Risk indicators of metabolic syndrome in young adults: A preliminary investigation on the influence of tobacco smoke exposure and gender

PRISMA-compliant meta-analysis: association of metabolic syndrome and its components with the risk of chronic obstructive pulmonary disease

A preferred reporting items for systematic reviews and meta-analyses-compliant meta-analysis was conducted to test the association of metabolic syndrome and its components with the risk of chronic obstructive pulmonary disease (COPD) based on observational studies. Literature retrieval, article selection and data extraction were done by two researchers independently. Total 16 articles (20 independent studies) were analyzed with 3915 COPD patients and 25,790 control participants. Overall analysis indicated that metabolic syndrome was significantly associated with 1.53-fold (95% confidence interval [CI]: 1.23–1.9, P<0.001) increased risk of COPD, with moderate heterogeneity (I² = 74.3%). Of four metabolic components, hypertension was significantly associated with 1.55-fold (95% CI: 1.14–2.11, P=0.005) increased risk, and averaged levels of systolic blood pressure (weighted mean difference [WMD] = 3.626 mmHg, 95% CI: 1.537–5.714, P<0.001) and glucose (WMD = 2.976 mmol/l, 95% CI: 0.141–5.812; P=0.04) were significantly higher in COPD patients than in control participants, yet that of body mass index (WMD = −1.463 kg/m², 95% CI: −2.716 to −0.211, P=0.022) were significantly lower. Gender, race, source of control participants, matched status and sample size were identified as accountable factors for significant heterogeneity. Altogether, the presence of metabolic syndrome, especially its component hypertension, was associated with significantly increased risk of COPD.

Lifestyle Factors and Metabolic Syndrome among Workers: The Role of Interactions between Smoking and Alcohol to Nutrition and Exercise

This study aimed to investigate (1) relations of smoking and alcohol to metabolic syndrome (MetS) and its components, with nutrition and exercise controlled; and (2) interactions between smoking/alcohol and nutrition/exercise on MetS. This cross-sectional study enrolled 4025 workers. Self-reported lifestyles, anthropometric values, blood pressure (BP), and biochemical determinations were obtained. Among males, smoking significantly increased the risk of low high-density lipoprotein cholesterol (HDL-C), high triglyceride, abdominal obesity (AO), and MetS. Additionally, smoking showed significant interaction effects with nutrition on high BP, AO, and MetS; after further analysis, nutrition did not decrease above-mentioned risks for smokers. However, there was no significant interaction of smoking with exercise on any metabolic parameter. Alcohol increased the risk of AO, but decreased low HDL-C. It also showed an interaction effect with exercise on AO; after further analysis, exercise decreased AO risk for drinkers. Among females, alcohol significantly decreased the risk of high fasting blood glucose, but did not show significant interaction with nutrition/exercise on any metabolic parameter. In conclusion, in males, smoking retained significant associations with MetS and its components, even considering benefits of nutrition; exercise kept predominance on lipid parameters regardless of smoking status. Alcohol showed inconsistencies on metabolic parameters for both genders.

A short-term smoking cessation may increase the risk of developing metabolic syndrome

Smoking cessation is beneficial for health. However, its potential harmful impact on metabolic syndrome has yet to be clarified. Six smokers who attended the smoking cessation clinic were recruited and given the nicotine replacement therapy for 3 months. The values of body weight, BMI, systolic blood pressure, and fasting glycemia were significantly elevated after smoking cessation. We recommend that clinicians should monitor these cardiovascular risk factors in subjects attempting smoking cessation.

Smoking is associated with impaired glucose regulation and a decrease in insulin sensitivity and the disposition index in first-degree relatives of type 2 diabetes subjects independently of the presence of metabolic syndrome

The aim of this study was to investigate glucose tolerance, insulin secretion and insulin resistance according to smoking habits in first-degree relatives of type 2 diabetes patients, a population at high risk for developing diabetes. One thousand three hundred (646 females and 654 males) subjects underwent an oral glucose tolerance test (OGTT) to investigate their glucose metabolism and answered questionnaires about their lifestyle habits. Smoker subjects showed significant impairment compared with non-smoker subjects in 2-h post-oral glucose tolerance test (2hOGTT, 129.3 ± 40.2 vs. 117.7 ± 37.6 mg/dl, p < 0.001), the OGTT insulin sensitivity (386.3 ± 54.9 vs. 400.5 ± 53.4 ml min(-1) m(2), p < 0.01) method and the insulin sensitivity and secretion index-2 (ISSI-2, 1.7 ± 0.8 vs. 2.0 ± 1.0, p < 0.005). Metabolic syndrome (MS) was higher in the smoker than in the non-smoker group (46.5 vs. 29.7 %, p < 0001), and smokers were more sedentary than non-smokers (3.94 ± 3.77 vs. 4.86 ± 4.41 h/week, p < 0.001). Smokers showed an increased risk of impaired glucose regulation (IGR: impaired glucose tolerance or diabetes mellitus) with a hazard ratio (HR) adjusted by gender, metabolic syndrome and physical activity of 1.78, 95 % CI 1.27-2.47 (p < 0.001). The association between smoking and MS conferred a risk of IGR that was five times higher (HR 5.495, 95 % CI 4.07-7.41, p < 0.001). Smoking habit was a significant explanatory variable in a multiple forward stepwise regression analysis performed using 2hOGTT and ISSI-2 as dependent variables (p < 0.0001, R = 0.313 and p < 0.0001, R = 0.347, respectively). In conclusions, our results show that tobacco smoking is tightly associated with impairments in glucose metabolism and insulin sensitivity and insulin secretion.

Acute physiologic effects of secondhand smoke exposure in children

INTRODUCTION

We investigated the hypothesis that exhaled carbon monoxide (eCO), heart rate (HR), and blood pressure (BP) would increase acutely in exposed but not in unexposed children.

METHODS

In a nonrandomized controlled design, parent-child dyads were assigned to groups based on exposure: child subjects, 7-18 years of age, exposed to smoking daily in the home (exposed) or with no household exposure (unexposed control). HR, BP, and eCO were measured before and after exposure to a parent smoking 1 cigarette (exposed) or a time-lapse equivalent (control). The primary analysis compared mean acute changes in physiological measures following intervention or control procedure.

RESULTS

Forty-one dyads were enrolled. At baseline, no differences in child gender, race, ethnicity, HR, BP, lipids, or fasting glucose were noted between exposure groups. Following experimental or control procedures, the median change in eCO was similar between groups (-0.1 ppm exposed vs. 0.0 ppm unexposed, p = .27). Acute hemodynamic changes were also similar between exposed and unexposed children, respectively: (HR change 4.2 vs. 2.6 beats per minute, p = .62; systolic blood pressure change 0.08 vs. 0.41 mm Hg, p = .91; diastolic blood pressure 0.08 vs. 2.27 mm Hg, p = .37).

DISCUSSION

This is the first study to report on acute physiologic changes of secondhand smoke exposure in children in a naturalistic setting. A single acute dose of passive smoke exposure in children did not alter the physiologic variables of HR or BP. Further in-home study using continuous monitoring is needed. Demonstration of acute effects may serve as clinical feedback to motivate parents to quit smoking.

Lower leptin levels in young non-obese male smokers than non-smokers

Since the effect of smoking on plasma leptin has been divergent in clinical trials, which might have occurred due to selection of heterogeneous study populations, we investigated whether there is such an association in a group of healthy, non-obese, young male adults. A total of 54 smokers (mean age: 21.18+/-1.62; body mass index (BMI): 19.60+/-0.85) and 26 non-smokers (mean age 21.69+/-3.0; BMI: 21.59+/-1.39) with similar daily physical activities and diet and without any documented disease were enrolled, and their plasma leptin levels were determined for the comparison between the two groups. The mean BMI and plasma leptin of smokers were significantly lower than in non-smokers. Plasma leptin in the smokers group correlated inversely with BMI and the amount of daily smoking. Below BMI 20 kg/m(2) and between 20.0 and 20.9 kg/m(2) the plasma leptin levels in smokers were significantly lower when compared to non-smokers. Plasma leptin is decreased in healthy, young non-obese male smokers independently of the amount of body fat. High amount of smoking is associated with lower serum leptin as well.

A complex web of risks for metabolic syndrome: race/ethnicity, economics, and gender

BACKGROUND

Metabolic syndrome is a recognizable clinical cluster of risks known to be associated in combination and independently with an increased risk for cardiovascular disease (CVD). Identifying and treating metabolic syndrome is one promising strategy to reduce CVD. The intersection of race/ethnicity, gender, and economic status complicates our understanding of who is at risk for metabolic syndrome, but understanding this social patterning is important for the development of targeted interventions. This study examines the relationship between metabolic syndrome (and the underlying contributing risk factors) and race/ethnicity, economic status, and gender.

METHODS

National Health and Nutrition Examination Survey data collected from 1999 through 2002 were used; analysis was completed in 2006-2007. Metabolic syndrome was defined using the Adult Treatment Panel III definition. Economic status was measured using income as a percentage of the poverty level. Prevalence of metabolic syndrome and each of its contributing risk factors were determined by race/ethnicity and economic group. Logistic regressions were estimated. All analyses were stratified by gender.

RESULTS

Economic effects were seen for women, but not men. Women in the lowest economic group were more likely to be at risk in four of the five risk categories when compared with women in the highest economic group. Differences in the contributing risk profiles for metabolic syndrome were seen by race/ethnicity.

CONCLUSIONS

Strategies to reduce CVD must be built on a clear understanding of the differences in contributing risk factors for metabolic syndrome across subgroups. The findings from this study provide further information to guide the targeting of these strategies.

Glucocorticoids produce whole body insulin resistance with changes in cardiac metabolism

Insulin resistance is viewed as an insufficiency in insulin action, with glucocorticoids being recognized to play a key role in its pathogenesis. With insulin resistance, metabolism in multiple organ systems such as skeletal muscle, liver, and adipose tissue is altered. These metabolic alterations are widely believed to be important factors in the morbidity and mortality of cardiovascular disease. More importantly, clinical and experimental studies have established that metabolic abnormalities in the heart per se also play a crucial role in the development of heart failure. Following glucocorticoids, glucose utilization is compromised in the heart. This attenuated glucose metabolism is associated with altered fatty acid supply, composition, and utilization. In the heart, elevated fatty acid use has been implicated in a number of metabolic, morphological, and mechanical changes and, more recently, in "lipotoxicity". In the present article, we review the action of glucocorticoids, their role in insulin resistance, and their influence in modulating peripheral and cardiac metabolism and heart disease.