Cardiovascular Risk Factors of Adults Age 20-49 Years in the United States, 1971-2012: A Series of Cross-Sectional Studies.

BACKGROUND
The health of younger adults in the U.S. has important public health and economic-related implications. However, previous literature is insufficient to fully understand how the health of this group has changed over time. This study examined generational differences in cardiovascular risk factors of younger adults over the past 40 years.

METHODS
Data were from 6 nationally representative cross-sectional National Health and Nutrition Examination Surveys (1971-2012; N = 44,670). Participants were adults age 20-49 years who self-reported sociodemographic characteristics and health conditions, and had examination/laboratory measures for hypertension, hyperlipidemia, diabetes, obesity, and chronic kidney disease. Prevalences of sociodemographic characteristics and health status were determined by study period. Logistic regression was used to determine the odds [odds ratio (OR), 95% confidence interval] of health conditions by study period: models adjusted only for age, sex, and race, and fully adjusted models additionally adjusted for socioeconomic characteristics, smoking, BMI, diabetes, and/or hypertension (depending on the outcome) were assessed.

RESULTS
Participants in 2009-2012 were significantly more likely to be obese and have diabetes compared to those in 1971-1975 (OR = 4.98, 3.57-6.97; OR = 3.49, 1.59-7.65, respectively, fully adjusted). Participants in 2009-2012 vs. 1988-1994 were significantly more likely to have had hypertension but uncontrolled hypertension was significantly less likely (OR = 0.67, 0.52-0.86, fully adjusted). There was no difference over time for high cholesterol, but uncontrolled high cholesterol was significantly less likely in 2009-2012 vs. 1988-1994 (OR = 0.80, 0.68-0.94, fully adjusted). The use of hypertensive and cholesterol medications increased while chronic kidney and cardiovascular diseases were relatively stable.

CONCLUSIONS
Cardiovascular risk factors of younger U.S. adults have worsened over the past 40 years, but treatment for hypertension and high cholesterol has improved. The sub-optimal and worsening health in younger adults may have a substantial impact on health care utilization and costs, and should be considered when developing health care practices.