Abstract 18185: Is the Obesity Epidemic Reversing Favorable Trends in Blood Pressure: Evidence from Cohorts Born between 1890 and 1990 in the United States.
Previous reports have described favorable temporal changes in the relationship between systolic blood pressure and age in recent birth cohorts. The obesity epidemic might threaten that pattern. We examined differences between birth cohorts in the relationship between systolic blood pressure and age to determine whether there is evidence of a reversal of the favorable trend of declining blood pressures associated with increases in obesity during the same period. We examined changes in the distributions of systolic blood pressure across birth cohorts born between 1890 and 1990 in 68,070 participants examined in the National Health and Nutrition Examination Surveys between 1960 and 2008. The blood pressure distributions were estimated as functions of age and birth-year to examine changes between birth cohorts. We postulated that the age-adjusted 10th, 25th, 50th, 75th, and 90th percentiles of systolic blood pressure had decreased in more recent versus earlier birth cohorts, and that this pattern had slowed or reversed in the most recent cohorts due, at least in part, to recent trends in obesity. After adjusting for sex, race, age and age2, the 10th, 25th, 50th, 75th, and 90th percentiles of systolic blood pressure were 1.0, 1.4, 1.9, 2.6, and 3.5 mmHg lower across birth cohorts for each decade more recently born (all p < 0.0001). Quadratic terms for birth cohort were positive and significant (p < 0.0001) for the 25th, 50th, 75th, and 90th percentiles, consistent with a decelerating cohort effect in the most recent birth cohorts and mediation of this deceleration was observed for body mass index (p < 0.01 at all percentiles). Among persons born in the US between 1890 and 1990, those born more recently have had less pronounced increases in systolic blood pressure with aging. As a consequence, at any given age, their systolic blood pressure distributions are shifted to lower levels relative to the earlier cohorts. These decreases would translate into 11.4 to 13.3 mmHg over 6 to 7 decades, a shift that would contribute importantly to lower rates of cardiovascular diseases. The favorable changes across birth cohorts in systolic blood pressure are slowing and may be reversing, and this adverse change may be due, at least in part, to the obesity epidemic.
- © 2010 by American Heart Association, Inc.