Daily walking reduces visceral adipose tissue areas and improves insulin resistance in Japanese obese subjects

Effect of a Customized Physical Activity Promotion Program on Visceral Fat and Glycemic Parameters in Individuals With Prediabetes: A Randomized Controlled Trial

BACKGROUND

Physical activity of any amount results in substantial health benefits. However, public awareness of physical activity benefits in chronic diseases is inadequate in India. Prediabetes is a significant health issue on a global scale. Visceral fat (VF) is considered as an early predictor of prediabetes. Ethnicity and race have a substantial impact on VF. Hence, this study intended to evaluate the effect of a customized physical activity promotion program on VF and glycemic parameters in individuals with prediabetes.

METHODS

In the current, parallel group randomized controlled trial, a total of 158 participants were recruited: 79 in intervention and 79 in control group. The study included the prediabetes individuals based on American Diabetes Association criteria. Participants from the intervention group received the customized physical activity promotion program for 24 weeks. The primary outcome measures of the study were VF level and glycemic parameters that included fasting blood sugar and glycosylated hemoglobin. Two-way mixed analysis of variance was used to study the mean difference of an outcome between 2 groups over time.

RESULTS

The study found a statistically significant interaction between the intervention and times on VF level, F1,136 = 23.564, fasting blood sugar levels, F1,136 = 8.762, and glycosylated hemoglobin levels, F1,136 = 64.582 at the end of 24 weeks (P < .05).

CONCLUSIONS

This study concluded that a customized physical activity promotion program was effective in reducing VF in individuals with prediabetes as compared with controls. It improved glycemic control by reducing fasting blood sugar and glycosylated hemoglobin levels.

Occupational and Leisure Physical Activity on Cardiovascular Risk and Body Composition Among Courier Workers

OBJECTIVE

There is some controversy about the beneficial effects of occupational physical activity (OPA) on cardiovascular risk (CVR). The main aim of this study was to explore the effect of the combination of different frequencies of leisure-time physical activity (LTPA) and two types of OPA on CVR and body composition, and whether the association between physical activity (PA) and CVR was mediated by visceral adipose tissue (VAT).

METHODS

This cross-sectional study included data from 2516 couriers living in Spain, delivering either by motorbike or foot, and practicing LTPA never, occasionally, or regularly. Couriers were classified into six categories according to LTPA and OPA; body composition was assessed by Bioelectrical Impedance, and CVR by the Framingham equation. General linear models were performed to explore the association between different categories with each outcome (CVR and body composition) and the possible role of VAT as a mediator between PA and CVR.

RESULTS

Compared with the most sedentary group (motorbike couriers that never practice PA), walking couriers who practice regular PA presented the lowest CVR [β -1.58 (95% CI -2.31; -0.85)] and the lowest VAT [β -2.86 (95% CI -3.74; -1.98) followed by the motorbike couriers who practiced regular PA [β -0.51 (95% CI -1.00; -0.03) for CVR and β -2.33 (95% CI -2.91; -1.75) for VAT]. The association between PA and CVR was partially mediated by VAT.

CONCLUSION

The present results indicated that both OPA and LTPA are protective factors for CVR and play an important role on VAT accumulation.

Comparisons of calorie restriction and structured exercise on reductions in visceral and abdominal subcutaneous adipose tissue: a systematic review

Exercise and low-calorie diets are common approaches taken to produce an energy deficit for weight loss in obesity. Changes in visceral and abdominal subcutaneous fat associated with weight loss are important questions but have not yet been concluded. We investigated the relationship between changes in visceral (VAT) and subcutaneous adipose tissue (SAT) areas obtained by abdominal imaging with the change in total body fat. The relevant databases were searched through January 2021 according to the PRISMA guidelines. Sixty-five studies were included. We found that the change in total body fat was associated with changes in both VAT and abdominal SAT areas, but the relationship between total body fat and the abdominal SAT area appeared stronger. Baseline values of VAT and abdominal SAT area were similar in the three treatment groups (calorie restriction, calorie restriction plus exercise, and exercise alone). The reduction in abdominal SAT area for a loss of 1 kg of total body fat was about 10 cm², which was similar among all the treatments. The change in VAT area (-26.3 cm²) was a similar level as the change in abdominal SAT area (-31.5 cm²) in the exercise, whereas in the calorie restriction with and without exercise, the change in VAT area (-33.6 and -51.6 cm², respectively) was approximately half of the reduction of SAT area (-65.1 and -87.2 cm², respectively). Absolute changes in VAT and abdominal SAT areas might differ between interventions for the exercise and calorie restriction with and without exercise.

Effects of Walking Speed on Total and Regional Body Fat in Healthy Postmenopausal Women

Introduction: This study had two aims: (1) To confirm the efficacy of exercise speed and impulse (session duration at a given speed) to produce total and abdominal fat loss in postmenopausal women, and (2) compare the exercise speed and impulse necessary for the stimulation of fat loss to the suppression of bone mineral loss. Of special interest was to compare these parameters of exercise on fat loss in the same study and with the same subjects where they were found to suppress bone mineral loss. We hypothesized that (1) more total fat will be lost with slow walking and a longer impulse than with fast speed and shorter impulse, and (2) more abdominal subcutaneous (SC) and visceral fat (VF) will be lost with fast walking speed. Materials and Methods: Fat loss and suppression of bone mineral loss were measured in the same 25 subjects after 15 weeks, and fat measurements were also taken after 30 weeks in 16 residual subjects. Study parameters were walking a 4.8 km distance 4 days/week at either 6.6 km/h (120% of ventilatory threshold (VT)) or at 5.5 km/h (101.6% of VT) and expending 300 kcal/session. Body composition (fat and lean body mass, LBM) was measured with dual-energy X-ray absorptiometry (DXA) and anthropometric methods. Results: Slow walkers in the residual group progressively lost a significant percent of total body fat over 30 weeks while no such loss occurred after 15 weeks in fast walkers in either group, supporting hypothesis 1. However, the 20% higher starting body fat in 16 residual slow relative to fast subjects suggests that exercise fat loss is greater in overweight than in lean subjects. In fast walkers, fat loss occurred after 30 weeks of training. Hypothesis 2 was not supported as both speeds led to equal VF loss in 30-week group as estimated by waist circumference (CF) confirming that VF responds to the magnitude of energy expenditure and not the walking speed. Conclusions: Total body fat is lost through walking at all speeds, but the change is more rapid, clear, and initially greater with slow walking in overweight subjects. A longer exercise impulse at a lower speed in our study initially produced greater total fat loss than a shorter one with fast walking speed. This was reversed in comparison to how the same exercise in the same subjects suppressed bone mineral loss. Data from other studies indicate that longer impulses may promote greater fat loss at both slow and high exercise speeds, and our study providing only a 4.8 km walking distance may have limited the walking impulse and the magnitude of fat loss. Increased exercise energy expenditure at either walking speed produces equivalent declines in visceral fat in postmenopausal women, and with sufficiently long impulses, should reduce disabilities associated with central obesity.

The Role of Exercise, Diet, and Cytokines in Preventing Obesity and Improving Adipose Tissue

The prevalence of obesity continues to rise worldwide despite evidence-based public health recommendations. The promise to adopt a healthy lifestyle is increasingly important for tackling this global epidemic. Calorie restriction or regular exercise or a combination of the two is accepted as an effective strategy in preventing or treating obesity. Furthermore, the benefits conferred by regular exercise to overcome obesity are attributed not only to reduced adiposity or reduced levels of circulating lipids but also to the proteins, peptides, enzymes, and metabolites that are released from contracting skeletal muscle or other organs. The secretion of these molecules called cytokines in response to exercise induces browning of white adipose tissue by increasing the expression of brown adipocyte-specific genes within the white adipose tissue, suggesting that exercise-induced cytokines may play a significant role in preventing obesity. In this review, we present research-based evidence supporting the effects of exercise and various diet interventions on preventing obesity and adipose tissue health. We also discuss the interplay between adipose tissue and the cytokines secreted from skeletal muscle and other organs that are known to affect adipose tissue and metabolism.

Machine learning prediction of susceptibility to visceral fat associated diseases

Classifying subjects into risk categories is a common challenge in medical research. Machine Learning (ML) methods are widely used in the areas of risk prediction and classification. The primary objective of such algorithms is to use several features to predict dichotomous responses (e.g., healthy/at risk). Similar to statistical inference modelling, ML modelling is subject to the problem of class imbalance and is affected by the majority class, increasing the false-negative rate. In this study, we built and evaluated thirty-six ML models to classify approximately 4300 female and 4100 male participants from the UK Biobank into three categorical risk statuses based on discretised visceral adipose tissue (VAT) measurements from magnetic resonance imaging. We also examined the effect of sampling techniques on the models when dealing with class imbalance. The sampling techniques used had a significant impact on the classification and resulted in an improvement in risk status prediction by facilitating an increase in the information contained within each variable. Based on domain expert criteria the best three classification models for the female and male cohort visceral fat prediction were identified. The Area Under Receiver Operator Characteristic curve of the models tested (with external data) was 0.78 to 0.89 for females and 0.75 to 0.86 for males. These encouraging results will be used to guide further development of models to enable prediction of VAT value. This will be useful to identify individuals with excess VAT volume who are at risk of developing metabolic disease ensuring relevant lifestyle interventions can be appropriately targeted.

Extracellular Vesicles: Delivery Vehicles of Myokines

Movement and regular physical activity are two important factors that help the human body prevent, reduce and treat different chronic diseases such as obesity, type 2 diabetes, heart diseases, hypertension, sarcopenia, cachexia and cancer. During exercise, several tissues release molecules into the blood stream, and are able to mediate beneficial effects throughout the whole body. In particular, contracting skeletal muscle cells have the capacity to communicate with other organs through the release of humoral factors that play an important role in the mechanisms of adaptation to physical exercise. These muscle-derived factors, today recognized as myokines, act as endocrine and paracrine hormones. Moreover, exercise may stimulate the release of small membranous vesicles into circulation, whose composition is influenced by the same exercise. Combining the two hypotheses, these molecules related to exercise, named exer-kines, might be secreted from muscle cells inside small vesicles (nanovesicles). These could act as messengers in tissue cross talk during physical exercise. Thanks to their ability to deliver useful molecules (such as proteins and miRNA) in both physiological and pathological conditions, extracellular vesicles can be thought of as promising candidates for potential therapeutic and diagnostic applications for several diseases.

Effect of downhill walking on next-day muscle damage and glucose metabolism in healthy young subjects

This study aimed to investigate the effect of downhill walking on muscle damage and glucose metabolism in healthy subjects. All ten healthy young men and women (age, 24.0 ± 1.4 years) performed rest, uphill walking, and downhill walking trials. In the exercise trials, uphill (+ 5%) or downhill (- 5%) treadmill walking was performed at 6 km/h for 30 min. On the next day, muscle soreness was significantly higher in the downhill trial than in the uphill trial (P < 0.01). Respiratory metabolic performance did not differ between trials. However, carbohydrate oxidation was negatively correlated with plasma creatine kinase (r = - 0.41) and muscle soreness (r = - 0.47). Fasting blood glucose was significantly lower in the uphill trial than in the rest trial (P < 0.01) but not in the downhill trial. These observations suggest that downhill but not uphill walking causes mild delayed-onset muscle damage, which did not cause marked impairment in glucose metabolism. However, higher muscle damage responders might exhibit lower glucose metabolism.

The relationship between the effect of matured hop extract and physical activity on reducing body fat: re-analysis of data from a randomized, double-blind, placebo-controlled parallel group study

BACKGROUND

We recently reported that successive ingestion of matured hop extract (MHE), produced by oxidation of hops, results in a reduction of body fat in healthy overweight participants. A combined effect of MHE and physical activity on body fat has not been investigated. Thus, we re-analyzed data from the previous study to explore the relationship between the effect of MHE and walking as an index of physical activity.

METHODS

This analysis uses existing data from a randomized, double-blind, placebo-controlled parallel group study in which MHE (active) or placebo was given for 12 w to 200 healthy overweight Japanese, from May to December 2014. Correlation between the change in abdominal fat areas at 12 w and the number of steps taken per day was tested by Spearman's correlation coefficient test. The subjects were stratified using the average number of steps per day of Japanese into walking less and walking more subgroups (WL and WM, respectively) as follows: placebo (WL, n = 43; WM, n = 44) and active (WL, n = 49; WM, n = 42). Reductions in total, visceral, and subcutaneous fat area (TFA, VFA and SFA, respectively) were evaluated. The interaction effect between ingestion (active/placebo) and walking (WL/WM) was analyzed using two-way analysis of variance (ANOVA).

RESULTS

There was a significant negative correlation between the change in VFA and daily steps taken in the active group (r = - 0.208, P = 0.048). No significant correlation in TFA or SFA. Although the interaction effect in TFA was not significant, the main effect of ingestion was significant (P = 0.045). In contrast, the interaction effect in VFA was suggested to be synergistic (P = 0.055).

CONCLUSION

The results suggested that MHE ingestion combined with light intensity exercise would induce a greater reduction in VFA which would be beneficial for obese or overweight individuals in reducing obesity and obesity-related diseases.

TRIAL REGISTRATION

UMIN-CTR UMIN000014185 registered 6 June 2014.

The hyperleptinemia state can downregulate cardiorespiratory fitness and energy expenditure in obese women

INTRODUCTION

In general, in obese people a state of hyperleptinemia may impair both energy balance and the inflammatory process. However, it has not been fully investigated whether there is a relationship between hyperleptinemia and cardiorespiratory fitness (CRF) and resting energy expenditure (REE), in obese women.

METHODS

83 obese women were enrolled in this cross-sectional study. Anthropometric measures, body composition, REE, CRF and serum concentration of leptin were measured. Pearson's correlation coefficient was performed to examine the relationship between circulating leptin level and other clinical variables. Multiple regression analysis was applied to determine predictors of REE and CRF. Effects were considered significant at p≤0.05.

RESULTS

The most important finding in the present study is that the hyperleptinemia state was inversely correlated with CRF (r=-0.382, p=0.001) and REE (r=-0.447, p<0.001). Moreover, a positive correlation with fat mass was confirmed (r=0.419, p<0.001). In addition, hyperleptinemia was an independent negative predictor of REE (r²=-2.649, p=0.010) and CRF (r²=-2.335, p=0.023).

CONCLUSION

Together our results may suggest a vicious cycle between the state of hyperleptinemia and a decrease in energy expenditure and cardiorespiratory fitness in obese women, which can impair whole body energy homeostasis. This information is important to contribute to clinical practices.

Impact of a walking program of 10,000 steps per day and dietary counseling on health-related quality of life, energy expenditure and anthropometric parameters in obese subjects

PURPOSE

The aim of this pilot study was to assess the impact of a physical activity program of walking 10,000 steps per day along with monthly dietary counseling on the body composition, biological parameters, resting energy expenditure (REE) and health-related quality of life (HRQoL) of obese individuals.

METHODS

Thirty-five obese adults (26 women; age: 39.2 ± 13.4 years, body mass, BM: 104.1 ± 18.7 kg and body mass index, BMI: 38.3 ± 6.6 kg m^-2) followed a walking program (instructions were provided so that the participants increase their walking distance by 1000 steps each week, until to perform at least 10,000 steps per day) and received qualitative dietary advice (cookbook presenting numerous recipes with low calories and dietary advices was provided) for 6 months. Before and after the intervention, anthropometric (BM, BMI, waist and hip circumferences, fat mass: FM and lean body mass: LBM) and biological data (total cholesterol, high-density lipoprotein, low-density lipoprotein, triglyceride and glucose concentrations), REE and HRQoL (including eight dimensions and two summaries) were assessed.

RESULTS

After the intervention, BM (difference: 3.8 kg or 3.7 %), BMI (difference: 1.4 kg m^-2 or 3.7 %), hip circumference (difference: 4.6 cm or 4.3 %), FM in kg (difference: 4.0 kg or 8.9 %) and FM in percentage of BM (difference: 1.6 kg or 6.1 %) were significantly decreased, whereas number of steps (difference: 7579 steps or 135 %), LBM in percentage of BM (difference: 2.6 kg or 4.5 %) and REE (difference: 78 kcal d^-1 or 4.8 %) were significantly increased (p < 0.05). Moreover, two HRQoL subdimension scores (physical functioning and physical component summary; increase by 15.3 and 4.6, respectively, p < 0.05) and anxiety (reduction by 1.2, p < 0.05) were also significantly improved. Conversely, the biological data showed no significant change (p > 0.05).

CONCLUSION

Walking 10,000 steps per day in association with dietary counseling improved anthropometric data, REE, the physical domains of HRQoL and anxiety in obese adults.

Purslane (Portulaca oleracea) Seed Consumption And Aerobic Training Improves Biomarkers Associated with Atherosclerosis in Women with Type 2 Diabetes (T2D)

The aim of this study was to investigate the responses of atherosclerosis plaque biomarkers to purslane seed consumption and aerobic training in women with T2D. 196 women with T2D were assigned into; (1) placebo (PL), (2) aerobic training+placebo (AT + PL), 3) purslane seeds (PS), aerobic training+purslane seeds (AT + PS). The training program and purslane seeds consumption (2.5 g lunch and 5 g dinner) were carried out for 16 weeks. The components of purslane seed were identified and quantified by GC–MS. Blood samples were withdrawn via venipuncture to examine blood glucose, low-density lipoprotein (LDL), high-density lipoprotein (HDL), cholesterol, triglycerides (TG), creatinine, urea, uric acid, NF-κB, GLP1, GLP1R, TIMP-1, MMP2, MMP9, CRP, CST3, and CTSS expressions. Blood glucose, LDL, cholesterol, TG, creatinine, urea, and uric acid levels in the (P), (AT), and (AT + PS) groups were significantly decreased compared to the pre-experimental levels or the placebo group, while HDL, significantly increased. Furthermore, the protein and mRNA levels of NF-κB, TIMP-1, MMP2 &9, CRP, CST3, and CTSS in the (P), (AT), (AT + PS) significantly decreased compared to pre-experimental or the placebo group, while level of GLP1 and GLP1-R increased drastically. Findings suggest that purslane seed consumption alongside exercising could improve atherosclerosis plaque biomarkers through synergistically mechanisms in T2D.

Effects of a 12-Month Pedometer-Based Walking Intervention in Women of Low Socioeconomic Status

This study examined the effects of a 12-month walking intervention in overweight/obese, low socioeconomic women. Forty-six women (48.2 ± 8.0 years) entered the study. Outcomes included weight, waist and hip circumferences, body mass index (BMI), blood pressure, glycosylated hemoglobin, blood lipids, fibrinogen, and high-sensitivity C-reactive protein (hsCRP). Both intention-to-treat analyses in all participants and group analyses in study completers only (3K group = increased steps/day by ≥3,000; No Δ group = did not increase steps/day by ≥3,000) were conducted. Group × time ANOVA was used. In study completers, 3K significantly increased steps/day (6,903 ± 3,328 to 12,323 ± 5,736) compared to No Δ (4,926 ± 3,374 to 5,174 ± 3,095) from baseline to 12 months. There was a significant time effect for weight (P = 0.030), BMI (P = 0.029), and hsCRP (P = 0.044). Low socioeconomic women who adhere to a long-term, pedometer-based walking intervention significantly increased steps/day and may improve body weight, BMI, and hsCRP. This could help reduce health disparities in this population over time.

Effects of a 10,000 Steps per Day Goal in Overweight Adults

Purpose.

This study was designed (1) to examine the effects of a 10,000 steps·d−1 exercise prescription on sedentary, overweight/obese adults, and (2) to examine the effects of adherence on body composition and cardiovascular risk factors.

Methods.

Fifty-six overweight/obese adults participated in the study. Body composition and cardiovascular risk factors were determined at baseline, 20 weeks, and 36 weeks. Adherence was defined as averaging ≥ 9500 steps·d−1 from week 4 to week 36.

Results.

38 participants (68%) wore pedometers daily for 36 weeks and were available for posttesting. Significant improvements were noted in mean values for walking volume (3994 steps·d−1), body weight (–2.4 kg), body mass index (–0.8 kg·m−2), percentage body fat (–1.9%), fat mass (–2.7 kg), waist circumference (–1.8 cm), hip circumference (–1.9 cm) and high-density lipoprotein (3 mg/dl). The adherers had large improvements in body composition measures, whereas the nonadherers showed little or no change in these variables.

Discussion.

A 10,000 steps·d−1 exercise prescription resulted in weight loss over 36 weeks in previously sedentary, overweight/obese adults. Adherence to the step goal had a marked effect on the outcome.

Improvement of pulmonary function with arm swing exercise in patients with type 2 diabetes

[Purpose] Obesity and hyperglycemia play roles in the impairment of pulmonary function in type 2 diabetes mellitus (T2DM) patients. Low-intensity exercise is known to reduce body fat and improve hyperglycemia. The arm swing exercise (ASE), a low-intensity exercise, is easy and convenient to perform without any equipment and is suitable for daily practice. Therefore, we aimed to investigate the effects of ASE on lung function and obesity in overweight T2DM patients. [Subjects and Methods] Twenty-four subjects continued their daily life routines for 8 weeks (control period), and then performed ASE for 8 weeks (30 minutes per day, 3 days per week) (ASE period). Pulmonary function tests were performed, and fasting blood glucose, haemoglobin A1c (HbA1c), lipid profiles, high-sensitive C-reactive protein (HSCRP), insulin concentration, and anthropometric parameters were measured before and after each period. [Results] After the ASE period, the forced vital capacity, forced expiratory volume in the first second of expiration, and maximal voluntary ventilation were increased when compared with after the control period. HbA1c, a low-density lipoprotein, malondialdehyde, oxidized glutathione, and the percent body fat were significantly decreased when compared with after the control period. However, other parameters, such as lung volume, anthropometric parameters, and fasting blood glucose, insulin, high-density lipoprotein, triglycerides, total cholesterol and glutathione concentrations, showed no differences between the two periods. [Conclusion] These data suggest that there is improvement of pulmonary functions in T2DM patients after ASE training.

Circulating leptin levels are associated with physical activity or physical fitness in Japanese

OBJECTIVE

The aim of this study was to evaluate the link between circulating leptin levels and physical activity and/or physical fitness in apparently healthy Japanese.

METHODS

A total of 85 men and 111 women who were not taking any medication were enrolled in this cross-sectional study. Circulating leptin levels, physical activity measured by tri-axial accelerometers and peak oxygen uptake were evaluated. We also assessed anthropometric data, blood pressure, blood examinations and energy intake.

RESULTS

Circulating leptin levels were 3.2 ± 2.3 ng/mL in men and 5.9 ± 3.8 ng/mL in women. Circulating leptin levels were significantly and positively correlated with body weight, body mass index, abdominal circumference, insulin and the homeostasis model assessment index, and significantly and negatively correlated with peak oxygen uptake in both sexes. Stepwise multiple regression showed that peak oxygen uptake in men and physical activity evaluated by Σ[metabolic equivalents h per week(METs h/w)]. in women were determinant factors for circulating leptin levels after adjusting for confounding factors.

Circulating adiponectin levels are associated with peak oxygen uptake in Japanese

OBJECTIVE

The aim of this study was to investigate the link between circulating adiponectin levels and peak oxygen uptake and/or physical activity in Japanese.

METHODS

A total of 528 subjects (188 men and 340 women) were enrolled in this cross-sectional study. Circulating adiponectin levels, physical activity measured by tri-axial accelerometers, peak oxygen uptake and metabolic risk parameters were evaluated. We also assessed anthropometric factors, blood pressure, blood examinations and energy intake.

RESULTS

Circulating adiponectin levels were 6.7 ± 3.0 μg/mL in men and 11.0 ± 4.9 μg/mL in women. Circulating adiponectin levels were positively correlated with physical fitness after adjusting for age, physical activity evaluated by Σ [metabolic equivalents × h per week (METs h/w)], cigarette smoking habit and energy intake in both sexes. However, these associations were attenuated further after adjusting for body mass index including other confounding factors, especially in men. However, circulating adiponectin levels were not associated with physical activity in either sex.

CONCLUSION

Circulating adiponectin levels were associated with peak oxygen uptake rather than physical activity.

Serum vaspin levels are associated with physical activity or physical fitness in Japanese: a pilot study

AIM

To investigate the link between serum vaspin levels and physical activity and/or physical fitness in Japanese.

METHODS

A total of 156 subjects (81 men and 75 women) was enrolled in this cross-sectional study. Serum vaspin levels, physical activity by uniaxial accelerometers, peak oxygen uptake, and metabolic risk parameters were evaluated. We also assessed anthropometric and body composition parameters.

RESULTS

Serum vaspin levels were over the level of 10 ng/mL in 15 subjects (9.6 %: Vaspin High group). In Vaspin Low group (<5 ng/mL: 74 men and 67 women), serum vaspin levels were 0.12 ± 0.18 ng/mL in men and 0.39 ± 0.70 ng/mL in women. Peak oxygen uptake was significantly and positively correlated with serum vaspin levels even after adjusting for age, physical activity evaluated by Σ[metabolic equivalents × h per week (METs[Symbol: see text]h/w)], BMI, and other confounding factors in men. In turn, physical activity was significantly and positively correlated with serum vaspin levels even after adjusting for confounding factors in women.

CONCLUSION

Serum vaspin levels were closely associated with physical fitness in men and physical activity in women independent of body composition in this Japanese cohort.

Step Monitoring to improve ARTERial health (SMARTER) through step count prescription in type 2 diabetes and hypertension: trial design and methods

Background

With increasing numbers of type 2 diabetes (DM2) and hypertension patients, there is a pressing need for effective, time-efficient and sustainable strategies to help physicians support their patients to achieve higher physical activity levels. SMARTER will determine whether physician-delivered step count prescriptions reduce arterial stiffness over a one-year period, compared with usual care, in sedentary overweight/obese adults with DM2/hypertension.

Design

Randomized, allocation-concealed, assessor-blind, multisite clinical trial. The primary outcome is change in arterial stiffness over one year. The secondary outcomes include changes in physical activity, individual vascular risk factors, medication use, and anthropometric parameters. Assessments are at baseline and one year.

Methods

Participants are sedentary/low active adults with 25 ≤ BMI < 40 kg/m² followed for DM2/hypertension by a collaborating physician. The active arm uses pedometers to track daily step counts and review logs with their physicians at 3 to 4-month intervals. A written step count prescription is provided at each visit, aiming to increase counts by ≥3,000 steps/day over one year, with an individualized rate increase. The control arm visits physicians at the same frequency and receives advice to engage in physical activity 30-60 minutes/day. SMARTER will enroll 364 individuals to detect a 10 ± 5% difference in arterial stiffness change between arms. Arterial stiffness is assessed noninvasively with carotid femoral pulse wave velocity using applanation tonometry.

Discussion

The importance of SMARTER lies not simply in the use of pedometer-based monitoring but also on its integration into a prescription-based intervention delivered by the treating physician. Equally important is the measurement of impact of this approach on a summative indicator of arterial health, arterial stiffness. If effectiveness is demonstrated, this strategy has strong potential for widespread uptake and implementation, given that it is well-aligned with the structure of current clinical practice.

Trial registration

ClinicalTrials.gov (NCT01475201)

Serum interleukin-18 levels are associated with physical activity in Japanese men

Objective

To investigate the link between serum interleukin-18 (IL-18) levels and physical activity in Japanese men.

Methods

A total of 81 men (45.7±17.6 years old) was enrolled in this cross-sectional investigation study. We assessed anthropometric and body composition parameters. Serum IL-18 levels, physical activity by uniaxial accelerometers, peak oxygen uptake and metabolic risk parameters were also evaluated.

Results

Serum IL-18 levels were 179.4±84.7 pg/mL. Physical activity evaluated by Σ[metabolic equivalents × h per week (METs⋅h/w)]was significantly and negatively correlated with serum IL-18 levels (r = −0.252, p = 0.0235). These associations remained even after adjusting for age, peak oxygen uptake and other confounding factors.

Conclusion

Serum IL-18 levels were closely associated with physical activity independent of peak oxygen uptake in Japanese men.

Effects of a year-long pedometer-based walking program on cardiovascular disease risk factors in active older people

We assessed the relationship between the number of daily steps and changes in cardiovascular disease (CVD) risk factors in a year-long pedometer-based walking program for physically active older people. A total of 36 physically active older people (68.3 ± 5.8 years) completed this 59-week program. The CVD risk parameters were measured at baseline and at weeks 21 and 59. The mean number of steps increased by week 21 and was maintained at week 59 (approximately 10 000 steps, increase in 1500 steps from the baseline; P < .05). Following a significant reduction in body mass index at week 21, systolic blood pressure levels were significantly reduced, and high-density lipoprotein cholesterol levels were significantly increased at week 59 (P < .05). In summary, even active older people can achieve further protection against CVD risks by minor, but sustained, physical activity using pedometers for a period of more than 1 year.

Several steps/day indicators predict changes in anthropometric outcomes: HUB City Steps

Background

Walking for exercise remains the most frequently reported leisure-time activity, likely because it is simple, inexpensive, and easily incorporated into most people’s lifestyle. Pedometers are simple, convenient, and economical tools that can be used to quantify step-determined physical activity. Few studies have attempted to define the direct relationship between dynamic changes in pedometer-determined steps/day and changes in anthropometric and clinical outcomes. Hence, the objective of this secondary analysis was to evaluate the utility of several descriptive indicators of pedometer-determined steps/day for predicting changes in anthropometric and clinical outcomes using data from a community-based walking intervention, HUB City Steps, conducted in a southern, African American population. A secondary aim was to evaluate whether treating steps/day data for implausible values affected the ability of these data to predict intervention-induced changes in clinical and anthropometric outcomes.

Methods

The data used in this secondary analysis were collected in 2010 from 269 participants in a six-month walking intervention targeting a reduction in blood pressure. Throughout the intervention, participants submitted weekly steps/day diaries based on pedometer self-monitoring. Changes (six-month minus baseline) in anthropometric (body mass index, waist circumference, percent body fat [%BF], fat mass) and clinical (blood pressure, lipids, glucose) outcomes were evaluated. Associations between steps/day indicators and changes in anthropometric and clinical outcomes were assessed using bivariate tests and multivariable linear regression analysis which controlled for demographic and baseline covariates.

Results

Significant negative bivariate associations were observed between steps/day indicators and the majority of anthropometric and clinical outcome changes (r = -0.3 to -0.2: P < 0.05). After controlling for covariates in the regression analysis, only the relationships between steps/day indicators and changes in anthropometric (not clinical) outcomes remained significant. For example, a 1,000 steps/day increase in intervention mean steps/day resulted in a 0.1% decrease in %BF. Results for the three pedometer datasets (full, truncated, and excluded) were similar and yielded few meaningful differences in interpretation of the findings.

Conclusions

Several descriptive indicators of steps/day may be useful for predicting anthropometric outcome changes. Further, manipulating steps/day data to address implausible values has little overall effect on the ability to predict these anthropometric changes.

Relationship between changes in body weight and waist circumference in Japanese

OBJECTIVES

We investigated the correlation between changes in body weight and body composition parameters.

METHODS

We used the data of 2635 Japanese (40.2±12.2 years) at baseline and at 1-year follow-up from a database of 13522 subjects, which is available at the Okayama Southern Institute of Health in Okayama prefecture, Japan. Body weight, waist circumference at the umbilical level, hip circumference, and body fat percentage were used in the analyses.

RESULTS

Body composition parameters were significantly reduced after 1 year. Changes in body weight significantly correlated with changes in waist circumference, changes in hip circumference, and changes in body fat percentage. A decrease in body weight of 3 kg corresponded to a 3.45 cm decrease in waist circumference in men and a 2.83 cm decrease in that in women.

CONCLUSION

A decrease in body weight of 3 kg corresponded to an almost 3 cm decrease in waist circumference at the umbilical level in Japanese men and women.

Body adipose distribution among patients with type 2 diabetes mellitus

SUMMARY

Both diabetes mellitus (DM) and obesity are prevalent in adults. The relationship between DM and body adipose tissue (AT) distribution is complex and although it has been investigated extensively, the subject remains controversial. Although a causal association between DM and obesity and AT distribution cannot be established on the basis of existing data, it is possible to conclude from many studies that gene, serum sex steroids level, daily physical activity and food supply can be the risk of obesity and AT redistribution factor among type 2 DM patients (T2DM). Obesity and AT redistribution of T2DM patients can increase the risk of insulin resistant (IR), cardiovascular disease and many other disorders. Even though obesity and AT redistribution screening or prophylactic treatment in all patients with T2DM is not being recommended at present, such patient populations should be given general guidelines regarding exercise, food intake control, and even medicinal treatment. The extent of diagnostic and therapeutic interventions should be based on the individual's risk profile.:

Effectiveness of male-only weight loss and weight loss maintenance interventions: a systematic review with meta-analysis

The objectives of this systematic review were to investigate the effectiveness of male-only weight loss and weight loss maintenance interventions and to identify intervention characteristics associated with effectiveness. In May 2011, a systematic literature search with no date restrictions was conducted across eight databases. Twenty-four articles describing 23 studies met the eligibility criteria. All studies included a weight loss intervention and four studies included an additional weight loss maintenance intervention. Study quality was mostly poor for weight loss studies (median = 3/10, range = 1-9) and weight loss maintenance studies (median = 3.5/10, range = 1-6). Twenty-three of 31 individual weight loss interventions (74%) from the eligible studies were considered effective. Meta-analysis revealed a significant difference in weight change favouring weight loss interventions over no-intervention controls at the last reported assessment (weighted mean difference -5.66 kg [-6.35, -4.97], Z = 16.04 [P < 0.00001]). Characteristics common to effectiveness were younger sample (mean age ≤ 42.8 years), increased frequency of contact (> 2.7 contacts/month), group face-to-face contact and inclusion of a prescribed energy restriction. Preliminary evidence suggests men-only weight loss programmes may effectively engage and assist men with weight loss. However, more high-quality studies are urgently needed to improve the evidence base, particularly for maintenance studies.

Consumption of sugar-sweetened beverages in relation to the metabolic syndrome among Iranian adults

BACKGROUND

Few data are available linking intake of sugar-sweetened beverages (SSBs) with the metabolic syndrome. Furthermore, findings from these studies are inconsistent and most are from Western societies; no information is available in this regard from Middle Eastern populations.

OBJECTIVE

This study was conducted to assess the relationship between SSB consumption and metabolic syndrome in an Iranian adult population.

METHODS

In this cross-sectional study, data from 1,752 people (782 men and 970 women) that were selected with the multistage cluster random sampling method from three counties of Isfahan, Najafabad and Arak were used. A validated food frequency questionnaire was used to assess participants' usual dietary intakes. Consumption of SSBs was calculated by summing up the consumption of 'soft drinks' and 'artificially sweetened fruit juices'. To categorize participants, we used three levels of SSB consumption: <1 time/week, 1-3 times/week, and >3 times/week. Biochemical assessments were done after an overnight fasting. Metabolic syndrome was defined according to the guidelines of Adult Treatment Panel III.

RESULTS

Subjects with high consumption of SSBs (>3 times/week) were younger than those with low consumption (<1 time/week). Mean BMI was not significantly different across SSB categories. High consumption of SSBs was associated with greater intakes of energy and almost all food groups. We found a significant difference in serum triglyceride levels between men consuming SSBs 1-3 times/week and those consuming <1 time/week. However, after controlling for potential confounders, this association disappeared. In crude models, no significant associations were found between SSB intake and prevalence of the metabolic syndrome in either gender. After adjustment for potential confounders including BMI, we found that men in the top category of SSB intake were 17% more likely to have the metabolic syndrome (odds ratio (OR) 1.17; 95% confidence interval (95% CI) 0.56-2.46), while women in the highest category were 20% less likely to have the syndrome (OR 0.80; 95% CI 0.46-1.42) as compared with those in the bottom category. However, these associations were not significant in either men or women.

CONCLUSION

Our results do not support the previous findings on the association between SSB consumption and metabolic syndrome. Prospective studies are needed to further explore for this association.

Lifestyle Interventions and the Prevention and Treatment of Type 2 Diabetes

The diabetes epidemic is fueled by a societal increase in insulin resistance, caused by lifestyle factors, particularly excessive caloric intake and physical inactivity. Aging also plays a role in the increase in insulin resistance; however, even in older populations, the increase in insulin resistance appears to be attributable mainly to age-related obesity and inactivity. Insulin resistance reflects deposition of visceral, hepatic, and intramyocellular fat, while toxic messages from the adipose organ (free fatty acids, cytokines, and oxidative stress) impair insulin action to restrain glucose production in the liver and promote glucose disposal in muscle. Unexercised muscle is also insulin resistant because of intracellular sequestration of glucose transporters. These processes lead to hyperglycemia if compensatory secretion of insulin is inadequate due to decreases in pancreatic β -cell function and mass, ultimately resulting in the development of prediabetes and, later, type 2 diabetes mellitus (T2DM). Lifestyle interventions, programs that promote diabetes risk reduction and weight loss through behavior change, increased physical activity, and dietary modification, can decrease insulin resistance and prevent or delay the development of prediabetes and progression to T2DM. Lifestyle interventions are also important to improve diabetes management, particularly early in the natural history before loss of β -cell function and mass is so extensive that multidrug pharmacologic therapy is required. Effective interventions often include both an increase in physical activity (ideally, at least 150 minutes per week of moderate-to-vigorous aerobic exercise and strength training) and dietary modification to promote weight loss. major contributor to morbidity and mortality. T2DM can lead to renal dysfunction, peripheral and autonomic neuropathy, vision problems, and cardiovascular disease.2 In the United States alone, from 2005 to 2050, the prevalence of diagnosed diabetes is expected to more than double from 5.6% to 12.0%.3 In 2005 to 2006, the prevalence of prediabetes and diabetes combined was estimated to be 42.3% for Americans aged 20 years or older. The total prevalence of

Steps to Better Cardiovascular Health: How Many Steps Does It Take to Achieve Good Health and How Confident Are We in This Number?

Pedometers and other types of step-counting devices are growing in popularity with both researchers and practitioners. The focus of this article is on describing the most recent pedometer-related advances in terms of cardiovascular health. The emergent body of evidence suggests that pedometer-determined physical activity is related to a number of cardiovascular health outcomes and that intervention participants can realize modest changes in body mass index and blood pressure. Taking into consideration individual baseline values, tailored messages congruent with public health recommendations should promote incremental increases in steps/day on the order of an extra 3,000 to 4,000 (approximately 30 min) of at least moderate intensity and taken in at least 10-minute bouts. Additional health benefits accrue with greater increases. Of course, even more benefits are possible from engaging in vigorous physical activity, but this seems less appealing for most people. Pedometer-based guidelines are not intended to supplant existing public health recommendations, but rather supplement them.

Evaluation of ventilatory threshold and its relation to exercise habits among Japanese

OBJECTIVE

The aim of this study was to evaluate aerobic exercise levels, expressed in terms of ventilatory threshold (VT), in a Japanese population and explore the relationship between VT and exercise habits in this population.

METHODS

This was a cross-sectional study in which data collected from 547 men and 524 women aged 20-69 years and not on medications, were used to assess exercise habits and parameters at VT, namely, oxygen uptake, work rate, and heart rate.

RESULTS

Age-related changes in parameters at VT were noted. Of the participants, 205 men (37.5%) and 142 women (27.1%) had exercise habits. Oxygen uptake and work rate at VT in subjects with exercise habits were significantly higher than those without exercise habits after age had been adjusted for in both sexes. Anthropometric parameters were significantly correlated with oxygen uptake at VT, and the highest correlation coefficient rate was found between oxygen uptake at VT and body fat percentage (men r = -0.589, women r = -0.631).

CONCLUSION

The mean values determined here may provide a useful database for evaluating VT in Japanese adult subjects.

Sports activity and risk of type 2 diabetes in Chinese

An association between physical inactivity and obesity risk has been established. However, the relationship between sports activity and the risk of diabetes among Chinese populations is still unclear. We prospectively investigated the association between sports activity and incidence of type 2 diabetes in a Chinese population. Habitual physical activity in the presumed last year was obtained from a questionnaire developed by Baecke and colleagues. During a median 9.02-year follow-up period among the 1936 participants with complete questionnaire data, 312 participants developed diabetes. After adjusting for age, gender and body mass index, the relative risk (RR) of diabetes according to quartiles of sports activity were 0.86, 0.71 and 0.72 (95% Confidence Interval [CI], 0.52-0.99, P for trend, 0.048). Participants with the highest quartiles of sports activity had a significantly lower risk than the participants with the lowest quartiles among the obese group (multivariate RR, 0.61, 95% CI, 0.41-0.92, P for trend=0.018). Furthermore, the RRs of diabetes were 2.24 (95% CI, 1.58-3.19) for participants who were obese and sedentary, compared with those who were of a healthy weight and participated actively in sports. The findings suggest a significant inverse association between sports activity and incidence of type 2 diabetes in middle to older-aged Chinese individuals.

[Effects of intermittent walk program on the body mass and composition in obese women]

The obese patients adhere weakly to rehabilitation programs; therefore the expected gains are often disappointing. This is possibly linked to the monotony of constant velocity exercises frequently proposed. Consequently, other less monotonous exercises such as the intermittent walk may be more appropriated.

OBJECTIVES

The main objectives of this study were to determine if the obese women prefer a constant velocity walk or an intermittent walk, and to analyze the effects of a rehabilitation program based on the intermittent walk.

MATERIALS AND METHODS

Twenty obese women were recruited. To determine the preferred walk modality, 10 obese women performed a constant velocity walk and an intermittent walk (with a similar duration and velocity) on a treadmill. The preferred walk modality was determined by lower ratings of perceived exertion. Then, these same 10 women participated in a rehabilitation program of 10 weeks (three days per week) consisting of intermittent walks. The 10 other women did not participate in a training program.

RESULTS

The ratings of perceived exertion were not significantly different between the two walk modalities. However, the women who participated in a training program increased their maximal distance during a 6 min walking test and they have stabilized theirs anthropometric data. Meanwhile, the untrained women have increased their body mass, body mass index and percentage of body fat.

CONCLUSION

The obese patients preferred similarly the constant velocity walk and the intermittent walk, and a rehabilitation program based on an intermittent walk is effective in avoiding the obesity aggravation.

Association between walking distance and percentiles of body mass index in older and younger men

OBJECTIVE

To assess the association of weekly walking distance to body weight and waist circumference in elderly (age > or =75 years), senior (55< or = age <75 years), middle-aged (35< or = age <55 years), and younger men (18< or = age <35 years old).

DESIGN

Cross-sectional analyses of baseline questionnaires from 7082 male participants of the National Walkers' Health Study.

RESULTS

Standard regression analyses showed that body mass index (BMI) was inversely and significantly associated with walking distance (kg/m(2) per km/week) in elderly (slope (SE): -0.032 (0.008)), senior (-0.045 (0.005)) and middle-aged men (-0.037 (0.007)), as were their waist circumferences (-0.090 (0.025), -0.122 (0.012) and -0.091 (0.015) cm per km/week, respectively), and that these slopes remained significant when adjusted statistically for reported weekly servings of meat, fish, fruit and alcohol. However, percentile regression analyses showed that the declines in BMI per km/week walked were greater at the higher than the lower percentiles of the BMI distribution. In men > or =74 years old the decline per km walked was 4.9-fold greater among the heaviest men (that is, 90th BMI percentile; -0.076 kg/m(2) per km/week) than among the leanest men (that is, 10th BMI percentile; -0.015 kg/m(2) per km/week). The differences in slope at the 90th compared to the 10th BMI percentile were 5.4-fold among men 55-74 years old and sixfold among men 35-54 years old. Per km/week walked, the declines at the 90th percentile of waist circumference were also greater than at its 10th percentile, and intermediate for percentiles in between. Whereas standard regression analyses suggest that the average declines in BMI per km/week walked reported here are consistent with those reported previously per km/week run in male runners 35-54 years old (-0.036 (0.001) kg/m(2) per km/week) and > or =50 years old (-0.038 (0.001) kg/m(2) per km/week), percentile regression analyses showed that when adjusted to the leaner body weights of the runners the declines per km walked were between 49% and 59% less for walkers than runners.

CONCLUSIONS

Declines in BMI and waist circumferences with walking distance depend upon the percentile of the BMI distribution, with the decline per km walked being significantly greater among heavier men.

Beneficial effects of rosiglitazone on novel cardiovascular risk factors in patients with Type 2 diabetes mellitus

AIM

Impaired exercise capacity, adiponectin, MMPs and TIMPs have all been implicated in the development of cardiovascular disease. The aim of our study was to determine the effects of rosiglitazone on these factors in diabetic patients.

METHODS

Seventy individuals with Type 2 diabetes were assigned randomly to either a rosiglitazone group (8 mg/day, RG) or a control group (CG) for 6 months. All participants took gliclazide 160 mg plus metformin 1700 mg in stable dose. None of the individuals had diabetic complications or had previously participated in an exercise programme. Anthropometric parameters, VO2 peak, oxygen pulse, glycaemic indices, lipid profile, adiponectin, insulin resistance, blood pressure and serum MMP-9, TIMP-1, TIMP-2 levels were assessed at baseline and at the end of the study. After Bonferroni adjustment, a P-value < 0.017 was assumed to be statistically significant.

RESULTS

Rosiglitazone treatment significantly increased VO2 peak (P < 0.0001), the duration of the exercise test (P < 0.0001), oxygen pulse (P = 0.010) and TIMP-2 levels (P = 0.008) in comparison with CG. Insulin resistance, hyperglycaemia, diastolic blood pressure and MMP-9 levels were also reduced (P < 0.017). Fat mass, lipid profile, TIMP-1 levels and MMP9 : TIMP-1 ratio were unaltered after rosiglitazone treatment. There were no significant changes in these parameters in control subjects. In univariate analysis, the rosiglitazone-induced increment of VO2 peak was associated with alterations in plasma adiponectin (r = 0.691), HOMA-IR (r = -0.782) and HbA(1c) (r = -0.676) (P < 0.017). These relationships retained significance after multiple regression analysis (P = 0.005).

CONCLUSIONS

Rosiglitazone treatment increases cardiorespiratory fitness and modulates favourably serum adiponectin, MMP-9 and TIMP-2 levels. Whether these effects produce cardiovascular benefits in the long term requires further investigation.

Factors associated with percent change in visceral versus subcutaneous abdominal fat during weight loss: findings from a systematic review

BACKGROUND

Visceral adipose tissue (VAT) is associated with greater obesity-related metabolic disturbance. Many studies have reported preferential loss of VAT with weight loss.

OBJECTIVE

This systematic review looks for factors associated with preferential loss of VAT relative to subcutaneous abdominal fat (SAT) during weight loss.

DESIGN

Medline and Embase were searched for imaging-based measurements of VAT and subcutaneous abdominal adipose tissue (SAT) before and after weight loss interventions. We examine for factors that influences the percentage change in VAT versus SAT (%deltaV/%deltaS) with weight loss. Linear regression analyses were performed on the complete data set and on subgroups of studies. Factors examined included percentage weight loss, degree of caloric restriction, exercise, initial body mass index (BMI), gender, time of follow-up and baseline VAT/SAT.

RESULTS

There were 61 studies with a total of 98 cohort time points extracted. Percentage weight loss was the only variable that influenced %deltaV/%deltaS (r=-0.29, P=0.005). Modest weight loss generated preferential loss of VAT, but with greater weight loss this effect was attenuated. The method of weight loss was not an influence with one exception. Very-low-calorie diets (VLCDs) provided exceptional short-term (<4 weeks) preferential VAT loss. But this effect was lost by 12-14 weeks.

CONCLUSIONS

Visceral adipose tissue is lost preferentially with modest weight loss, but the effect is attenuated with greater weight loss. Acute caloric restriction, using VLCD, produces early preferential loss of VAT. These observations may help to explain the metabolic benefits of modest weight loss.

A meta-analysis of pedometer-based walking interventions and weight loss

PURPOSE

Cross-sectional studies show that individuals who walk more tend to be thinner than those who walk less. This does not mean, however, that the association between higher step counts and lower weight is causal or that encouraging sedentary individuals to increase step counts helps them lose weight.

METHODS

In this meta-analysis, we searched 6 electronic databases and contacted pedometer experts to identify pedometer-based walking studies without a dietary intervention that reported weight change as an outcome. We included randomized controlled trials and prospective cohort studies published after January 1, 1995, in either English or Japanese, with 5 or more adult participants and at least 1 cohort enrolled in a pedometer-based walking intervention lasting at least 4 weeks.

RESULTS

Nine studies met the study inclusion criteria. Cohort sample size ranged from 15 to 106, for a total of 307 participants, 73% of whom were women and 27% of whom were men. The duration of the intervention ranged from 4 weeks to 1 year, with a median duration of 16 weeks. The pooled estimate of mean weight change from baseline using a fixed-effects model and combining data from all 9 cohorts was -1.27 kg (95% confidence interval, -1.85 to -0.70 kg). Longer intervention duration was associated with greater weight change. On average, participants lost 0.05 kg per week during the interventions.

CONCLUSION

Pedometer-based walking programs result in a modest amount of weight loss. Longer programs lead to more weight loss than shorter programs.

Comparison of ventilatory threshold and exercise habits between Japanese men with and without metabolic syndrome

OBJECTIVE

We compared the levels of ventilatory threshold (VT) and exercise habits in subjects with metabolic syndrome with those in age, sex-matched subjects without metabolic syndrome.

METHODS

We used data of 155 Japanese men (47.1+/-9.2 years) with metabolic syndrome; the diagnosis was given by the definition and the diagnostic standard for metabolic syndrome in Japan. The influence of metabolic syndrome on oxygen uptake, work rate and heart rate at VT, and exercise habits were evaluated.

RESULTS

Oxygen uptake and work rate at VT in subjects with metabolic syndrome were significantly lower than those in subjects without metabolic syndrome even after adjusting for body mass index (BMI). The number of subjects with exercise habits was significantly lower in metabolic syndrome. The subjects with exercise habits were significantly older than that in subjects without exercise habits. Furthermore, oxygen uptake and work rate at VT were significantly higher in subjects with exercise habits than those in subjects without exercise habits.

CONCLUSION

Lower level of VT was characteristic in subjects with metabolic syndrome. Promotion of exercise habits is necessary for preventing and improving metabolic syndrome in Japanese men.

Hyperhomocysteinemia is associated with visceral adiposity in Japanese patients with type 2 diabetes mellitus

This study aims to investigate the relationship between the circulating level of homocysteine and body adiposity in Japanese patients with type 2 diabetes mellitus. We measured the body mass index (BMI), waist and hip circumferences, visceral and subcutaneous adiposities, visceral/subcutaneous (V/S) adiposity ratio, and insulin resistance as assessed by the Homeostasis Model Assessment (HOMA) index in patients with hyperhomocysteinemia. The study group consisted of 17 Japanese patients with type 2 diabetes and hyperhomocysteinemia (age: 62+/-10 years, mean+/-S.D.), and the control group consisted of 24 age-matched type 2 diabetes patients with normohomocysteinemia (60+/-11 years). The visceral adiposity, HOMA index, and V/S ratio were significantly higher in the hyperhomocysteinemia group than in the normohomocysteinemia group (P<0.05). In contrast, the BMI, hip circumference, and subcutaneous adiposity were similar between the two groups (P>0.1). Furthermore, multiple regression analysis showed that hyperhomocysteinemia was closely related to insulin resistance and visceral adiposity. Our results indicate that the presence of hyperhomocysteinemia in our population of Japanese patients with type 2 diabetes-associated insulin resistance was associated with increased visceral but not subcutaneous adiposity.

A dose–response relation between aerobic exercise and visceral fat reduction: systematic review of clinical trials

OBJECTIVE

It has been suggested that exercise has preferential effects on visceral fat reduction. However, the dose-response effect remains unclear because of limited evidence from individual studies. The purpose of this study was to systematically review the current literature to establish whether reduction of visceral fat by aerobic exercise has a dose-response relationship.

METHODS

A database search was performed (PubMed, 1966-2006) with appropriate keywords to identify studies exploring the effects of aerobic exercise as a weight loss intervention on visceral fat reduction. Visceral fat reduction was expressed as the percentage of visceral fat change per week (%DeltaVF/w). The energy expenditure by aerobic exercise was expressed as Sigma (metabolic equivalents x h per week (METs x h/w)).

RESULTS

Nine randomized control trials and seven non-randomized control trials were selected. In most of the studies, the subjects performed aerobic exercise generating 10 METs x h/w or more. Among all the selected groups (582 subjects), visceral fat decreased significantly (P<0.05) in 17 groups during the intervention, but not in the other 4 groups. There was no significant relationship between METs x h/w from aerobic exercise and %DeltaVF/w in all the selected groups. However, when subjects with metabolic-related disorders were not included (425 subjects), METs x h/w from aerobic exercise had a significant relationship with %DeltaVF/w (r=-0.75). Moreover, visceral fat reduction was significantly related to weight reduction during aerobic exercise intervention, although a significant visceral fat reduction may occur without significant weight loss.

CONCLUSION

These results suggest that at least 10 METs x h/w in aerobic exercise, such as brisk walking, light jogging or stationary ergometer usage, is required for visceral fat reduction, and that there is a dose-response relationship between aerobic exercise and visceral fat reduction in obese subjects without metabolic-related disorders.

Visceral abdominal fat is correlated with whole-body fat and physical activity among 8-y-old children at risk of obesity

BACKGROUND

Abdominal fat is more related to health risk than is whole-body fat. Determining the factors related to children's visceral fat could result in interventions to improve child health.

OBJECTIVE

Given the effects of physical activity on adults' visceral fat, it was hypothesized that, after accounting for whole-body fat, physical activity would be inversely related to children's visceral (VAT), but not to subcutaneous (SAT), abdominal adipose tissue.

DESIGN

In this cross-sectional observational study conducted in forty-two 8-y-old children (21 boys, 21 girls) at risk of obesity [>75th body mass index (BMI) percentile, with at least one overweight parent], familial factors (eg, maternal BMI), historic weight-related factors (eg, birth weight), and the children's current physical activity (self-reported and measured with accelerometry) and diet were examined as potential correlates of the children's whole-body composition (measured with BMI and dual-energy X-ray absorptiometry) and abdominal fat distribution (measured by magnetic resonance imaging).

RESULTS

Accelerometer-measured physical activity was related to whole-body fat (r = -0.32, P < 0.10), SAT (r = -0.29, P < 0.10), and VAT (r = -0.43, P < 0.05). In regression models, whole-body fat was positively associated with and the only significant correlate of SAT. Whole-body fat was positively related and accelerometer-measured physical activity was negatively and independently related to the children's VAT.

CONCLUSIONS

Both SAT and VAT in 8-y-old children at risk of obesity are most closely associated with whole-body fat. However, after control for whole-body fat, greater physical activity is only associated with lower VAT, not SAT, in these children.

Central Obesity and Health-related Factors among Middle-aged Men: a Comparison among Native Japanese and Japanese-Brazilians Residing in Brazil and Japan

The objective of this study was to investigate the influence of different cultural environments on the development of obesity by examining the association of central obesity, lifestyle, and selected coronary risk factors among people with identical Japanese genetic backgrounds living in Japan and Brazil. One hundred and four native Japanese and 286 Japanese-Brazilians residing in Brazil and Japan aged 35 years or over were studied. Obesity, metabolic risk factors for coronary disease, and history of regular sports activity, daily physical activity, and eating habits were assessed. The results showed Japanese-Brazilians residing in Brazil with significantly higher waist circumference values, and greater prevalence of central obesity compared to native Japanese and Japanese-Brazilians residing in Japan. The risk of developing central obesity was found to be 2.8 times higher among Japanese-Brazilians residing in Brazil. However, this association was no longer found to be significant after adjusting for lifestyle factors in the logistic model. Additionally, waist circumference was found to be significantly associated with metabolic risk factors for coronary disease. These findings suggest substantial variation in measures of central obesity among the three groups of Japanese ancestry, and underscore the heterogeneity of risk factors among communities of Japanese ancestry living in different cultural environments. The results also suggest that immigrant men exposed to the Brazilian cultural environment are more susceptible to the development of central obesity, and it seems to be associated with various lifestyle items and metabolic risk factors for coronary disease.

Even low-intensity and low-volume exercise training may improve insulin resistance in the elderly

OBJECTIVE

Moderate to high intensity exercise training is known to ameliorate the coronary risk factors in relation to an improvement in body composition. However, the benefit of low-intensity and low-volume training for these risk factors remains unclear in elderly people. Therefore, we investigated the effects of low-intensity and low-volume exercise training on blood lipid values and insulin resistance in the elderly.

METHODS

A total of 56 healthy elderly individuals (42 females and 14 males) aged 64+/-6 years participated in a 12-week exercise program, comprising aerobic training and resistance training.

RESULTS

After the program, there were no significant changes in high-density lipoprotein cholesterol, triglyceride serum levels, or in peak oxygen uptake on average. However, the homeostasis of minimal assessment of insulin resistance (HOMA-IR) value was significantly reduced by 21%. The participants were categorized into tertiles based on initial Body Mass Index (BMI). The Middle-BMI group (non-obese subjects) showed reduced HOMA-IR (2.0-->1.3, P<0.01), but this reduction was not associated with the reduction in BMI (r=0.08, P=0.74), whereas the two reductions were significantly associated in the High-BMI group (r=0.61, P=0.01).

CONCLUSION

Even low-intensity and low-volume exercise training, which would ordinarily be insufficient for improving mean lipid values or aerobic fitness, was found to be effective in improving insulin resistance in the elderly. The improvement in insulin resistance was independent of the improvement in obesity.

The inverse relationship between number of steps per day and obesity in a population-based sample – the AusDiab study

BACKGROUND

Physical activity (PA) is inversely associated with obesity but the effect has been difficult to quantify using questionnaires. In particular, the shape of the association has not yet been well described. Pedometers provide an opportunity to better characterize the association.

METHODS

Residents of households over the age of 25 years in randomly selected census districts in Tasmania were eligible to participate in the AusDiab cross-sectional survey conducted in 1999-2000. 1848 completed the AusDiab survey and 1126 of these (609 women and 517 men) wore a pedometer for 2-weekdays. Questionnaire data on recent PA, TV time and other factors were obtained. The outcomes were waist circumference (in cm) and body mass index (BMI) (kg/m(2)).

RESULTS

Increasing daily steps were associated with a decline in the obesity measures. The logarithmic nature of the associations was indicated by a sharper decline for those with lower daily steps. For example, an additional 2000 steps for those taking only 2000 steps per day was associated with a reduction of 2.8 (95% confidence interval (CI): 2.1,4.4) cm in waist circumference among men (for women; 2.2 (95% CI: 0.6, 3.9 cm)) with a baseline of only 2000, steps compared to a 0.7 (95% CI 0.3, 1.1) cm reduction (for women; 0.6 (95% CI: 0.2, 1.0)) for those already walking 10,000 steps daily. In the multivariable analysis, clearer associations were detected for PA and these obesity measures using daily step number rather than PA time by questionnaire.

INTERPRETATION

Pedometer measures of activity indicate that the inverse association between recent PA and obesity is logarithmic in form with the greatest impact for a given arithmetic step number increase seen at lower levels of baseline activity. The findings from this study need to be examined in prospective settings.