Association between a lifestyle-based healthy heart score and risk of frailty in older women: a cohort study

BACKGROUND: Evidence on the comprehensive role of lifestyle in frailty risk is scarce. To assess the association between a lifestyle-based Healthy Heart Score (HHS), which estimates the 20-year risk of cardiovascular disease (CVD), and risk of frailty among older women. METHODS: Prospective cohort study in 121,700 nurses from the USA participating at the Nurses' Health Study. This study included 68,416 women aged ≥60 year with a follow-up from 1990 to 2014. The HHS was computed using the gender-specific beta-coefficients of the nine lifestyle factors, including current smoking, high body mass index, low physical activity, lack of moderate alcohol intake and unhealthy diet. Frailty incidence was assessed every 4 years from 1992 to 2014 as having ≥3 of the following five criteria from the FRAIL scale: fatigue, low strength, reduced aerobic capacity, having ≥5 illnesses and weight loss ≥5%. RESULTS: During 22 years of follow-up, 11,041 total incident cases of frailty were ascertained. Compared to women in the lowest quintile of the HHS (lowest estimated CVD risk), the multivariable-adjusted hazard ratio of frailty across quintiles was: Q2:1.67 (95% confidence interval 1.53, 1.82); Q3: 2.34 (2.15, 2.53); Q4: 3.54 (3.28, 3.83) and Q5: 5.92 (5.48, 6.38); P-trend > 0.001. Results were consistent for each frailty criterion, among participants with 0 frailty criteria at baseline, when using only baseline exposure or in 6-year-, 10-year- and 14-year-exposure lagged analyses, and after excluding participants with diabetes and CVD at baseline. CONCLUSIONS: The HHS, based on a set of modifiable-lifestyle factors, is strongly associated with risk of frailty in older women.