Exercise training, without weight loss, increases insulin sensitivity and postheparin plasma lipase activity in previously sedentary adults

Primary care physicians' knowledge, attitudes and practices related to metabolic syndrome screening and management in Alahsa, Saudi Arabia

BACKGROUND

The metabolic syndrome (Metabolic syndrome) is a cluster of the most dangerous risk factors for type 2 diabetes mellitus and cardiovascular diseases (CVD), two of the main causes of morbidity and mortality worldwide, which include hyperglycemia, abdominal obesity, lipid abnormalities and high blood pressure.

STUDY DESIGN

a cross-sectional descriptive study.

RESULTS

A predominant number (94.1%) knew what constitutes MS. However, merely more than a quarter of the participant (28%) knew correctly the serum LDL cutoff value for the diagnosis of MS according to IDF criteria. The aim of lipid lowering treatment was known by slightly more than three fourth (78%) of the participants. Two third also knew the target of antihypertensive therapy. More than two third (69.5%) were also aware that waist circumference is one of the criteria for diagnosis of Metabolic syndrome.

CONCLUSION

There is a need to increase the awareness of MS among the PHC Physicians. More training programs need to be planned. A better awareness among primary care physician is warranted for an early diagnosis and effective management of MS in Saudi Arabia.

Cognitive predictors of physical activity behaviors among rural patients with type 2 diabetes: applicability of the Extended Theory of Reasoned Action (ETRA)

Background: This study aims to examine the cognitive-behavioral determinants of physical activity behaviors (PABs) of patients diagnosed with type 2 diabetes. Subjects and methods: In this cross-sectional study, census sampling was employed to enroll 120 rural patients with type 2 diabetes in the Chalderan County in 2015. To collect data, a valid and reliable instrument, based on the Extended Theory of Reasoned Action (ETRA) constructs, was used. Data were analyzed by SPSS 21 software using descriptive and inferential statistical methods. Results: Using the one-way ANOVA test, it was found that PABs had statistically significant correlation with all ETRA constructs except subjective norms (P=0.574). Knowledge (P=0.015), self-efficacy (P<0.001) and behavioral intention (P<0.001) had a significant association with PABs, respectively. Also, ETRA structures were able to reflect 41.0% of the behavioral changes. Among structures, knowledge (P=0.014), self-efficacy (P<0.001), and behavioral intention (P=0.020) were significant predictors of PABs (R2=0.414). Conclusions: Health care providers may consider the ETRA an appropriate framework to design educational interventions aimed at improving PABs among rural patients with type 2 diabetes.

Randomised controlled trial to study the efficacy of exercise with and without metformin on women with polycystic ovary syndrome

OBJECTIVES

1. To study the efficacy of exercise in improving clinical symptoms, anthropometry, glucose tolerance and laboratory profile in women with Polycystic ovarian syndrome. 2. To study the combined efficacy of exercise and metformin on above parameters in women with polycystic ovary syndrome.

STUDY DESIGN

A Randomised double blinded placebo controlled trial was performed at a district hospital in New Delhi. Sixty six women were included in the study. Block randomisation was done to divide the women into two groups. Women were treated with fixed exercise schedule along with oral placebo in Group A and exercise with oral metformin in Group B. Outcomes stated in objectives were studied and statistically analysed. Quantitative variables were compared using unpaired t-test and Paired t-test within the groups across follow-ups. Qualitative variable has been compared using Chi-Square test /Fisher's exact test.

RESULTS

In Group A and B significant improvement was noted in menstrual cycles, mean waist circumference, mean waist-hip ratio and body mass index. The mean weight loss was 0.78 ± 0.19 kg and 1.71 ± 0.19 kg in group A and B respectively after 3 months. The mean weight loss was 1.08 ± 0.30 kg and 1.71 ± 0.19 kg in group A and B respectively. The mean difference in modified Ferriman Gallwey score at 0, 3 and 6 months were statistically significant in both groups. On comparing group A with group B at 6 months, significant improvement was found in menstrual cycle symptoms (55.17% vs 83.33%), mean weight loss (1.08 kg vs 2.5 kg), waist circumference reduction (2.56 cm vs 4.75 cm) and change in mean waist hip ratio (0.02 vs 0.04). Significant changes were noted in OGTT and Serum testosterone level at 6 months in Group B, but not in Group A. Statistically no significant differences were found in acne, acanthosis nigricans and other biochemical parameters.

CONCLUSION

Regular exercise should be recommended for the women with PCOS. It results in statistically significant improvement in menstrual cycle pattern, hirsutism, body mass index, weight, waist circumference waist-hip ratio. Addition of metformin resulted in added benefits on menstrual cycle, hirsutism, weight, body mass index, waist circumference, waist hip ratio, serum testosterone and Oral Glucose Tolerance Test (OGTT).

Effective Weight Loss and Maintenance by Intensive Start with Diet and Exercise

INTRODUCTION

This 24-month study aimed to determine whether exercise intervention added to weight loss treatment at 6 months is effective for weight loss and maintenance.

METHODS

A total of 120 obese subjects (body mass index > 30) were randomly assigned to intensified behavioral modification (iBM) (n = 30), behavioral modification + exercise from 0 to 3 months (circuit weight training group 1 [CWT1]) (n = 30), behavioral modification + exercise from 6 to 9 months (CWT2) (n = 30), and a control group (CON) (n = 30). Health behavior, weight, waist circumference, and 2-h glucose tolerance test with insulin measurements were measured at 0, 3, 9, and 24 months.

RESULTS

Eighty-five subjects (mean age = 46 yr, body mass index = 36.3, 75.3% women) completed the trial. A significant weight loss occurred in CWT1 (-8.5 kg, P > 0.001), iBM (-5.5 kg, P > 0.001), and CWT2 (-4.4 kg, P = 0.007). CWT1 showed the highest reduction in waist circumference at 9 months (mean difference = -11.5 cm, P < 0.001) and 24 months (mean difference = -8.8 cm, P < 0.001). Both fasting and 2-h insulin values improved in the intervention groups compared with CON. A significant decrease in 2-h insulin values from baseline was found in CWT1 and CWT2. Matsuda index improved in the CWT1 group from the baseline to 24 months (2.03, P = 0.025).

CONCLUSION

The most effective weight loss regimen is a combination of iBM and weight training introduced from the very beginning of the weight loss period. Treatment of morbid obesity should include an intensive start with exercise and diet regardless of weight status.

Liraglutide Reduces Postprandial Hyperlipidemia by Increasing ApoB48 (Apolipoprotein B48) Catabolism and by Reducing ApoB48 Production in Patients With Type 2 Diabetes Mellitus

Objective—

Treatment with liraglutide, a GLP-1 (glucagon-like peptide-1) agonist, has been shown to reduce postprandial lipidemia, an important feature of diabetic dyslipidemia. However, the underlying mechanisms for this effect remain unknown. This prompted us to study the effect of liraglutide on the metabolism of ApoB48 (apolipoprotein B48).

Approach and Results—

We performed an in vivo kinetic study with stable isotopes (D 8 -valine) in the fed state in 10 patients with type 2 diabetes mellitus before treatment and 6 months after the initiation of treatment with liraglutide (1.2 mg/d). We also evaluated, in mice, the effect of a 1-week liraglutide treatment on postload triglycerides and analysed in vitro on jejunum, the direct effect of liraglutide on the expression of genes involved in the biosynthesis of chylomicron. In diabetic patients, liraglutide treatment induced a dramatic reduction of ApoB48 pool (65±38 versus 162±87 mg; P =0.005) because of a significant decrease in ApoB48 production rate (3.02±1.33 versus 6.14±4.27 mg kg -1 d -1 ; P =0.009) and a significant increase in ApoB48 fractional catabolic rate (5.12±1.35 versus 3.69±0.75 pool d -1 ; P =0.005). One-week treatment with liraglutide significantly reduced postload plasma triglycerides in mice and liraglutide, in vitro, reduced the expression of ApoB48, DGAT1 (diacylglycerol O-acyltransferase 1), and MTP (microsomal transfer protein) genes.

Conclusions—

We show that treatment with liraglutide induces a significant reduction of the ApoB48 pool because of both a reduction of ApoB48 production and an increase in ApoB48 catabolism. In vitro, liraglutide reduces the expression of genes involved in chylomicron synthesis. These effects might benefit cardiovascular health.

Clinical Trial Registration—

URL: https://www.clinicaltrials.gov . Unique identifier: NCT02721888.

Hypothesis: Postprandial remnant lipoproteins are the causal factors that induce the insulin resistance associated with obesity

We have long thought that remnant lipoproteins (RLP) in plasma are significantly increased as the result of disturbed lipoprotein metabolism followed by obesity and insulin resistance. Therefore, it was believed that insulin resistance causes and enhances RLP formation. In contrast, this hypothesis states that RLP induces insulin resistance as the result of obesity associated with the excessive fat intake. The majority of plasma TG increased after fat intake is TG in RLP (RLP-TG) and the majority of postprandial RLP is VLDL remnants, not CM remnants. RLP is newly formed lipoproteins primarily for energy supply against starvation, like blood sugar after carbohydrate intake. Since RLP bearing apoE, LPL and Lp(a) function as ligands for the VLDL receptor, RLP interacts with the VLDL receptor in visceral fat adipocytes and stored as TG similar to excessive blood sugar. However, the excessive VLDL remnants induces obesity and its associated insulin resistance, which plays a major role as the initiator of metabolic domino effects, similar to blood sugar primarily serving as an energy supply to protect against starvation.

Compound but non-linked heterozygous p.W14X and p.L279 V LPL gene mutations in a Chinese patient with long-term severe hypertriglyceridemia and recurrent acute pancreatitis

BACKGROUND

Variants in the lipoprotein lipase (LPL), apolipoprotein C-II (APOC2), apolipoprotein A-V (APOA5), GPIHBP1 and LMF1 genes may cause severe hypertriglyceridemia (HTG), which is now the second-leading aetiology of acute pancreatitis in China.

METHODS

The patient and his family were assessed for gene variants by Sanger sequencing of exons and exon-intron junctions of the LPL, GPIHBP1, APOA5, APOC2, and LMF1 genes. Post-heparin blood was collected for LPL mass and activity detection.

RESULTS

The patient had suffered from long-term severe hypertriglyceridemia and recurrent abdominal pain for over 30 years, since age 26, and 3 bouts of acute pancreatitis. Two heterozygous LPL single-nucleotide polymorphisms (SNPs) were compound but dislinked: a single-nucleotide substitution (c.42G > A) resulting in the substitution of tryptophan with a stop codon (p.W14X) in one allele, and a single-nucleotide substitution (c.835C > G) resulting in a leucine-to-valine substitution (p.L279 V) in another allele. Only one SNP, p.L279 V, was detected in his son. Post-heparin LPL activity and mass were also lower in the patient.

CONCLUSION

Two heterozygous LPL SNPs, W14X and L279 V, were newly found to be compound but dislinked, which may cause long-term severe hypertriglyceridemia and recurrent acute pancreatitis.

Targeting risk factors for type 2 diabetes in American Indian youth: the Tribal Turning Point pilot study

BACKGROUND

American Indian (AI) youth are at high risk for type 2 diabetes.

OBJECTIVES

To partner with Eastern Band of Cherokee Indians and Navajo Nation to develop a culturally sensitive behavioural intervention for youth (Tribal Turning Point; TTP) and assess feasibility in an 8-month randomized pilot study.

METHODS

We enrolled 62 overweight/obese AI children (7-10 years) who participated with ≥1 parent/primary caregiver. Intervention participants (n = 29) attended 12 group classes and five individual sessions. Control participants (n = 33) attended three health and safety group sessions. We analysed group differences for changes in anthropometrics (BMI, BMI z-score, waist circumference), cardiometabolic (insulin, glucose, blood pressure) and behavioural (physical activity and dietary self-efficacy) outcomes.

RESULTS

Study retention was 97%, and intervention group attendance averaged 84%. We observed significant treatment effects (p = 0.02) for BMI and BMI z-score: BMI increased in control (+1.0 kg m^-2 , p < 0.001) but not intervention participants (+0.3 kg m^-2 , p = 0.13); BMI z-score decreased in intervention (-0.17, p = 0.004) but not control participants (0.01, p = 0.82). There were no treatment effects for cardiometabolic or behavioural outcomes.

CONCLUSIONS

We demonstrated that a behavioural intervention is feasible to deliver and improved obesity measures in AI youth. Future work should evaluate TTP for effectiveness, sustainability and long-term impact in expanded tribal settings.

Prevalence of Pediatric Metabolic Syndrome and Associated Risk Factors among School-Age Children of 10-16 Years Living in District Shimla, Himachal Pradesh, India

INTRODUCTION

Recently, an increasing trend in the prevalence of pediatric metabolic syndrome (PMS) among school-age children has been documented in different parts of India. There is lack of data on the prevalence of PMS and its associated risk factors among school-age children living in district Shimla, Himachal Pradesh. Hence, to fill in the gap in the existing knowledge, the present study was conducted.

METHODOLOGY

A cross-sectional study was conducted during 2015-2016. Thirty clusters (schools) were identified from a list of all schools using population proportionate to size sampling methodology. From each school, 70 children in the age group of 10-16 years were selected. Data was collected on the sociodemographic characteristics, anthropometry, waist circumference, blood pressure, and physical activity. Fasting venous blood samples were collected for estimation of blood glucose, triglycerides, and high-density lipoprotein levels.

RESULTS

The prevalence of PMS using International Diabetes Federation classification was 3.3% and using modified-adult treatment panel classification criteria was 3.5%. Risk factors identified to be associated with PMS among school-age children were (i) male gender, (ii) high family monthly income, (iii) sedentary lifestyle, (iv) consumption of evening snack, (v) television/computer viewing, and (vi) motorized transportation for commuting to school.

CONCLUSION

The PMS prevalence was 3.3% in school-age children residing in District Shimla. There is a need to formulate interventions to prevent and correct metabolic syndrome among them for reducing early onset of cardiovascular disease during adulthood.

Is regular exercise an effective strategy for weight loss maintenance?

Weight regain after weight loss is one of the most significant challenges to successful obesity treatment. Regular exercise has long been touted as a strategy for weight loss maintenance, but the lack of clear evidence in clinical trials has caused some to question its effectiveness. In this review, we present the arguments both questioning and in support of exercise as an obesity therapeutic. Our purpose is to bring clarity to the literature, present a unified perspective, and identify the gaps in knowledge that need to be addressed in future studies. Critical questions remain including sex differences, individual variability and compensatory behaviors in response to exercise, exercise adherence, the role of energy flux and the molecular mechanisms mediating the beneficial effects of exercise after weight loss and during weight regain. Future research should focus on these critical questions to provide a more complete understanding of the potential benefits of exercise on weight loss maintenance.

Objectively Measured Physical Activity and Sedentary Time Are Associated With Cardiometabolic Risk Factors in Adults With Prediabetes: The PREVIEW Study

OBJECTIVE

The aim of the present cross-sectional study was to examine the association among physical activity (PA), sedentary time (ST), and cardiometabolic risk in adults with prediabetes.

RESEARCH DESIGN AND METHODS

Participants (n = 2,326; 25-70 years old, 67% female) from eight countries, with a BMI >25 kg ⋅ m^-2 and impaired fasting glucose (5.6-6.9 mmol ⋅ L^-1) or impaired glucose tolerance (7.8-11.0 mmol ⋅ L^-1 at 2 h), participated. Seven-day accelerometry objectively assessed PA levels and ST.

RESULTS

Multiple linear regression revealed that moderate-to-vigorous PA (MVPA) was negatively associated with HOMA of insulin resistance (HOMA-IR) (standardized β = -0.078 [95% CI -0.128, -0.027]), waist circumference (WC) (β = -0.177 [-0.122, -0.134]), fasting insulin (β = -0.115 [-0.158, -0.072]), 2-h glucose (β = -0.069 [-0.112, -0.025]), triglycerides (β = -0.091 [-0.138, -0.044]), and CRP (β = -0.086 [-0.127, -0.045]). ST was positively associated with HOMA-IR (β = 0.175 [0.114, 0.236]), WC (β = 0.215 [0.026, 0.131]), fasting insulin (β = 0.155 [0.092, 0.219]), triglycerides (β = 0.106 [0.052, 0.16]), CRP (β = 0.106 [0.39, 0.172]), systolic blood pressure (BP) (β = 0.078 [0.026, 0.131]), and diastolic BP (β = 0.106 [0.39, -0.172]). Associations reported between total PA (counts ⋅ min^-1), and all risk factors were comparable or stronger than for MVPA: HOMA-IR (β = -0.151 [-0.194, -0.107]), WC (β = -0.179 [-0.224, -0.134]), fasting insulin (β = -0.139 [-0.183, -0.096]), 2-h glucose (β = -0.088 [-0.131, -0.045]), triglycerides (β = -0.117 [-0.162, -0.071]), and CRP (β = -0.104 [-0.146, -0.062]).

CONCLUSIONS

In adults with prediabetes, objectively measured PA and ST were associated with cardiometabolic risk markers. Total PA was at least as strongly associated with cardiometabolic risk markers as MVPA, which may imply that the accumulation of total PA over the day is as important as achieving the intensity of MVPA.

Mechanical stress regulates insulin sensitivity through integrin-dependent control of insulin receptor localization

Kim et al. show that insulin signaling in Drosophila adipocytes is abolished in the absence of physical activity and mechanical stress. The insulin receptor and downstream components are recruited to the plasma membrane upon stress sensing mediated by integrins.

Insulin resistance, the failure to activate insulin signaling in the presence of ligand, leads to metabolic diseases, including type 2 diabetes. Physical activity and mechanical stress have been shown to protect against insulin resistance, but the molecular mechanisms remain unclear. Here, we address this relationship in the Drosophila larval fat body, an insulin-sensitive organ analogous to vertebrate adipose tissue and livers. We found that insulin signaling in Drosophila fat body cells is abolished in the absence of physical activity and mechanical stress even when excess insulin is present. Physical movement is required for insulin sensitivity in both intact larvae and fat bodies cultured ex vivo. Interestingly, the insulin receptor and other downstream components are recruited to the plasma membrane in response to mechanical stress, and this membrane localization is rapidly lost upon disruption of larval or tissue movement. Sensing of mechanical stimuli is mediated in part by integrins, whose activation is necessary and sufficient for mechanical stress-dependent insulin signaling. Insulin resistance develops naturally during the transition from the active larval stage to the immotile pupal stage, suggesting that regulation of insulin sensitivity by mechanical stress may help coordinate developmental programming with metabolism.

Effects of Exercise Training Alone on Depot-Specific Body Fat Stores in Youth: Review of Recent Literature

The prevalence of childhood obesity has increased at an alarming rate. The increased obesity rate in pediatrics parallels the increased risks for developing metabolic abnormalities, such as insulin resistance, type 2 diabetes, and nonalcoholic fatty liver disease. In particular, the strong relationship between obesity and such health consequences is well explained by the excessive accumulation of depot-specific body adiposity, such as visceral adipose tissue, intrahepatic lipid content, intermuscular adipose tissue, and/or intramyocellular lipid content. Limited evidence suggests that both aerobic and resistance exercise alone, independent of weight loss, can be an effective therapeutic strategy for improving risk markers of metabolic abnormalities as well as inducing positive changes in depot-specific body adiposity in obese children and adolescents. However, the independent role of exercise alone (without calorie restriction) in body fat distribution is still unclear, and the results are less conclusive in pediatrics. In this brief review, the effects of aerobic and resistance exercise on depot-specific body adiposity changes in children and adolescents are discussed.

Natural products, an important resource for discovery of multitarget drugs and functional food for regulation of hepatic glucose metabolism

Imbalanced hepatic glucose homeostasis is one of the critical pathologic events in the development of metabolic syndromes (MSs). Therefore, regulation of imbalanced hepatic glucose homeostasis is important in drug development for MS treatment. In this review, we discuss the major targets that regulate hepatic glucose homeostasis in human physiologic and pathophysiologic processes, involving hepatic glucose uptake, glycolysis and glycogen synthesis, and summarize their changes in MSs. Recent literature suggests the necessity of multitarget drugs in the management of MS disorder for regulation of imbalanced glucose homeostasis in both experimental models and MS patients. Here, we highlight the potential bioactive compounds from natural products with medicinal or health care values, and focus on polypharmacologic and multitarget natural products with effects on various signaling pathways in hepatic glucose metabolism. This review shows the advantage and feasibility of discovering multicompound-multitarget drugs from natural products, and providing a new perspective of ways on drug and functional food development for MSs.

Nutritional Programming Effects on Development of Metabolic Disorders in Later Life

Developmental programming resulting from maternal malnutrition can lead to an increased risk of metabolic disorders such as obesity, insulin resistance, type 2 diabetes and cardiovascular disorders in the offspring in later life. Furthermore, many conditions linked with developmental programming are also known to be associated with the aging process. This review summarizes the available evidence about the molecular mechanisms underlying these effects, with the potential to identify novel areas of therapeutic intervention. This could also lead to the discovery of new treatment options for improved patient outcomes.

Physical activity, mediating factors and risk of colon cancer: insights into adiposity and circulating biomarkers from the EPIC cohort

Background

There is convincing evidence that high physical activity lowers the risk of colon cancer; however, the underlying biological mechanisms remain largely unknown. We aimed to determine the extent to which body fatness and biomarkers of various biologically plausible pathways account for the association between physical activity and colon cancer.

Methods

We conducted a nested case-control study in a cohort of 519 978 men and women aged 25 to 70 years followed from 1992 to 2003. A total of 713 incident colon cancer cases were matched, using risk-set sampling, to 713 controls on age, sex, study centre, fasting status and hormonal therapy use. The amount of total physical activity during the past year was expressed in metabolic equivalent of task [MET]-h/week. Anthropometric measurements and blood samples were collected at study baseline.

Results

High physical activity was associated with a lower risk of colon cancer: relative risk ≥91 MET-h/week vs <91 MET-h/week = 0.75 [95% confidence interval (CI): 0.57 to 0.96]. In mediation analyses, this association was accounted for by waist circumference: proportion explained effect (PEE) = 17%; CI: 4% to 52%; and the biomarkers soluble leptin receptor (sOB-R): PEE = 15%; 95% CI: 1% to 50% and 5-hydroxyvitamin D (25[OH]D): PEE = 30%; 95% CI: 12% to 88%. In combination, these factors explained 45% (95% CI: 20% to 125%) of the association. Beyond waist circumference, sOB-R and 25[OH]D additionally explained 10% (95% CI: 1%; 56%) and 23% (95% CI: 6%; 111%) of the association, respectively.

Conclusions

Promoting physical activity, particularly outdoors, and maintaining metabolic health and adequate vitamin D levels could represent a promising strategy for colon cancer prevention.

The effect of combined diet and exercise intervention on body weight and the serum GPIHBP1 concentration in overweight/obese middle-aged women

BACKGROUND

The relationship between the effects of diet and exercise intervention and the body weight associated with the serum lipoprotein lipase (LPL), hepatic triglyceride lipase (HTGL) and glycosylphosphatidylinositol anchored high density lipoprotein binding protein 1 (GPIHBP1) concentrations has not been elucidated.

METHODS

Sixty-six overweight/obese middle aged women were assigned to the diet and exercise intervention for 4months. They were divided into 2 groups followed by the body mass index (BMI) decreased >3% (n=41) and <3% (n=25). Serum lipids, lipoproteins and the LPL, HTGL, GPIHBP1 concentrations were determined.

RESULTS

The cases in which the BMI decreased >3% exhibited significant improvement of diagnostic markers compared with the cases with <3% decrease after the intervention. The LPL concentration did not significantly change, but GPIHBP1 increased significantly after the intervention. The increased GPIHBP1 was significantly associated with decreased body weight. Multiple regression analysis indicated a strong association between GPIHBP1 and percentage of body fat.

CONCLUSIONS

The diet and exercise intervention significantly increased the serum GPIHBP1 concentration in association with a decrease in body weight and percentage of body fat. These results suggest that GPIHBP1 is a better marker for body weight decrease than LPL.

Voluntary running of defined distances reduces body adiposity and its associated inflammation in C57BL/6 mice fed a high-fat diet

This study investigated the effect of voluntary running of defined distances on body adiposity in male C57BL/6 mice fed a high-fat diet. Mice were assigned to 6 groups and fed a standard AIN93G diet (sedentary) or a modified high-fat AIN93G diet (sedentary; unrestricted running; or 75%, 50%, or 25% of unrestricted running) for 12 weeks. The average running distance was 8.3, 6.3, 4.2, and 2.1 km/day for the unrestricted, 75%, 50%, and 25% of unrestricted runners, respectively. Body adiposity was 46% higher in sedentary mice when fed the high-fat diet instead of the standard diet. Running decreased adiposity in mice fed the high-fat diet in a dose-dependent manner but with no significant difference between sedentary mice and those running 2.1 km/day. In sedentary mice, the high-fat instead of the standard diet increased insulin resistance, hepatic triacylglycerides, and adipose and plasma concentrations of leptin and monocyte chemotactic protein-1 (MCP-1). Running reduced these variables in a dose-dependent manner. Adipose adiponectin was lowest in sedentary mice fed the high-fat diet; running raised adiponectin in both adipose tissue and plasma. Running 8.3 and 6.3 km/day had the greatest, but similar, effects on the aforementioned variables. Running 2.1 km/day did not affect these variables except, when compared with sedentariness, it significantly decreased MCP-1. The findings showed that running 6.3 kg/day was optimal for reducing adiposity and associated inflammation that was increased in mice by feeding a high-fat diet. The findings suggest that voluntary running of defined distances may counteract the obesogenic effects of a high-fat diet.

Physical Activity and Abnormal Blood Glucose Among Healthy Weight Adults

INTRODUCTION

Physical activity has been linked to prevention and treatment of prediabetes and diabetes in overweight and obese adults. This study examines the relationship between low physical activity levels and risk of abnormal blood glucose (prediabetes or undiagnosed diabetes) in healthy weight adults.

METHODS

Data from the 2014 Health Survey for England were analyzed in July 2016, focusing on adults with a BMI ≥18.5 and <25 who had never been diagnosed with diabetes (N=1,153). Abnormal blood glucose was defined as hemoglobin A1c ≥5.7. Physical activity was measured through the International Physical Activity Questionnaire. Bivariate analyses and Poisson models were conducted on the effect of physical activity on abnormal blood glucose, controlling for age, sex, waist to hip ratio, sitting time, age X physical activity interaction, sex X physical activity, and race.

RESULTS

Abnormal blood glucose was detected in 23.7% of individuals with low activity levels, 14.8% of those with medium activity levels, and 12.2% of those with high activity levels (p<0.003). Similarly, 25.4% of inactive individuals (physically active for <30 minutes per week) were more likely to have abnormal blood glucose levels than active individuals (13.4%, p<0.0001). Higher physical activity was associated with a lower likelihood of abnormal blood glucose in an adjusted Poisson regression.

CONCLUSIONS

Among healthy weight adults, low physical activity levels are significantly associated with abnormal blood glucose (prediabetes and undiagnosed diabetes). These findings suggest that healthy weight individuals may benefit from physical exercise.

Weight cycling and the subsequent onset of type 2 diabetes mellitus: 10-year cohort studies in urban and rural Japan

OBJECTIVE

To investigate how weight cycling (gaining and losing weight) affects the risk of diabetes.

DESIGN

Cohort studies.

SETTING

Primary healthcare in urban and rural Japan.

PARTICIPANTS

20 708 urban and 9670 rural residents.

PRIMARY OUTCOME MEASURES

ORs for diabetes in those with weight loss, weight loss-gain, stable weight, weight gain-loss and weight gain over 10 years. Weight gain and loss were defined as a change of more than ±4% from baseline weight.

RESULTS

In the urban region, the ORs relative to the stable group for the loss-gain and gain-loss groups were 0.63 (95% CI 0.45 to 0.89) and 0.51 (95% CI 0.32 to 0.82) for men and 0.72 (95% CI 0.39 to 1.34) and 1.05 (95% CI 0.57 to 1.95) for women. In the rural region, they were 1.58 (95% CI 0.78 to 3.17) and 0.44 (95% CI 0.15 to 1.29) in men and 0.41 (95% CI 0.12 to 1.44) and 0.77 (95% CI 0.28 to 2.14) in women. The ORs for an increase in weight between 5 and 10 kg from the age of 20 years were 1.54 (95% CI 1.03 to 2.30) in men and 0.96 (95% CI 0.55 to 1.65) in women.

CONCLUSIONS

In Japan, weight cycling was associated with a significant reduction in the risk of diabetes for men from urban regions. The associations were unclear for women from urban regions and both men and women from rural regions. These results differ from those in Western studies, probably because of differences in diet, insulin secretion and sensitivity and weight-consciousness.

Effects of Exergaming on Physical Activity in Overweight Individuals

BACKGROUND

The majority of patients with overweight and type 2 diabetes show insufficient levels of daily physical activity (PA) and usually are among the least likely to engage in or adhere to any form of generic PA. Active video games (exergames) may be a solution to motivate these individuals to overcome their sedentary lifestyle.

OBJECTIVES

This systematic review was conducted to review the current evidence for the effectiveness of exergaming in overweight and type 2 diabetes mellitus and thus to evaluate the suitability of these games to be used as tools for exercise promotion that meet current PA guidelines.

METHODS

We searched electronic bibliographic databases (PubMed, Embase, Web of Science, OpenGrey, and the Cochrane Central Register of Controlled Trials) up to March 2015. Randomized controlled trials (RCT) and cross-sectional studies published in English in a peer-reviewed journal and analyzing the effects of exergames on objectively measured intensity parameters of PA in overweight (body mass index [BMI] ≥25 kg/m(2)) adults (mean age ≥18 years) with and without type 2 diabetes were included. Study selection, data extraction, and quality assessment were performed independently by two review authors. Primary outcomes included changes in oxygen uptake (VO2), energy expenditure (EE), heart rate (HR), or activity counts. Secondary outcomes were enjoyment of treatment, exercise adherence, ratings of perceived exertion (RPE), changes in body composition, and changes in blood parameters (serum glucose, long-term blood glucose, blood cholesterol, triglycerides, or serum lactate).

RESULTS

Of 2845 records, 14 publications (11 studies) met the inclusion criteria. All included studies (ten experimental, cross-sectional laboratory studies and one RCT) were able to show increases in either VO2, EE, HR, or activity counts. However, effects of exergaming in terms of changes in these intensity parameters varied significantly between game modes and consoles as well as because of the vastly differing durations of exergame activity between studies. One of the included studies had a low risk of bias, and three had a high risk of bias; seven studies had an unclear risk of bias as the study description was insufficient. No studies were found investigating the changes in objectively measured PA intensity parameters in patients with type 2 diabetes.

CONCLUSION

This review suggests that exergames are able to increase PA among overweight individuals. However, the inconsistent results and the overall poor or moderate methodological quality do not permit judgment on whether exergames are suitable to meet PA guidelines in this target group. The lack of research regarding the effects of exergames in type 2 diabetes indicates a great need for future research.

Integrated Social- and Neurocognitive Model of Physical Activity Behavior in Older Adults with Metabolic Disease

BACKGROUND

Despite the proven benefits of physical activity to treat and prevent metabolic diseases, such as diabetes (T2D) and metabolic syndrome (MetS), most individuals with metabolic disease do not meet physical activity (PA) recommendations. PA is a complex behavior requiring substantial motivational and cognitive resources. The purpose of this study was to examine social cognitive and neuropsychological determinants of PA behavior in older adults with T2D and MetS. The hypothesized model theorized that baseline self-regulatory strategy use and cognitive function would indirectly influence PA through self-efficacy.

METHODS

Older adults with T2D or MetS (M age = 61.8 ± 6.4) completed either an 8-week physical activity intervention (n = 58) or an online metabolic health education course (n = 58) and a follow-up at 6 months. Measures included cognitive function, self-efficacy, self-regulatory strategy use, and PA.

RESULTS

The data partially supported the hypothesized model (χ2 = 158.535(131), p > .05, comparative fit index = .96, root mean square error of approximation = .04, standardized root mean square residual = .06) with self-regulatory strategy use directly predicting self-efficacy (β = .33, p < .05), which in turn predicted PA (β = .21, p < .05). Performance on various cognitive function tasks predicted PA directly and indirectly via self-efficacy. Baseline physical activity (β = .62, p < .01) and intervention group assignment via self-efficacy (β = -.20, p < .05) predicted follow-up PA. The model accounted for 54.4 % of the variance in PA at month 6.

CONCLUSIONS

Findings partially support the hypothesized model and indicate that select cognitive functions (i.e., working memory, inhibition, attention, and task-switching) predicted PA behavior 6 months later. Future research warrants the development of interventions targeting cognitive function, self-regulatory skill development, and self-efficacy enhancement.

TRIAL REGISTRATION NUMBER

The trial was registered with the clinical trial number NCT01790724.

Lipoprotein lipase activity does not predict very low-density lipoprotein-triglyceride fatty acid oxidation during exercise

Exercise lowers plasma triglyceride levels, but the physiological mechanisms remain not fully elucidated. Lipoprotein lipase (LPL) is a key enzyme in facilitating fatty acid uptake from lipoproteins. As exercise increases the efficiency of very low-density lipoprotein-triglyceride (VLDL-TG) oxidation, we hypothesized that muscle LPL activity would be a rate-limiting step and predict VLDL-TG Fatty acids oxidation during exercise. Sixteen healthy, lean subjects (eight men and eight women) were examined before and during an acute exercise bout (90 minutes at 50% of VO2-max). Heparin-releasable LPL activity was measured in muscle and adipose tissue biopsies. Breath ¹⁴ CO₂ was measured after a primed-constant infusion of ex vivo labeled [¹⁴ C]-triolein VLDL-TG. Fractional VLDL-TG storage was measured in adipose tissue biopsies. Exercise did not affect muscle LPL activity (P=.30). No association was observed between muscle LPL activity and VLDL-TG oxidation, neither in the basal state (P=.17) nor during exercise (P=.83). Exercise did not affect upper body or lower body adipose tissue LPL activity (both P=.92). The basal adipose tissue fractional VLDL-TG storage (abdominal.13%±9%; femoral 17%±10% (P=.18)) was not associated with upper body (P=.56) or lower body (P=.44) subcutaneous adipose tissue LPL activity. Muscle LPL activity does not predict VLDL-TG oxidation during rest or exercise. In addition, adipose tissue LPL activity was not associated with VLDL-TG storage during rest. This suggests that LPL activity is present in excess of what is required to facilitate lipid uptake for oxidation during both rest and exercise.

Mobile Exergaming for Health-Effects of a serious game application for smartphones on physical activity and exercise adherence in type 2 diabetes mellitus-study protocol for a randomized controlled trial

Background

Exergaming is a novel approach to increase motivation for regular physical activity (PA) among sedentary individuals such as patients with type 2 diabetes mellitus (T2DM). Because existing exergames do not offer fitness-level adjusted, individualized workouts and are normally stationary (TV bound), thus not enabling PA anywhere and at any time, we developed a smartphone-based, game-like software application (MOBIGAME) specifically designed for middle-aged T2DM patients to induce a healthier, more active lifestyle as part of successful T2DM treatment and management. In a randomized controlled trial we aim to examine whether our smartphone-based game application can lead to increases in daily PA in T2DM patients that are persistent in the mid to long term and whether these increases are greater than those in a control group.

Methods

This study is designed as a randomized controlled trial. We plan to recruit a total of 42 T2DM patients [45-70 years, body mass index (BMI) ≥25 kg/m², low daily PA, regular smartphone use].

The experimental intervention (duration 24 weeks) includes individualized multidimensional home-based exercise and daily PA promotion administered through MOBIGAME. The control intervention consists of a one-time standard lifestyle counseling including the promotion of baseline activities.

The primary outcome is daily PA measured as steps per day. Secondary outcome is exercise adherence measured via the usage data from the participants’ smartphones (experimental intervention) and as self-recorded exercise log entries (control intervention).

We will test the hypothesis that there will be differences between the experimental and control group with respect to post-interventional daily PA (as well as all other outcomes) using analysis of covariance. For each analysis, an estimate (with 95% confidence interval) of the difference in outcome between both groups will be reported.

Discussion

This research will investigate the effectiveness of a novel smartphone-based, game-like software application to be used as a way to promote regular daily PA among inactive T2DM patients. The results of this trial may have important implications for future PA-promoting interventions and provide relevant information for the general transferability of such applications to be used as part of the treatment in other chronic diseases.

Trial registration

ClinicalTrials.gov, NCT02657018. Registered on 11 January 2016. Last status update on 3 May 2016. Kofam.ch, SNCTP-number:SNCTP000001652. Registered on 21 January 2016.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-1853-3) contains supplementary material, which is available to authorized users.

The Association between Leisure-Time Physical Activity and Risk of Undetected Prediabetes

Aims. The purpose of the study was to assess the effects of leisure-time physical activity on undetected prediabetes. Methods. Data from the National Health and Nutrition Examination Survey 2007-2012 were used in our analyses. Logistic regression was conducted to estimate the odds ratios (ORs) with 95% confidence intervals (CIs) of prediabetes associated with leisure-time physical activity. Results. A total of 8204 subjects were eligible for our analyses. For all subjects, high level of total leisure-time physical activity (OR = 0.78, 95% CI: 0.66, 0.94) and low level of vigorous leisure-time physical activity (OR = 0.72, 95% CI: 0.58, 0.90) were inversely associated with the risk of prediabetes in multivariate-adjusted model. For subjects under 45 years of age, high level of total leisure-time physical activity (OR = 0.78, 95% CI: 0.61, 0.99) and low (OR = 0.61, 95% CI: 0.45, 0.83) and high (OR = 0.72, 95% CI: 0.53, 1.00) level of vigorous leisure-time physical activity were associated with a decreased risk of prediabetes. In the 45 to 65 age group, only high level of total leisure-time physical activity (OR = 0.73, 95% CI: 0.57, 0.95) had protective effect on prediabetes. Conclusions. Leisure-time physical activity may be associated with a decreased risk of prediabetes.

Effects of a Community-Based Healthy Lifestyle Intervention Program (Co-HELP) among Adults with Prediabetes in a Developing Country: A Quasi-Experimental Study

BACKGROUND

The prevalence of type 2 diabetes among Malaysian adults has increased by more than two folds over the past two decades. Strategies to collaborate with the existing community partners may become a promising channel for wide-scale dissemination of diabetes prevention in the country. The objectives of this study were to determine the effects of community-based lifestyle interventions delivered to adults with prediabetes and their health-related quality of life as compared to the usual care group.

METHODS

This was a quasi-experimental study conducted in two sub-urban communities in Seremban, Malaysia. A total of 268 participants with prediabetes aged between 18 to 65 years old were assigned to either the community-based lifestyle intervention (Co-HELP) (n = 122) or the usual care (n = 146) groups. The Co-HELP program was delivered in partnership with the existing community volunteers to incorporate diet, physical activity, and behaviour modification strategies. Participants in the Co-HELP group received twelve group-based sessions and two individual counselling to reinforce behavioural change. Participants in the usual care group received standard health education from primary health providers in the clinic setting. Primary outcomes were fasting blood glucose, 2-hour plasma glucose, and HbA1C. Secondary outcomes included weight, BMI, waist circumference, total cholesterol, triglyceride, LDL cholesterol, HDL cholesterol, systolic and diastolic blood pressure, physical activity, diet, and health-related quality of life (HRQOL).

RESULTS

An intention-to-treat analysis of between-groups at 12-month (mean difference, 95% CI) revealed that the Co-HELP participants' mean fasting plasma glucose reduced by -0.40 mmol/l (-0.51 to -0.28, p<0.001), 2-hour post glucose by -0.58 mmol/l (-0.91 to -0.24, p<0.001), HbA1C by -0.24% (-0.34 to -0.15, p<0.001), diastolic blood pressure by -2.63 mmHg (-3.79 to -1.48, p<0.01), and waist circumference by -2.44 cm (-4.75 to -0.12, p<0.05) whereas HDL cholesterol increased by 0.12 mmol/l (0.05 to 0.13, p<0.01), compared to the usual care group. Significant improvements were also found in HRQOL for both physical component (PCS) by 6.51 points (5.21 to 7.80, p<0.001) and mental component (MCS) by 7.79 points (6.44 to 9.14, p<0.001). Greater proportion of participants from the Co-HELP group met the clinical recommended target of 5% or more weight loss from the initial weight (24.6% vs 3.4%, p<0.001) and physical activity of >600 METS/min/wk (60.7% vs 32.2%, p<0.001) compared to the usual care group.

CONCLUSIONS

This study provides evidence that a culturally adapted diabetes prevention program can be implemented in the community setting, with reduction of several diabetes risk factors and improvement of HRQOL. Collaboration with existing community partners demonstrated a promising channel for the wide-scale dissemination of diabetes prevention at the community level. Further studies are required to determine whether similar outcomes could be achieved in communities with different socioeconomic backgrounds and geographical areas.

TRIAL REGISTRATION

IRCT201104106163N1.

Physical activity and type 2 diabetes mellitus risk: population studies review

Physical activity is one of the most important components of a healthy lifestyle. Regular physical activity helps to maintain normal blood glucose levels and reduce the risk of type 2 diabetes mellitus. This review presents population studies investigating physical activity as a factor for type 2 diabetes mellitus risk. A search using the keywords ‘physical activity’, ‘type 2 diabetes mellitus’ and ‘risk’ identified more than 40 relevant original studies and meta-analyses, which are presented in this review. Different types of physical activity have positive protective effects on type 2 diabetes mellitus risk and reduce the risk of death in patients with type 2 diabetes mellitus.

Lifestyle Approaches and Glucose Intolerance

Glucose intolerance is a global health concern that encompasses glucose metabolism abnormalities such as impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and type 2 diabetes (T2D). There is an urgent need to focus on the prediabetes (ie, IGT and IFG) stage before the disease actually occurs. The progression from IGT to T2D can be prevented or delayed by modifying the lifestyles in high-risk individuals, and these health benefits are well documented in various ethnicities with prediabetes across the world. Specifically, consuming a healthy diet (high in polyunsaturated fatty acids, monounsaturated fatty acids, fiber, and whole grains), losing weight, quitting smoking, consuming alcohol in moderation, and increasing physical activity can improve glucose tolerance and reduce the risk of T2D. Also, pharmacological agents and botanicals can be used to manage glucose intolerance if the implementation of lifestyle changes is challenging. Pharmacological treatments have been successful in managing glucose intolerance; however, they have adverse effects. Also, more research on botanicals is warranted before a definitive recommendation can be made for their use in managing glucose intolerance. To make progress on this worldwide problem, efforts are needed to improve the awareness of prediabetes, increase promotion of healthy behaviors, and improve the availability of evidence-based lifestyle intervention programs to the community.

Comparisons of physical activity, adipokines, vitamin D status and dietary vitamin D intake among adolescents

BACKGROUND

Considering that lifestyle and diet are key factors responsible for the increases in adiposity in youth, it is important to understand how vitamin D, adipokines and markers of glucose metabolism are related to physical activity level (PAL) during growth. The present study aimed to investigate associations between physical activity level, adiponectin/leptin ratio, vitamin D status and dietary vitamin D intake among adolescents.

METHODS

A cross-sectional study was conducted with adolescents aged 14-18 years old who were living in São Paulo, Brazil. Serum 25 hydroxyvitamin D [25(OH)D], adiponectin (A), leptin (L), glucose and insulin were obtained after 12 h of fasting. Dietary calcium and vitamin D intake were measured by 24-h food record, as repeated in 62.6% of the sample. PAL was measured by the International Physical Activity Questionnaire (IPAQ). Pearson's chi-square test, Pearson correlation and linear regression analysis were performed.

RESULTS

A total of 198 subjects, mean (SD) age 16.3 (1.4) years, 51% male, were enrolled in the study. Some 9% of participants were sedentary, 22% were insufficiently active (IA), 51% were active and 18% were very active (VA). The A/L ratio was lower among sedentary/IA subjects [2.2 (4.0) versus 5.6 (12.3); P = 0.01] compared to active/VA subjects. PAL was not associated with vitamin D status or markers of glucose metabolism. Serum 25(OH)D positively associated with vitamin D intake, after adjusting for sex, sun exposure and season of the year in regression analysis (partial r² =0.026, P = 0.02).

CONCLUSIONS

Low PAL was associated with a lower A/L ratio. Vitamin D status was not associated with sun exposure habits, although it was positively correlated with vitamin D intake.

Physical Activity: The Role of Physical Activity and Fitness in the Prevention and Management of Type 2 Diabetes Mellitus

More than 18 million people in the United States are estimated to have type 2 diabetes mellitus (T2DM). The prevalence of coronary heart disease has been estimated to be as high as 55% in adult diabetics, and cardiovascular disease (CVD) is responsible for at least two thirds of deaths in persons with T2DM. The metabolic syndrome, a clustering of interrelated risk factors, is predictive of T2DM and CVD and prevalent in the T2DM population. Increased aerobic fitness and/or physical activity (3 hours per week moderate activity and/or 1 hour per week vigorous activity) have been demonstrated to be protective of metabolic syndrome. Regular moderate to vigorous physical activity (150 minutes per week moderate activity and/or 90 minutes per week vigorous activity) has been shown to reduce the risk of developing T2DM, even in high-risk individuals. Sedentary behaviors such as television watching are associated with increased risk for T2DM independent of diet and physical activity levels. Glycemic control is related more to exercise intensity than volume. Exercise should be performed at least 3 days per week, with no more than 2 days between exercise bouts. Long-term weight loss may require 7 hours per week of moderate to vigorous exercise. Strength training, alone or in combination with regular aerobic exercise, has been shown to improve glycemic control, hypertension, and other T2DM-related risk factors. Unless specifically contraindicated, strength training is safe for persons with T2DM. The American Diabetes Association now recommends 150 minutes per week of moderate activity and/or 90 minutes per week of vigorous aerobic activity and strength training 3 days per week as part of a program to prevent or manage T2DM. Guidelines for preparticipation screening and consideration for specific conditions are also presented.

Strength Training Prevents Hyperinsulinemia, Insulin Resistance, and Inflammation Independent of Weight Loss in Fructose-Fed Animals

The aim of this study was to compare the effects of aerobic, strength, and combined training on metabolic disorders induced by a fructose-rich diet. Wistar rats (120 days old) were randomized into five groups (n = 8-14): C (control diet and sedentary), F (fed the fructose-rich diet and sedentary), FA (fed the fructose-rich diet and subject to aerobic exercise), FS (fed the fructose-rich diet and subject to strength exercise), and FAS (fed the fructose-rich diet and subject to combined aerobic and strength exercises). After the 8-week experiment, glucose homeostasis, blood biochemistry, tissue triglycerides, and inflammation were evaluated and analyzed. The strength protocol exerted greater effects on glucose homeostasis, insulin sensitivity, and liver lipid contents than other protocols (all P < 0.05). All three exercise protocols induced a remarkable reduction in inflammation, tissue triglyceride content, and inflammatory pathways, which was achieved through c-Jun NH2-terminal kinase (JNK) phosphorylation and factor nuclear kappa B (NFkB) activation in both the liver and the muscle. Our data suggest that strength training reduced the severity of most of the metabolic disorders induced by a fructose-rich diet and could be the most effective strategy to prevent or treat fructose-induced metabolic diseases.

Outcomes of a community-based weight management programme for morbidly obese populations

BACKGROUND

Morbid obesity is an ongoing concern worldwide. There is a paucity of research reporting primary care outcomes focussed on complex and morbidly obese populations. The National Institute for Health and Care Excellence (NICE) recommends a specialist, multidisciplinary weight management team for the successful management of such populations. This is the first service evaluation reporting both primary (weight change) and secondary [body mass index (BMI), waist circumference, physical activity levels, fruit and vegetable intake, Rosenberg self-esteem score] outcomes in these patients.

METHODS

The present study comprised a prospective observational study of a cohort data set for patients (n = 288) attending their 3-month and 6-month (n = 115) assessment appointments at a specialist community weight management programme.

RESULTS

Patients had a mean (SD) initial BMI of 45.5 (6.6) kg m^- ²; 66% were females. Over 80% of patients attending the service lost some weight by 3 months. Average absolute weight loss was 4.11 (4.95) kg at 3 months and 6.30 (8.41) kg at 6 months, equating to 3.28% (3.82%) and 4.90% (6.26%), respectively, demonstrating a statistically significant weight change at both time points (P < 0.001). This meets NICE best practice guidelines for the commissioning of services leading to a minimum of 3% average weight loss, with at least 30% of patients losing at ≥5% of their initial weight. Waist measurement and BMI were reduced significantly at 3 months. Improvements were also seen in physical activity levels, fruit and vegetable consumption, and self-esteem levels (P < 0.001).

CONCLUSIONS

This service was successful in aiding weight loss in morbidly obese populations. The findings of the present study support the view that weight-loss targets of 3% are realistic.

A Single Dose of Prednisolone as a Modulator of Undercarboxylated Osteocalcin and Insulin Sensitivity Post-Exercise in Healthy Young Men: A Study Protocol

BACKGROUND

Undercarboxylated osteocalcin (ucOC) increases insulin sensitivity in mice. In humans, data are supportive, but the studies are mostly cross-sectional. Exercise increases whole-body insulin sensitivity, in part via ucOC, while acute glucocorticoid treatment suppresses ucOC in humans and mice.

OBJECTIVES

A single dose of prednisolone reduces the rise in ucOC produced by exercise, which partly accounts for the failed increase in insulin sensitivity following exercise.

METHODS

Healthy young men (n=12) aged 18 to 40 years will be recruited. Initial assessments will include analysis of fasting blood, body composition, aerobic power (VO2peak), and peak heart rate. Participants will then be randomly allocated, double-blind, to a single dose of 20 mg of prednisolone or placebo. The two experimental trials will involve 30 minutes of interval exercise (90%-95% peak heart rate), followed by 3 hours of recovery and 2 hours of euglycaemic- hyperinsulinaemic clamp (insulin clamp). Seven muscle biopsies and blood samples will be obtained at rest, following exercise and post-insulin clamps.

RESULTS

The study is funded by the National Heart Foundation of Australia and Victoria University. Enrollment has already commenced and data collection will be completed in 2016.

CONCLUSION

If the hypothesis is confirmed, the study will provide novel insights into the potential role of ucOC in insulin sensitivity in human subjects and will elucidate pathways involved in exercise-induced insulin sensitivity.

[Prevention of cardiovascular diseases through sport and physical activity: A question of intensity?]

Coronary artery disease is the leading cause of death worldwide. A sedentary lifestyle accounts for 9% of premature mortality and creates a substantial health economic burden. Measurement of physical activity in daily practice refers to metabolic equivalent tasks and assessment of cardiopulmonary fitness to measurements of peak oxygen uptake during ergometry, which can be used to classify an individual's physical activity and maximum exercise capacity. Physical activity is a multifunctional intervention tool in prevention, which exerts its effects on multiple biochemical pathways, in contrast to conventional drug therapy. These changes reduce cardiovascular morbidity and mortality. Moderate physical exercise reduces blood pressure, improves insulin sensitivity and dyslipidemia, improves body composition and enhances weight reduction. Exercise of higher intensity seems to have superior effects compared to moderate intensity training; however, the training volume also seems to be important, as negative effects of long-term intensive training have been reported, e.g. atrial fibrillation or coronary sclerosis. Overall, exercise training has a major role in primary prevention of cardiovascular disease but seems to have a maximum threshold for benefit, which may be exceeded by some individuals.

A role for exercise after bariatric surgery?

Obesity predisposes an individual to develop numerous comorbidities, including type 2 diabetes, and represents a major healthcare issue in many countries worldwide. Bariatric surgery can be an effective treatment option, resulting in profound weight loss and improvements in metabolic health; however, not all patients achieve similar weight loss or metabolic improvements. Exercise is an excellent way to improve health, with well-characterized physiological and psychological benefits. In the present paper we review the evidence to determine whether there may be a role for exercise as a complementary adjunct therapy to bariatric surgery. Objectively measured physical activity data indicate that most patients who undergo bariatric surgery do not exercise enough to reap the health benefits of exercise. While there is a dearth of data on the effects of exercise on weight loss and weight loss maintenance after surgery, evidence from studies of caloric restriction and exercise suggest that similar adjunctive benefits may be extended to patients who perform exercise after bariatric surgery. Recent evidence from exercise interventions after bariatric surgery suggests that exercise may provide further improvements in metabolic health compared with surgery-induced weight loss alone. Additional randomized controlled exercise trials are now needed as the next step to more clearly define the potential for exercise to provide additional health benefits after bariatric surgery. This valuable evidence will inform clinical practice regarding much-needed guidelines for exercise after bariatric surgery.

Effect of short term aerobic exercise on fasting and postprandial lipoprotein subfractions in healthy sedentary men

Background

Our goal was to investigate the effect of short term exercise on fasting and postprandial lipoprotein profile.

Methods

Healthy sedentary men exercised 20 min for four days. The intensity of exercise was modulated to maintain 75–80 % of a calculated HRmax. Before and after the exercise program, fasting and postprandial (4 h after standard meal) concentrations of lipoprotein subfractions were measured by an electrophoresis in polyacrylamide gel and total concentrations of TAG, LDL and HDL by enzymatic colorimetric method. After 2 days of rest, fasting and postprandial concentrations of lipoprotein fractions and subfractions were measured to determine a persistency of a changes in the lipoprotein profile.

Results

4 days of physical exercise led to statistically significant decrease of concentration of triacylglycerol in fasting (76.29 ± 20.07, 53.92 ± 10.90, p < 0.05) and postprandial state (139.06 ± 23.72, 96.55 ± 25.21, p < 0.05) VLDL in fasting (21.88 ± 3.87, 18.00 ± 3.93, p < 0.05) and postprandial state (23.88 ± 3.52, 19.25 ± 3.62, p < 0.05), total cholesterol in fasting (162.26 ± 23.38, 148.91 ± 17.72, p < 0.05) and postprandial state (163.73 ± 23.02, 150.08 ± 18.11, p < 0.05). Atherogenic medium LDL decreased also in fasting (9.89 ± 3.27, 6.22 ± 2.55, p < 0.001) and postprandial state (8.88 ± 6.51, 6.88 ± 5.57, p < 0.001). However decrease of large IDL (25.38 ± 3.54, 23.88 ± 3.91, p < 0.05) and large LDL particles (42.89 ± 11.40, 38.67 ± 9.30) was observed only in postprandial state. Total HDL concentration remained unchanged but we observed statistically significant decrease of small HDL particles in fasting (6.11 ± 2.89, 4.22, p < 0.05) and postprandial state (6.44 ± 3.21, 4.56 ± 1.33, p < 0.05). Concentration of these particles are associated with progression of atherosclerosis. All changes of fasting and postprandial lipoprotein profile disappeared after 2 days of rest.

Conclusion

Just 4 daily settings of 20 min of physical exercise can lead to significant positive changes of fasting and postprandial lipoprotein profile.

Morning Circadian Misalignment during Short Sleep Duration Impacts Insulin Sensitivity

Short sleep duration and circadian misalignment are hypothesized to causally contribute to health problems including obesity, diabetes, metabolic syndrome, heart disease, mood disorders, cognitive impairment, and accidents. Here, we investigated the influence of morning circadian misalignment induced by an imposed short nighttime sleep schedule on impaired insulin sensitivity, a precursor to diabetes. Imposed short sleep duration resulted in morning wakefulness occurring during the biological night (i.e., circadian misalignment)-a time when endogenous melatonin levels were still high indicating the internal circadian clock was still promoting sleep and related functions. We show the longer melatonin levels remained high after wake time, insulin sensitivity worsened. Overall, we find a simulated 5-day work week of 5-hr-per-night sleep opportunities and ad libitum food intake resulted in ∼20% reduced oral and intravenous insulin sensitivity in otherwise healthy men and women. Reduced insulin sensitivity was compensated by an increased insulin response to glucose, which may reflect an initial physiological adaptation to maintain normal blood sugar levels during sleep loss. Furthermore, we find that transitioning from the imposed short sleep schedule to 9-hr sleep opportunities for 3 days restored oral insulin sensitivity to baseline, but 5 days with 9-hr sleep opportunities was insufficient to restore intravenous insulin sensitivity to baseline. These findings indicate morning wakefulness and eating during the biological night is a novel mechanism by which short sleep duration contributes to metabolic dysregulation and suggests food intake during the biological night may contribute to other health problems associated with short sleep duration.

Effects of Light Intensity Activity on CVD Risk Factors: A Systematic Review of Intervention Studies

The effects of light intensity physical activity (LIPA) on cardiovascular disease (CVD) risk factors remain to be established. This review summarizes the effects of LIPA on CVD risk factors and CVD-related markers in adults. A systematic search of four electronic databases (PubMed, Academic Search Complete, SPORTDiscus, and CINAHL) examining LIPA and CVD risk factors (body composition, blood pressure, glucose, insulin, glycosylated hemoglobin, and lipid profile) and CVD-related markers (maximal oxygen uptake, heart rate, C-reactive protein, interleukin-6, tumor necrosis factor-alpha, and tumor necrosis factor receptors 1 and 2) published between 1970 and 2015 was performed on 15 March 2015. A total of 33 intervention studies examining the effect of LIPA on CVD risk factors and markers were included in this review. Results indicated that LIPA did not improve CVD risk factors and CVD-related markers in healthy individuals. LIPA was found to improve systolic and diastolic blood pressure in physically inactive populations with a medical condition. Reviewed studies show little support for the role of LIPA to reduce CVD risk factors. Many of the included studies were of low to fair study quality and used low doses of LIPA. Further studies are needed to establish the value of LIPA in reducing CVD risk.

The effect of hyperinsulinaemic-euglycaemic clamp and exercise on bone remodeling markers in obese men

Bone remodelling markers (BRMs) are suppressed following a glucose load and during glucose infusion. As exercise increases indices of bone health and improves glucose handling, we hypothesised that, at rest, hyperinsulinaemic-euglycaemic clamp will suppress BRMs in obese men and that exercise prior to the clamp will prevent this suppression. Eleven obese nondiabetic men (age 58.1±2.2 years, body mass index=33.1±1.4 kg m(-2) mean±s.e.m.) had a hyperinsulinaemic-euglycaemic clamp (HEC) at rest (Control) and 60 min post exercise (four bouts × 4 min cycling at 95% of hazard ratiopeak). Blood samples were analysed for serum insulin, glucose, bone formation markers, total osteocalcin (tOC) and procollagen type 1 N-terminal propeptide (P1NP), and the bone resorption marker, β-isomerised C-terminal telopeptides (β-CTx). In the control trial (no exercise), tOC, P1NP and β-CTx decreased with HEC by >10% compared with baseline (P<0.05). Fasting serum glucose, but not insulin, tended to correlate negatively with the BRMs (β range -0.57 to -0.66, p range 0.051-0.087). β-CTx, but not OC or P1NP, increased within 60 min post exercise (∼16%, P<0.01). During the post-exercise HEC, the glucose infusion rate was ∼30% higher compared with the no exercise trial. Despite this, BRMs were only suppressed to a similar extent as in the control session (10%). HEC suppressed BRMs in obese men. Exercise did not prevent this suppression of BRMs by HEC but improved glucose handling during the trial. It remains to be tested whether an exercise intervention of longer duration may be able to prevent the effect of HEC on bone remodelling.

Higher daily physical activity is associated with higher osteocalcin levels in adolescents

BACKGROUND

Exercise stimulates bone remodeling and improves insulin sensitivity (Si), even without associated weight loss. Osteocalcin (OCN), a bone-derived protein, is associated with improved Si.

PURPOSE

We examined how daily physical activity is associated with OCN and Si.

METHODS

Physical activity was measured through questionnaires completed in Minneapolis from 2010-2012. A physical activity score (PAQsum) was calculated to quantify physical activity (range 1-5). OCN and bone specific alkaline phosphatase (BAP) were measured by ELISA. Si was measured by the insulin modified frequently sampled IV glucose tolerance test.

RESULTS

The mean PAQsum value was 2.4±0.8 in 47 participants (12-17.9 years old). PAQsum was positively associated with OCN (p= 0.006). Participants with PAQsum<2 had significantly lower OCN levels compared to participants with PAQsum>2 (p<0.02). Obesity did not modify the association between PAQsum and OCN. There was no statistically significant association between PAQsum and Si or between OCN and Si, even after adjustment for percent body fat.

CONCLUSIONS

OCN is higher in more physically active individuals. More research is needed to clarify the relationship between OCN, physical activity and Si.

Impact of a brief intervention on self-regulation, self-efficacy and physical activity in older adults with type 2 diabetes

Despite evidence of the benefits of physical activity, most individuals with type 2 diabetes do not meet physical activity recommendations. The purpose of this study was to test the efficacy of a brief intervention targeting self-efficacy and self-regulation to increase physical activity in older adults with type 2 diabetes. Older adults (Mage = 61.8 ± 6.4) with type 2 diabetes or metabolic syndrome were randomized into a titrated physical activity intervention (n = 58) or an online health education course (n = 58). The intervention included walking exercise and theory-based group workshops. Self-efficacy, self-regulation and physical activity were assessed at baseline, post-intervention, and a follow-up. Results indicated a group by time effect for self-regulation [F(2,88) = 14.021, p < .001, η (2) = .24] and self-efficacy [F(12,77) = 2.322, p < .05, η (2) = .266] with increases in the intervention group. The intervention resulted in short-term increases in physical activity (d = .76, p < .01), which were partially maintained at the 6-month follow-up (d = .35, p < .01). The intervention increased short-term physical activity but was not successful at maintaining increases in physical activity. Similar intervention effects were observed in self-efficacy and self-regulation. Future research warrants adjusting intervention strategies to increase long-term change.