Anxiety and depression associated cardiovascular health behaviors among patients with hypertension

Background: Anxiety and depression in hypertensive patients may lead to poor blood pressure control and increases the risk of disease mortality. Lifestyle impacts depression and anxiety. This study aimed to assess cardiovascular health behaviors (CHBs) associated with co-morbid anxiety and depression among patients with hypertension. Methods: We included 488 hypertensive patients from Changsha, China. We measured anxiety and depression using the self-rating anxiety scale (SAS), and the self-rating depression scale (SDS), respectively. CHBs (smoking, overweight/obesity, leisure physical activity (LPA), and fruit and vegetable consumption (FVC)) were assessed using the Cardiovascular Health in Ambulatory Care Research Team (CANHEART) index. We compared anxiety and depression prevalence of participants in different socio-demographic, CHBs, co-morbidities, family histories, assessed risk factors and their biological synergistic interaction. Results: The proportion of not ideal in smoking, overweight/obesity, LPA, and FVC were 63.9%, 49.8%, 30.7%, 78.3%, respectively. Displaying comorbidity of HLP and not obtaining adequate amounts of LPA were risk factors for both anxiety and depression. The synergy interaction between obtaining secondary education or less and displaying comorbidity of hyperlipidemia (HLP) for anxiety (OR=5.238, 95% CI=2.784, 9.856), and between not obtaining adequate amounts of LPA and obtaining manual labor for depression (OR=7.164, 95% CI=3.553, 14.443) was statistically signicant. Conclusion: Our study indicated that doctors should pay more attention to the psychiatric health of hypertensive patients at lower education levels and with second comorbidities. More importantly, patients with hypertension working on manual jobs need to pay closer attention to how they spend their leisure time and strengthen LPA.

and the exploration of risk factors in co-morbid hypertensive patients is rare. This study aimed to explore cardiovascular health behaviors (smoking, overweight/obesity, LPA, and FVC) and comorbidities (diabetes mellitus (DM), HLP, and cardiovascular disease other than stroke (CVD)) that associated with anxiety and depression among patients with hypertension, to develop a tailored intervention for the hypertension cases.

Study design
This cross-sectional study was conducted from January to June 2018, with a total of 488 patients with hypertension that had been recruited from hospital cardiology outpatient clinics. Patients were asked to complete an electronic questionnaire and the data were collected anonymously. Investigators provided detailed instructions for lling and checked for integrity after submission. The following inclusion criteria were used: (1) 18 years or elder, (2) with hypertension, (3) commitment to complete the questionnaire. Hypertension was de ned as systolic blood pressure ≥ 140 mmHg, and/or diastolic blood pressure ≥ 90 mmHg when measured three times on different days. Alternatively, patients met the inclusion criteria if they were already being treated for hypertension [9]. Exclusion criteria were: (1) marked cognitive impairment, (2) active suicidal intent or plan, (3) inability to speak Chinese. This study was approved by the Human Ethics Committee of the Third Xiangya Hospital.

Measures
The questionnaire was used to collect the information described below.
Zung's Self-Rating Anxiety Scale (SAS) and Self-Rating Depression Scale (SDS): The main outcomes were anxiety and depression, which were assessed using the SAS and SDS, respectively. Both the SAS and the SDS are 20 item Likert scales, which are measured on a 4-point (1)(2)(3)(4) scale. Items refer to affective and somatic symptoms. For SAS, 15 items express a negative experience, and 5 express a positive experience and are reverse scored. SDS, on the other hand, includes 10 items that express a negative experience, and 10 that express a positive experience and are reverse scored. For both the SAS and SDS, the total raw score ranges from 20 to 80, which is converted to an index score by multiplying 1.25. The cut-off points are usually used as an index score of 45 and above (raw score 36 and above) for anxiety and an index score of 50 and above (raw score 40 and above) for depression (28). Cardiovascular Health Factors and Behaviors: The CANHEART index is a tool for measuring cardiovascular health using data from the Canadian Community Health Survey. There are 6 cardiovascular health factors/behaviors (smoking, overweight/obesity, LPA, FVC, diabetes, and hypertension) in the CANHEART index for adults aged 20 years and older, and 4 health factors/behaviors (smoking, overweight/obesity, LPA, and FVC) for youth aged 12-19 years. This study used the CANHEART index as a reference to explore the relationship between cardiovascular health behaviors and depression or anxiety disorder among patients with hypertension. We used the 4 items from both the adult and youth CANHEART index as behavior-related risk factors for patients aged 18 years and older. The values were 0 (not ideal) and 1(ideal) for each item.
Ideal cardiovascular health for these 4 items was de ned as follows: (1) Smoking: nonsmoker or former daily or occasional smoker who quit more than 12 months ago for adults, and never tried smoking or never smoked a whole cigarette for youth.
Independent variables: The independent variables included socio-demographic characteristics (age, sex, marital status, education, occupation, and residential location), co-morbidities, and family history. Age categories were recorded as 18-44 years, 45-59 years, 60-75 years, or 75 ~ years. Marital status was recorded as never married, married, or separated/divorced/widowed. Education was grouped as secondary or less, or pre-college or more. The occupation was recorded as mental labor or manual labor. Residential location was recorded as urban or rural. Co-morbidities included DM, HLP, and CVD. Family history included family history of hypertension (FM-HYP) and cardiovascular disease (FM-CVD).

Statistical Analysis
Continuous variables were presented as mean ± standard deviation (SD) and categorical variables were summarized as proportions. We compared continuous factors using Student's t-tests and compared categorical variables using chi-square or Fisher's exact tests. For those with obviously skewed distribution, median (1st quartile, 3rd quartile) was utilized to describe their features, and comparisons in the two sets were carried out with Mann-Whitney U tests. We used bivariate logistic regression models to uncover factors associated with, 1) anxiety among hypertension patients (yes = 1/no = 0), 2) depression among hypertension patients (yes = 1/no = 0). Determinants were selected from potential variables using the stepwise binary logistic regression forward likelihood ratio. The interaction effects between determinants were calculated using three metrics for biological synergistic interaction: RERI, the relative excess risk due to interaction; AP, the attributable proportion due to interaction; and S, the synergy index, RERI CI > 0, AP CI > 0, S CI > 1 at the same time were set as a signi cant level of biological interaction (30). All tests were two-sided and p < 0.05 was set as the signi cant level. All data management and statistical analyses were carried out using SPSS version 21.0 (IBM SPSS Statistics, IBM Corporation).

Study population
A total of 488 patients with hypertension completed the questionnaire. The mean age of the participants was 52.1 years and 62.9% of the sample was male. 88.9% of the sample was married, and 59.8% with secondary education or less. About 56.1% of patients undertaken mental labor and about 70.1% lived in urban areas. DM, HLP, and CVD were present in 20.7%, 40.6%, and 38.7% of the patients, respectively. More than half of the participants had an FM-HYP (55.1%), and about a third of the sample had an FM-CVD (32.6%) ( Table 1).

Cardiovascular Health Factors and Behaviors
The proportion of patients that not displayed the ideal status of smoking, overweight/obesity, leisure physical activity, and fruit and vegetable consumption behaviors were 63.9%, 49.8%, 30.7%, 78.3%, respectively (Table 1).

Anxiety and depression
The SAS and SDS results are shown in Table 1. The mean SAS and SDS index scores were 40.54 ± 8.91 (raw score was 32.43 ± 7.13) and 45.09 ± 12.11 (raw score was 36.07 ± 9.69). Overall, about 31.1% and 36.5% of all patients with hypertension showed a potential clinical diagnosis of anxiety and depression, respectively.
The following characteristics were shown to be potential risk factors for anxiety among patients with hypertension: 60-74 years, female, secondary education or less, a career in manual labor, residing in a rural area, the existence of comorbidities with DM, HLP, or CVD, and lack of leisure physical activity (p-values all < 0.05). Potential risk factors for depression in patients with hypertension were secondary education or less, a career in manual labor, the existence of comorbidities with DM, HLP, or CVD, and lack of leisure physical activity (p-values all < 0.05) ( Table 1).
Results of bivariate logistic regression analysis for predictors of anxiety and depression are shown in

Interaction effects analysis
In patients with both hypertension and anxiety, the synergistic interaction between obtaining a secondary education or less and co-morbid HLP was statistically signi cant, and the proportion attributed to this interaction was 58.7% (interaction OR =  Notes: *** signi cant biological synergistic interaction; Sex, reference male; Education, reference pre-college and above; HLP: reference no; LPA, reference not ideal; Occupation, reference mental labor.

Discussion
In this cross-sectional study, anxiety and depression appeared in 31.1% and 36.5% of patients with hypertension, respectively.
Anxiety was associated with female, secondary education or less, comorbid HLP, and lack of LPA, and the results indicated that a synergistic interaction exists between comorbid HLP and secondary education or less. Depression was associated with manual labor, comorbid HLP, and lack of LPA, and the results indicated that a synergistic interaction exists between a manual labor career and lack of LPA.
In our study, the prevalence of depression in patients with hypertension was slightly higher than the pooled prevalence of 29.8% that was previously reported in a meta-analysis using the same scale (15). This difference was mainly due to the overestimation of depression rates when analyzing patients with hypertension in a hospital setting. The pooled rate of depression in patients with hypertension in a hospital setting was higher than the rate of depression in hypertension patients in the community (27.2% vs 26.3%, however not all studies used the same assessment). The prevalence of anxiety was ranged from 8.9-55.3%, as determined by different anxiety measures (16). Differences may also result from using different threshold scores for anxiety, and different patient's ages. However, there is no reported pooled prevalence of anxiety in patients with hypertension.
Hypertension, DM, and HLP are the three most common major chronic conditions that can lead to severe vascular events and deaths. The prevalence of concurrent hypertension and hypercholesterolemia was 6.3% in 2011-2012 and has increased signi cantly in the past 12 years (31). Emotional distress may occur in response to the disease manifestation, complications, progression, impact on self-image, and the need for continuous non-pharmacological and pharmacological treatment (32).
People diagnosed with chronic disease can have a lower quality of life, develop somatic symptoms, and experience role impairment, all of which may lead patients to develop feelings of distress. Anxiety is a common psychological problem in the general adult population, and it is not speci cally related to hypertension, as other chronic illness is also associated with an increased incidence of anxiety or severity of anxiety symptoms (33). Taking into consideration the ndings of this study, we suggest that the presence of a second chronic disease, especially HLP, may affect the ability of hypertension patients to control their emotions, and can lead to an increased risk of anxiety in hypertension patients.
It is well established that LPA is a critical component of a healthy lifestyle and that it plays an important role in the prevention of chronic diseases, including hypertension and HLP (34). A high prevalence of anxiety disorder (17.0%) and depression disorder (39.1%) were found in a sample of chronic disease patients from three Southeast Asian countries, of these patients, 39.0% engaged in low physical activity (35). People with chronic conditions are more likely to have anxiety or depressive disorders than the general population and are also more likely to partake in low levels of LPA. Physical activity has bene ts for physical health, as well as for the treatment of depression. In this study, insu cient LPA is one of the risk factors that increased the incidence of both anxiety and depression in patients with hypertension, which is consistent with previous studies (36,37).
In this study, we found that patients with lower levels of education were at a higher risk for anxiety in combination with hypertension. Additional studies have also uncovered this relationship between lower education and anxiety (38). Patients with a lower level of education may nd it more di cult to get adequate information to control the illness and promote a healthy lifestyle. We also found that patients with hypertension that performed manual labor were at a higher risk for depression. Manual work is typically characterized by repetitive work, manual handling and prolonged static postures, and the need to work for a long time, with insu cient time for recovery. Workers in manual jobs are more likely to suffer from musculoskeletal disorders, which are also commonly associated with depressive symptoms (39).
Our study found that working a manual job and not partaking in su cient LPA could increase the risk of depression among patients with hypertension independently. Moreover, the two factors also had a clear interaction on depression in patients with hypertension. When patients with hypertension worked a manual job and did not partake in LPA, the risk of depression was 7.164 times that of those who worked in non-manual jobs and partook in su cient amounts of LPA. 68.0% of the results could be attributed to the interaction between labor style and leisure-time physical activity. Whereas the health effects of LPA are considered to be bene cial, the physical activity paradox suggests there are contrasting health effects for occupational physical activity and LPA (40), which could lead to the observed synergistic effect between manual labor and lack of LPA. A previous study revealed that both male and female manual workers may be less likely to engage in LPA (41), and both physical inactivity and sedentary lifestyle appear to be signi cantly related to symptoms of depression (36).
Our study has several limitations. Due to the cross-sectional design of this study, we cannot conclude the causal relationship between these two risk factors and depression among patients with hypertension. Secondly, although LPA was one of the potential risk factors in our initial design, LPA measurement guidelines are not detailed enough and need further structuring.

Conclusion
Our results, obtained from patients with hypertension recruited from hospital cardiology outpatient clinics, suggest that the prevalence of depression is higher than anxiety in this group. Patients with HLP and low levels of LPA are at a higher risk of developing anxiety and depression. Patients with lower levels of education, of which have comorbidities, such as HLP, are more likely to suffer from anxiety, while those working in manual labor are more likely to experience depression. Our work indicates that doctors should pay more attention to the psychiatric healthy of hypertension patients at lower education levels and with second comorbidities. More importantly, patients with hypertension working on manual jobs need to pay closer attention to how they spend their leisure time and strengthen LPA.

Declarations
Ethics approval and consent to participate: This study was approved by the Human Ethics Committee of the Third Xiangya Hospital. Signed informed consent was obtained from each participant.
Consent for publication: The consent for publication was obtained from each included author, and the authors approved the nal manuscript for submission.
Availability of data and materials: The data of this study is obtainable upon sending a request to the corresponding authors.