Low BMI, Malay/Indian ethnicity predict CV recurrence in ischaemic stroke patients with diabetes

A Singapore study has found that Malay and Indian ethnicities, BMI of <23 kg/m², and a prior diagnosis of diabetes independently predict recurrent cardiovascular (CV) events in ischaemic stroke patients with diabetes.

“To date, no major clinical trials have examined CV prevention strategies targeting high-risk ischaemic stroke patients with diabetes, who are undergoing intensive glucose-lowering treatment and tighter control of vascular risk factor,” the researchers said. “These findings provide insights on the predictors of outcomes in an Asian cohort of ischaemic stroke patients with diabetes, which may have implications in the design of future interventional studies.”

Between July 2011 and December 2013, 720 consecutive patients with ischaemic stroke (mean age 60.6 years, 71 percent me, 43 percent with diabetes; with median National Institute Health Stroke Severity score of 2) were recruited from the National University Hospital, Singapore.

The researchers obtained data on age, gender, ethnicity, risk factors (eg, diabetes status and BMI), stroke severity, and mechanisms. The participants were then followed up until the day of the first CV event or July 2016, whichever was earlier.

Overall, 175 CV events (133 cerebrovascular and 42 coronary artery events) occurred during a median follow-up of 3.25 years (6.90 events per 1,000 person-month). The adjusted hazard ratio for diabetes was 1.50 (95 percent confidence interval [CI], 1.08–2.10). [Ann Acad Med Singap 2021;50:16-25]

In a multivariable Cox proportional hazards model, the following factors were independently associated with recurrent CV events in this cohort: prior diagnosis of diabetes, BMI of <23 kg/m², and Malay and Indian ethnicities.

“Despite wide access to healthcare resources in Singapore, stroke outcomes vary considerably between different ethnic groups,” the researchers said, noting how more Malays and Indians were diabetic and had a higher risk for recurrent CV events than the Chinese.

These findings agreed with population registry data showing more Malays and Indians with diabetes compared with the Chinese, as well as poorer outcomes for Malays and Indians in other diseases such as end-stage renal failure and coronary artery disease. [Ann Acad Med Singap 2020;49:137-154; Ann Acad Med Singap 2017;46:374-391; Diabet Med 2016;33:332-339; PLoS One 2015;10:e0132278]

Interestingly, several studies have shown a protective effect of obesity on stroke, especially after a prior CV event, which is called the “obesity paradox.” However, data on diabetic patients were limited. [Int J Stroke 2015;10:99-104; Stroke 2011;42:30-36]

“In the current study, all diabetic patients fulfilled the criteria for adult-onset type 2 diabetes mellitus wherein close to a quarter of patients developed ischaemic stroke despite a BMI of <23 kg/m² and who have a twofold increased risk of recurrent CV events,” the researchers said. “By contrast, the presence of central obesity does not confer an increased risk of CV recurrence.”

These results stressed the prognostic significance of having a “normal” BMI in ischaemic stroke patients with diabetes and expanded on previous studies reporting the development of diabetes at lower BMI thresholds in Asians, according to the researchers.