4.2 Comparing with previous studies
Our finding were consistent with preiouvs cohort studies in European, USA and Asia and suggested an protective effect between healthy lifestyle score and the risk of CVD in extensive Chinese population. Evidence have shown combined Mediterranean diet in healthy lifestyle score in Western with an inverse association with the CVD
incidence37, 42, adjusted HR ranging 0.22-0.43 and CVD death77, adjusted HR ranging 0.54-0.62. In a follow-up 7.2 years cohort study in China45, combined healthy lifestyle
factors had decreasing the risk of CVD but diet pattern in the study defined from the habitual intake of 12 conventional food was insignificant protective effect. Our study had validate the Mediterran diet pattern had benefit in reduction of CVD events.
Previous cohort studies of lifestyle score and incident CVD are limited in the adjuted covariates. Most controlled covariates in those analyses hazard including age, sex, soci-economical status, parenal history of CVD, hypertension, diabetes,
hyperlipidemia status at baseline and medication exposure, such as aspirin, hormone, anti-hypertensive, anti-diabetic or lipid-lowering agent. Several cohort studies had estimated the hazard ratio with part of additional adjuted clinical factors, like systolic blood pressure, serum level of glucose, hemoglobine A and total cholesterol33, 36, 39-42,
46-47. In our study, we estimated the hazard ratio after adjusted for age, sex, social-economical and healthy status at baseline and clinical factors such as blood pressure, serum level of glucose, triglyceride and non-HDL. All of those including clinical factor as adjustment covariates studies implies that combined lifestyles had additional benefit for the decreasing incidence of CVD other than the mechanism of blood pressure, glucose and lipid-controlling.
Comparison of weighted lifestyle score and simple lifestyle score to exam the
assumption of each lifestyle factor with the same magnititude effect of the CVD risk by the area under curve, IDI nad NRI demonstrated silimar predictive performance of the incidence of CVD. The result was consistent with previous studies about healthy lifestyle and risk of heart failure49 and as the first study of the weighted healthy lifestyle and CVD risk. The result of the simple and weighted lifesytle score with similar impact on CVD risk may imply there were no more benefits of focusing on single one or two healthy behaviors than intergration of all healthy lifestyle factors.
Moreover, adapting overall healthy lifestyles rather than strong emphasis of particular lifestyle were an optimal strategy to improving cardiovascular health.
Compared with previous studies about WCRF/AICR lifestyle score
Multiple observed studies have suggested a inverse association between adherence to high numbers of WCRF/AICR lifestyle score and varitety cancer, such as colorectal cancer78-80, breast cancer81 (Hastert, 2013, Adherence to WCRF/AICR cancer prevention recommendations and risk of postmenopausal breast cancer), esophageal adenocarcinoma, prostate cancer78 and total cancer incidence. Previous studies of the association between greater adherence to WCRF/AICR lifestyle score and the CVD risk factors were limited and have yielded inconsistent findings. A cross-section study reported, increasing numbers of adherence to WCRF/AICR recommendation
decreased the incidence of metabolic syndrome in breast cancer patients82. On the contrary, a cross-sectional based study of 2267 European adults, greater adherence to WCRF/AICR lifestyle scores was observed with higher serum level of
thrombomodulin and thrombopoietin which might increase the risk of CVD83 and be explained by lower alcohol and meat consumption among persons with higher WCRF/AICR lifestyle score. To our knowledge, our study was the first prospective cohort of adherence to WCRF/AICR lifestyle score and the incidence of CVD and the association was demonstrated nonsignificantly. The result suggested that greater numbers of adherence to WCRF/AICR lifestyle score decreasing the incidence of metabolic syndrome but increasing pro-coagulative status lead to an nonsignificantly protective effect of CVD.
Compared with previous Life's Simple 7
The association between Life's Simple 7 and CVD in observational studies has been confirmed in repeated re-analyses. Most of the variables included in our model were silimar to those in previous studies84-93. Moreover, several clinical risk factors and biomaker, such as blood pressure, triglyceride, non- high-density lipoprotein, fasting glucose and hemoglobin A were found to be attenuated the cardiovascular protection from Life's Simple 7 in our study. The CVD preventive effect decling among Life's
Simple 7 imply the protective benefits attributable from clinical risk factors more than lifestyle factors. When a CVD risk score both considering lifestyle factors and clinical risk factors, including blood pressure, cholesterol and glucose, which are downstream of lifestyle factors, clinical factors may mediate the lifestyle factors on CVD risk furthermore diminish the predictive value of lifestyle factors. More emphasis on clinical factors rather than lifestyle factors may drive the CVD risk score from primodrial prevention to primary prevention and identify individuals with higher short-term risk of CVD than long-term risk.
Comparion among lifestyle scores
In our study, simple Taiwan healthy lifestyle score and weighted Taiwan healthy lifestyle score had better predictive performance according to comparions of area under curve, IDI and NRI. The different components among healthy lifestyle scores includes fish, eggs, dairy diet, smoking status and optimal amount of alcohol
consumption. Mediterranean diet used by Taiwan lifestyle score was defined fish as an optimal food for CVD protection but limited egg and dairy diet in daily intake.
Taiwan lifestyle score defined redular adequate alcohol consumption as optimal lifestyle. However, WCRF/AICR lifestyle score considered non-alochol as and ideal lifestyle and Life's Simple 7 didn't consider the amount of alcohol consumption into
score. Additionaly, the status of non-smoking or quit more than 12 months from smoking were suggested in Taiwan healthy lifestyle score and Life's Simple 7 score but not calculated in WCRF/AICR lifestyle score.
Simple Taiwan healthy lifestyle score, weighted Taiwan healthy lifestyle score and Life's Simple 7 score were observated the association between greater adherence to score and lower CVD incidence in model 2. However, regarding the adjustment of clinical factors, Life's Simple 7 failed to find an significant inverse association of CVD risk might explained by the different definition of healthy diet, physical activity and lack of alcohol component. Taiwan lifestyle score compared with Life's Simple 7 might be more suitable for primodrial prevention among population without no clinical risk factors.
Alcohol
However, regarding with the variations in both amount of alcohol consumed and patterns of consumption, the burden of alcohol in CVD deaths are varies in different area. (13,94) Such as in Russia and estern Europe, former soviet republics, the risk in harmaful alcohol use has led to a massive burden of CVDs due to the change of social and political situation. Alcohol drinking is not a common lifestyle culture in Taiwan
compared with European or Russia, and the amount of alcohol consumed may less than those area. That might be the reason why the highest frequence of alcohol
consumped status compared with none or less drinking with cardioprotective effect.
Physical Activity
The diverse patterns of daily activity during occupation or leisure time between countries leaded the mearsurement of physical activity as an major challenge. Further, exsiting evidence showed the inconsistent result of the association between
occupational and leisure time physical activity and the risk of CVD.94 Not like the inversely associated between leisure time physical activity and CVD risk, commuting physical activity were no statistically significat associated with CVD.95 More and more evidence reported the association between physical activity and the risk of CVD were affected by the variate domain of physical activity, including occupational physical activity, leisure activity, active travel, household chore, family activities were an important covariates should be emphasis.
All agree physical activity reduce the incidence of CVD. However, some evidence demonstrated a U or reverse J-shaped relationship between higher physical activity dose and CVD in observational studies. Physical activity at extreme volume such as
strenuous activitiy daily compared with moderate (2-3 times per week) had higher incidence of coronary artery diseases, cerebral vascular disease and venous
thromboembolic events and CVD mortality rate.96-97 The J-shaped relationship between the physical activity level and CVD were also demonstrated in our study.