The American Heart Association (AHA) recently issued new cardiovascular health (CVH) measurements that are collectively described as Life’s Essential 8 (LE8). As compared to Life's Simple 7 (LS7), LE8 also includes sleep health as an additional behavioral metric of CVH.

In a recent study posted to the medRxiv preprint server, researchers determine the relationship between LE8 scores and cardiovascular disease (CVD), subtype CVD events, and all-cause mortality.

*Important notice: medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.

About the study

Individual-level information was obtained from six contemporary United States-based cohort studies from the Cardiovascular Lifetime Risk Pooling Project (LRPP). Participants from the Cardiovascular Health Study, Atherosclerosis Risk in Communities Study, Framingham Heart Study, Coronary Artery Risk Development in Young Adults Study, Multi-Ethnic Study of Atherosclerosis Study, and Framingham Offspring cohort study were included in the analysis.

The composite LE8 score, LE8 score without sleep, and LS7 scores were calculated individually. Multivariate Cox regression modeling was performed to determine the relationship between LE8 scores and CVDs, CVD subtype events, and all-cause mortality among young, middle-aged, and older individuals between 20-39, 40-59, and 60-79 years of age, respectively. Covariates included age, sex, ethnicity, race, and educational attainment.

The participants were reclassified according to the LS7 and LE8 quartile ranks across ages. Data were obtained between 1985 and 2002, with participants monitored until August 30, 2020. The LE8 score comprises four health factors including blood glucose, lipid, blood pressure, and body mass index (BMI), in addition to four health behaviors of physical activity, smoking, sleep, and diet.

Nicotine exposure was assessed using self-documented tobacco usage and questionnaire responses. Dietary intake was evaluated using food frequency questionnaires (FFQs) linked to Dietary Approaches to Stop Hypertension (DASH) scores.

The primary study outcome was major CVD events, including new-onset myocardial infarction, heart failure, stroke, or cardiovascular death. Individuals with prior cardiovascular events were excluded, with all study participants closely monitored until the initial cardiovascular event or death from other causes.

Study findings

The sample population comprised 32,896 adult individuals, among whom the mean age was 54 years, 24% were Black, 45% were male, and 55% had received college or higher-level education. The mean LE8, LE8 no sleep, LE8 health factor, and LE8 health behavior sub-scores were 64, 62, 68, and 61, respectively.

The participants contributed to 642,262 individual-years with a mean follow-up of 20 years, with 9,391 individuals experiencing CVD events. Higher LE8 scores were significantly related to CVD events after covariate adjustment. Higher total LE8 scores, LE8 health behavior scores, and health factor scores showed significant associations with lower CHD, stroke, heart failure, cardiovascular death, and all-cause death risks across ages.

Each 10-point increase in LE8 scores was significantly associated with 43%, 35%, and 25% lower CVD risks for younger, middle-aged, and older individuals, respectively. This association was strongest for young individuals, with hazard ratios (HRs) of 0.6, 0.7, and 0.8 for young, middle-aged, and older individuals, respectively.

The overall LE8 score with sleep had non-significantly stronger relationships with cardiovascular risk as compared to the LE8 score without sleep, with HR values of 0.6, 0.7, and 0.8 for young, middle-aged, and older individuals, respectively. The sensitivity analysis, which considered different follow-up durations of 10, 20, and 30 years, yielded consistent findings.

Nicotine exposure was highest among older individuals. Younger and middle-aged individuals had 20 and 10 point higher LE8 health factors scores than health behavior scores, respectively, whereas older individuals showed scores for higher behaviors.

The incorporation of the sleep metric modestly improved LE8 scores across ages. Higher LE8 scores, including health behaviors and factors, were observed among women, Whites, and more educated individuals across ages.

The agreement between LS7 and LE8 scoring was 65%, 66%, and 63% for older, middle-aged, and young individuals, respectively. Over 75% of the uppermost and lowermost quartiles remained unaltered, whereas 50% of middle statistical quartiles were reclassified downward or upward. Similar findings were observed across ages.

As compared to upwardly reclassified individuals, the downwardly reclassified study participants had lower total LE8 scores, LE8 without sleep scores, health behavior, and factor scores. These individuals were more likely to be male, younger, less educated, and Black.

After adjusting for baseline LS7 scores, LE8 reclassification showed independent associations with cardiovascular risk, which were stronger for older individuals, but non-significant associations with cardiovascular risk among young individuals.

Conclusions

The study findings provide evidence supporting the use of LE8 for assessing overall cardiovascular health and future CVD risk. Each 10-point increase in LE8 scores was associated with a 23-40% reduced risk of CVD across ages.

*Important notice: medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.

Written by

Pooja Toshniwal Paharia

Dr. based clinical-radiological diagnosis and management of oral lesions and conditions and associated maxillofacial disorders.