Assessment of the quality of life and the relationship between its level and sociodemographic factors and physical activity in the group of patients with Parkinson’s disease

Parkinson’s disease is a nervous system disorder that significantly affects quality of life (QOL) [1]. It is the second most common neurodegenerative disorder in the world [2–4]. This disease results in the progressive loss of dopamine [5]: a neurotransmitter whose deficiency causes symptoms of the disease [6]. Every year, worldwide, 4.5 to 19 people per 100.00 are diagnosed with this disease [5], and the number of cases increases with age [1]. For people over 55 years of age it affects 1.4% of the population, while in people over 75 years of age it affects 3.4%. It is estimated that in Poland, about 80,000 people are affected and the forecasts predict that by 2020 this number may increase to 110,000 [1]. Parkinson’s typically starts in the fifth or sixth decade of life [5] and is more common among men [7,8].

The cause of Parkinson’s disease is not fully understood. The neurodegeneration process may occur due to genetic or environmental factors, and nerve cells may die due to chronic inflammatory processes, toxic factors, accelerated aging, oxidative stress or protein metabolism disorders [1,9].

Parkinson’s disease is characterized by motor and non-motor symptoms associated with decrease availability of dopamine and non-dopamine neurons [10,11]. Typical motor symptoms include: bradycardia, muscle stiffness, resting tremor, impairment of postural reflexes and motor coordination [2,3,10,12,13], which lead to a decrease in muscle strength, imbalance, gait and functional efficiency [2]. The disease is also often accompanied by emotional symptoms, autonomic disorders or sleep disorders [3,14]. Moreover, cognitive disorders, memory problems, depressive symptoms, anxiety, pain or faster fatigue may also occur [10,15]. As the disease progresses, its symptoms intensify and disability increases [3].

The interest in the QOL of people with chronic disease has been growing [16]. It is an important element of evaluate of health status and effectiveness of treatment. QOL is related to sociodemographic factors, such as age, gender or education, social and living conditions, and the level and availability of medical services [17]. An important element related to a greater level of QOL of patients is maintaining physical activity at an appropriate level [10,18,19,20]. Physical activity prolongs the period of physical independence, positively influences sleep, mood, memory and QOL of people with chronic diseases [21]. It has been demonstrated that people who do not participate in regular physical activity appear to have greater levels of disability [22]. Moreover, people with a decreased level of physical activity show a lesser degree of participation in social life [23], which results in a decreased QOL [24].

The aim of the study was to evaluate the QOL of patients with Parkinson’s disease and to determine the relationship between QOL’s level and sociodemographic factors and physical activity.

The study group consisted of 44 persons (15 women and 29 men) with Parkinson’s disease from the Krakow Association of People Affected by Parkinson’s disease and the Association of People Affected by Parkinson’s disease Ostoja in Krakow. The mean age of the participants was 67.5 years and the mean time from the diagnosis of Parkinson’s disease was 9.6 years.

The criteria for inclusion in the study were: Parkinson’s disease diagnosis, aged 30 to 85, diagnosis >3 years, no serious systemic diseases, and consent to participate in the study.

The Bioethics Committee of the University of Rzeszów approved the research project.

The following questionnaires were used for the study:

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  WHOQOL-Bref-is an abbreviated version of the questionnaire, which aims to assess the QOL in four areas: physical, psychological, social and environmental. Respondents answer questions in a 5-point scale, which determines the nature of the aspect of a given QOL domain. The questionnaire also includes two questions, which are analyzed separately and focus on the individual assessment of the QOL by respondents and their general health. In accordance with the WHO recommendation, the conversion of raw points was used to obtain a scoring scale. The obtained results range from 0 to 100 points, where 0 is associated with low QOL and 100 with high QOL [24,25].

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  International Physical Activity Questionnaire (IPAQ) - serves to assess the level of physical activity. The short version of the questionnaire, containing 7 questions, was used in the study. The questions refer to time spent on physical activity, ranging from sedentary to vigorous. On the basis of the study, the intensity coefficient was determined and the examined person was qualified to one of the three levels of activity:

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  high, where the respondents obtain a result in excess of 1500 METs/week

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  sufficient, where the respondents obtain a result in the range of 600-1500 METs/week

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  insufficient, where the respondents score a result lower than 600 METs/week [26].

The following data were collected using a questionnaire: age, gender, education, marital status, place of residence, material status, duration of Parkinson’s disease, occurrence of other chronic diseases (hypertension, degenerative disease, others) and sporting activity in the past.

A statistical study was carried out using Statistica software version 13.1. Arithmetic means, standard deviations, medians, minimum and maximum values were calculated to describe the distribution of numerical values of features. In the study, the Pearson correlation coefficient was used.

The Mann-Whitney test was also used in the analysis of the results to compare two independent groups.

The level of statistical significance was set at p<0.05.

The study group consisted of 44 people with Parkinson’s disease, including 15 women (34%) and 29 men (66%). The mean age was 67.5 years [±7.5]. The characteristics of the respondents are presented in Table 1.

The lowest domain of QOL observed in the study group was psychological area (44.6 points), and the highest was environmental area (60.5 points). Figures characterizing the QOL are presented in Table 2.

A correlation between the QOL and various sociodemographic factors and physical activity of people with Parkinson’s disease was observed (Table 3).

It was found that age affects the subjective evaluation of QOL and QOL in the physical domain. People with greater level of education were characterized by better QOL in the social domain (p=0.002) and in the environmental domain (p=0.04). It was also noted that single people had better QOL in the physical domain than those in a relationship (p=0.005). Persons living in rural areas were characterized by better QOL in the social domain (p=0.02). The occurrence of hypertension significantly affected the QOL in the psychological domain (p=0.01). The respondents with good or very good material status showed a better QOL in the environmental field (p=0.001). The duration of the disease decreased the QOL in the physical domain (p=0.011) as well as subjective assessment of QOL (p=0.006) and subjective assessment of health status (p=0.009). The level of physical activity affected the physical domain (p=0.005), psychological domain (p=0.001) and social domain (p=0.0001), where its decrease was significantly associated with a decrease in the QOL in these areas.

Simpson et al. [27] noted that psychological interventions with their potential to improve the QOL in the emotional area become important in the therapy of Parkinson’s disease. In our own research it was observed that the lowest domain of QOL was found in the psychological area, which seems to demonstrate Simpson et al.’s thesis about the essence of psychological care in the life of people with Parkinson’s disease.

There are many factors affecting QOL, both modifiable and unmodifiable. These factors may determine the QOL of patients to a different degree [28].

Gender is one of the factors determining the QOL. The literature reports that Parkinson’s disease is more frequently diagnosed in men than in women [5]. However, Tu et al. did not show any relationship between gender and QOL, just like Schraag et al. Similar results were obtained by Augustyniuk et al [16]. Also, in our own research, no correlation between the QOL in the group of women and men was found.

Another study attempted to determine the relationship between the QOL and the age of the respondents. It was found that the disease progresses faster with age and the reaction to pharmacological treatment (levodopa) decreases. Gait and posture disorders, cognitive impairment and dementia development progress [31], which affects the QOL of patients. Augustyniuk et al. [16] observed a correlation between age and QOL. The authors found the best QOL for people between 50 and 60 years of age, while the worst in those over 70 years of age. The dependence in this regard was also demonstrated by Tu et al. Moreira et al. [32] who proved that with increasing age, the QOL in some areas of life deteriorates, i.e. by the decrease of independence in activity of daily living and cognitive functions. Our own research demonstrated the occurrence of dependence as QOL decreased. With the increase in age, the QOL in the physical domain and subjective evaluation of the QOL were reduced.

This study also explored the relationship between the QOL and the level of education. Education plays an important role in individual’s personal and social development and supports and enriches the understanding of oneself and the world [33]. He et al. [34] noted that higher levels of education were associated with improved QOL. This study supports these findings with greater levels of education being associated with higher reported QOL in both the social and environmental domains.

Marital status is another factor that could influence the QOL of individuals with Parkinson’s disease. Moreira et al. [32] reported worse QOL in the social domain in married patients. This dependence seems to be surprising, since persons in a relationship are usually considered to have greater support and acceptance. On the other hand, this correlation can be explained by the fact that chronic disease, resulting in growing dependence on the partner, may be a source of conflict and thus weaken family and social ties [35]. Our own research also found that single people had a significantly greater level of QOL in the physical domain, in contrast to persons in relationships. This result may be related to the fact, that the average duration of the disease was 8.6 years for single persons and 10.3 years for persons in a relationship, which, given the progressive nature of the disease, could explain the occurrence of this dependence.

Studies have also examined the relationship between the QOL and the place of residence of individuals with Parkinson’s disease. Rural areas are typically characterized by informal interactions with strong social links and urban areas are more formal and thus weaker ties between inhabitants are formed [36]. Augustyniuk et al. [16] found a significant difference between the inhabitants of smaller towns and cities, with higher levels of QOL being reported by people from smaller towns and cities. In our own research it was also found that people living in rural areas reported greater levels of QOL in the social domain, in contrast to city dwellers. Our respondents from the rural environment reported greater levels of personal relationships with other people and were more satisfied with the support they received from their friends.

This study also identified a link between the QOL and the duration of the illness. Parkinson’s disease is a progressive disorder with increasing motor and non-motor symptoms over time [37]. The duration of the disease has a negative impact on the QOL of patients due to the deterioration of physical and emotional condition [38]. Tu et al. observed that a longer duration of the disease led to a deterioration in the QOL of patients [30]. Moreira et al. [32] also observed a decrease in the QOL in various domains of the disease (daily activities, emotional domain) in patients with longer duration of the disease. Augustyniuk et al. [16] noted a worse QOL in patients with disease duration exceeding 15 years, slightly better in patients whose disease duration was 5 years. In our study we found that longer duration of Parkinson’s disease caused poorer QOL in the physical domain. Respondents were also less satisfied with the overall quality of their lives and the status of their health. Further evaluation of QOL’s changes related to the progression of the disease is very important, as it may lead to more effective targeting of interventions [37].

This study also identified the relationship between the level of physical activity and the QOL of patients with Parkinson’s disease. Research by Van Uem et al. [39] confirmed that greater levels of physical activity are associated with greater level of QOL. Our own research also demonstrated this relationship, referring to three domains: physical, psychological and social. Patients who undertook greater physical effort were characterized by greater level of QOL in the above-mentioned domains. Physical activity is a modifiable lifestyle factor that may influence the course of Parkinson’s disease [40]. For this reason, it is important to combine traditional therapeutic procedures with an appropriate physical activity strategy in order to reduce motor disorders, postural instability and improve the QOL of people struggling with this disease [41].

Finally, this study examined the relationship between the QOL and material status and hypertension. Previous studies report that the occurrence of hypertension decreases the QOL of patients with this disease [42,43]. In our study, coexistence of hypertension led to deterioration of QOL in the psychological domain. On the other hand, the decreased QOL in the environmental area was associated with poor or average material status. These dependencies have not been studied in a group of patients with Parkinson’s disease previously. Therefore, it is not possible to compare one’s own results with those of other authors.

A limitation to this study was the small sample size. Given the findings of this study it is clear that more work needs to be done to better understand the effects that Parkinson’s disease has on QOL. Therefore, it is important to continue this work in a larger group of patients and to extend this work by exploring a broader range of factors that may affect QOL in this population.

The study demonstrates the relationship between the QOL and various sociodemographic factors (age, education, marital status, place of residence, material status, duration of the disease and coexistence of hypertension) and the level of physical activity in individuals with Parkinson’s disease.