Associations were established between recovery from and development of metabolic syndrome (MetS) and reduced and elevated risk for major adverse cardiovascular events (MACE), respectively, according to Korean population-based study results published in the Annals of Internal Medicine.
Although MetS is known to increase the risk for and be a predictor of MACE, relatively little research has evaluated the impact of change in MetS status on MACE risk.
In this nationwide cohort study, data from the National Health Insurance Database of Korea, which included 9,553,042 adult patients who had received at least 3 health screenings between 2009 and 2014 and had a definable MetS status were examined. Patients in this cohort were divided into 4 groups according to their MetS status: absence of MetS (n=6,940,663; mean age, 45.1 years; 54.1% men), long-standing MetS (MetS-chronic; n=1,486,485; mean age, 58.4 years; 51.1% men), MetS developed over the course of 3 screenings (MetS-developed; n=587,088; mean age, 54.8 years; 56.1% men), and recovery from MetS across 3 screenings (MetS-recovery; n=538,806; mean age, 52.1 years; 62.7% men). Follow-up for MACE began 1 day after the third screening exam; patients with a history of MACE prior to this point or with impaired kidney function were excluded.
The primary study outcome was occurrence of MACE, which included acute myocardial infarction, revascularization, and acute ischemic stroke. Adjusted incidence rate ratios (aIRRs) were calculated via Poisson regression following multivariable adjustments for comorbidity scores, body mass index, and several other clinical and demographic variables.
The median follow-up period was 3.54 years. Using the MetS-free group as a reference, the other 3 groups all had increased risks for MACE, with aIRRs of 1.48, 1.71, and 2.01 for the MetS-recovery, MetS-developed and MetS-chronic groups, respectively (P <.001 for all).
Compared with the MetS-chronic group (incidence rate, 8.52/1,000 person-years), the MetS-recovery group (incidence rate, 4.55/1,000 person-years) had a reduced MACE risk (aIRR, 0.85; 95% CI, 0.83-0.87; P <.001). The MetS-developed group (incidence rate, 6.05/1000 person-years) was found to have a greater MACE risk compared with the MetS-free group (incidence rate, 1.92/1000 person-years; aIRR, 1.36; 95% CI, 1.33-1.39; P <.001). These results indicate that changes in the dynamic status of MetS may have an impact on the risk of developing MACE. The MetS component that had the most impact on MACE risk was change in hypertension status.
Participants in the MetS-recovery vs the MetS-free group with similar current status were found to have a higher risk for MACE (aIRR, 1.19; 95% CI, 1.16-1.22; P <.001). However, when the MetS-developed and MetS-chronic groups were compared, the findings were equivocal (aIRR, 1.00; 95% CI, 0.98-1.02; P =.70).
Study strengths include the use of a large national sample with complete data. Study limitations include its retrospective design, potential hidden confounders, short follow-up period, a lack of evaluation of the impact of lifestyle variables on MACE risk, the inability to assess short-term changes in MetS status, and a possible lack of generalizability to other countries/populations.
“Although the findings can be explained by traditional concepts of controlling metabolic risk factors to reduce MACE risk, such nationwide results provide unique evidence supporting the benefits of MetS recovery and prevention,” noted the authors.
Disclosures: This work was supported by a grant from the Korea Healthcare Technology R&D Project, Ministry of Health and Welfare, Republic of Korea (HI17C0530).
Dr. Kim reports a grant from the Ministry of Health and Welfare, Republic of Korea. Authors not named here have disclosed no conflicts of interest. Disclosures can also be viewed at www.acponline.org/authors/icmje/ConflictOfInterestForms.do?msNum=M19-0563.
Park S, Lee S, Kim Y, et al. Altered risk for cardiovascular events with changes in the metabolic syndrome status [published online November 26, 2019]. Ann Intern Med. doi:10.7326/m19-0563