Objective:
To compare trends in the prevalence of metabolic syndrome (MetS) by race/ethnicity among US women ages 18-49 years between 1988 and 2016.
Methods:
Using data from the National Health and Nutrition Examination Survey (NHANES), we classified MetS according to AHA/NHLBI criteria and calculated age-standardized prevalence of MetS in the following periods: 1988-94, 1999-04, 2005-10, and 2011-16. Our sample included nonpregnant women 18-49 years of age who self-reported as non-Hispanic White, non-Hispanic Black, or Mexican American. For each period, we estimated relative (prevalence ratio, PR) and absolute (prevalence difference, PD) differences by race/ethnicity. We tested heterogeneity of these estimates using ANOVA to determine if the differences between groups significantly widened or narrowed over time. All analyses were stratified by gravidity (nulligravida vs. primi- and multigravida).
Results:
Between 1988-94 and 2011-16, the age-standardized prevalence of MetS for nulligravida and primi-/multigravida women increased from 10% to 19% and 16% to 28%, respectively. Among
nulligravida women
, the relative differences in MetS between NH Black and NH White women decreased (PR
1988-94
=1.6, PR
1999-04
=1.4, PR
2005-10
=1.4, PR
2011-16
=1.0), while the difference between Mexican American and NH White women declined in 1999-04, but increased after (PR
1988-94
=2.2, PR
1999-04
=1.0, PR
2005-10
=1.5, PR
2011-16
=1.7). Compared to NH White women, the absolute differences for NH Black (PD
1988-94
=5.8%, PD
1999-04
=9.2%, PD
2005-10
=7.5%, PD
2011-16
=-0.5%) and Mexican American women (PD
1988-94
=11.1%, PD
1999-04
=-0.2%, PD
2005-10
=9.3%, PD
2011-16
=11.9%) followed similar patterns. Moreover, and among
primi-/multigravida women
, the relative differences between NH Black and NH White women remained stable (PR
1988-94
=1.3, PR
1999-04
=1.3, PR
2005-10
=1.5, PR
2011-16
=1.3), while the differences between Mexican American and NH White women declined (PR
1988-94
=1.8, PR
1999-04
=1.6, PR
2005-10
=1.3, PR
2011-16
=1.3). Again, compared to NH White women, absolute differences for NH Black (PD
1988-94
=4.4, PD
1999-04
=8.5, PD
2005-10
=10.7, PD
2011-16
=7.0) and Mexican American women (PD
1988-94
=12.2, PD
1999-04
=15.4, PD
2005-10
=5.7, PD
2011-16
=7.1) were similar. We found no evidence of significant heterogeneity of PRs and PDs across time for any group.
Conclusions:
Since 1988, prevalence of MetS among US women ages 18-49 has nearly doubled. The increase in prevalence was similar across NH White, NH Black and Mexican American women. Among nulligravida women, those that self-reported as Mexican American had the highest burden of MetS, while among primi-/multigravida women, the prevalence of MetS was consistently higher among both Mexican American and non-Hispanic Blacks.