Researchers discover that metabolic syndrome (MetS) is associated with poorer executive function (EF), but the syndrome's components aren't additive.
Metabolic syndrome (MetS) has been on the healthcare radar since 1998, when it was discovered that it increases a patient’s risk of developing cardiac disease. Previous research has found that some MetS components — such as hypertension, dyslipidemia, or elevated blood glucose concentration below the diagnostic threshold of a clinical disorder — may impair executive function (EF).
However, it remains unclear whether the sum of all MetS components collectively increases EF deficits, which begs the question: Do patients who have several MetS components have more severe cognitive deficits than those who only have the minimum amount for diagnosis? Since EF deficits may weaken intervention strategies that rely on cognitive input to produce behaviorial change, the answer has important implications.
Researchers from the University of Texas set out to describe the relationship between EF, MetS, and the syndrome’s components. They conducted a study targeting 4 EF tasks in 395 participants from a multiethnic rural population, given that MetS’s prevalence is higher among those with lower socioeconomic status.
The authors hypothesized that participants with 3 or more MetS components would have poorer EF performance than normal controls. They also theorized that participants’ EF performance would decline incrementally as the number of MetS components increased.
Mean patient age was 61.3 years old, and 71.4% of participants were women, 37.0% were Hispanic, and 53.7% were white non-Hispanic. According to the researchers, 60% of participants met the National Heart, Lung, and Blood Institute-American Heart Association criteria for MetS — a much higher prevalence compared to the MetS rate typically reported in communities.
Using a clinical interview and neuropsychological battery, the researchers assessed EF. With the results, they derived a factor score to compare participants with and without MetS.
Participants with MetS performed significantly more poorly than those without the syndrome. Even though the magnitude of the association was small, it was still significant. However, while MetS was associated with poorer EF, the syndrome’s components weren’t additive. Thus, the study authors concluded that treating individual MetS components might lessen cognitive EF decline.