For Stroke Survivors, Metabolic Syndrome Linked to Increased Risk of Second Events, Mortality

A meta-analysis with data from nearly 60k patients suggests presence of metabolic syndrome was associated with a 46% increase in risk of a second stroke and a 27% increase in risk of mortality among stroke survivors when compared to their counterparts without metabolic syndrome.

A meta-analysis with data from more than a dozen studies and nearly 60,000 participants is detailing the apparent increase in risk of secondary stroke events associated with metabolic syndrome and its individual components in older patients.

Results of the study indicate patients with metabolic syndrome were 46% more likely to have a second stroke and 27% more likely to die than their counterparts without who did not have metabolic syndrome. Results also shed light on the potential for increased risk associated with individual components of metabolic syndrome.

“Studies have shown conflicting results on whether metabolic syndrome, which has been tied to an increased risk of a first stroke, also increases the risk of a second stroke and death, so we wanted to analyze all of the research available,” said study author Tian Li, MD, of Fourth Military Medical University in Xi’an, China, in a statement.“These findings will help people with metabolic syndrome and their health care providers know that they should be screened for risk of recurrent stroke and given preventative treatments.”

As the presence and burden of metabolic syndrome continue to increase throughout the world, Li and a team of colleagues from institutions in China sought to describe the impact of metabolic disease on secondary prevention of stroke events. Investigators designed the current study as a meta-analysis of observational cohort studies published in the PubMed, Embase, and the Cochrane Library databases from inception to April 23, 2020.

For inclusion in the final analyses, studies needed to be prospective or retrospective observational studies, included individuals with metabolic syndrome, and examined outcomes including all-cause mortality or stroke recurrence. Investigators noted studies providing inadequate data to calculate risk ratio were excluded from final analyses.

The primary outcome of interest in the study was stroke recurrence. Incidence of mortality served as the secondary outcome. Investigators planned to use random-effects models with 95% confidence intervals to determine effect estimates of metabolic syndrome on these outcomes. Additionally, investigators noted plans to use leave-one-out sensitivity analyses as well as nonparametric trim and fill method to identify the stability of results.

The Investigators initial data query yielded more than 4300 citations. After application of inclusion criteria and removal of duplicates, investigators identified 13 studies with 59,919 participants for inclusion in their analyses. The mean or median follow-up duration of these studies ranged from 3 months to 5.5 years and sample size ranged from 57 to 23,998 participants, with an average sample size of 4609. Overall, 9 studies reported on the outcome of stroke recurrence and 8 reported on all-cause mortality.

Additionally, of the 13 studies included, 8 were conducted in Asian countries, 3 in multiple countries, 1 in the USA, and 1 in Africa. All the studies included in final analysis were published from 2008-2019.

Analysis revealed presence of metabolic syndrome was significantly associated with increased risk of stroke recurrence. When assessing individual components, low levels of HDL-C (RR 1.32 [95% CI 1.11-1.57]; P=.002) and presence of multiple metabolic syndrome components (RR 1.68 [95% CI, 1.44-1.94]; P< .001) were associated with a significantly increased risk of stroke recurrence. In contrast, elevated triglyceride, elevated waist circumference, hyperglycemia, or hypertension were not considered predictors of stroke recurrence.

Further analysis suggested presence of metabolic syndrome was associated with increased risk of all-cause mortality (RR, 1.27 [95% CI, 1.18-1.36]; P <.001). Similar to previous analyses examining stroke recurrence, results suggested individual components metabolic syndrome were not considered significant predictors of mortality. Investigators noted stability of these results was confirmed in leave-one-out analyses and nonparametric trim and fill method.

“These results add to the evidence that people with metabolic syndrome should take steps to modify their risk of second stroke and even death where possible, through medication, diet, exercise and other recommended lifestyle changes such as stopping smoking,” Li said.

This study, “Association of Metabolic Syndrome and Its Components With Risk of Stroke Recurrence and Mortality: A Meta-analysis,” was published in Neurology.