tracking blood pressure and subclinical CAD

The CARDIA study of 3442 black and white men and women aged 18-30 in 4 cities (Birmingham AL, Chicago IL, Minneapolis MN, Oakland CA) were followed 25 years (1985-2010), and were assessed for BP measured at baseline, 2,5,7,10,15,20, and 25 years, then evaluated for subclinical CAD by their coronary artery calcification (CAC), perhaps the best predictor of atherosclerotic disease (confirmed in the recent AHA guidelines) -- (see htn young and CAD middleage jama 2104 in dropbox, or doi:10.1001/jama.2013.285122). they assessed 5 different BP trajectories, with the following adjusted odds ratios for high CAC score (comparing the 4 other categories with the low-stable cohort):

--low-stable bp (19.9% of population), with SBP 101-104, DBP 62-64 over the 25 yrs -- this group had an elevated CAC score developing in 5.8%
--moderate-stable (42.3%), with SBP 109-118, DBP 68-74 over the 25 yrs -- odds ratio 1.44, with absolute increase above the low-stable group of 2.7% (not reaching statistical significance)
--moderate-increasing (12.2%), with SBP 111-142, DBP 69-89 over the 25 yrs -- odds ratio 1.86, with absolute increase above the low-stable group of 5% (not reaching statistical significance)
--elevated-stable (19%), with SBP 120-123, DBP 76-77 over the 25 yrs -- odds ratio 2.28, with absolute increase above the low-stable group of 6.3%
--elevated-increasing (4.8%), with SBP 125-146, DBP 80-92 over the 25 yrs -- odds ratio 3.70, with absolute increase above the low-stable group of 12.9%
--more of the low-stable group with female, white, more educated, and fewer concurrent cardiovasc risk factors
--rapid increases in BP more in African-American men, also with higher rates of smoking, and more increases in BMI. Af-Amer women more represented in the moderate-increasing group.  only minimal changes in above risks for increased CAC after controlling for demographics, other cardiovasc risk factors, or use of antihypertensive meds.

so, interesting to see longitudinal data of individuals, instead of just cross-sectional data. most of the individuals were within the "pre-hypertensive" category. this study strongly reinforces assessing blood pressure regularly and promoting healthy lifestyle in younger people (though this was not an intervention study of lifestyle changes, it certainly makes sense to inform pre-hypertensive individuals, and esp those with increasing blood pressure, that they are at increased risk of CAD and that it would be prudent to decrease this risk through targeted lifestyle interventions).

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