Introduction:
Adults who reach middle age with ideal blood pressure, cholesterol, and glucose levels have lower rates of CVD mortality compared to those with one or more adverse levels. AHA identified four healthy lifestyle factors (HLFs) - BMI, smoking, diet, and physical activity - important for preventing loss of this low CVD risk state. The purpose of this study was to quantify associations between combinations of HLFs measured in young adulthood and loss of ideal CVH factors into middle age.
Methods:
Analyses included 2,421 young adults (age 18-30 years at baseline in 1985-6) in the Coronary Artery Risk Development in Young Adults study who met criteria for ideal CVH factors at baseline: untreated blood pressure <120/80 mmHg, total cholesterol <200 mg/dL, fasting blood glucose <100 mg/dL and absence of CVD. Cox proportional hazards regression models were used to estimate hazard ratios for loss of all ideal CVH factors status over 25 years of follow-up according to 16 combinations of HLFs measured in young adulthood: BMI <25kg/m2, physical activity >300 exercise units, never smoking/quitting ≥ 12 months prior, and scoring in the top tertile of the AHEI diet score. Models were adjusted for age, sex, race, education, and study center.
Results:
Most (86%, 69 of 80) young adults with 0 HLFs lost the all ideal CVH factor status by middle age. Relative to young adults with no ideal HLFs, those with all 4 ideal HLFs were least likely to lose the low risk CVD state (HR 0.53, 95% CI 0.40-0.70). In the absence of ideal BMI, no combination of other HLFs was significantly protective (Figure 1). When analysis was restricted to the 1,708 young adults with ideal BMI, participants with ideal smoking, diet, and physical activity had a lower likelihood of losing the ideal CVH factor state compared to those with ideal BMI only (HR 0.79, 95% CI: 0.63-0.99).
Conclusions:
Ideal BMI in early young adulthood was protective against loss of ideal CVH factors over time. Among those with ideal BMI, ideal smoking status, diet, and physical activity conferred additional benefit.