Background
Cardiovascular disease (CVD) is the leading cause of premature death world-wide [
1], with abdominal obesity, hypertension and dyslipidaemia being central risk factors in the etiology of CVD. Conversely, modifiable lifestyle habits including physical activity (PA), limited time spent sedentary, a healthy diet and smoking cessation have all been shown to have beneficial effect on CVD risk, mediated partly by improving traditional intermediating CVD risk factors [
2‐
4]. A healthy lifestyle is the first choice for prevention and treatment of CVD [
5], and according to the World Health Organization, a healthy lifestyle combined with optimal medical treatment could prevent 75% of all CVD world-wide [
6].
Previous Swedish prevention studies have showed that increased PA, decreased sedentary behaviour and a healthier food pattern improved cardiovascular risk factors and decreased CVD risk after 1 months in individuals with high CVD-risk [
7,
8]. Multidisciplinary secondary preventive programs with focus on a healthy lifestyle, risk factor management and medication adherence have been proven effective to reduce CVD risk [
2,
4,
9,
10]. However, an inadequate risk factor control in patients with coronary disease has been reported, with the large majority of patients not achieving the secondary prevention guideline standards [
11]. Furthermore, lifestyle habits have deteriorated over time with an increase in physical inactivity and sedentary time, unhealthy food pattern, central obesity and diabetes, and stagnating rates of persistent smoking [
11‐
16]. Moreover, scientific evaluations of lifestyle interventions in clinical practice are still limited [
7,
9], despite the attention given to lifestyle intervention in current CVD guidelines.
In 2008, a one-year structured lifestyle outpatient clinic program at the Karolinska University Hospital setting in Stockholm, with the aim to guide individuals with increased cardiovascular risk to a change in unhealthy lifestyle habits, with a potential subsequent effect on cardiovascular risk. In a previous publication, significant positive changes in multiple lifestyle habits after 1 year was reported, including increased PA and decreased time spent sedentary, a more healthy food pattern and decreased alcohol intake [
17].
The aim of the present study is to investigate the effects on cardiovascular risk factors and cardiovascular risk after 6 months and 1 year, in individuals with increased cardiovascular risk enrolled in the above referred structured lifestyle program.
Discussion
The main findings in the present study were that participating in a structured lifestyle program over a year was associated with significant improvement in multiple cardiovascular risk factors and decreased overall cardiovascular risk in individuals with increased cardiovascular risk. We noted significantly lower waist circumference, systolic BP, diastolic BP and total cholesterol over 1 year in the participants enrolled in the lifestyle program. Moreover, there was a 15% reduction in estimated probability of developing a CVD within 10 years according the cardiovascular risk based on Framingham risk-score. This reduction was seen in both men and women as well as in participants with or without a history of CVD. In parallel, an overall beneficial change in dichotomized CVD risk factors was observed over year.
There is a call for studies evaluating different approaches for lifestyle interventions in everyday practice with a focus on risk factor management [
7,
9,
21]. The present findings are comparable to findings in previous studies. For example, the innovative family-centred preventive cardiology programme MyAction [
9] revealed improvements in lifestyle habits as increased PA, improved food habits and improved quality of life and risk factors like blood pressure, lipids and glycemic targets after 1 year in patients with CVD. We previously reported similar results in participants of the present lifestyle program regarding lifestyle habits [
17]. While the focus in the MyAction study was on secondary prevention in participants with coronary events, the present study had both a primary and a secondary preventive focus, and included a more heterogeneous study population with different diagnoses and risk profiles. Moreover, Hellénius and co-workers showed in a randomized controlled trial in male participants with high cardiovascular risk, that lifestyle counselling on dietary habits and PA improved several individual risk factors after 6 months, with a reduced estimated cardiovascular risk of 12–14% according to Framingham 10-year risk score [
7]. Moreover, 68-year old sedentary individuals with abdominal overweight showed significant improvements in cardiovascular risk factors such as waist circumference, S-cholesterol, ApoB /ApoA1 ratio after 6 months when after participating in a randomized controlled trial to improve PA habits by using physical activity on prescription [
8]. In the present study, we also used PA on prescription as one of the tools to motivate the participant to increase the level of daily activity and reduce sedentary time. The OASIS study showed a risk reduction of 47% for developing a new cardiovascular event in individuals with CVD that reporting improvements in lifestyle including more PA and a healthier diet after 6 months [
21].
In a previous publication, we aimed at investigating the effect of the intervention program on changes in unhealthy lifestyle habits in the participants of the present study. The results showed that physical inactivity and sedentary time decreased, and diet improved, over 1 year [
17]. The decrease in sedentary time and increase in exercise may partly explain some of the favourable changes in risk factors seen in the present study. For example, replacing 2 h of daily sitting with stepping has been associated with a reduction in waist circumference of − 7.5 cm, 11% lower BMI, 11% lower 2-h plasma glucose, 14% lower triglycerides, and 0.10 mmol/L higher HDL cholesterol in overweight adults [
22]. Also, a decrease in waist circumference and a more healthy body composition have been shown after increasing daily PA with more exercise and less sitting in an RCT using PAP [
8], with similar reduction in systolic and diastolic BP as for the participants in the present study. High systolic and diastolic BP is shown to be reduced by increased exercise levels in previous studies [
23,
24], but more recently, also small amounts of low intensity activity have been shown powerful. In a randomized experimental crossover trial in individuals with type-2 diabetes, a first experimental condition of 7 h of uninterrupted sitting was compared to additional experimental conditions in the same participants on two separate days including a) light intensity walking for 3 min every 30 min while seated, and b) simple resistance breaks for 3 min every 30 min while seated [
25]. They found a significant reduction both in systolic and diastolic BP after including short breaks with light intensity walk or simple resistance activities compared to continuous sitting. In our study a significant positive-trend in both systolic and diastolic BP were shown both for individuals with hypertensive treatment and not. Also healthy food habits have been shown effective in reducing high BP. For example, the Dietary Approach to Stop Hypertension (DASH) in individuals with hypertension (BP systolic > 160 and diastolic > 90) showed that a more healthy food pattern with more vegetables, fish and vegetable fat lead to reduced systolic and diastolic BP [
26].
In the present study, the mean baseline value of S-cholesterol in the total study population was 5.1 mmol/l, which is almost in target according to guidelines for individuals without CVD risk (< 5.0 mmol/L) [
5], and was followed by a mean reduction of 0.2 mmol/l (3.9%) after 1 year. This can be compared with previous epidemiological and intervention studies, which has linked a reduction of 1% in total cholesterol to a CVD risk reduction of 2–3% [
5,
27]. The reduction was somewhat smaller in participants taking statins (4.5 to 4.4 mmol/l, equal to a 2.2% reduced risk) compared to the participants not taking statins (5.4 to 5.1 mmol/l, equal to a 5.6% reduced risk). The positive effects on cholesterol levels regardless statin treatment on not, indicate that this program could be used in both primary and secondary prevention settings.
There was a significant reduction of 15% between baseline and 1 year follow-up in the overall CVD risk according to general cardiovascular risk profile based on the Framingham 10 year risk estimation. Men and participants with a history of CVD had a significantly higher Framingham risk score at baseline compared to women and non-CVD participants. However, importantly, a significant reduction was seen in both men and women (− 22 and − 20%, respectively), as well as in CVD and non-CVD participants (− 21 and − 28%, respectively) over 1 year. The significant decrease in two of the variables included in the risk estimation, systolic BP and total cholesterol, may explain the large part of the reduction of the risk score at group level. Knowing that these are small groups, the findings could still suggest that the program is suitable for both genders as well as for individuals with a history of CVD and without a history of CVD when targeting overall cardiovascular risk, and could hence be used both in primary and secondary prevention.
In lifestyle interventions like the present one, it is important to have a multidisciplinary approach with different health professionals working together with a focus on behavioural changes of unhealthy lifestyle habits, cardiovascular risk factor management and optimized medication treatment [
2,
3,
7,
10]. In the present study, the focus was to strengthen the individual’s ability to change their lifestyle with a person-centered approach, which have shown positive effects on risk factor management and reaching treatment guidelines for individuals with CVD and diabetes [
28].
A strength of this study include the evidence based approach of the lifestyle program and the long-term follow-up (1 year). The high attendance to the program (88% at 6 months and 80% at one-year follow-up) indicates that the program is acceptable for individuals with increased cardiovascular risk. Another strength is the beneficial effect on multiple lifestyle style related risk factors, with the subsequent effect on cardiovascular risk over 1 year in both genders and participants with and without a history of CVD. This indicates that the program may be implemented and used in both primary and secondary preventive every day clinical work. There are also some limitations to be mentioned. This study was not a randomized controlled trial, but a prospective observational intervention study without a control arm. The latter hampers the analyses of the causal relationship between program participation and effects on cardiovascular risk, and regression towards the mean affecting the results have to be taken into account. Moreover, individuals who participated in the program may be more motivated, which may limit the generalizability. Another limitation is the small samples size in the subgroup analyzes, potentially influencing the power of the analyses.
We have previously shown positive effects on lifestyle habits and quality of life in individuals with cardiovascular risk both from a primary and secondary approach [
17]. The present study indicates potential subsequent effects on cardiovascular risk factors and cardiovascular risk in the same study population. This intervention was initiated and run at an outdoor clinic in a hospital setting with both a primary and secondary preventive focus on cardiovascular risk management, and could serve as one example of how to work with this in clinical practice. Moreover, in our current landscape of finite and limited resources, an economic cost-effectiveness evaluations of the intervention program would be highly valuable for expenditure decisions and enable long-lasting implementation strategies.
Acknowledgements
Special thanks to all the staff at the department of cardiology taking part in the structured lifestyle program, Karin Björklund-Jonsson, Mattias Damberg, Anna Norhammar, Mattias Ekström, Agneta Nordwall, Sofia Trygg Lycke, Ellen Segerhag and Cecilia Linde.