Guzel Discigil

Assistant Professor, Adnan Menderes University, Department of Family Medicine
Erdem Ozkisacik
Assistant Professor, Adnan Menderes University, Department of Cardiovascular Surgery

Address correspondence to:
Guzel Discigil MD
Assistant Professor, Department of Family Medicine, Adnan Menderes University Medical Faculty
1962 Sokak No:30/1Aydin, 09100 TURKEY
Phone: +90 256 213 9373, Fax: +90 256 214 6495, E-mail: guzeld@yahoo.com
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Key words: Health related quality of life, Mediterranean diet, east Mediterranean community.
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INTRODUCTION

Quality of life is a multidimensional construct including individuals' overall satisfaction with life assessing functional status in physical, emotional and social dimensions (1).
Chronic diseases alter well-being and health related quality of life (HRQOL) (2,3,4)
The relationship between health measurements and chronic conditions are well studied in a variety of age groups including the elderly and HRQOL found declining with chronic disease presence such as coronary heart disease, hypertension, diabetes (2,3,5,6,7,8,9). Several hospital-based studies have previously addressed impact of medical or surgical treatment of chronic conditions on HRQOL (3,4,7,8,9). However relatively fewer studies have evaluated HRQOL and its relationship with dietary habits and physical activity which are currently not very well addressed (2,5) .
In the present study, we aimed to verify the relationship between quality of life and health behaviors such as dietary habits, physical activity and frequently seen chronic diseases.

The current study is based on a sample from the registered residents in the county of Datca, ancient name known as Knidos. Datca is a semi-urban, partly agricultural west Anatolian county located on the east Mediterranean coast, with an adult population of around 3000. The study was announced to adults living in Datca by mail, hand-outs and loudspeaker announcement system via local municipal organizations. Volunteers were interviewed face to face by trained physicians. Approval consent was taken from each participant. 108 men and 219 women completed a questionnaire and Turkish version of SF-36v2 form.

SF-36v2 Form:
Short form 36 version 2 (SF-36v2) is a widely used as an extensive health related quality of life measurement. The major domains of SF-36v2 form are physical functioning (PF), social functioning (SF), role-emotional (RE), role-physical (RP), bodily pain (BP), vitality (VT), mental health (MH) and general health perception (GH). The calculated score of each scale was transformed to have a mean of 50 and standard deviation of 10 in general population, with higher scores indicating a better state of health(10). A Turkish version of SF-36v2 was used with permission of the Medical Outcome Trust .

Questionnaire:
Elements of the questionnaire consisted of demographics, chronic disease history, physical activity and dietary habits.

Age, gender and smoking habits were integrated in the demographics section of the questionnaire.

Four categories were included in the physical activity part of the questionnaire.

1. Sedentary, mostly sitting during the day.
   
2. Mild activity such as walking at least 20 minutes at a time and 3 days a week.
   
3. Moderate activity such as biking or running at least 20 minutes at a time and 3 days a week.
   
4. Vigorous activity such as weight lifting or hoeing in the garden at least 20 minutes at a time and 3 days a week.

For each category, time spent for the addressed physical activity was asked. Swimming 30 minutes at a time 3 days a week was considered as regular swimming. Swimming period of months in a year were asked separately in the physical activity part of the questionnaire.

Presence of coronary heart disease (CHD), hypertension (HT), type 2 Diabetes Mellitus (DM), and family history of these chronic diseases were questioned in the chronic disease part of the questionnaire.

Dietary habits were questioned in 5 categories and in a scale of 5. The five categories questioned were red meat, fish, fruit, olive oil and vegetables (raw and cooked) consumption. Scale One signifiedconsuming every day; scale Two, =3 times/week; scale Three, 1-3 times/week; scale Four: <once/week; scale Five, <once/month or never eaten.

All participants reported olive oil preference in their daily cooking. Participants consuming vegetable and fruit everyday, fish, equal or more than once a week and red meat less than once a week and preferring olive oil rather than butter, were considered as using a Mediterranean diet.

Height and weight of each participant was measured using a standard procedure. BMI was calculated as weight in kilograms divided by the square of the height in meters [weight (kg) / height (m) ² and participants were grouped as normal, overweight and obese according to their BMI values (11).

Blood pressure was measured after 20 minute of resting.

Statistical Analysis:
Data were analyzed using the Statistical Package for the Social Sciences program (SPSS 10.0). Values are expressed as mean ± S.D. Pearson² - test was used to analyze differences between demographic factors and chronic diseases. Correlation between quality of life dimensions, demographic, medical and health behavior indices were analyzed by Spearman's rank correlation coefficient. In order to study association between eight major domains of SF-36 questionnaire and certain categorical variables such as age, gender, health behaviors and chronic diseases, multiple linear regression analysis was carried out.

Demographics:
The majority of the participants were born in Datca. Mean age of the total group was 50.3 ±12.0. Mean BMI was 27.5 ± 4.6. Participants who were active swimmers were swimming in an average of 2.3 months in a year. One in five participants had co-morbidity of the chronic disease that was included in the questionnaire. Demographic features are shown in Table 1.

Physical function, role physical, role emotional, mental health, vitality and general health perception domains of SF-36 were negatively affected by advanced age. Men rated higher scores on social function, mental health and vitality. Non- smokers rated high on physical function and role physical scale of the SF-36. (Table 2 and Table 3).
Number of chronic diseases (r=0.348 p<0.001), BMI (r=0.260 p<0.001), systolic blood pressure (r=0.527 p<0.001) and diastolic blood pressure (r=0.393 p<0.001) were seen to be increasing with age. Smoking years were positively associated with number of chronic diseases (r=0.131 p=0.02).

Chronic Conditions:
Both mental and physical dimensions of SF-36v2 were affected by CHD, HT and DM. Scores in the physical function dimension of SF-36v2 were lower for those with CHD and HT whereas both RP and RE were affected in DM. On the contrary, mental health was not affected by any of the chronic diseases (Table 2).

Co-morbidity was more common in sedentary (OR:1,955 p=0.01), non-swimmer (OR:4,340 p<0.001), overweight and obese (OR: 9,450 p<0.001) participants.
Overweight was associated with HT (OR: 9.404 p<0.001), CHD (OR: 2.706 p=0.001) and DM (OR: 7.714 p<0.001).

Physical Activity:
Sedentary or mildly active participants had significantly lower scores in PF, SF, VT, BP and GH scales of the HRQOL (Table 2 and Table 3).

BMI (r= - 0.188 p=0.001) inversely, physical function (r = 0.274 p<0.001), social function (r=0.192 p<0.001) and bodily pain (r= 0.143 p=0.01) directly correlated with increased physical activity.

Swimming was seen to have a positive effect on both mental and physical components of HRQOL. Regular swimmers had higher scores in PF, RE, and GH scales of the SF-36v2.

Dietary Habits:
Scores in many dimensions of the SF-36v2 were higher for those having Mediterranean style of diet. Non-obese participants rated higher scores on SF, RP, and VT scales of the SF-36v2 (Table 2 and Table 3).

It is remarkable that higher consumption of raw vegetables (r=0.230 p<0.001) and fruit (r=0.126 p=0.02), increased physical activity (r=0.179 p=0.001) and swimming period in a year (r=0.219 p=0.001) were positively correlated with overall quality of life. On the contrary, BMI (r=-0.147 p=0.01), systolic blood pressure ((r=-0.173 p=0.005) and diastolic blood pressure (-0.179 p=0.003) were negatively correlated with overall quality of life. Furthermore, higher BMI was associated with increased red meat consumption (r=0.130 p=0.02).

Mediterranean diet, at least moderate physical activity and regular swimming more than 3 months in a year have better impact on general health perception. However, general health perception declines in the presence of CHD, and over 40 years of age.

In the present study, HRQOL have been analyzed in a sample of semi-urban east Mediterranean community with a multivariate approach to identify associations with health behavior along with some chronic diseases.

Several studies have shown that older age results in worse HRQOL, reflecting physical health but not in scales reflecting mental health. (12,13). However, in our study population, age affected both physical and mental parameters.

There is a strong correlation with obesity and anxiety, depression, personal dissatisfaction and disturbed eating attitude (14). Additionally, poor perceived health status and increased chronic disease risk factors are reported more prevalently in obese people (15). In our study mental and physical component of HRQOL was better in non-obese participants.

It must be pointed out that, HT, DM and myocardial infarction adversely affect HRQOL (2). It is remarkable that chronic diseases affect quality of life not only by physical means but emotionally as well. It has been reported that anxiety, depression and negative beliefs about DM were related to lower physical and mental functioning in diabetics (3). Participants in our study, with CHD, HT and DM rated lower scores in some of the physical and mental components of SF-36v2.

Moreover, low HRQOL can be a risk factor for cardiovascular events or complications which might result in increased mortality rate (2,16). Several studies report lower scores on most dimensions in HRQOL with general health perception being the most influenced domain (2,5). On a lighter note, GH is assumed to reflect both physical and mental health. Related to this is that a low general health perception indicates a belief that health is likely to get worse whereas psychosocial factors such as labeling effect might affect HRQOL among hypertensives (2). However, there is conflicting data about HT in relation to lower scores both in PCS and MCS (2,17). Our study results show that both physical function and role emotional, were affected in hypertensive participants.

Many studies address relationship between increased levels of exercise and improved health status. Sedentary people reported lowest scores on physical health (18). Besides daily physical activity, we have questioned swimming separately and evaluated if it has a unique affect on HRQOL. We have found that regular swimming, more than 3 months in a year, is associated with better outcomes on both physical and mental components and general health perception of HRQOL.

Dietary habits are linked to socioeconomic conditions and lifestyle, possibly reflecting cultural development of past habits and may be influenced by diseases (19). High intake of fat, sugar and milk products and low intake of vegetables and fruits are considered to be related to cardiovascular disease (16). Furthermore, fish consumption had been linked to a decrease of coronary heart disease in women (20,21). As it was pointed out previously, higher intake of fruits, vegetables, fish and preference of olive oil and lower intake of red meat and fat are characteristics of Mediterranean diet. Mediterranean life style programs produced significant improvement on behavioral risk factors of coronary heart disease such as eating patterns and physical activity and improvement in quality of life was also significant (20). As a result, in our study, better scores on HRQOL were obtained by participants with Mediterranean dietary habits, which include regular fish consumption.

Limitations of our study are the relatively small number of participants for general population studies and lack of detailed energy intake information. Nevertheless, we designed our study on a voluntary basis and Datca-Knidos is a well preserved typical east Mediterranean county. In addition, information bias is a possibility in self-reported studies. We believe inclusion of biological outcomes assessment and detailed dietary information should be a focus of further research.

Consequently, the present study focuses on related factors on quality of life in a group of people living in east Mediterranean. Mediterranean diet, at least moderate physical activity and regular swimming are associated with better outcomes on HRQOL.

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