Effects of aerobic exercise on metabolic syndrome improvement in response to weight reduction

Objective: The objective was to test effects of aerobic exercise training on metabolic syndrome (MetSyn) improvement in response to weight reduction. Research Methods and Procedures: A total of 459 overweight and obese women (age, 49 ± 9 years; BMI, 28 ± 3 kg/m²) were recruited for a baseline examination to test the relationship between cardiorespiratory fitness and metabolic syndrome prevalence; among these, 67 subjects with MetSyn were treated with 14‐week weight‐loss programs, which included low‐calorie diet and aerobic exercise. The MetSyn was defined according to the Examination Committee of Criteria for “Metabolic Syndrome” in Japan. Maximal oxygen uptake (V?o _2max) during a maximal cycling test was measured as an index of cardiorespiratory fitness at baseline and after the intervention. Results: In the baseline examination, age‐ and BMI‐adjusted odds ratios for MetSyn prevalence in the low, middle, and upper thirds of V?o _2max were 1.0 (referent), 0.50 (95% confidence interval, 0.26 to 0.95), and 0.39 (95% confidence interval, 0.14 to 0.96), respectively (linear trend, p = 0.02). The adjusted odds ratios for MetSyn improvement in the two interventions with diet alone and diet plus exercise were 1.0 and 3.68 (95% confidence interval, 1.02 to 17.6; p = 0.04), respectively. Discussion: These results suggest that adding aerobic exercise training to a dietary weight‐reduction program further improves MetSyn (adjusted odds ratio, 3.68) in obese women, compared with diet alone. Further studies on an association between V?o _2max change and MetSyn improvement are needed.     

Obesity and Cardiovascular Disease Risk Factors in Firefighters: A Prospective Cohort Study

Objective: Obesity, despite being a significant determinant of fitness for duty, is reaching epidemic levels in the workplace. Firefighters’ fitness is important to their health and to public safety. Research Methods and Procedures: We examined the distribution of BMI and its association with major cardiovascular disease (CVD) risk factors in Massachusetts firefighters who underwent baseline (1996) and annual medical examinations through a statewide medical surveillance program over 5 years of follow‐up. We also evaluated firefighters’ weight change over time. Results: The mean BMI among 332 firefighters increased from 29 at baseline to 30 at the follow‐up examination (2001), and the prevalence of obesity increased from 35% to 40%, respectively (p < 0.0001). In addition, the proportion of firefighters with extreme obesity increased 4‐fold at follow‐up (from 0.6% to 2.4%, p < 0.0001). Obese firefighters were more likely to have hypertension (p = 0.03) and low high‐density lipoprotein‐cholesterol (p = 0.01) at follow‐up. Firefighters with extreme obesity had an average of 2.1 CVD risk factors (excluding obesity) in contrast to 1.5 CVD risk factors for normal‐weight firefighters (p = 0.02). Finally, on average, normal‐weight firefighters gained 1.1 pounds, whereas firefighters with BMI ≥ 35 gained 1.9 pounds per year of active duty over 5 years of follow‐up. Discussion: Obesity is a major concern among firefighters and shows worsening trends over time. Periodic medical evaluations coupled with exercise and dietary guidelines are needed to address this problem, which threatens firefighters’ health and may jeopardize public safety.     

The effect of fatigue and training status on firefighter performance

Firefighting is a strenuous occupation that requires optimal levels of physical fitness. The National Fire Protection Association suggests that firefighters should be allowed to exercise on duty to maintain adequate fitness levels. However, no research has addressed the effect of exercise-induced fatigue on subsequent fire ground performance. Therefore, the primary purpose of this study was to determine the effect that a single exercise session had on the performance of a simulated fire ground test (SFGT). Secondarily, this study sought to compare the effect of physical training status (i.e., trained vs. untrained firefighters) on the performance of an SFGT. Twelve trained (age: 31.8 ± 6.9 years; body mass index [BMI]: 27.7 ± 3.3 kg·m(-2); VO2peak: 45.6 ± 3.3 ml·kg(-1)·min(-1)) and 37 untrained (age: 31.0 ± 9.0 years; BMI: 31.3 ± 5.2 kg·m(-2); VO2peak: 40.2 ± 5.2 ml·kg(-1)·min(-1)) male career firefighters performed a baseline SFGT. The trained firefighters performed a second SFGT after an exercise session. Time to complete the SFGT, heart rate, and blood lactate were compared between baseline and exercise SFGT (EX-SFGT) conditions. In the trained firefighters, time to complete the SFGT (9.6% increase; p = 0.002) and heart rate (4.1% increase; p = 0.032) were greater during the EX-SFGT compared with baseline, with no difference in post-SFGT blood lactate (p = 0.841). The EX-SFGT time of the trained firefighters was faster than approximately 70% of the untrained firefighters' baseline SFGT time. In addition, the baseline SFGT time of the trained firefighters was faster than 81% of the untrained firefighters. This study demonstrated that on-duty exercise training reduced the work efficiency in firefighters. However, adaptations obtained through regular on-duty exercise training may limit decrements in work efficiency because of acute exercise fatigue and allow for superior work efficiency compared with not participating in a training program.     

Prevalence of the Metabolic Syndrome across Cardiorespiratory Fitness Levels in Women

Objectives : To determine the prevalence of the metabolic syndrome across age strata and cardiorespiratory fitness (CRF) levels in women. Research Methods and Procedures : 7104 women underwent a physical examination, including a maximal treadmill exercise test. Participants were divided into CRF quintiles according to age. The metabolic syndrome was identified using Adult Treatment Panel‐III Guidelines. Tests for trend were performed on demographic variables across CRF quintiles, as well as prevalence of the metabolic syndrome across CRF quintiles, age strata, and maximal workload achieved [maximal metabolic equivalent (MET) level]. Results : The overall prevalence of the metabolic syndrome was 6.5%. Age‐ and smoking‐adjusted prevalence was lower across quintiles of CRF (19.0%, 6.7%, 6.0%, 3.6%, and 2.3% for quintiles I to V, respectively, p for trend = 0.001). Smoking‐adjusted prevalence of the metabolic syndrome was higher across age strata (2.4%, 2.7%, 6.4%, 8.7%, 15.3%, and 16.1% for ages 20 to 29, 30 to 39, 40 to 49, 50 to 59, 60 to 69, and 70 to 80, respectively, p for trend = 0.001). Prevalence of the metabolic syndrome in the different age groups for women who achieved a maximal MET level of 11 or higher was one‐third to one‐fourth that of women who achieved lower maximal MET levels. Discussion : Prevalence of the metabolic syndrome was markedly lower across progressively higher levels of CRF in women of different age strata. Because regular physical activity improves components of the metabolic syndrome, modest increases in CRF among low fit women may ameliorate the metabolic syndrome in some instances.     

Evaluation of circuit-training intensity for firefighters

Firefighters are required to perform a variety of strenuous occupational tasks that require high levels of both aerobic and anaerobic fitness. Thus, it is critical that firefighters train at an appropriate intensity to develop adequate levels of aerobic and anaerobic fitness. Circuit training is a unique training method that stresses both energy systems and therefore may be a viable training method to enhance firefighter preparedness. Thus, the purpose of this study was to compare the aerobic and anaerobic intensities of a circuit-based workout to physiological data previously reported on firefighters performing fire suppression and rescue tasks. Twenty career firefighters performed a workout that included 2 rotations of 12 exercises that stressed all major muscle groups. Heart rate was recorded at the completion of each exercise. Blood lactate was measured before and approximately 5 minutes after the workout. The workout heart rate and post-workout blood lactate responses were statistically compared to data reported on firefighters performing fire suppression and rescue tasks. The mean circuit-training heart rate was similar to previously reported heart rate responses from firefighters performing simulated smoke-diving tasks (79 ± 5 vs. 79 ± 6% maximum heart rate [HRmax], p = 0.741), but lower than previously reported heart rate responses from firefighters performing fire suppression tasks (79 ± 5 vs. 88 ± 6% HRmax, p < 0.001). The workout produced a similar peak blood lactate compared to that when performing firefighting tasks (12 ± 3 vs. 13 ± 3 mmol·L(-1), p = 0.084). In general, the circuit-based workout produced a lower cardiovascular stress but a similar anaerobic stress as compared to performing firefighting tasks. Therefore, firefighters should supplement low-intensity circuit-training programs with high-intensity cardiovascular and resistance training (e.g., ≥85% 1-repetition maximum) exercises to adequately prepare for the variable physical demands of firefighting.     

Independent Associations Between Cardiorespiratory Fitness and Abdominal Obesity With Metabolic Risk in Adolescents and Adults

Our objective was to examine the independent association between abdominal obesity (waist circumference (WC)) and cardiorespiratory fitness (CRF) with metabolic syndrome (MetS) in 2,197 adults (ages 20–49 years) and 3,223 adolescents (ages 12–19 years). Individuals were stratified by CRF and WC using sex‐ and age‐specific MetS criteria for adolescents and adults. Adolescents had a lower prevalence rate of MetS (5.4% vs. 12.8%) and high WC (15.5% vs. 35.7%), but a higher prevalence rate of low CRF (37.6% vs. 15.9%) than adults. As compared to adolescents and adults with low WC, those with a high WC (odds ratio (OR) = 5.5–16.5, P < 0.001) were more likely to have a clustering of MetS factors than those with low WC (OR = 1.2–3.8, P = 0.3 to <0.001), regardless of fitness level. Conversely, the beneficial effects of having moderate/high CRF on MetS were only observed in individuals with low WC, and not high WC. Thus, in conclusion, both high WC and low CRF are associated with increased odds of MetS in adolescents and adults. However, increased abdominal obesity is more strongly associated with MetS in adolescents and adults.     

Metabolic syndrome in healthy obese,overweight, and normal weight individuals: The atherosclerosis risk in communities study

Objective:

There is recent interest in characterizing the subset of obese (OB) individuals who have healthy metabolic profiles yet only two studies have examined this group prospectively but not in racially diverse populations.

Design and Methods:

We analyzed factors associated with the prevalence and incidence of metabolic syndrome (MetSyn) among individuals grouped by BMI categories in a multi‐center, community‐based cohort of 14,663 African‐American and white men and women aged 45‐64 years at recruitment in 1987‐1989, the Atherosclerosis Risk in Communities (ARIC) Study. Logistic and proportional hazards regression were utilized to estimate odds ratios (ORs) for the prevalence and hazard ratios (HRs) for incidence of MetSyn with 95% confidence intervals (CIs).

Results:

At visit 1, MetSyn was positively associated with age, female gender, African‐American race, and inversely related to education, associations being more pronounced among normal weight (NW) subjects. Among those without MetSyn at visit 1, OB subjects were more likely to develop MetSyn compared with NW (HR (95% CI): 4.53 (4.09‐5.01)). Several factors were associated with incident MetSyn among NW, including older age (per year: 1.05 (1.03‐1.06)), female gender (vs. male: 1.29 (1.10‐1.52)), heavy alcohol intake (vs. never: 0.75 (0.59‐0.94)), and physical activity (tertile 3 vs. tertile 1: 0.71 (0.58‐0.86)) but not OB. Weight gain (>5%) was also more highly associated with MetSyn in NW (1.61 (1.28‐2.02)) compared with OB (1.01 (0.85‐1.20)).

Conclusions:

We conclude that lifestyle factors may play a stronger role in the development of MetSyn in NW individuals compared with OB and that metabolically healthy obesity may not be a stable condition.     

Obesity and injury-related absenteeism in a population-based firefighter cohort

A consistent relationship has been demonstrated between obesity and absenteeism in the workplace. However, most studies have focused on primarily sedentary occupational groups. Firefighting is a physically demanding profession that involves significant potential for exposure to dangerous situations and strenuous work. No studies to date have evaluated the impact of obesity on risk for absenteeism among firefighters. We examined the cross-sectional association between BMI and obesity and injury-related absenteeism. BMI, body fat percentage (BF%), waist circumference (WC), injury, and injury-related absenteeism were assessed in 478 career male firefighters. One hundred and fifteen firefighters reported an injury in the previous year and the number of days absent from work due to their injury. BMI was an independent predictor of absenteeism due to injury even after adjustment for confounding variables. Firefighters meeting the definition of class II and III obesity had nearly five times (odds ratio (OR) = 4.89; 95% confidence interval (CI) = 3.63-6.58) the number missed work days due to injury when compared to their normal weight counterparts and their elevated risk was greater than firefighters with class I obesity (OR = 2.71; 95% CI = 2.01-3.65) or those who were overweight (OR = 2.55; 95% CI = 1.90-3.41). The attributable per capita costs of class II and III obesity-related absenteeism over the last year were $1,682.90 per firefighter, $254.00 per firefighter for class I obesity, and $74.41 per firefighter for overweight. Our findings suggest that class II and III obesity were associated with substantial attributable costs to employers and our cost estimates probably underestimate the actual financial burden.     

Metabolic syndrome: from epidemiology to systems biology

Metabolic syndrome (MetSyn) is a group of metabolic conditions that occur together and promote the development of cardiovascular disease (CVD) and diabetes. Recent genome-wide association studies have identified several novel susceptibility genes for MetSyn traits, and studies in rodent models have provided important molecular insights. However, as yet, only a small fraction of the genetic component is known. Systems-based approaches that integrate genomic, molecular and physiological data are complementing traditional genetic and biochemical approaches to more fully address the complexity of MetSyn.     

Association between Cardiorespiratory Fitness and Health-Related Quality of Life among Patients at Risk for Cardiovascular Disease in Uruguay

To date, few studies have examined the relationship between cardiorespiratory fitness (CRF) and health-related quality of life (HRQoL) in populations at high risk for developing cardiovascular disease (CVD).

Purpose

To examine the association between objectively measured CRF and physical and mental components of HRQoL in a Uruguayan cohort at risk for developing CVD.

Methods

Patient data records from 2002–2012 at the Calidad de Vida Center were examined. To assess CRF, participants performed a submaximal exercise test. During the evaluation, participants also completed the SF-36, a HRQoL measure comprised of eight dimensions that are summarized by physical and mental component scores (PCS and MCS, respectively). ANCOVA was used to examine the relationship between HRQoL dimensions and CRF. Logistic regression was then used to compare the odds of having a HRQoL component score above the norm across CRF. All analyses were performed separately for males and females with additional stratified analyses across age and BMI conducted among significant trends.

Results

A total of 2,302 subjects were included in the analysis. Among females, a significant relationship was observed between CRF and vitality, physical functioning, physical role, bodily pain, and general health dimensions. However, for males the only dimension found to be significantly associated with CRF was physical health. After adjusting for potential confounders, a significant linear trend (p<0.001) for PCS scores above the norm across CRF levels was observed for females only.

Conclusion

Among females with one or more risk factors for developing CVD, higher levels of CRF were positively associated with the vitality and physical dimensions of HRQoL, as well as the overall PCS. However, among males the only dimension associated with CRF was physical functioning. Future studies should examine this relationship among populations at risk for developing CVD in more detail and over time.     

IgA antibodies to Chlamydia trachomatis and metabolic syndrome

Chlamydia pneumoniae may trigger atherogenesis. Chlamydia trachomatis (CT) can also induce endothelial activation. However, its role in metabolic syndrome (METS), a proatherogenic entity, has remained unexplored. In this study the frequencies of IgA and IgG anti-CT antibodies were evaluated by immunoenzymatic assay in METS patients and healthy controls. The survey included 238 individuals (148 with METS). The mean age was 59.7 years. IgA anti-CT antibodies were found significantly more frequently in METS patients (16.9%) than in controls (5.6%) (P= 0.015). The role of such IgA response in METS should be further investigated.     

Serum Vitamin D status and its relations to body fatness and fitness and risk factors in young adults

The study examined the relations of serum vitamin D levels to body fatness, cardiorespiratory fitness (CRF), and metabolic risk factors in young adults in Korea. A total of 593 young men completed a health examination, body fatness, maximal treadmill exercise test, and assessment of metabolic risk factors. Participants were classified by serum vitamin D levels as deficient (< 20 ng/mL), insufficient (20~30 ng/mL), and sufficient (> 30 ng/mL). Body fatness, CRF, and metabolic risk factors were evaluated according to serum vitamin D classification. Significant inverse trends in body fatness and metabolic risk factors were observed, as was a significant linear trend for CRF across incremental vitamin D categories in this study population. Serum vitamin D levels were negatively associated with body fatness parameters, blood pressures, total cholesterol, triglycerides, and insulin and positively associated with high-density lipoprotein cholesterol and CRF. Compared to the BMI-based lean group, the obese groups had significantly higher odds ratio for serum vitamin D insufficiency before and after adjusting for age, CRF, and physical activity. Similarly, compared to percent body fat- and waist circumference-based lean groups, the obese groups had significant higher odds ratios for serum vitamin D insufficiency. In conclusion, the current findings of the study suggest that along with vitamin D intakes, body fat loss and outdoor physical activity should be promoted as non-pharmacologic means to improve metabolic risk factors in young adults.     

Seasonality and coronary heart disease deaths in United States firefighters

United States firefighters have a high on-duty fatality rate, and coronary heart disease is the leading cause. Seasonality affects the incidence of cardiovascular events in the general population, but its effects on firefighters are unknown. This study statistically examined the seasonal and annual variation of all on-duty coronary heart disease deaths among US firefighters between 1994 and 2004 using the chi-square distribution and Poisson regression model of the monthly fatality counts. It also examined the effect of ambient temperature (apparent as well as wind chill temperature) on coronary heart disease fatalities during the study span using a time-stratified, case-crossover study design. When grouped by season, we observed the distribution of the 449 coronary heart disease fatalities to show a relative peak in winter (32%) and relative nadir in spring (21%). This pattern was significantly different (p=0.005) from the expected distribution under the null hypothesis of season having no effect. The pattern persisted in additional analyses, stratifying the deaths by the type of duty in which the firefighters were engaged at the time of their deaths. In the Poisson regression model of the monthly fatality counts, the overall goodness-of-fit between the actual and predicted case counts was excellent (χ₄²=16.63; p=0.002). Two distinct peaks were detected: one in January-February and the other in August-September. Overall temperature was not associated with increased risk of on-duty death. After allowing for different effects of temperature in mild/hot versus cold periods, a 1°C increase was not protective in cold weather; nor did it increase the risk of death in warmer weather. The findings of this study reveal statistical evidence for excess coronary heart disease deaths among firefighters during winter; however, the temporal pattern of coronary heart disease deaths was not linked to temperature variation. The seasonal pattern was also found to be independent of duty-related risks.     

Relationship of body fat and cardiorespiratory fitness with cardiovascular risk in Chinese children

Backgrounds/Objectives

Cardiorespiratory fitness (CRF) and body fat play an important role in elevated risk for cardiovascular disease (CVD). However, the combined effects of CRF and obesity on metabolic health in Chinese children are unclear. The purpose of this study was to investigate the independent and combined associations between body fat, CRF, and CVD risk in Chinese schoolchildren.

Methods

The study subjects comprised 676 schoolchildren (392 boys and 284 girls, aged 9.6±0.7 yrs old) in Wuhan, China. Their body mass index (BMI), waist circumference (WC), CRF, blood pressure (BP), lipids, glucose, and pubertal status were assessed. Children were categorized into different groups based on their BMI, WC, and CRF using Chinese obesity cut-off points and CRF sex-specific median points. Metabolic Risk Score (MRS) was computed based on the standardized scores of BP, lipids, and glucose.

Results

Multiple linear regression models showed that, in the separate models, body fat was positively associated with MRS while CRF was inversely associated with MRS (p<0.001). However, when assessed simultaneously, only body fat had a significant association with MRS (p<0.001). In general, low-fit children had a lower MRS compared to their counterparts, and a significant difference between the two extreme groups was observed (low CRF and high fat vs. high CRF and low fat, p<0.001).

Conclusions

These findings suggest that both body fat and CRF should be considered when interpreting CVD risk in Chinese children, while body fat may be correlated with CVD risk more than CRF.     

The association of lipoprotein lipase PvuII polymorphism and niacin intake in the prevalence of metabolic syndrome: a KMSRI-Seoul study

Lipoprotein lipase (LPL) polymorphism correlated with LPL activity is associated with plasma lipid and lipoprotein levels. We aimed to investigate the frequency of LPL PvuII polymorphism and effects of LPL PvuII polymorphism and niacin intake on the prevalence of metabolic syndrome (MetSyn) in Koreans. Lifestyle questionnaires, anthropometry, and dietary records were completed, and LPL PvuII polymorphism, LPL mass, and lipid profiles were determined in 548 Koreans (MetSyn: 278, Non-MetSyn: 270). The MetSyn group showed a significantly lower frequency of P1P1 (wild type) and a higher frequency of P1P2 (hetero type) than the non-MetSyn group. The P2P2 (mutant type) group significantly showed lower levels of HDLc and LPL mass and a higher level of TG than the P1P1 group. As niacin intake increased, LPL mass decreased in the P2P2 group (r ² = 0.07). In particular, the lowest niacin intake group (≤14.82 mg/day) increased more than 3 times with regard to a higher risk of MetSyn than the others in the P2P2 mutant groups. However, the MetSyn risk declined 74% at the optimal levels of niacin intake (14.83–17.80 mg/day) in the P2P2 group compared to those of the P1 allele group. The findings indicate that optimal levels of niacin intake effectively decreased Korean MetSyn prevalence in the P2P2 mutant group.     

Physical fitness of an industrial fire department vs. a municipal fire department

Both industrial and municipal firefighters need to maintain high levels of physical fitness and minimize cardiovascular risk factors. The nature of firefighter responsibilities in industrial and municipal settings may vary, affecting the ability to sustain high levels of physical fitness. We compared the working conditions, physical fitness, and exercise training practices of an industrial fire department (n = 17) to those of a nearby municipal fire department (n = 55). After informed consent, aerobic capacity, muscular strength, muscular endurance, body composition, flexibility, blood lipid concentrations, and blood pressure levels were measured. Exercise training practices and related factors were assessed using a questionnaire. Despite programmatic differences, these departments demonstrated similar, relatively high degrees of physical fitness and similar blood lipid concentrations, blood pressure levels, and cardiac risk factors. It is recommended that fire departments involve appropriately trained staff, schedule on-duty times for exercise, offer well-equipped exercise facilities, and follow National Strength and Conditioning Association (NSCA) and American College of Sports Medicine (ACSM) guidelines for exercise conditioning in order to maintain a high degree of physical fitness.     

Impairments in the intrinsic contractility of mesenteric collecting lymphatics in a rat model of metabolic syndrome

Numerous studies on metabolic syndrome (MetSyn), a cluster of metabolic abnormalities, have demonstrated its profound impact on cardiovascular and blood microvascular health; however, the effects of MetSyn on lymphatic function are not well understood. We hypothesized that MetSyn would modulate lymphatic muscle activity and alter muscularized lymphatic function similar to the impairment of blood vessel function associated with MetSyn, particularly given the direct proximity of the lymphatics to the chronically inflamed adipose depots. To test this hypothesis, rats were placed on a high-fructose diet (60%) for 7 wk, and their progression to MetSyn was assessed through serum insulin and triglyceride levels in addition to the expression of metabolic and inflammatory genes in the liver. Mesenteric lymphatic vessels were isolated and subjected to different transmural pressures while lymphatic pumping and contractile parameters were evaluated. Lymphatics from MetSyn rats had significant negative chronotropic effects at all pressures that effectively reduced the intrinsic flow-generating capacity of these vessels by ～50%. Furthermore, lymphatics were remodeled to a significantly smaller diameter in the animals with MetSyn. Wire myograph experiments demonstrated that permeabilized lymphatics from the MetSyn group exhibited a significant decrease in force generation and were less sensitive to Ca(2+), although there were no significant changes in lymphatic muscle cell coverage or morphology. Thus, our data provide the first evidence that MetSyn induces a remodeling of collecting lymphatics, thereby effectively reducing their potential load capabilities and impairing the intrinsic contractility required for proper lymph flow.     

Physical fitness and telomere length in patients with coronary heart disease: findings from the Heart and Soul Study

Background

Short telomere length (TL) is an independent predictor of mortality in patients with coronary heart disease (CHD). However, the relationship between physical fitness and TL has not been explored in these patients.

Methods

In a cross sectional study of 944 outpatients with stable CHD, we performed exercise treadmill testing, assessed self-reported physical activity, and measured leukocyte TL using a quantitative PCR assay. We used generalized linear models to calculate mean TL (T/S ratio), and logistic regression models to compare the proportion of patients with short TL (defined as the lowest quartile), among participants with low, medium and high physical fitness, based on metabolic equivalent tasks achieved (METs).

Results

229 participants had low physical fitness (<5 METS), 334 had moderate physical fitness (5–7 METS), and 381 had high physical fitness (>7 METS). Mean ± T/S ratio ranged from 0.86±0.21 (5349±3781 base pairs) in those with low physical fitness to 0.95±0.23 (5566±3829 base pairs) in those with high physical fitness (p<.001). This association remained strong after adjustment for numerous patient characteristics, including measures of cardiac disease severity and physical inactivity (p = 0.005). Compared with participants with high physical fitness, those with low physical fitness had 2-fold greater odds of having TL in the lowest quartile (OR 2.39, 95% CI 1.60–3.55; p<.001). This association was similar after multivariable adjustment (OR 1.94, 95%CI, 1.18–3.20; p = 0.009). Self-reported physical inactivity was associated with shorter TL in unadjusted analyses, but not after multivariable adjustment.

Conclusions

We found that worse objectively-assessed physical fitness is associated with shorter leukocyte telomere length in patients with CHD. The clinical implications of this association deserve further study.     

The Associations between Serum Zinc Levels and Metabolic Syndrome in the Korean Population: Findings from the 2010 Korean National Health and Nutrition Examination Survey

The prevalence of metabolic syndrome has been increasing rapidly worldwide. The functions of zinc may have a potential association with metabolic syndrome, but such associations have not been investigated extensively. Therefore, we examined the relationship between serum zinc levels and metabolic syndrome or metabolic risk factors among South Korean adults ≥20 years of age. The analysis used data from the Korean National Health and Nutrition Examination Survey, a cross-sectional survey of Korean civilians, conducted from January to December 2010. A total of 1,926 participants were analyzed in this study. Serum zinc levels in men were negatively associated with elevated fasting glucose (adjusted odds ratio [aOR], 0.58; 95% confidence interval [CI], 0.36–0.93) and positively associated with elevated triglycerides (aOR, 1.47; 95% CI, 1.01–2.13). A difference in serum zinc levels was detected in women, depending on the number of metabolic syndrome components (p = 0.002). Furthermore, serum zinc levels showed a decreasing trend with increasing numbers of metabolic syndrome components in women with metabolic syndrome. These findings suggest that serum zinc levels might be associated with metabolic syndrome or metabolic risk factors. Further gender-specific studies are needed to evaluate the effect of dietary or supplemental zinc intake on metabolic syndrome.