In this study, three dietary patterns were obtained by clustering analysis. There were significant differences in some individual metric scores among the three patterns, but the overall CVH scores showed little difference. Most people had a moderate CVH status. Compared with the elderly men aged 70 years and above and those with lower education, the proportion of women, 60–69 years and those with college and above were higher in high CVH, and this subgroup and those in pattern 2 characterized by higher consumption of aquatic products, fruits and vegetables were likely to have more ideal metrics.
Lloyd-Jones et al. found that the total CVH score of Americans aged 65–79 years was 63.3, and physical activity score was the lowest [20]. In our study, the total CVH score of ≥ 60 years was 68.50, which was far lower than the highest score, and the blood pressure score was the lowest, and the number of people who had the highest score was only about 10%. Studies have found that hypertension has the strongest association with CVD, as the largest risk factor for CVD, accounting for 22.3% of its PAF [21]. Results from the CHNS showed that 71.3% of the elderly aged 60 years and above had elevated blood pressure (SBP ≥ 130mmHg and/or DBP ≥ 85mmHg). Therefore, it is necessary to pay attention to the pre-prevention of hypertension in the elderly to reduce the incidence of hypertension related diseases. In addition, the dietary score was relatively low, less than half of the highest score. Entering the aging stage, physical and mental function will decline to varying degrees, such as decreased chewing and digestion, delayed taste responses. Therefore, on the basis of a balanced diet for general adults, the elderly should be provided with a variety of foods that are high in energy and nutrient density and easy to digest and absorb, as well as animal foods and soy products that are rich in high quality protein. At the same time, the elderly should be encouraged to take active outdoor activities and maintain a healthy weight [22].
In the analysis of demographic characteristics, the overall CVH score ranged from 66.70 to 70.62, which may appear modest. But in the prior studies of LS7, Lee et al. followed up Korean adults aged 20–39 years for 16.1 years and found that the risk of cardiovascular events was reduced by 24%-42% for every 1 point increase in CVH score [23]. In the United States, a 31.9 year follow-up of adults aged 18–30 years found that for every 1 point increase, the risk of CVD and death was reduced by 27% and 31%, respectively [24]. Thus, higher CVH scores were strongly associated with better health outcomes. In addition, among the eight metrics, 60%-80% of the elderly had the highest scores in sleep, physical activity and nicotine exposure, indicating that most people maintain good living habits, but smoking among the elderly still needs to be taken seriously. The report showed that the number of deaths caused by tobacco use in China accounted for nearly one third of the world, and tobacco use was far more harmful to the health of Chinese people than the global average, which further suggested the necessity of intervention and provided a basis for government departments to formulate tobacco control policies for special populations [3].
Our study found that the number of people with ≥ 6 ideal metrics in the three patterns was 6%-8%, 2% of people had the highest score in all 8 metrics only in pattern 1. In the United States, 4.1% of the elderly had ≥ 5 and 0.7% have ≥ 6 of the 7 ideal metrics [25]. The prevalence of ideal CVH behaviors and factors in the elderly was alarming. Previous studies have shown that having a higher number of ideal CVH metrics could significantly reduce the risk of CVD morbidity and mortality. In American adults, compared with those with 0–1 ideal metrics, those with ≥ 6 ideal metrics had a 76% lower risk of death from CVD (HR = 0.24, 95%CI = 0.13–0.47), and the risk showed a downward trend with the increase of the number of metrics [26]. Another meta-analysis of 9 prospective cohort studies involving 12 878 participants showed that having a higher number of ideal metrics was associated with 45% reduction in all-cause mortality, 75% in CVD mortality, 80% in CVD, and 69% in stroke [27]. Female had better CVH than male and were more likely to have more ideal metrics. Studies have shown that this difference was mainly attributed to the significantly higher smoking rate of males than females. If all smokers quit smoking, the ideal CVH rate would be increased by more than two times [28]. People with college and above had better CVH, and they may have better health awareness and be more likely to adopt health-related behaviors.
Analysis of different dietary patterns showed that people in pattern2 were more likely to have more ideal CVH metrics, and this pattern had higher intake of aquatic products, vegetables and fruits. The “Eastern healthy diet pattern”, represented by coastal areas such as Shanghai, Jiangsu and Zhejiang, was proposed for the first time in the Dietary Guidelines for Chinese residents. The main characteristics are diverse food, light and less oil, especially rich vegetables and fruits, fish and seafood, milk and beans [22]. Dietary guidelines for improving CVH proposed by the AHA that dietary patterns containing fish and seafood were associated with a lower risk of CVD [29], possibly due to the high omega-3 unsaturated fatty acids in fish [30]. In addition, the fish is softer, facilitating the digestion and absorption of the elderly. In the other two dietary patterns, the intake of aquatic products was only one-third of the recommended value. In addition, we should pay attention to the insufficient dairy intake, about 10% of the recommended amount in pattern 1 and pattern 2, and only 5% in pattern 3. Milk is an important source of dietary calcium and high quality protein, rich nutrition and easy to digest and absorb, the elderly should be instructed to choose suitable dairy products, and stick to use for a long time. According to the Burden of Disease Collaboration in the United States, low levels of each CVH metric led to substantial morbidity and mortality, and the main risk factor associated with the total burden of disease was an suboptimal diet [31]. Studies have shown that improving CVH score, especially dietary score, was of great significance to health [20].
In our study, “Life’s Essential 8” was used for the first time to evaluate the CVH status of Chinese elderly people based on differentiated regional dietary patterns, which was closely related to the LS7, but the “Life’s Essential 8” was more sensitive to individual differences. There are still some limitations in this study: 1) The 3d-24h dietary recalls may have recall bias and usually cannot assess the daily dietary intake. However, compared with the food consumption frequency collected by the food frequency method, the specific food intake collected by3d-24h was more accurate; 2) Our study only had lipid measurements and did not ask individuals if they were receiving lipid therapy, so the calculated scores could be high; 3) Nicotine exposure included e-cigarettes and electronic atomizer in addition to traditional cigarettes, but this study only collected traditional cigarettes, so the calculated score may be high. Therefore, caution should be exercised when comparing with similar results and extrapolating.