Sex and Age Differences in Association between Physical Activity and Metabolic Syndrome: Results from NHANES 2003-2006

OBJECTIVE

To examine whether and how sex and age modify the association between accelerometer-based physical activity (PA) and metabolic syndrome (MetS) among American (US) adults.

METHOD

Adults aged ≥20 years old who participated in the mobile center examination during 2003-2006 in the National Health and Nutrition Examination Survey were included for analysis. The total minutes per day of moderate-to-vigorous PA (MVPA) was estimated using ActiGraph. Multivariable logistic regression was used to estimate the odds ratio (OR) of having MetS at an increasing MVPA time. The modification effects of gender and age on the association between MetS and MVPA time were examined by testing for two-way and three-way interaction terms of MVPA time, sex, and age in the model after adjusting for relevant covariates.

RESULTS

The prevalence of MetS generally decreased with the MVPA time and was lower in females than in males, although the sex difference varied across age groups. After adjusting for demographic and lifestyle covariates, there was a significant sex difference in how an increased MVPA time lowered the odds of MetS. This interactive effect also varied with age. MVPA benefitted young and middle-age populations up until about 65 years old for both sexes, and the protective effect weakened with age. Although the effect of MVPA was stronger for males than females at young ages, the rate at which it attenuated was quicker in males. The OR of MetS between males and females per unit change of MVPA time was 0.73 (95% CI: [0.57, 0.93]) at age = 25 years, compared to OR = 1.00 (95% CI: [0.88, 1.16]) at age = 60 years. Before the age of 50, the gender difference in the protective effect on MetS was larger at low MVPA levels and became smaller at higher MVPA levels. The male advantage was quite stable with an increasing MVPA time for ages 50-60, and no longer significant at older ages.

CONCLUSIONS

Young and middle-age populations benefitted from MVPA, lowering the risk of MetS for both sexes. A longer MVPA time was associated with a greater decrease in the risk of MetS in young men than in women, but the sex difference reduced with age and was no longer apparent in older populations.

Long-term exposure to airborne particulate matter and NO2 and prevalent and incident metabolic syndrome - Results from the Heinz Nixdorf Recall Study

INTRODUCTION

Recently, epidemiological studies have found a link between air pollution (AP) and individual components of the metabolic syndrome (MetS), a condition predisposing to cardiometabolic diseases. However, very few studies have explored a possible association between air pollution and MetS.

OBJECTIVE

We analyzed the effects of long-term exposure to airborne particulate matter and NO₂ on prevalence and incidence of MetS.

METHODS

We used data of the population-based prospective Heinz Nixdorf Recall study (baseline 2000-2003) to investigate the association(s) between AP exposure and MetS prevalence at baseline (n = 4457) and MetS incidence at first follow-up visit (n = 3074; average follow-up: 5.1 years). Mean annual exposure to size-fractioned particulate matter (PM₁₀, PM_2.5, PM_coarse, and PM_2.5abs) and nitrogen dioxide (NO₂) was assessed using a land use regression model. MetS was defined as central obesity plus two out of four additional risk factors (i.e., elevated triglycerides, reduced high-density lipoprotein cholesterol, elevated blood pressure or elevated plasma glucose). We estimated odds ratios (ORs) of MetS prevalence and incidence per interquartile range (IQR) of exposure, adjusting for demographic and lifestyle variables.

RESULTS

We observed a MetS prevalence of 20.7% (n = 922) and an incidence of 9.7% (n = 299). NO₂ was positively associated with MetS prevalence, with an OR increase per IQR of 1.12 (95%-CI 1.02-1.24, IQR = 6.1 μg/m³). PM₁₀ and PM_2.5 were both borderline positively associated with MetS incidence, with ORs of 1.14 (95%-CI 0.99-1.32, IQR = 2.1 μg/m³) and 1.19 (95%-CI 0.98-1.44, IQR = 1.5 μg/m³) per IQR, respectively.

CONCLUSION

In summary, we found a weak positive association between air pollution and MetS. The strongest and most consistent effects were observed between NO₂ and prevalent MetS.

Pharmacokinetic comparisons of berberine and palmatine in normal and metabolic syndrome rats

ETHNOPHARMACOLOGICAL RELEVANCE

San-Huang formula is a popular traditional Chinese medicine (TCM) preparation to replenish Qi, resolve phlegm, dissipate blood stasis, and therapy metabolic syndrome in China. Metabolic syndrome, which is accompanied by Qi and blood stasis, mainly arises from spleen deficiency in essence. There is limited information available for differences of pharmacokinetic properties of San-Huang formula between normal and metabolic syndrome rats. The present study was conducted to compare the pharmacokinetics of berberine as well as palmatine in normal and metabolic syndrome rats following oral administration of San-Huang formula extract.

MATERIALS AND METHODS

The animals were orally administered with San-Huang formula extract with the equivalent dose of 60.4 and 12.5mg/kg for berberine and palmatine, respectively. The blood samples were collected according to the time schedule. The concentrations of berberine and palmatine in rat plasma were determined by LC-ESI/MS. Various pharmacokinetic parameters were estimated from the plasma concentration versus time data using non-compartmental methods.

RESULTS

It was found that AUC0-t, Cmax, Vd and CL of berberine and palmatine in metabolic syndrome rats were significantly different (P<0.05) from normal rats.

CONCLUSIONS

The results indicated that berberine and palmatine have higher uptake and slower elimination in the rats with metabolic syndrome, which suggests that the rate and extent of drug metabolism were altered in metabolic syndrome rats.

The cat as a model for human obesity and diabetes

Obesity is the most common nutritional disorder of cats and is a risk factor for diabetes. Similar to developments in obese people, obese cats show peripheral tissue insulin resistance and may demonstrate glucose intolerance when challenged with pharmacological amounts of glucose. However, they compensate well for the insulin resistance and do not show elevated glucose concentrations when monitored during their regular daily routine, including postprandial periods. This is possible because obese cats in the fasted and postprandial state are able to maintain hepatic insulin sensitivity and decrease endogenous glucose production, which allows them to maintain normoglycemia. Also dissimilar to what is seen in many obese humans, cats do not develop atherosclerosis and clinical hypertension. The time course for progression to overt diabetes of obese cats is unknown. One might speculate that diabetes develops when the liver finally becomes insulin resistant and/or insulin secretion becomes too low to overcome increased glucose production. In addition, amyloid, demonstrated to be deposited in islet of chronically obese cats, may contribute to a reduction in insulin secretion by reducing functional β-cell mass.

Pioglitazone: an agent which reduces stroke, myocardial infarction and death and is also a key component of the modern paradigm for the optimum management of type 2 diabetes

A randomised controlled trial (RCT), the PROactive study, was undertaken to see if pioglitazone improved cardiovascular outcomes in type 2 diabetes. Initially the results were controversial and pioglitazone was not widely recognised as a beneficial agent for cardiovascular disease. A meta-analysis of rosiglitazone studies raising the possibility that it was associated with cardiovascular harm received worldwide media attention and the negative concern spread to involve pioglitazone through presumed ‘class-effect’. A careful re-look at the detail of the PROactive’s primary composite endpoint, which led to the controversy over the outcome, suggests that medical statistics may have been inadequate to reveal the real clinical effect. A number of other studies support the interpretation that pioglitazone significantly improves cardiovascular outcomes. While the potential risk:benefit of pioglitazone needs to be acknowledged, it now also needs to be recognised that pioglitazone and metformin are the only glucose-lowering agents with RCT data demonstrating a reduction in stroke, myocardial infarction and death in type 2 diabetes. Furthermore there now exists a strong case that even in type 2 diabetes patients without known cardiovascular disease, the modern paradigm for management should involve the combination of metformin, pioglitazone and glucagon-like peptide 1 agonists used early and aggressively to achieve a target glycated haemoglobin A1C <6%.

Prevalence of metabolic syndrome and associated socioeconomic and demographic factors among Palestinian adults (20-65 years) at the Gaza Strip

OBJECTIVES

Metabolic syndrome (MetS) is a multifaceted syndrome and has been described as a clustering of several risk factors for cardiovascular disease. This study was conducted to estimate the prevalence of MetS and its individual components among Palestinian adults, 20-65 years old in Gaza Strip. In addition to find any possible associations with socioeconomic and demographic factors.

MATERIAL AND METHODS

The study sample included 230 adults aged 20-65 years. Data were collected by questionnaire interviews, anthropometrics, and biochemical analysis that included: serum glucose, total cholesterol, triglyceride, HDL, and LDL. MetS was defined according to the NCEP/ATP III diagnostic criteria.

RESULTS

Overall prevalence of MetS was 23.0% among the study subjects, with no significant differences between males (18.1%) and females (28.1%). The prevalence of MetS increased significantly with age and was associated significantly with physical activity and martial status, while no significant associations were found with household income; geographical locality; smoking; watching TV; or family history.

CONCLUSIONS

Age, sex, physical activity and marital status are risk factors independently associated with MetS in the Palestinian population at the Gaza Strip. National health awareness and preventive programs should be established aiming at decreasing of MetS trends in the Palestinian population at Gaza Strip.

Improving metabolite knowledge in stable atherosclerosis patients by association and correlation of GC-MS and 1H NMR fingerprints

The plasma of patients with stable carotid atherosclerosis (n = 9), and healthy subjects (n = 10) have been fingerprinted with both GC-MS and (1)H NMR. Principal component analysis (PCA), partial least-squares-discriminant analysis (PLS-DA) and orthogonal partial least-squares-discriminant analysis (OPLS-DA) have been applied to the profiles from each technique both separately and in combination. These techniques complement each other and enable a clearer picture of the biological samples to be interpreted not only for classification purposes, but also more importantly to define the metabolic state of patients with carotid atherosclerosis. The results showed at least 24 metabolites that were significantly modified in the group of atherosclerotic patients by this nontargeted procedure. Most of the changes can be associated to alterations of the metabolism characteristics of insulin resistance that can be strongly related to the metabolic syndrome. In addition, correlations among variables accounting for the classification show amino acids as variables whose changes showed a high degree of correlation. GC-MS and (1)H NMR fingerprints can provide complementary information in the identification of altered metabolic pathways in patients with carotid atherosclerosis. Moreover, correlations among the results with both techniques, instead of a single study, can provide a deeper insight into the patient state.

Overweight and obesity: the pathogenesis of cardiometabolic risk

Obesity, particularly abdominal adiposity, is increasingly recognized as a cause of elevated cardiometabolic risk--the risk of developing type 2 diabetes mellitus (DM) and cardiovascular disease (CVD). The predominate mechanisms appear to involve the promotion of insulin resistance, driven largely by excess free fatty acids secreted by an expanded adipose tissue mass, and the development of an inflammatory milieu due to increased secretion of inflammatory cytokines and adipokines from adipose tissue. Key proinflammatory cytokines secreted by adipocytes include tumor necrosis factor-alpha, interleukin-6, leptin, resistin, and plasminogen activator inhibitor-1. All have been variously associated with hyperinsulemia, hyperglycemia, insulin resistance, diabetes, and endothelial dysfunction, as well as plaque development, progression, and rupture. Adiponectin, another important adipocyte, has protective cardiometabolic actions; however, adiponectin levels decline with increasing obesity. Understanding the role of obesity in the pathogenesis of cardiometabolic risk is crucial for the development of treatment strategies that will provide maximum benefit for patients with, or at risk for, type 2 DM and CVD.

Current pharmacotherapeutic concepts for the treatment of obesity in adults

Obesity is one of the greatest public health challenges of the twenty-first century. The World Health Organization (WHO) reports that in 2005 approximately 1.6 billion adults were overweight and at least 400 million adults were obese. The prevalence of obesity is still continuing to increase dramatically. Overweight and obese people carry a higher risk for a variety of cardiovascular diseases including hypertension, coronary heart disease, stroke and peripheral occlusive artery disease. Weight loss is considered to be the initial step which helps to prevent or to control the clinical consequences of obesity. In a great number of patients who are not able to reduce weight by means of non-pharmacological measures, drug therapy can assist in reaching the weight management targets. Drug treatment should only be considered as part of a systematic weight management program including dietary and lifestyle changes. This review summarizes current pharmacotherapeutic concepts for the treatment of obesity in adults focusing on efficacy and safety of anti-obesity drugs.