Metabolic syndrome is a constellation of risk factors associated with a 5-fold increase in incidence of Type 2 diabetes and 2-3-fold increase in the incidence of CVDs (17).
Based on our findings concerning anthropometric measurement, obesity based on BMI, about 44% of the study populations were overweight/obese, in which 6.9% were obese and 37.1% were overweight. This finding is higher than similar studies conducted in Ethiopia national survey (1.2% obese and 5.2% overweight) (18), northern Ethiopia Mekele (4.1% obese and 26% overweight) (19) and Northwest Ethiopia Jimma obese (5.1%) and overweight (10.4%) (20). The possible explanation for the higher prevalence of overweight/obesity in our study may be due to the difference in physical activity, sample size, sedentary behavior, and lifestyle.
Hypertension, the second most common criteria for metabolic syndrome with the frequency of 23.6% was higher than those reported in earlier studies 15.8% conducted in Ethiopia in 2015 national survey(18), 9.3% at Gilgel Gibe field research center (21) and 20% in male and 14% in female among working adults in Addis Ababa (22). Possible explanations for the difference in hypertension were, in addition to stress condition, lifestyle and genetic difference; the alcohol consumption behavior of our study participants was more prevalent as compared to these studies. This showed that there is a need for appropriate interventions to reduce the burden of alcohol use, which could help to lower blood pressure levels (23). The prevalence of hypertension was also higher when compared to a study done in Angola, 17.9% among workers in private tertiary center (24) but lower in comparisons with studies done in Eastern Ethiopia among adults lived in Jigijiga city 28.3% (25), Nigeria Lagos 38.2% among urban slum dwellers (26) and in Ghana 55.3% among urban & rural adults in the Keta Municipality (27). The possible explanation for the disparities of hypertension prevalence among different studies was due to family history, socio-demography, attitude, and awareness and geographic location and/or may be life style of study participants.
The result of our research showed that the prevalence of Diabetes Mellitus was 2.4% which is in line with a study done in rural Koladiba town northwest Ethiopia (28). Our result was slightly similar to the 2010 global estimate of the prevalence of Diabetes in the Ethiopian population, 2.0% (29) and study has done in South Western Nigeria population that found a prevalence of Diabetes Mellitus,2.5% (30). However, our result was lower than that of a study done in the Ethiopian national crude prevalence rate 3.2% (31) and study done in Northern Ethiopia among public employees 10.1% (31). This may be because off biochemical analysis differences since in our study we had used only fasting blood glucose to define the prevalence of diabetes but the study done by Gebremariam et al. (19) used a combination of FBG and HgA1c, which results in observed prevalence differences.
Dyslipidemia, especially low HDL levels with 41.3% was a common finding in our study participants next to central obesity 80.2% based on IDF criteria. The prevalence of low HDL in our study is in line with the study done by Martinez Torres and his colleagues among Colombian college students, 40.3% (32), by Oladapo and his colleagues among rural Southwestern Nigerian population 43.1% (30) and with the study done among Saudi University employees 36.8% (33). The similarity of this result may be explained with the mean age group of study participants in Saudi Arabia University employee was 40.4 ± 9.8 years which was comparable to our study mean age (36.5 ± 10) years and also volunteering based sampling method was used which was similar to our study. On the contrary, a higher prevalence of low HDL was observed in Ethiopian national survey (68%) and among public employees in northern Ethiopia (71.3%) (19, 31). Environmental factors, physical activity status, nutrient intake and sample size and age of study participants may be used as part of an explanation for this difference.
Regarding the prevalence of hypertriglyceridemia, which is (19.3%) in our study is nearly similar with a result reported in the Ethiopian national survey. But higher prevalence is found in the following studies Northern Ethiopia (55%), Saudi University Employee (36.1%), and among Jordanian adults (50.2%) (19, 33, 34). Dietary intake, level of physical activity, lifestyle difference, and level of awareness may be part of a possible explanation for this variation.
Abdominal obesity drives the development of cardiometabolic risks through altered secretion of adipocyte-derived active substances called adipokines, including free fatty acids, adiponectin, interleukin-6, tumour necrosis factor-alpha, and plasminogen activator inhibitor-1, and through exacerbation of insulin resistance and associated cardiometabolic risk factors (35). In the present study, we demonstrated that elevation of waist circumference based on IDF criteria was the most prevalent criterion with a total frequency of 80.2% which is 87.9% and 72% among males and females, respectively that was the superior component to yield larger metabolic syndrome prevalence. This result is higher than the community-based study done among Andean highlanders (75.9%) (36) and the study done in South African Asian Indians who found a prevalence of (73.1%) even though harmonized criteria was used (37). This may be due to differences in sample size, level of physical activity difference, and dietary intake. Concerning sex- difference, it is noted that males had a higher frequency of central obesity (87.9%). The reason for this difference may be the majority (65%) of female participants were younger as compared to male (35%) and central obesity increases with increasing age (38).
Findings from this study showed that the prevalence of metabolic syndrome among staff members of EPHI was 16.7% using NCEP ATP III criteria while the IDF criteria yielded a higher prevalence of 27.6%. This higher prevalence of metabolic syndrome based on IDF criteria was due to a higher prevalence of central obesity which is one of the pre-request criteria for defining metabolic syndrome. Our result was fairly comparable to study conducted in systematic review of Madagascar (27.7%), Nigeria (28.1%), Spain (24.3%), South Asia (29.8%), and Australia (30.7%) based on IDF criteria (39–43). The prevalence of metabolic syndrome in our study was less than from other studies conducted in Kenya among urban population (34.6%), Nigeria among apparently healthy adults in Ogun state (36.8%), among Turkey adults (44%), among Jourdan adults (51%) (34, 44–46). Differences in the age of study subjects, sample size, socioeconomic status, residence & lifestyle, dietary intake, and physical activity may contribute to the different prevalence of metabolic syndrome in these different studies.
High prevalence of metabolic syndrome has been linked to urbanization, westernization, nutritional and epidemiological transition (47). Our result was also lower than the recent study conducted in Northern Ethiopia involving public employees in Mekele found a prevalence of metabolic syndrome to be 40% using IDF criteria (19). The explanation for this discordant may be due to the environmental and sampling methods in which we had used random sampling. However, the finding in this study was higher than other community-based studies conducted among working adults in Addis Ababa Ethiopia (17.9% using IDF criteria and 12.5% using ATP criteria), in Jimma town (16.7%) using IDF criteria) and a community-based study conducted in Ethiopia in 2015 (4.8%) (18, 20, 22). Our result is also showed higher prevalence from studies conducted among adults in the rural area of West China (10.8%) and the study conducted among health professionals in Brazil (4.5%) (48, 49). This could be due to a result of differences in socioeconomic backgrounds, lifestyle variations and the difference in ethnicity.
The result also showed that the prevalence of metabolic syndrome was 35.8% in males and 18.8%in females based on IDF criteria. This was in line with the study reported in Colombia who observe that the prevalence of metabolic syndrome in males was three times higher than in the females (32). The possible explanation for the higher prevalence of metabolic syndrome in males is because; the majority of female participants are younger as compared to males (38). The other possible explanation for higher metabolic syndrome prevalence in males can be because of central obesity which was more prevalent in males (72%) than females (28%). However, our result was contradicted with a study that found greater occurrences of metabolic syndrome were observed in females. Our result finding also showed that the prevalence of metabolic syndrome was high in older age. Increasing age group from 39–48, 49–58 and 59–69 years was significantly associated with metabolic syndrome which showed that five, two, four, one and eighty-one times, respectively increased getting the odds risk of metabolic syndrome compared to age group of 18–28 years. This is in line with different studies (20, 50). This is because of ageing is characterized by a progressive deterioration in physiological functions and metabolic processes that generate reactive oxygen species as a by-product of biological oxidation. The oxidative damage of reactive oxygen species induces cellular dysfunction playing an important role in many pathological conditions like chronic low-level inflammation-induced metabolic syndrome (51). The predisposing factors for having metabolic syndrome in this study, includes being under overweight (OR = 4.67, (95% CI; 2.27–9.6)), having raised blood pressure (OR = 28, (95% CI; 9.46–86.9)), raised fasting blood glucose (OR = 126, (95% CI; 6.7–2374)) and dyslipidemia (OR = 210, (95% CI; 52–849)) were also in line with another studies (20, 32, 50). Overweight characterized by unbalanced energy intake and expenditure which could result in continues raised blood glucose level (52, 53). These further results in hyper-secretion of insulin and leading to insulin resistance over time. Once insulin resistance occurs in different target organs metabolic process dysregulation will be initiated such as lipid profile abnormalities, endothelial dysfunction, and inflammatory reactions (54, 55)
Three fourth of the participants had at least one component of metabolic syndrome. This result revealed that characteristics, including smoking habits, alcohol consumption, physical activity and serving of fruit and vegetables per week were not individual predictors for metabolic syndrome. Even though the study participants were not apparently healthy, our result was consistent with the finding from Hawassa University Hospital and Jimma health centre among peoples living with HIV/AIDS (56, 57). The study done by Owolabi and his colleagues among adults attending healthcare in Eastern Cape South Africa contradicts our findings. They found that smoking, alcohol use, fruit, and vegetable consumption were statistically significant factors for metabolic syndrome (47). The discordant with smoking and alcohol use might be because of the amount and type of alcohol and smoking products taken by the study populations. However, sex, age, BMI, raised blood pressure, raised blood glucose, dyslipidemia and raised hsCRP had statistical significance with metabolic syndrome in bivariate analysis. After adjusting confounders in logistic regression only age, BMI, raised blood glucose, raised blood pressure and dyslipidemia were independent predictors for metabolic syndrome. This was also in line with the study done by Salas et al. among Mexican adult population and Brazilian health professionals (49, 59) In general prevalence of central obesity expressed as increased waist circumference was the most common abnormality, followed by low HDL and raised Blood pressure were acquiesced with many researchers (34, 60). It is assumed that the modern luxurious lifestyle lies behind abdominal obesity and dyslipidemia being the most common components of metabolic syndrome (61). The high prevalence of abdominal/central obesity, low HDL and raised blood pressure emphasizes the susceptibility of the study population to CVD and Type 2 DM, especially in older age. Controlling weight and body fat with physical activity and a more appropriate diet were important in reducing the risk of CVDs (62). The prevalence also has been linked to urbanization, westernization, nutritional and epidemiological transition and this calls for urgent action by the policymakers and health managers to further emphasize the need for routine screening for all the components of Metabolic syndrome.