Central and general adiposity have independent and contrasting associations with risk of different stroke types: JAMA

A cohort study from the U.K. found a positive association between waist circumference, ischemic stroke, and intracerebral haemorrhage risk. There is an inverse association between BMI and the risk of subarachnoid and intracerebral haemorrhage. The researchers also mentioned the adverse correlation of low BMI with an increased risk of intracerebral and subarachnoid hemorrhage, and further investigations are required to confirm the findings.

In the UK, stroke incidence is increasing due to an increased prevalence of major modifiable cardiovascular risk factors, including adiposity, BP, dyslipidemia, and diabetes. There is limited evidence and uncertainty on different measures of adiposity with different stroke types.

The question is, "What are the independent associations of general adiposity and central adiposity with ischemic stroke, intracerebral hemorrhage, and subarachnoid hemorrhage?"

This is researched by a cohort study of 490 071 adults in the UK. The exposures in the study were General adiposity (BMI) and central adiposity (waist circumference). Incident ischemic stroke, intracerebral and subarachnoid hemorrhage are recorded through the linkage of records with electronic hospital records. Cox regression estimated stroke type (adjusted hazard ratio).

The study's lead researcher was Preyanka Pillay from Clinical Trial Service Unit and Epidemiological Studies Unit, UK.

The conclusive study summary is as follows:

• The study had 490 071 participants with a mean age of 56.5 years.
• There were 54.6% female and 94.2% White.
• Follow-up was of 12 years (median).
• The researcher identified 7117 incident ischemic strokes, 1391 intracerebral hemorrhages, and 834 subarachnoid hemorrhages.
• BMI had no independent association with ischemic stroke (After mutual adjustment for waist circumference)
• BMI is inversely associated with intracerebral and subarachnoid hemorrhage, with HR 0.85 and 0.82, respectively.
• There was a positive association between Waist circumference and ischemic stroke of HR per 10-cm higher waist circumference, 1.19, and intracerebral hemorrhage with HR, 1.17. It was not associated with subarachnoid hemorrhage with HR, 1.07.

To conclude, there is an independent and contrasting association of BMI and waist circumference with the type of stroke types, so it is important to consider the distribution of body fat to stroke risk.

Further reading:

Pillay P et al. Body Fat Distribution, and Risk of Major Stroke Types Among Adults in the United Kingdom. JAMA Netw Open. 2022;5(12):e2246613.

https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2799554