH) or aSAH (n=428) were included, who were enrolled in an ongoing prospective registry of 8 university hospital as part of the Parelsnoer Initiative.
Risk factors for ischemic stroke:
- male gender, particularly in patients aged between 55 and 75 years
- non-white origin in patients aged <55 years (7.5%) or between 55 to 65 years (6.8%) compared with those in the reference age group of 65 to 75 years (3.8%)
- obesity in all age groups, up to patients aged ≥75 years
- hypertension with increasing age
- hyperlipidemia and DM up to the age of 75 years
- smoking in the youngest subgroup (43.9%)
- family history of early-onset CVD in younger patients
Ischemic stroke risk factors varied further, according to the etiology, e.g. large artery atherosclerosis (LAA), small vessel disease (SVD), or cardio-embolism.
Risk factors for spontaneous intracerebral hemorrhage:
- male gender, up to 75 years of age
- non-white origin (21.5%) compared with the reference group (4.6%; MD: 16.9%; 95% CI: -28.1 to -5.8), in patients aged <55 years
- obesity in those aged <55 years (25.0%; MD: 11.3%; 95% CI: -2.8 to 25.4) and aged 55 to 65 years (28.0%; MD: 14.3%; 95% CI: -0.8 to 29.4) compared with the reference group (13.7%)
- hypertension in all age groups, up to 75 years of age
- hyperlipidemia and DM with increasing age
- smoking in the youngest age group (34.8%)
- family history of early onset CVD in a third of patients aged <65 years
Risk factors for aneurysmal subarachnoid hemorrhage:
- female gender (73.8%)
- age <55 years (81.1%) and between 65 to 75 years (79.7%)
- non-white origin (8.8%) as compared with the reference group (55–65 years: 2.5%; MD: 6.2%; 95% CI: 1.3–11.2) in patients aged <55 years
- smoking in those aged <65 years
- hypertension with increasing age, but less in the youngest group (19.6%) as compared with the reference group (33.1%; MD: -13.5%; 95% CI: -23.7 to -3.2)
Various stroke subtypes have different risk profiles that vary according to age. Obesity was common (>20%) in patients younger than 55 years with sICH and in those with IS caused by either LAA or SVD. Age-specific prevalences of potentially modifiable risk factors were similar in those with LAA and SVD, showing more hypertension, hyperlipidemia, and diabetes mellitus than patients with IS of cardiac origin. The latter differences became less pronounced with increasing age.
In younger individuals, premature atherosclerosis is a very important risk factor for stroke. These results support a more tailored primary and secondary stroke prevention strategy, particularly for younger individuals.