Depression : an important comorbidity with metabolic syndrome in a general population

OBJECTIVE—There is a recognized association among depression, diabetes, and cardiovascular disease. The aim of this study was to examine in a sample representative of the general population whether depression, anxiety, and psychological distress are associated with metabolic syndrome and its components.

RESEARCH DESIGN AND METHODS—Three cross-sectional surveys including clinical health measures were completed in rural regions of Australia during 2004–2006. A stratified random sample (n = 1,690, response rate 48%) of men and women aged 25–84 years was selected from the electoral roll. Metabolic syndrome was defined by the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults, Adult Treatment Panel III (NCEP ATP III), and International Diabetes Federation (IDF) criteria. Anxiety and depression were assessed by the Hospital Anxiety and Depression Scale and psychological distress by the Kessler 10 measure.

RESULTS—Metabolic syndrome was associated with depression but not psychological distress or anxiety. Participants with the metabolic syndrome had higher scores for depression (n = 409, mean score 3.41, 95% CI 3.12–3.70) than individuals without the metabolic syndrome (n = 936, mean 2.95, 95% CI 2.76–3.13). This association was also present in 338 participants with the metabolic syndrome and without diabetes (mean score 3.37, 95% CI 3.06–3.68). Large waist circumference and low HDL cholesterol showed significant and independent associations with depression.

CONCLUSIONS—Our results show an association between metabolic syndrome and depression in a heterogeneous sample. The presence of depression in individuals with the metabolic syndrome has implications for clinical management.

Chemerin is associated with metabolic syndrome phenotypes in a Mexican-American population

Context: Chemerin is a novel adipokine previously associated with metabolic syndrome phenotypes in a small sample of subjects from Mauritius. Objective: The aim of the study was to determine whether plasma chemerin levels were associated with metabolic syndrome phenotypes in a larger sample from a second, unrelated human population. Design, Setting, Patients, and Intervention: Plasma samples were obtained from the San Antonio Family Heart Study (SAFHS), a large family-based genetic epidemiological study including 1431 Mexican-American individuals. Individuals were randomly sampled without regard to phenotype or disease status. This sample is well-characterized for a variety of phenotypes related to the metabolic syndrome. Main Outcomes: Plasma chemerin levels were measured by sandwich ELISA. Linear regression and correlation analyses were used to determine associations between plasma chemerin levels and metabolic syndrome phenotypes. Results: Circulating chemerin levels were significantly higher in nondiabetic subjects with body mass index (BMI) greater than 30 kg/m2 compared with those with a BMI below 25 kg/m2 (P < 0.0001). Plasma chemerin levels were significantly associated with metabolic syndrome-related parameters, including BMI (P < 0.0001), fasting serum insulin (P < 0.0001), triglycerides (P < 0.0001), and high-density lipoprotein cholesterol (P = 0.00014), independent of age and sex in nondiabetic subjects. Conclusion: Circulating chemerin levels were associated with metabolic syndrome phenotypes in a second, unrelated human population. This replicated result using a large human sample suggests that chemerin may be involved in the development of the metabolic syndrome.

Central obesity as a precursor to the metabolic syndrome in the AusDiab study and Mauritius

Evidence from epidemiologic studies that central obesity precedes future metabolic change and does not occur concurrently with the appearance of the blood pressure, glucose, and lipid abnormalities that characterize the metabolic syndrome (MetS) has been lacking. Longitudinal surveys were conducted in Mauritius in 1987, 1992, and 1998, and in Australia in 2000 and 2005 (AusDiab). This analysis included men and women (aged 25 years) in three cohorts: AusDiab 2000–2005 (n = 5,039), Mauritius 1987–1992 (n = 2,849), and Mauritius 1987–1998 (n = 1,999). MetS components included waist circumference, systolic blood pressure, fasting and 2-h postload plasma glucose, high-density lipoprotein (HDL) cholesterol, triglycerides, and homeostasis model assessment of insulin sensitivity (HOMA-S) (representing insulin sensitivity). Linear regression was used to determine which baseline components predicted deterioration in other MetS components over 5 years in AusDiab and 5 and 11 years in Mauritius, adjusted for age, sex, and ethnic group. Baseline waist circumference predicted deterioration (P < 0.01) in four of the other six MetS variables tested in AusDiab, five of six in Mauritius 1987–1992, and four of six in Mauritius 1987–1998. In contrast, an increase in waist circumference between baseline and follow-up was only predicted by insulin sensitivity (HOMA-S) at baseline, and only in one of the three cohorts. These results suggest that central obesity plays a central role in the development of the MetS and appears to precede the appearance of the other MetS components.

The metabolic syndrome in Australia : prevalence using four definitions

Objective : To compare the prevalence of the Metabolic Syndrome (MetS) defined by four definitions and to determine which definition best identifies those at high cardiovascular disease (CVD) risk and with insulin resistance.

Methods : AusDiab is a population-based survey of 11,247 Australians. Participants had anthropometry, blood pressure, and fasting biochemistry. Ten-year CVD risk was calculated.

Results : The prevalence of the MetS using the ATPIII, WHO, IDF, and EGIR definitions was 22.1% (95%Cl: 18.8, 25.4), 21.7% (19.0, 24.3), 30.7% (27.1, 34.3), and 13.4% (11.8, 14.9), respectively. Comparing those with to those without the MetS, the odds ratios (95%CI) for having a 10 year CVD risk ≥15% were 6.6 (5.4, 8.2), 5.5 (4.7, 6.5), 5.6 (4.8, 6.6), and 3.5 (3.0, 4.1), for the WHO, ATPIII, IDF, and EGIR definitions, respectively. The population attributable risk (PAR) of high CVD risk due to the MetS was highest for the IDF (23.4%). Insulin resistance was detected in 56.1, 69.7, 50.9, and 91.1% of those meeting the ATPIII, WHO, IDF, and EGIR definitions, respectively.

Conclusion : The WHO definition was associated with the greatest CVD risk, but is not practical for clinical use. The higher PAR due to the IDF definition, with only slightly lower CVD risk than WHO, and clinical utility of the IDF definition, indicates that it may be a useful tool for CVD prevention.

Epidemiology of metabolic syndrome

Metabolic syndrome (MetS), also previously known by a variety of other names, including insulin resistance syndrome and the deadly quartet, is characterized by clustering of abdominal (visceral and retroperitoneal) obesity and other cardiovascular risk factors, including impaired glucose regulation, raised triglycerides, decreased high-density lipoprotein cholesterol (HDL-C), elevated blood pressure (BP).

Associated with increased risk of both type 2 diabetes and cardiovascular disease (CVD), MetS is believed to be a contributor to the modern-day epidemics of diabetes and CVD and has become a major public health challenge around the world [I]. Currently, there are five different sets of criteria which have been developed to characterize the syndrome. These definitions differ in the components included and the cut-points used for each component. The prevalence of MetS in the westernized world is significant (10-50%) and believed to be increasing over time. The pathophysiology of the syndrome is unclear, but it is thought that obesity and/or insulin resistance are key underlying components. Genetics, lifestyle and environment factors are also important causes of MetS.

This chapter provides:

• a historical overview of the evolution of MetS;
• a summary of the value of the different definitions used to characterize the syndrome;
• a summary of the underlying pathophysiology, the causes and other important risk factors of MetS;
• a summary of the evidence describing the association of MetS with CVD and diabetes;
• a summary of the prevalence of MetS using the various definitions in different countries.

Effect of low and high glycaemic index diets on developing the risk of metabolic syndrome in rats

Several observational studies have shown that the chronic consumption of high glycaemic index diet is associated with an increased risk of developing metabolic syndrome.  This study was performed to identify the direct influences on the lipid profile and the adipose tissue deposition and the subsequent development of the risk of metabolic syndrome in rats by feeding diets of low glycaemic index (LGI) and high glycaemic index (HGI). Fifty rat weanlings (three weeks old) were equally divided into two groups and fed on either low glycaemic index diet based on high amylose, or isocaloric high glycacmic index diet for 12 weeks. Postprandial blood and tissue samples were collected at the end of the 12 weeks of feeding. The total white adipose tissue weights of the HGl fed rats (24.74 ± 0.53 glrat) were significantly higher than the LGl fed rats (15.37 ± 0.36 gh·at). The HO! led rats had higher postprandial leptin concentrations (1.86 ± 0.17 ng/ml) than LGI fed rats (1.34 ± 0.12 ng/ml). The postprandial insulin, and postprandial insulin glucose ratio were higher in the HGI fed rats (7.06 ± 0.90 ng/ml and 0.67 ± 0.01 ng/mlxmM) compared to the LGl fed rats (3.91 ± 0.4 ng/ml and 0.44 ± 0.01 ng/mlxmM). Triglycerides of the l-IGI fed rats showed higher values (I .56 ± 0.10 mM) than the LO! fed rats (l.07 ± 0.08 mM). The results indicated that LGI feeding was beneficial in preventing the conditions enhancing the cardio vascular disease whereas long-term feeding of HGI diet may increase the risk of developing metabolic syndrome in rats.

The association of levels of physical activity with metabolic syndrome in rural Australian adults

Background:  Physical activity (PA) reduces risk factors related to metabolic syndrome. Rurality influences the way people incorporate physical activity into daily life. The aim of this study is to determine the association of PA level with metabolic syndrome in a rural Australian population. The influence of adiposity on these associations is also investigated.

Methods: Three cross-sectional population health surveys were conducted in south-east Australia during 2004–2006 using a random population sample (n = 1563, participation rate 49%) aged 25–74 years. PA was assessed via a self-administered questionnaire, and components of the metabolic syndrome via anthropometric measurements taken by specially trained nurses and laboratory tests.

Results: Approximately one-fifth of participants were inactive in leisure-time and over one-third had metabolic syndrome (men 39%, women 33%; p = 0.022). There was an inverse association between level of PA and metabolic syndrome (p < 0.001). Men who were inactive in leisure-time were more than twice as likely and women more than three times as likely to have metabolic syndrome compared with those having high PA. Body mass index (BMI) is a mediating factor in the association between level of PA and metabolic syndrome.

Conclusion: Some PA is better than none if adults, particularly women, are to reduce their risk of metabolic syndrome and associated vascular diseases. Specialised interventions that take rurality into consideration are recommended for adults who are inactive.