Metabolic syndrome affects nearly four in 10 U.S. adults, while rates are increasing in older and black populations

Metabolic syndrome affects nearly four in 10 U.S. adults, while rates are increasing in older and black populations

Despite stable national trends over the past decade, new JAMA data shows growing age and racial disparities in metabolic syndrome, highlighting where prevention and care efforts may need to be stepped up.

In a recent study published inThe Journal of the American Medical Association (JAMA)Researchers examined the prevalence and trends of metabolic syndrome among adults in the United States (US).

Metabolic syndrome is the presence of a number of cardiovascular risk factors and is associated with increased morbidity and mortality. Disruptions in lifestyle and access to healthcare during the coronavirus disease 2019 (COVID-19) pandemic may have impacted the prevalence of metabolic syndrome; However, data on current estimates remains limited.

Study design and data sources

In the present study, researchers examined changes in the prevalence of metabolic syndrome among US adults between 2013 and August 2023. They analyzed data from the National Health and Nutrition Examination Survey (NHANES) in adults aged 20 years and older. Response rates fell from 68.5% to 25.7% between the 2013-14 and 2021-23 cycles. Survey weights were applied to nonresponse rates, and additional analyzes revealed no evidence of nonresponse bias.

Diagnostic criteria for metabolic syndrome

Participants met criteria for metabolic syndrome if they had at least three of the following: hypertriglyceridemia, hypertension, elevated fasting plasma glucose or treated diabetes, large waist circumference (more than 88 cm in women and more than 102 cm in men), or low levels of HDL cholesterol (less than 40 mg/dL in men or less than 50 mg/dL in women). Hypertriglyceridemia was defined as a triglyceride level of 150 mg/dL or higher, and hypertension was defined as the use of antihypertensive medications or a systolic or diastolic blood pressure of at least 130/85 mmHg.

Elevated fasting plasma glucose or diabetes was defined as taking antidiabetic medications or a fasting plasma glucose level of 100 mg/dL or higher. Ethnicity and race were self-reported. Age-standardized prevalence estimates were calculated based on the 2020 US Census. Logistic regression models with interaction terms were used to assess trends across survey cycles and test subgroup differences.

Overall prevalence and component trends

The analysis sample included 11,570 adults. The weighted prevalence of metabolic syndrome was 38.7%. The overall prevalence increased from 35.4% to 38.5% between the 2013-14 and 2021-23 cycles, but the increase was not statistically significant. A statistically significant non-linear trend was observed in hypertriglyceridemia, decreasing from 23.7% in 2013-14 to 20% in 2017-20 and then increasing to 25.1% in 2021-23.

Other components of the metabolic syndrome did not show significant fluctuations across survey cycles.

Age, gender, and racial subgroup differences

Subgroup analyzes showed a significant increase in the prevalence of metabolic syndrome in adults aged 60 years and older, from 50.2% in 2013–14 to 62.4% in 2021–23.

The prevalence remained largely stable in the younger age groups; there were no significant differences by gender. Among ethnic and racial groups, a significant increase was observed among non-Hispanic black individuals. No significant trends were found in the poverty income rate or other subgroups, and some fluctuations may be due to limited statistical robustness.

Interpretation, limitations and public health implications

Approximately 4 in 10 U.S. adults met criteria for metabolic syndrome in 2023. The overall prevalence did not change significantly from 2013 to 2023 and most components remained stable. A mild increase in hypertriglyceridemia may be due to obesity-related dyslipidemia, worsening dietary habits, or disruptions in medication adherence or preventive care during the COVID-19 pandemic.

Notable demographic differences included an increase in older adults and non-Hispanic black individuals, which may reflect greater exposure to chronic stressors, behavioral factors, or barriers to accessing health care.

Limitations include declining survey response rates and the cross-sectional design, which precludes causal inference. Sustained efforts to improve lifestyle factors, continuity of care, and preventive management remain critical to reducing cardiovascular risk, particularly in vulnerable populations.

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