1. Background
Today, non-communicable diseases (NCDs) such as cardiovascular diseases (CVD), diabetes mellitus (DM), chronic obstructive pulmonary diseases (COPD), and cancer are the main cause of death in the world, especially in developing countries (1-3). Based on the report of World Health Organization (WHO) in 2017, NCDs are responsible for 70% of deaths worldwide, and these diseases kill 15 million people between the ages of 30 and 70 each year (4). Recent evidence indicates that CVD, DM, COPD, and cancer are responsible for 82.2% of deaths in Iran. Also, NCDs’ mortality has increased by14.5% over the past 20 years in Iran (5).
According to the literature, the most important risk factors of NCDs worldwide include tobacco use, hypertension, overweight and obesity, air pollution, alcohol use, drug use, unhealthy diet, and physical inactivity (5-7). Regular and adequate physical activity (PA) is a protective factor for NCDs such as CVD, DM, stroke, and breast and colon cancer. It also prevents some NCDs risk factors such as hypertension, overweight, and obesity and can improve mental health, quality of life, and well-being and delay the onset of dementia (8, 9).
Nevertheless, the current global situation of PA is not appropriate and the increase in PA is slow (8, 10). Based on international reports, 23% of adults and 81% of adolescents are physically inactive. Physical inactivity in adults is highest in the Eastern Mediterranean and the Americas and is lowest in Southeast Asia. Also, the level of PA is lower in girls, women, older adults, people with disabilities and chronic diseases, and people who live in high-income countries (8, 11).
2. Objectives
In order to implement effective programs for prevention of NCDs in the Iranian population, policymakers need to identify the current status of PA. In this study, we described the level and related factors of PA among adults in a middle part of Iran (Kerman).
3. Methods
We conducted this population-based cross-sectional survey from January to May 2018, in Kerman, the capital city of Kerman province. The city of Kerman is the largest city in southeast Iran with a population of nearly 800000.
The inclusion criteria included individuals age ≥ 18-year-old and residing in Kerman ≥ 5 years. A thousand people were enrolled in the study using a multistage cluster sampling method. Based on municipality areas, Kerman was divided into four regions. In each region, several blocks were selected randomly. In each block, some houses were selected randomly, and finally, in each house, one participant was chosen. Considering the gender ratio in Kerman, 500 men and 500 women participated in the study. Door-to-door and face-to-face interviews were conducted by trained interviewers. Verbal informed consent was received from each participant.
The level of PA was assessed by a valid and reliable short form of the International Physical Activity Questionnaire (IPAQ). This questionnaire included seven questions about four domains, including vigorous PA, moderate PA, walking, and sitting in the past seven days (14). The Metabolic Equivalents (METs) was used to estimate total PA per week for each participant. MET was calculated according to the short form IPAQ guideline using this formula:
1. Walking MET-minutes/week = 3.3 × walking minutes × walking days.
2. Moderate MET-minutes/week = 4.0 × moderate-intensity activity minutes × moderate days.
3. Vigorous MET-minutes/week = 8.0 × vigorous-intensity activity minutes × vigorous-intensity days.
4. Total PA MET-minutes/week = sum of walking + moderate + vigorous MET-minutes/week scores.
Then, METs were classified as weak (< 600 MET-minutes/week), moderate (600 - 3000 MET-minutes/week), and vigorous (> 3000 MET-minutes/week) (15). Socio-demographic characteristics including age, gender, income, employment status, level of education, marital status, and living in deprived areas were asked at the end of the questionnaire. The participants’ income (Rials per month) was categorized as very low (< 5milion), low (5 to 15 million), moderate (15 to 25 million), and high (> 25 million).
Chi-square and one-way ANOVA tests were applied to assess the association between independent variables and the level of PA. Then, ordinal regression analysis was used to determine the predictors of PA. The level of significance was set to 0.05.
This study was approved by the Ethical Committee of Kerman University of Medical Sciences. The ethics approval code is IR.KMU.REC.1395.366.
4. Results
A total of 1000 participants were enrolled in this study. Due to the fact that 70 of the questionnaires were returned incomplete or filled with irrelevant data, a total of 930 questionnaires were finally analyzed (response rate: 93%). The age range of participants was from 18 to 88 (Mean ± SD: 34.04 ± 12.7). About half of the participants were women (50.9%), the majority were married (55.7%), employed (48.5%), university-educated (51.5%), and earned less than 15 million rails per month (55.6%) (Table 1).
Table 1.Comparing Socio-Demographic Characteristics of Participants, According to Physical Activity Levels Using Chi-Square and One-way ANOVA
| Variables | No. (%) | Level of Physical Activity, % | P Value | ||
|---|---|---|---|---|---|
| Low | Moderate | Vigorous | |||
| Gender | < 0.001 | ||||
| Men | 457 (49.1) | 19.5 | 42.7 | 37.8 | |
| Women | 473 (50.9) | 31.5 | 46.1 | 22.4 | |
| Marital status | < 0.001 | ||||
| Single | 361 (38.8) | 19.1 | 41.8 | 39.1 | |
| Married | 518 (55.7) | 28.8 | 46.3 | 24.9 | |
| Divorced / Widowed | 51 (5.5) | 38 | 44 | 18 | |
| Level of education | < 0.001 | ||||
| Illiterate | 15 (1.6) | 46.7 | 33.3 | 20 | |
| < High school diploma | 143 (15.4) | 35.7 | 49 | 15.3 | |
| High school diploma | 293 (31.5) | 23.5 | 41.6 | 34.8 | |
| University | 479 (51.5) | 23.3 | 45.3 | 31.4 | |
| Employment status | 0.053 | ||||
| Employed | 451 (48.5) | 25.1 | 44 | 30.9 | |
| Retired | 61 (6.6) | 24.6 | 57.4 | 18 | |
| Student | 183 (19.7) | 22.4 | 43.2 | 34.4 | |
| Housewife | 172 (18.5) | 31.6 | 45 | 23.4 | |
| Unemployed | 63 (6.8) | 23.8 | 36.5 | 39.7 | |
| Level of income | < 0.001 | ||||
| Very low | 137 (14.7) | 35.8 | 40.9 | 23.3 | |
| Low | 380 (40.9) | 28.2 | 44.5 | 27.3 | |
| Moderate | 238 (25.6) | 17.6 | 44.5 | 37.9 | |
| High | 162 (17.4) | 21.6 | 47.5 | 30.9 | |
| Living in deprived areas | 0.025 | ||||
| No | 757 (81.4) | 23.9 | 44.6 | 31.5 | |
| Yes | 173 (18.6) | 32.9 | 43.4 | 23.7 | |
| Age, Mean ± SD | 36.28 ± 13.2 | 34.97 ± 13.1 | 30.77 ± 10.8 | < 0.001 | |
The median (range) of PA was 1584 (0 - 10850) (men: 2106; women: 1356) MET-minutes/week with an interquartile range (IQR) of 594 - 3764 MET-minutes/week. The median reported sitting time was 300 minutes/day with an IQR of 240 - 480 minutes/day. The level of PA was low in 25.6%, moderate in 44.4%, and vigorous in 30% of the participants (Figure 1).
Figure 1.
Description frequency the levels of physical activity
The results of the univariate analysis showed that there is a significant association between age, gender, marital status, level of education, income (P < 0.001), and living in a deprived area (P = 0.025) with the level of PA, whereas there is no significant association between employment status and the level of PA (P = 0.053) (Table 1).
Analytic results of ordinal regression model showed that there is a significant negative association between age and the level of PA (OR = 0.98; P = 0.008). Also, men compared to women (OR = 2.17; P < 0.001) and moderate-income compared to high-income (OR = 1.53; P = 0.027) had a higher probability to be in a high level of PA, however, those with pre-college education (under high school diploma) compared to those with a university education (OR = 0.63; P = 0.027) and students compared to the unemployed (OR = 0.50; P = 0.019) had a lower probability to be in a high level of PA. Marital status (P = 0.584) and living in deprived areas (P = 0.155) were not significantly associated with level of PA (Table 2).
Table 2.Prognostic Factors of Physical Activity, According to Ordinal Regression Model
| Variable | β | OR | P Value | 95% CI |
|---|---|---|---|---|
| Constant 1 | -1.34 | 0.26 | 0.009 | -2.34, -0.34 |
| Constant 2 | 0.75 | 2.10 | 0.137 | -0.24, 1.75 |
| Age | -0.02 | 0.98 | 0.008 | -0.03, -0.005 |
| Gender a | ||||
| Men | 0.78 | 2.17 | < 0.001 | 0.50, 1.06 |
| Marital status b | ||||
| Single | 0.61 | 7.46 | 0.052 | -0.004, 1.22 |
| Married | 0.16 | 1.16 | 0.584 | -0.40, 0.72 |
| Level of education c | ||||
| Illiterate | -0.49 | 0.61 | 0.345 | -1.51, 0.53 |
| < High school diploma | -0.46 | 0.63 | 0.027 | -0.87, -0.05 |
| High school diploma | 0.10 | 1.1 | 0.479 | -0.18, 0.39 |
| Employment status d | ||||
| Employed | -0.48 | 0.62 | 0.82 | -1.03, 0.06 |
| Retired | -0.16 | 0.85 | 0.681 | -0.93, 0.61 |
| Student | -0.68 | 0.50 | 0.019 | -1.25, -0.11 |
| Housewife | 0.07 | 1.07 | 0.808 | -0.53, 0.68 |
| Level of income e | ||||
| Very low | -0.38 | o.68 | 0.106 | -0.85, 0.08 |
| Low | -0.11 | 0.89 | 0.536 | -0.47, 0.24 |
| Moderate | 0.43 | 1.53 | 0.027 | 0.05, 0.82 |
| Living in deprived areas f | ||||
| No | 0.23 | 1.25 | 0.155 | -0.09, 0.56 |
Reference group: a women, b divorced/widowed, c university, d unemployed, e high, f yes
5. Discussion
According to the results of this study, the median of PA was 1584 (men: 2106; women: 1356) MET-minutes/week and the level of PA was low in 25.6%, moderate in 44.4%, and vigorous in 30% of the participants. Results of the Third National Surveillance of Risk Factors of Non-Communicable Diseases (SuRFNCD-2007) showed that the median of PA was 1442 (men: 2394; women: 903) MET-minutes/week and the level of PA in 40% of Iranian adults was low (12). The national survey on NCDs in 2011 showed that the prevalence of low PA in Iranian adults was 44.8% (13). The international study among adults in 28 European countries in 2015 revealed the mean of PA was 2151 MET-minutes/week (16). The median reported sitting time was 300 minutes/day with an IQR of 240 - 480 minutes/day in this study. Another international study in 20 countries showed that the median sitting time was 300 minutes/day with an IQR of 180 - 480 minutes/day, which is very close to our results (17). The level of PA in our study was higher than previous studies in Iran, especially in women, however, it is not adequate, and we need more effective interventions to increase the level of PA among Iranian adults.
This study showed that PA decreases as age increases. Most studies have revealed that inactivity prevalence significantly increases with increase in age (11, 12, 18). It seems that the lack of PA is related to chronic diseases and less social support in older adults.
In the present study, PA was higher in men than in women, which is similar to the results from other developing countries (11, 12, 19-21). Cultural, social, and environmental factors lead to the high prevalence of low PA in Iranian women. These factors include fewer women’s participation in PA, especially in the open spaces, women’s role as caregivers with limited time for PA, less social support, and lack of sports facilities.
We demonstrated that participants with university education have a higher level of PA compared to those with a pre-college education; this was similar to results of studies in Spain and Oman (22, 23). It seems that academic education improves the knowledge of participants about the benefits of PA.
Students were significantly less active than individuals who were unemployed in the current study. Some studies have shown that students are at risk for insufficient PA in Iran (24, 25). The level of PA was higher in unemployed participants than employers, however, not to a significant extent in this study. Some studies have revealed that employment is a risk factor for inactivity (22).
Our findings revealed that people with moderate income have a higher level of PA compared to those with a high income. This is consistent with findings from a cross-sectional study of Irish older adults, which showed that people with middle SES were less likely to be classified as inactive than people with high SES (18). However, some studies have showed that income is not associated with PA (20). It seems that people with a lower level of SES have jobs that require more PA compared with those with a higher level of SES.
Although the level of PA was lower in married people than it was in single individuals, there was no significant association between marital status and PA, according to the adjusted regression model in this study. However, some studies have found a significant association between marital status and PA. For example, the results of a study in Oman showed that unmarried men aged 30 - 39 years and unmarried women above the age of 40 were more active than their married counterparts (23). Also, a study in Brazil revealed that physical inactivity was higher in those living with a partner (26).
To the best of our knowledge, no population-based study with a large sample size has been performed on the level of PA and associated factors in southeast Iran. This study was a cross-sectional survey; therefore, we cannot examine causal relationships. Future studies to examine the barrier factors of regular and adequate PA are suggested.
5.1. Conclusion
Based on our findings, the level of PA is relatively low in Kerman. In addition, there are disparities in the level of PA across population groups. It seems that PA is influenced by personal, social, cultural, and environmental factors. Therefore, a comprehensive plan is needed to cover the whole community with special attention to more vulnerable subgroups such as those who are older, women, students, and those who have a high income and pre-college education.
It seems that increasing awareness of PA benefits, creating a positive attitude towards PA, providing healthy transportation options including safe walking and cycling, increasing PA facilities including sports spaces especially for women, and enhancing social support for older adults and women are the most important strategies for increasing level of PA in the Iranian society.
