Clinical characteristics of metabolic syndrome in Korea,and its comparison with other Asian countries

Metabolic syndrome is referred to as syndrome X or insulin resistance syndrome, and is primarily composed of abdominal obesity, diabetes, glucose intolerance, dyslipidemia and high blood pressure. Asians have a lower frequency of obesity than Caucasians, but have an increasing tendency toward metabolic syndrome. Thus, metabolic syndrome poses a major challenge for public health professionals, and is set to become a social and economic problem in Asian populations. Most data on metabolic syndrome are based on studies from Western countries with only limited information derived from Asian populations. Recently, several studies were carried out on a large scale that represents the general Korean population. The prevalence of metabolic syndrome in Korean adults has varied depending on the study designs and different criteria, but shows a distinct increasing trend of metabolic syndrome driven by an increase in abdominal obesity and dyslipidemia. Given the rapid economic progression of Korea over the past 30 years along with a rise of the aged population, it is expected that the prevalence of metabolic syndrome will further increase. Therefore, a proactive strategy at the governmental level for metabolic syndrome prevention should be implemented, reducing abdominal obesity and dyslipidemia. Healthy dietary habits and regular exercise should be emphasized as a part of such a strategy.     

Metabolic syndrome as a predictor of type 2 diabetes,and its clinical interpretations and usefulness

Metabolic syndrome is defined as a cluster of glucose intolerance, hypertension, dyslipidemia and central obesity with insulin resistance as the source of pathogenesis. Although several different combinations of criteria have been used to define metabolic syndrome, a recently published consensus recommends the use of ethnic‐specific criteria, including waist circumference as an indicator of central obesity, triglyceride and high‐density lipoprotein (HDL) cholesterol as indicators of dyslipidemia, and blood pressure greater than 130/85 mmHg. The definition of dysglycemia, and whether central obesity and insulin resistance are essential components remain controversial. Regardless of the definition, the prevalence of metabolic syndrome is increasing in Western and Asian countries, particularly in developing areas undergoing rapid socioenvironmental changes. Numerous clinical trials have shown that metabolic syndrome is an important risk factor for cardiovascular disease (CVD), type 2 diabetes mellitus and all‐cause mortality. Therefore, metabolic syndrome might be useful as a practical tool to predict these two major metabolic disorders. Comprehensive management of risk factors is very important to the improvement of personal and public health. However, recent studies have focused on the role metabolic syndrome plays as a risk factor for CVD; its importance in the prediction of incident diabetes is frequently overlooked. In the present review, we summarize the known evidence supporting metabolic syndrome as a predictor for type 2 diabetes mellitus and CVD. Additionally, we suggest how metabolic syndrome might be useful in clinical practice, especially for the prediction of diabetes.     

Potential effect of insulin resistance and cardiovascular risk factors on metabolic syndrome in subjects with normal fasting plasma glucose levels

The prevalence of metabolic syndrome has progressively increased with increasing fasting plasma glucose (FPG) levels. This study aimed to investigate the influence of insulin resistance and cardiovascular risk factors on metabolic syndrome in individuals with normal FPG. Study subjects with FPG levels below 100 mg/dL were divided into 5 groups depending on the exact FPG levels. We then evaluated the association of metabolic syndrome with insulin resistance and total cholesterol/ high density lipoprotein-cholesterol ratio (TC/HDL ratio). The odds ratio of insulin resistance in the level of HOMA-IR above 2.34 group [3.483(95 % CI, 1.110?～?10.932)] was significantly increased in the group of FPG level from 93 mg/dL to 99 mg/dL compared to the group below 80 mg/dL. The odds ratio of metabolic syndrome in the group of FPG level from 89 mg/dL to 92 mg/dL [2.459, (95%CI, 1.275?～?4.741)] and 93 mg/dL to 99 mg/dL [2.079, (95%CI, 1.052?～?4.110)] was significantly increased compared to the group below 80 mg/dL after adjusting age, sex, smoking status, physical activity, heavy drinking, TC/HDL ratio. Higher FPG levels within the normoglycemic range may constitute a risk of insulin resistance and is associated more strongly with the risks of metabolic syndrome.     

Metabolic syndrome in the elderly

The prevalence of metabolic syndrome is increasing worldwide, especially among the elderly. Due to multiple age-related physiologic mechanisms, the elderly are at increased risk of developing intra-abdominal obesity and the metabolic syndrome, including nonalcoholic steatohepatitis. Metabolic syndrome consists of obesity, insulin resistance, dyslipidemia, and hypertension leading to increased risk of cardiovascular disease (CVD) and renal events. With the future population dynamics, the metabolic syndrome should be emphasized among the health care field, researchers, and clinicians. Without proactive and preventative efforts, elderly patients and the health care system will likely experience an epidemic of the metabolic syndrome and the associated CVD.     

Metabolically Healthy Obesity—Does it Exist?

The prevalence of obesity has been increasing worldwide over the past 30 years and is a major public health concern. Obesity is known to be associated with metabolic disturbances including insulin resistance and inflammation; however, there is a subset of obese subjects who have normal metabolic profiles, and they have been identified as the metabolically healthy obese (MHO). Several studies have described MHO as obese individuals who have high levels of insulin sensitivity and the absence of diabetes, dyslipidemia, or hypertension. The prevalence of MHO varies from 20 to 30 % among obese individuals. This review will discuss the MHO phenotype; the differences between MHO and metabolically unhealthy obese (MUO) individuals; and the possible underlying mechanisms including adipocyte differentiation, immune regulation, and cellular energy metabolism.     

Pharmacological treatment and therapeutic perspectives of metabolic syndrome

Metabolic syndrome is a disorder based on insulin resistance. Metabolic syndrome is diagnosed by a co-occurrence of three out of five of the following medical conditions: abdominal obesity, elevated blood pressures, elevated glucose, high triglycerides, and low high-density lipoprotein-cholesterol (HDL-C) levels. Clinical implication of metabolic syndrome is that it increases the risk of developing type 2 diabetes and cardiovascular diseases. Prevalence of the metabolic syndrome has increased globally, particularly in the last decade, to the point of being regarded as an epidemic. The prevalence of metabolic syndrome in the USA is estimated to be 34 % of adult population. Moreover, increasing rate of metabolic syndrome in developing countries is dramatic. One can speculate that metabolic syndrome is going to induce huge impact on our lives. The metabolic syndrome cannot be treated with a single agent, since it is a multifaceted health problem. A healthy lifestyle including weight reduction is likely most effective in controlling metabolic syndrome. However, it is difficult to initiate and maintain healthy lifestyles, and in particular, with the recidivism of obesity in most patients who lose weight. Next, pharmacological agents that deal with obesity, diabetes, hypertension, and dyslipidemia can be used singly or in combination: anti-obesity drugs, thiazolidinediones, metformin, statins, fibrates, renin-angiotensin system blockers, glucagon like peptide-1 agonists, sodium glucose transporter-2 inhibitors, and some antiplatelet agents such as cilostazol. These drugs have not only their own pharmacologic targets on individual components of metabolic syndrome but some other properties may prove beneficial, i.e. anti-inflammatory and anti-oxidative. This review will describe pathophysiologic features of metabolic syndrome and pharmacologic agents for the treatment of metabolic syndrome, which are currently available.     

Familial aggregation of metabolic syndrome among the Chinese: report from the Chin-Shan community family study

Genetic study on metabolic syndrome is a great challenge, due to its complex traits and the pleiotropic manifestation of atherosclerosis. Familial aggregation and recurrence risk ratio can provide the insight of possible genetic mechanism. The Chin-Shan community family study was based on adolescent probands and their relatives (1356 subjects) who were recruited from one junior high school in the community. Structured questionnaires and biochemical measures were obtained in standard procedures. Definition of metabolic syndrome was followed using the criteria defined by the third adult treatment panel, with a modification of the criteria for adolescent and Asian population. Grandmothers had the highest frequencies (70%) in metabolic syndrome and various atherosclerotic risks. Three factors were found and thus explained 68% of the overall variance. Estimated heritability was the highest in LDL and cholesterol factor (0.36 and 0.40), then blood pressure/obesity factor (0.27), and insulin resistance/dyslipidemia (0.27). Recurrence risk ratio among siblings was 2.95 (95% confidence interval [CI]: 1.39-6.26). The adjusted odds ratio (OR) of proband's metabolic syndrome status was 1.99 (95% CI: 1.08-3.66). The adjusted odds ratios for the three factors for predicting metabolic syndrome were all significant, with highest risk in blood pressure/obesity factor (OR: 1.27, CI: 1.22-1.33), then insulin resistance/dyslipidemia (OR: 1.29, CI: 1.16-1.23). This study demonstrated clearly familial aggregation and recurrence risk ratio of metabolic syndrome and components among the general ethnic Chinese population in Taiwan.     

Different association of hypertension and insulin-related metabolic syndrome between men and women in 8437 nondiabetic Chinese

Insulin resistance may cause a metabolic syndrome but whether insulin resistance causes hypertension is very controversial. Furthermore, it remains unclear whether the link between the insulin-resistance-related metabolic syndrome and hypertension is different between men and women. We examined fasting insulin, glucose, triglyceride and high-density lipoprotein (HDL)-cholesterol levels, systolic blood pressure, body mass index, and waist-to-hip ratio in a dataset from 8437 nondiabetic residents (age range, 30 to 89 years) in Kinmen. Factor analysis, a multivariate correlation statistical technique, was used to investigate the clustering and interdependence of these risk variables. Factor analysis identified two factors for men (n = 3659) and three factors for women (n = 4778, respectively. In men, a cluster of insulin, triglyceride, HDL-cholesterol, body mass index, and waist-to-hip ratio (metabolic syndrome) accounted for 29.7%, and a cluster of systolic blood pressure and glucose (hyperglycemia plus hypertension) accounted for 18.1% of the total variance in all variables considered. In women, a cluster of insulin, triglyceride, body mass index, waist-to-hip ratio, and systolic blood pressure (metabolic syndrome plus hypertension) accounted for 29.4%, a cluster of systolic blood pressure, glucose, and triglyceride (hyperglycemia plus hypertension plus dyslipidemia) accounted for 14.0%, and a cluster of triglyceride and HDL-cholesterol (dyslipidemia) accounted for 16.2% of the total variance. In conclusion, a distinct insulin-resistance-related metabolic syndrome characterized by hyperinsulinemia, dyslipidemia, and obesity was observed for both men and women in this Chinese population. However, hypertension was linked to the metabolic syndrome in women only.     

The combined effect of serum cystatin C and dyslipidemia on hypertension in a large health check-up population in China

ABSTRACT

OBJECTIVE: Some studies have reported that both serum cystatin C (Cys C) and dyslipidemia are independently associated with hypertension. However, the combined effect of the two factors is still unknown. The present study was aimed at investigating the effect of Cys C combined with dyslipidemia on hypertension in a large health check-up population in China.

METHODS: A total of 203 233 health check-up subjects from January 2011 to July 2016 were recruited into this cross-sectional study. A multivariate logistic regression model was used to evaluate the combined effect of Cys C and dyslipidemia on hypertension.

RESULTS: In univariate analysis, Cys C, high-density lipoprotein cholesterol, low-density lipoprotein, total cholesterol, and triglycerides were independently correlated with hypertension (p < 0.001). A concentration-dependent combined effect of serum Cys C and dyslipidemia on hypertension was observed in multivariate regression analysis. When compared with Cys C of <0.82 mg/L, the risk of hypertension in Cys C of <0.82 mg/L with dyslipidemia, Cys C of 0.82–0.94 mg/L with dyslipidemia, Cys C of 0.94–1.08 mg/L with dyslipidemia, and Cys C of ≥1.08 mg/L with dyslipidemia was increased 1.946 (95% confidence interval [CI]: 1.827–2.074), 1.973 (95% CI: 1.864–2.088), 2.047 (95% CI: 1.941–2.158), and 2.038 (95% CI: 1.937–2.143) folds, respectively, after adjustment.

CONCLUSION: There was an association between hypertension and the combined effect of Cys C with dyslipidemia.     

功能性食品与代谢综合征

由于代谢综合征在世界范围内日益增多,饮食干预越发受到人们重视.近年来研究发现一些食物或成分(即功能性食品或成分)有希望改善代谢综合征,尤其是肥胖、糖尿病、血脂异常.此文主要从这三方面举例并评估了一些潜在功能性食品或成分.     

Prevalence of metabolic syndrome in urban Pakistan (Karachi): comparison of newly proposed International Diabetes Federation and modified Adult Treatment Panel III criteria

The clustering of central obesity, dyslipidemia, hypertension, and hyperglycemia known as metabolic syndrome has been associated with a two- to three-fold increase in type 2 diabetes (T2DM) and cardiovascular disease (CVD). It is recognized that the features of the metabolic syndrome can be present 10 years preceding T2DM and CVD. The objective of our study was to determine the prevalence of metabolic syndrome in adults aged 25 years and older from an urban population of Karachi, Pakistan, according to the International Diabetes Federation (IDF) definition and modified Adult Treatment Panel III (ATP III) criteria. This study involved a survey conducted from July, 2004, to December, 2004, by generating a computerized random sample of households in Lyari Town using a geographical imaging system (GIS). Out of the 85,520 households, 532 households were randomly selected and 867 adults > or =25 years old consented to take part in the survey; 363 of these subjects gave blood samples. The prevalence of diabetes was 9.4%, whereas 5.6% had impaired fasting glucose (abnormal glucose tolerance 15%). The prevalence of metabolic syndrome according to the IDF definition and modified ATP III criteria was 34.8% and 49%, respectively. Inclusion of modified waist circumference and specific body mass index (BMI) cut offs for Asians may help predict metabolic syndrome at an early stage. High prevalence of metabolic syndrome was identified irrespective of the definition applied in this population. This may call for immediate action to halt the accelerating risk of diabetes and CVD that would lead to a possible unparalleled rise in the cost of health care and human suffering.     

Association between metabolic syndrome and prevalence of gastroesophageal reflux disease in a health screening facility in Japan

Background

Abdominal fat accumulation, which induces high intra-abdominal pressure that causes increase in the gastroesophageal pressure gradient and hiatal hernia, as well as obesity, has been shown to increase the prevalence of gastroesophageal reflux disease (GERD). This study was performed to clarify the association between metabolic syndrome and the prevalence of GERD.

Methods

The study subjects were an adult population who visited a medical center for annual medical check-ups from April 2010 to March 2011. GERD was diagnosed by the presence of endoscopically proven reflux esophagitis, GERD symptoms (QUEST score ≥6), or current medical therapy for GERD. The presence of metabolic or pre-metabolic syndrome was diagnosed based on the Japanese criteria for metabolic syndrome.

Results

Six hundred four (16.0 %) of 3775 study subjects were positively diagnosed with GERD, with the number of those with metabolic and pre-metabolic syndrome being 477 (12.6 %) and 384 (10.2 %), respectively. Multiple logistic regression analysis showed that male gender, presence of hiatal hernia, and metabolic or pre-metabolic syndrome, as well as absence of gastric mucosal atrophy, were significant predictive factors for the prevalence of GERD, as were visceral fat accumulation and untreated dyslipidemia. Untreated hypertension and untreated hyperglycemia were also considered to be positive risk factors. Subjects undergoing treatment for hypertension showed an increased risk of GERD, while those undergoing treatment for dyslipidemia and diabetes mellitus showed a decreased risk.

Conclusion

Metabolic syndrome is a reliable predictive factor for the prevalence of GERD, and medical therapy for metabolic syndrome may modify the risk of GERD occurrence.     

Cardiometabolic Risk in the Latino/Hispanic Population

The Latino/Hispanic population constitutes the largest minority group in the country, accounting for 16 % of the total U.S. population. It is a heterogeneous group with several racial, biological, social, and cultural backgrounds. In general, the prevalence of traditional cardiovascular risk factors such as type 2 diabetes, hypertension, dyslipidemia and obesity is quite elevated and imposes a tremendous challenge to the health care system. According to the recently reported baseline characteristics of Latinos/Hispanics participating in the Hispanic Community Health Study/Study of Latinos, the prevalence of hypercholesterolemia was 52 % in men and 37 % in women. The prevalence of hypertension was 27 % in men and 25 % in women; the prevalence of diabetes was 16.7 % in men and 17.2 % in women; the prevalence of obesity was 36.5 % in men and 42.6 % in women and the prevalence of smoking was 26 % in men and 15 % in women. Studies performed by the Latino Diabetes Initiative at the Joslin Diabetes Center in Boston have identified significant endothelial dysfunction and vascular inflammation in overweight young Hispanic adults with a mean of 29 years of age and parental history of type 2 diabetes as well as in normoglycemic, normotensive, non-dyslipidemic overweight Hispanic children and adolescents with a mean of 13 years of age. Thus, the Hispanic/Latino population exhibits a high cardiovascular risk and therefore, effective preventive strategies are needed to tackle the burden of frequent and significant metabolic and vascular abnormalities in this population.     

Insulin resistance, inflammation, and nonalcoholic fatty liver disease in non-obese adults without metabolic syndrome components

Purpose

The purpose of the present study was to examine the association of insulin resistance and inflammation with nonalcoholic fatty liver disease (NAFLD) in non-obese adults without metabolic syndrome components.

Methods

This was a cross-sectional study of 759 subjects aged 50 years and older. Diagnosis of NAFLD was based on sonographic evidence of fatty liver without significant alcohol consumption and another cause of chronic liver disease. Subjects without metabolic syndrome components were defined as having none of the following: high blood pressure (≥130/85 mmHg), elevated fasting glucose (≥100 mg/dl), hypertriglyceridemia (≥150 mg/dl), low high-density lipoprotein-cholesterol (men <40 mg/dl; women <50 mg/dl), and abdominal obesity measured by waist circumference ≥90 cm for men and ≥80 cm for women. The subjects were divided into quartile groups according to levels of high-sensitivity C-reactive protein (hs-CRP), homeostasis model assessment of insulin resistance (HOMA-IR), and uric acid. Odds ratios (ORs) were computed for each quartile relative to the lowest quartile group.

Results

After adjustment for age, sex, smoking status, regular exercise, hs-CRP, HOMA-IR, and uric acid, a significant association was found between NAFLD and higher levels of hs-CRP, HOMA-IR, and uric acid. After adjustment for age, sex, smoking status, regular exercise, hs-CRP, HOMA-IR, and uric acid, the Ors (95 % confidence interval) of NAFLD with the highest quartile of hs-CRP, HOMA-IR, and uric acid compared with the lowest quartile were 2.58 (1.03–6.50), 2.55 (1.08–6.05), and 5.15 (1.78–14.89), respectively.

Conclusions

Insulin resistance and inflammation are independently associated with NAFLD in non-obese adults without metabolic syndrome components.     

The Role of High-Fructose Corn Syrup in Metabolic Syndrome and Hypertension

Obesity and related diseases are an important and growing health concern in the United States and around the world. Soft drinks and other sugar-sweetened beverages are now the primary sources of added sugars in Americans’ diets. The metabolic syndrome is a cluster of common pathologies, including abdominal obesity linked to an excess of visceral fat, fatty liver, insulin resistance, hyperinsulinemia, dyslipidemia, and hypertension. Trends in all of these alterations are related to the consumption of dietary fructose and the introduction of high-fructose corn syrup (HFCS) as a sweetener in soft drinks and other foods. Experimental and clinical evidence suggests a progressive association between HFCS consumption, obesity, and the other injury processes. However, experimental HFCS consumption seems to produce some of the changes associated with metabolic syndrome even without increasing the body weight. Metabolic damage associated with HFCS probably is not limited to obesity-pathway mechanisms.     

Associations between persistent organic pollutants and metabolic syndrome in morbidly obese individuals

Background and aims

Persons with “metabolically healthy” obesity may develop cardiometabolic complications at a lower rate than equally obese persons with evident metabolic syndrome. Even morbidly obese individuals vary in risk profile. Persistent organic pollutants (POPs) are widespread environmental chemicals that impair metabolic homeostasis. We explored whether prevalence of metabolic syndrome in morbidly obese individuals is associated with serum concentrations of POPs.

The metabolic syndrome: Insulin resistance

Insulin resistance is the most accepted unifying theory explaining the pathophysiology of the metabolic syndrome. However, epidemiologic studies indicate that a substantial proportion of patients with the metabolic syndrome do not have evidence of insulin resistance, and the correlation between insulin resistance and individual components of the syndrome is weak to moderate. Insulin resistance may play an important role in the development of hyperglycemia and dyslipidemia, which can further aggravate insulin resistance. The implication of insulin resistance in hypertension appears to be less strong than its role in causing hyperglycemia and dyslipidemia. Obesity may be another pathogenic factor in the metabolic syndrome that may help initiate or worsen insulin resistance. However, like insulin resistance, obesity is not universal in the metabolic syndrome, and many obese subjects do not have metabolic abnormalities. This review provides an update on the relationship between insulin resistance and main components of the metabolic syndrome: hyperglycemia, dyslipidemia, hypertension, and obesity.     

An update on metabolic syndrome: Metabolic risk markers and adipokines in the development of metabolic syndrome

BackgroundMetabolic syndrome is a collection of physiological and biochemical abnormalities about 20–25% of adult population in developing countries is suffering from metabolic syndrome. Previous research demonstrated that adipose tissue plays an important role in energy regulation via endocrine, paracrine and autocrine signals as results of obesity due to accumulation of adipose tissue to excess that by time affects negatively both physical and psychological health and well being, it has been found that adipose tissues produces a variety of factors known as “adipokines” which play a key role in the development and progression of the disease and also hypothesized that adipokines are a possible link between obesity and the other risk components of the Metabolic syndrome. Many of the adipokines exert multiple actions in a variety of cellular processes leading to a complex array of abnormal characteristic of Metabolic syndrome. Abnormal production of these adipokines by expanded visceral fat during Adiposity contributes to a pro-inflammatory state. Increasing evidence suggests that aberrant production/release of adipokine from adipocyte i.e. adiponectin, leptin and resistin etc, may contribute to the health problems associated with Adiposity such as dyslipidemia, insulin resistance and atherosclerosis. This study conclusively have shown a significant role of adipokines secreted by adipose tissue and various metabolic risk markers play a important role in the development of Metabolic syndrome.     

Incidence of type 2 diabetes,hypertension, and dyslipidemia in metabolically healthy obese and non-obese

Background and aims

Metabolically healthy obese (MHO) individuals are devoid of many metabolic abnormalities, but how this condition is maintained over time remains debated. We assessed the prevalence of MHO over time and the incidence of hypertension (HTN), dyslipidemia, and type 2 diabetes mellitus (T2DM) in MHO as compared with metabolically healthy non obese (MHNO).

Tumor necrosis factor alpha gene G-308A polymorphism in the metabolic syndrome

Tumor necrosis factor alpha (TNF-alpha) is a multifunctional cytokine constitutively produced by adipose tissue that may mediate insulin resistance. Studies in Caucasian subjects have suggested that the G-308A transition in the 5' region of the TNF-alpha gene may be associated with insulin resistance and obesity. These factors have been proposed to underlie the clustering of type 2 diabetes, hypertension, and dyslipidemia found in the metabolic syndrome, the prevalence of which is reaching epidemic proportions in Hong Kong Chinese. We investigated the association of this gene polymorphism with the components of the metabolic syndrome including the lipid profile, as well as with the indices of obesity and insulin resistance as measured by the insulin-glucose product, in 440 Chinese subjects (healthy [27.5%] and overlapping groups with type 2 diabetes [54.1%], hypertension [38.8%], dyslipidemia [39.3%], or obesity [39.5%]). The frequency of the mutant A allele was 7.4% in 121 healthy controls and 9.0% in the total population. The mutation was not associated with any component of the metabolic syndrome or with the prevalence of albuminuria and retinopathy in these subjects. Furthermore, there was no difference in anthropometric measures, insulin resistance, or lipid levels between subjects with the GG genotype and those with the mutant allele. In summary, the TNF-alpha gene G-308A polymorphism is unlikely to play an important role in the development of these disorders in this population.