Prevalence and Associated Factors of the Metabolic Syndrome Among a National Population Based Sample of 18-108 Year-olds in Iraq: Results of the 2015 Steps Survey

Background:Thisstudyaimed to assess the prevalence and associated factors of the metabolic syndrome (MetS)among 18-108 year-old persons inIraq. Method: Nationally representative cross-sectional data were analysed from 3,703 18-108 year old persons (32 years median age) that participated in the “2015Iraq STEPS survey,” with complete MetS measurements. Results: Results indicate that39.4% of 18-108 year-olds had MetS (harmonized denition), 39.8% among women and 39.0% among men, and the mean number of MetS components was 2.4 (SD=1.4), 2.4(SD=1.4) among women and 1.5 (SD=1.4) among men. In adjusted logistic regression analysis, older age, current and past smoking and general overweight and obesity were associated with MetS. In addition, in unadjusted analysis, having lower education, ever alcohol use, and low physical activity were associated with MetS. In adjusted linear regression analysis, male sex, lower education, and obesity were associated with greater number of MetS components. Conclusion: Two in ve participants had MetS and several associated indicators were found which couldbe supportive in designing interventionactivities.


Results
: Results indicate that39.4% of 18-108 year-olds had MetS (harmonized de nition), 39.8% among women and 39.0% among men, and the mean number of MetS components was 2.4 (SD=1.4), 2.4(SD=1.4) among women and 1.5 (SD=1.4) among men. In adjusted logistic regression analysis, older age, current and past smoking and general overweight and obesity were associated with MetS. In addition, in unadjusted analysis, having lower education, ever alcohol use, and low physical activity were associated with MetS. In adjusted linear regression analysis, male sex, lower education, and obesity were associated with greater number of MetS components.
Conclusion: Two in ve participants had MetS and several associated indicators were found which couldbe supportive in designing interventionactivities.

Background
Non-communicable diseases (NCDs) are "estimated to account for 55% of all deaths in Iraqin 2016," which includes 27% cardiovascular diseases and 4% diabetes [1].Compared with people without metabolic syndrome (MetS), individuals with MetS have a twofold higher risk for cardiovascular disease and vefold higher risk for type 2 diabetes [2][3][4]."A cluster of risk factors for cardiovascular disease and type 2 diabetes mellitus, which occur together more often than by chance alone, have become known as the metabolic syndrome." [5]"The risk factors include raised blood pressure, dyslipidaemia (raised triglycerides and lowered high-density lipoprotein cholesterol), raised fasting glucose, and central obesity." [5]Globally, it is estimated that "25% of the adult population can be characterized as having the MetS."[2,6]The prevalence of MetS is increasing in low-and middle-income countries with "improvement in economic situation, increasing urbanization, nutrition transition, and reduced physical activity." [7]In order to prevent and control MetS it is important that national population-based surveys are conducted periodically [8]There is a lack of national population-based data on the prevalence and associated factors of MetS in Iraq, anupper-middle income country in the Middle East.
In a cross-sectional study among adults recruited from different institutions (19-80 years) (N=566) in Erbil City, Northern Iraq, the prevalence of MetS (ATP IV criteria) was 30.6% [9], in an hospital outpatient sample (N=300) (30-75 years) in Baghdad in Iraq the prevalence of MetS (IDF criteria) was 42% [10], and among 320 hospital out-patients (25-85 years) in Baghdad in Iraq the prevalence of MetS (ATP III criteria) was 37.8% [11]. In national surveys in countries of the Eastern Mediterranean region, the

Methods
Nationally representative cross-sectional data from the "2015Iraq STEPS Survey" were analyzed [36].The data and more detailed survey methods can be accessed; theoverall response rate for STEP III was 93.5%, STEP II 98.6% and STEP I 98.8% [36,37].Brie y, a"multi-stage cluster sampling was used with strati cation to urban and rural areas. Primary sampling units (PSUs) (N=412) were the blocks, which consisted of 70 households or more before selection.One person from each household was randomly selected." The "sample was weighted to be representative for Iraqi population." [37].

Measures
Outcome variable: Metabolic syndrome Body Mass Index (measured <18.5kg/m 2 underweight, 18.5-24.4kg/m 2 normal weight, 25-29.9kg/m 2 overweight and ≥30 kg/m 2 obesity);blood pressure (BP) measurements (average of the last two of three readings) were conducted with an electronic blood pressure monitorSpengler® ES 60; Blood samples were drawn (after 10-14 fasting) to determine levels of "fasting plasma glucose and fasting total cholesterol and lipid pro le. The enzymatic method (Glucose Oxidase for fasting blood glucose and Cholesterol Oxidase for total cholesterol) was used." [37] Health risk behaviour variables included current and past smoking, past month passive smoking at home and/or at closed spaces at work, ever alcohol use, inadequate fruit and vegetable intake (<5 servings/day), and based on the "Global Physical Activity Questionnaire" low, moderate or high physical activity and sedentary behaviour (≥8 hours/day) [37].

Data analysis
Statistical analyses were done with "STATA software version 15.0 (Stata Corporation, College Station, Texas, USA),"taking into account the complex study design. The data were weighted "to make the sample representative of the target population in Iraq(by sex and by age groups: 18-39, 40-59, 60and over)." [37] Chi-square tests were used to test for differences in proportions.Unadjusted and adjusted logistic regression was used to assesspredictors ofMetS and linear regression for the number of MetS components. Missing values were excluded from the statistical analysis. P<0.05 was accepted as signi cant.

Sample and MetS status characteristics
The sample comprised of 3,703 18-108 year old persons (32 years median age, 22 years interquartile range)with complete MetS measurements. More than one in ve of the participants (59.5%) were female, 37.6% had more than primary education, and 75.9% lived in urban areas. More than one in ten participants (21.3%) reported current smoking, 7.3% past smoking, 60.3% past month passive smoking, 2.5% ever alcohol use, 79.5% inadequate fruit and vegetable intake, 52.3% low physical activity, 26.3% sedentary behaviour, and 34.0% obesity.The prevalence of MetS was 39.4%, 39.8% among women and 39.0% among men, and the mean number of MetS components was 2.4 (SD=1.4), 2.4(SD=1.4) among women and 2.5 (SD=1.4) among men(see Table 1).

Associations with MetS
In adjusted logistic regression analysis,older age, current and past smoking and general overweight and obesity were associated with MetS. In addition, in unadjusted analysis, having lower education, ever alcohol use, and low physical activity were associated with MetS. In adjusted linear regression analysis, male sex, lower education, and obesity were associatedwith greater number of MetS components (see Table 2).

MetS components
Overall, high WC was 43.8%, high BP 51.0%, high FBC 31.8%, high TG 35.4% and low HDL 54.5%.Low HDL was signi cantly higher in women than in men, and high TG was signi cantly higher among men than women, while high WC, high BP and high FBG did not differ signi cantly between the sexes. All ve MetS components did not signi cantly differ by residence status. Between both sexes,all ve MetS components signi cantly increased with age. Among men, high WC, high BP and high FBG increased with age, high TG increased from the 18-39 year-old age group to the 40-59 year-old age group and decreased among the 60 years and older age group. Low HDL did not signi cantly differ among age groups in men. Among men, high BP, high FBG, high TG and low HDL increased with age, while high WC increased from the 18-39 yearold age group to the 40 to 59 year-old age groups and slightly decreased among the 60 years and older age group (see Table 3).

Discussion
The  [17].The high prevalence of MetS in Iraq may be attributed to "improvement in economic situation, increasing urbanization, nutrition transition, and reduced physical activity." [7] The study found that the most prevalent MetS components were low HDL, high BP, and high WC.
Similar results were found in nationalsurveys in Iran [14]and in Nepal [21].In this study, we saw a decline of two MetS components (high WC among women and high TG among men) in persons 60 years and older. One possible explanation for this could be mortality prior to 60 years [18].
Consistent with former research[18, 19,12,13,21],this investigation showed an association between older ageand MetS. While several studies found a higher prevalence of MetS among women than men [18,19,20,21],this study did not show any signi cant sex differences. In fact, men seemed to have a greater number of MetS components than women in this study.Several studies showed an increased risk of MetS in people with lower education [13,15], which was con rmed in our study in unadjustedanalysis and in adjusted analysis in terms of greater number of MetS components. Persons with lower education may have lesser knowledge on health risk behaviours that are implicated in the development of MetS [10].
While several previous research studies showed an association between urban residence and MetS [12,20,21], this survey did not nd signi cant rural-urban differences. This could mean that MetS risk behaviours (sedentary lifestyle, stress and diet changes) have penetrated rural areas as well as urban areas.
In agreement with previous research ndings [21,22], this survey showed that having general overweight or obesity increased the odds for MetS. Consistent with previous studies [22][23][24][25],this investigation showed in unadjusted analysis an inverse association between high physical activity and MetS. Several studies and reviews [27-30], found a signi cant association between inadequate fruit and vegetable consumption and MetS, while this survey did not nd any signi cant association between the two. This study found in unadjusted analysis that ever alcohol use and in adjusted analysis that current and past smoking were associated with MetS. Regarding alcohol use, our ndings con rm former research conducted in China [16]. Since the proportion of current alcohol users were too small in this study population, we are not able to distinguish heavy from moderate alcohol users. In terms of smoking, our

Study Limitations
The strength of the study was to cover a nationally representative adult sample in Iraq, but was limited because of its cross-sectional design as well as the self-report of the interview data. The variable on household income was not available on the publically available dataset and could therefore not be included in the analysis.

Conclusion
The 2015 Iraq STEPS survey found among a nationally representative population of adults that two in ve participants had MetS. Several risk factors for MetS were identi ed,including older age, current and past smoking and general overweight and obesity, and in unadjusted analysis, having lower education, ever alcohol use, and low physical activity,which can facilitate inaiding interventions to prevent and control MetS in thegeneral population in Iraq.      g ( ) g p (systolic BP ≥130 or diastolic BP ≥85 mm Hg and or on anti-hypertensive medication); High FBG=Fasting blood glucose (≥100 mg/dL or on antidiabetic medication); High TG=Triglycerides (≥150 mg/dL and/or on anti-cholesterol medication); Low HDL=High-density lipoprotein cholesterol (<40 mg/dL in men; <50 mg/dL in women and/or on anti-cholesterol medication)