Predictive Roles of Basal Metabolic Rate and Muscle Mass in Lung Function among Patients with Obese Asthma: A Prospective Cohort Study

BACKGROUND

The metabolic-status-related mechanisms underlying the deterioration of the lung function in obese asthma have not been completely elucidated.

OBJECTIVE

This study aimed to investigate the basal metabolic rate (BMR) in patients with obese asthma, its association with the lung function, and its mediating role in the impact of obesity on the lung function.

METHODS

A 12-month prospective cohort study (n = 598) was conducted in a real-world setting, comparing clinical, body composition, BMR, and lung function data between patients with obese (n = 282) and non-obese (n = 316) asthma. Path model mediation analyses for the BMR and skeletal muscle mass (SMM) were conducted. We also explored the effects of the BMR on the long-term lung function in patients with asthma.

RESULTS

Patients with obese asthma exhibited greater airway obstruction, with lower FEV1 (1.99 vs. 2.29 L), FVC (3.02 vs. 3.33 L), and FEV1/FVC (65.5 vs. 68.2%) values compared to patients with non-obese asthma. The patients with obese asthma also had higher BMRs (1284.27 vs. 1210.08 kcal/d) and SMM (23.53 vs. 22.10 kg). Both the BMR and SMM mediated the relationship between obesity and the lung function spirometers (FEV1, %FEV1, FVC, %FVC, and FEV1/FVC). A higher BMR or SMM was associated with better long-term lung function.

CONCLUSIONS

Our study highlights the significance of the BMR and SMM in mediating the relationship between obesity and spirometry in patients with asthma, and in determining the long-term lung function. Interventions for obese asthma should focus not only on reducing adiposity but also on maintaining a high BMR.

Association of diabetes with coronary artery calcium in South Asian adults and other race/ethnic groups: The multi-ethnic study of atherosclerosis and the mediators of atherosclerosis in South Asians living in America study

PURPOSE

South Asian (SA) persons have increased risks for diabetes mellitus (DM) and atherosclerotic cardiovascular disease (ASCVD). We examined whether the association of DM with subclinical atherosclerosis assessed by coronary artery calcium (CAC) differs in SA versus other ethnic groups.

METHODS

We studied adults from the Multi-Ethnic Study of Atherosclerosis and the Mediators of Atherosclerosis in South Asians Living in America studies without ASCVD. CAC was examined among those normoglycemic, pre-DM and DM. Logistic regression examined pre-DM and DM with the odds of any CAC > 0 and CAC ≥ 100.

RESULTS

Among 7562 participants, CAC > 0 and CAC ≥ 100 in those with DM was highest in non-Hispanic White (NHW) (80% and 48%) and SA (72% and 41%) persons. Adjusted Ln (CAC + 1) was highest in NHW (3.68 ± 0.21) and SA (3.60 ± 0.23) (p < .01) DM patients. SA and NHW adults with DM (vs normoglycemic) had highest odds of CAC > 0 (2.13 and 2.27, respectively, p < .01). For CAC ≥ 100, SA and Chinese adults had the highest odds (2.28 and 2.27, respectively, p < .01). Fasting glucose and glycated hemoglobin were most strongly associated with CAC among SA.

CONCLUSIONS

Diabetes mellitus most strongly relates to any CAC in SA and NHW adults and CAC ≥ 100 in SA and Chinese adults, helping to explain the relation of DM with ASCVD in these populations.

The Impact of the Metabolic Syndrome and Its Components on Resting Energy Expenditure

We determined whether metabolic syndrome (MetS) and the increasing number of its components influenced the resting energy expenditure (REE). Data on adult men (n = 72, 40%) and women (n = 108, 60%) from European (n = 154, 86%) and Sub-Saharan African (n = 26, 14%) ancestry were used. Ninety-five (53%) participants had MetS (MetS+), while 85 (47%) were without MetS (MetS−). REE was determined through indirect calorimetry, body composition by DEXA, and clinical biochemistry by standard laboratory techniques. MetS+ had a significantly higher REE (mean ± se: MetS+: 5995 ± 87.3 vs. MetS−: 5760 ± 86.3 kJ/d, p = 0.025) when adjusted for age, gender, fat mass (FM), fat-free mass (FFM), ethnicity, season, 25OHD, insulin sensitivity, and time of data collection. Within each MetS status group, an increase in the number of components (C) resulted in a stepwise increase in REE. Relative to zero components, those with 1C had adjusted REE higher by +526 ± 248.1 kJ/d (p = 0.037), while 2C were higher than 1C by +298 ± 140.8 kJ/d (p = 0.037). Similarly, relative to 3C, those with 4C had REE higher by +242 ± 120.7 kJ/d (p = 0.049). The higher REE of 5C over 4C by 132 ± 174.5 kJ/d did not achieve statistical significance. MetS was associated with a significantly higher REE. This greater energetic cost varied directly with the numbers of its components but was most evident in those not diagnosed with the syndrome.

Mitochondrial and metabolic dysfunction in ageing and age-related diseases

Organismal ageing is accompanied by progressive loss of cellular function and systemic deterioration of multiple tissues, leading to impaired function and increased vulnerability to death. Mitochondria have become recognized not merely as being energy suppliers but also as having an essential role in the development of diseases associated with ageing, such as neurodegenerative and cardiovascular diseases. A growing body of evidence suggests that ageing and age-related diseases are tightly related to an energy supply and demand imbalance, which might be alleviated by a variety of interventions, including physical activity and calorie restriction, as well as naturally occurring molecules targeting conserved longevity pathways. Here, we review key historical advances and progress from the past few years in our understanding of the role of mitochondria in ageing and age-related metabolic diseases. We also highlight emerging scientific innovations using mitochondria-targeted therapeutic approaches.

Glycemic and cardiometabolic effects of exercise in South Asian Sri Lankans with type 2 diabetes mellitus: A randomized controlled trial Sri Lanka diabetes aerobic and resistance training study (SL-DARTS)

BACKGROUND AND AIMS

To examine the effects of aerobic training (AT) and resistance training (RT) compared to standard care on glycemic control in South Asian Sri Lankan adults with Type 2 Diabetes Mellitus (T2DM).

METHODS

Randomized controlled trial (RCT) with parallel-group design recruited 86 sedentary Sri Lankans (aged 35-65 years) with T2DM into aerobic training (AT, n = 28), resistance training (RT, n = 28) and control (CN, n = 30) groups. Supervised progressive exercise training consisting of 75 min per session, 2 days per week for 12 weeks was conducted. The primary outcome was pre- and post-intervention absolute change in hemoglobin A1c (HBA1c). Secondary outcomes were serum lipids, liver enzymes, chronic inflammatory status, anthropometry, body composition and blood pressure.

RESULTS

The absolute change in HbA1c of RT vs. CN was -0.08% (95% CI, 0.8% to -0.7%, p = 0.8) and AT vs. CN was -0.22% (95% CI, 0.95% to -0.5%). Subgroup analysis (n = 49) with a high baseline HbA1c (>7.5%), absolute reduction in HbA1c in exercise groups were statistically significant (RT vs. CN was -0.37%; 95% CI 1.3% to -0.6%, p = 0.04 and AT vs. CN was -0.57%; 95% CI 1.7% to -0.6%, p = 0.03). The effect sizes (total and subgroup HbA1c >7.5%) ranged from 0.7 to 1.0 in AT, 0.4 to 1.1 in RT compared to 0.35 to 0.6 for the CN. Secondary outcomes did not significantly differ among groups.

CONCLUSIONS

Exercise training 2 days/week improved glycemic control in Sri Lankan adults with T2DM and the effects were significant in high baseline HbA1c (>7.5%) groups (RT > AT).

Wand Stretching Exercise Decreases Abdominal Obesity Among Adults With High Body Mass Index Without Altering Fat Oxidation

Rationale

We designed a wand-based muscle stretching (WE) exercise program, which has become increasingly popular in physical therapy and has been used for elderly patients with adhesive capsulitis. However, studies regarding the effects of WE training on abdominal obesity and measures of cardiovascular risk factors among overweight/obese adults aged ≥55 years are rare.

Purpose

The objective of this study is to evaluate the effects of a 15-week wand stretching exercise program on waist circumference and cardiovascular risk factors in sedentary adults aged 55–70 years.

Methods

A total of 124 participants were randomly assigned to either participate in wand stretching exercise (WE) over a 15-week period or a control group (n = 62 each). Sixty participants in the WE group (26 overweight and 34 obese) and 51 in the control group (29 overweight and 22 obese) completed the study. The WE program included wand-assisted muscle stretching exercise on both the upper body and lower body for 40 min per day, 5 days per week, whereas the control group maintained their sedentary lifestyle.

Results

No significant improvements were observed in plasma glucose, insulin, and the homeostatic model assessment of insulin resistance (HOMA-IR) after exercise training. Compared with the control group, the WE group had more significant reductions in waist circumference among participants with a body mass index (BMI) < 25 kg/m² (−2.6 cm, 95% CI: −4.19 to −0.97 cm, d = 0.48) and BMI > 25 kg/m² (−2.5 cm, 95% CI: −4.1 to −0.9 cm, d = 0.59) (both P < 0.01). Furthermore, within groups, a significant increase in % fat free mass was observed after WE training. The basal metabolic rate was slightly increased, but the fat oxidation rate remained unaltered in the WE group. Improvements in low-density lipoprotein cholesterol to high-density lipoprotein cholesterol were minimal after WE. Significant reductions in high-sensitivity C-reactive protein were observed after WE only for participants with a BMI <25 kg/m².

Conclusion

The results suggest redistribution of a carbon source from the abdominal region to challenged skeletal muscle, following prolonged WE training. This abdominal fat reducing outcome of the WE is unlikely to be associated with fatty acid oxidation.

Nutrients, Mitochondrial Function, and Perinatal Health

Mitochondria are active independent organelles that not only meet the cellular energy requirement but also regulate central cellular activities. Mitochondria can play a critical role in physiological adaptations during pregnancy. Differences in mitochondrial function have been found between healthy and complicated pregnancies. Pregnancy signifies increased nutritional requirements to support fetal growth and the metabolism of maternal and fetal tissues. Nutrient availability regulates mitochondrial metabolism, where excessive macronutrient supply could lead to oxidative stress and contribute to mitochondrial dysfunction, while micronutrients are essential elements for optimal mitochondrial processes, as cofactors in energy metabolism and/or as antioxidants. Inadequate macronutrient and micronutrient consumption can result in adverse pregnancy outcomes, possibly through mitochondrial dysfunction, by impairing energy supply, one-carbon metabolism, biosynthetic pathways, and the availability of metabolic co-factors which modulate the epigenetic processes capable of establishing significant short- and long-term effects on infant health. Here, we review the importance of macronutrients and micronutrients on mitochondrial function and its influence on maternal and infant health.

The alterations of mitochondrial DNA in coronary heart disease

Coronary heart disease (CHD) is the major cause of death in modern society. CHD is characterized by atherosclerosis, which could lead to vascular cavity stenosis or obstruction, resulting in ischemic cardiac conditions such as angina and myocardial infarction. In terms of the mitochondrion, the main function is to produce adenosine triphosphate (ATP) for cells. And the alterations (including mutations, altered copy number and haplogroups) of mitochondrial DNA (mtDNA) are associated with the abnormal expression of oxidative phosphorylation (OXPHOS) system, resulting in mitochondrial dysfunction, then leading to perturbation on the electron transport chain and increased ROS generation and reduction in ATP level, contributing to ATP-producing disorders and oxidative stress, which may further accelerate development or vulnerability of atherosclerosis and myocardial ischemic injury. Therefore, the mtDNA defects may play an important role in making an early diagnosis, identifying disease-specific biomarkers and therapeutic targets, and predicting outcomes for patients with atherosclerosis and CHD. In this review, we aim to summarize the contribution of mtDNA mutations, altered mtDNA copy number and mtDNA haplogroups on the occurrence and development of CHD.

Study protocol: a randomised controlled trial of supervised resistance training versus aerobic training in Sri Lankan adults with type 2 diabetes mellitus: SL-DART study

Background

The prevalence of type 2 diabetes mellitus (T2DM) and cardiovascular diseases (CVD) is rising globally. T2DM is particularly problematic in South Asia with an estimated 10–15% of Sri Lankans diagnosed with the disease. Exercise is known to improve blood glucose, lipid profiles, blood pressure and adiposity, key goals in the management of T2DM. However, much of the evidence to date has been gained from white Caucasians who have a different body composition and disease profile compared to South Asians. Similarly, the recreational exercise culture is new to Sri Lankans and the effects of exercise on T2DM has not been studied in this population.

Methods

The Sri Lanka Diabetes Aerobic and Resistance Training (SL-DART) Study will be comprised of 2 components. Component 1 is a 12-week randomized controlled trial (RCT) to compare the effects of a supervised progressive resistance exercise program (RT) and aerobic exercise program (AT) with standard treatment/control (CN). Sedentary Sri Lankan adults with T2DM (aged 35–65 years) and with no contraindications to exercise will be randomized into one of 3 groups (AT, RT, CN). Exercise sessions will be conducted 2 days/week for 3 months. Baseline and post-intervention biochemical (glycemic control, lipid and liver profiles, inflammatory markers), anthropometric (height, weight, body circumferences), body composition, physical fitness, food preference (liking and wanting food) and quality of life parameters will be measured and compared between groups. Component 2 will be a qualitative study conducted immediately post-intervention via in-depth interviews to assess the barriers and facilitators for adherence to each exercise program.

Discussion

SL-DART Study represents one of the first adequately powered methodologically sound RCTs conducted in South Asia to assess the effects of resistance and aerobic exercise in participants with T2DM. Triangulation of quantitative and qualitative outcomes will enable the design of a culturally appropriate therapeutic physical activity intervention for Sri Lankans with T2DM, and the initiation of a professionally driven and specialized clinical exercise prescription service.

Trial registration

Sri Lanka Clinical Trials Registry; SLCTR/2016/017. Date registered 17.06.2016. Universal trial number U1111–1181-7561.

Prevalence of Selected Intermediate Risk Factors for Non-communicable Diseases in an Apparently Healthy Indian Community in KwaZulu-Natal, South Africa

South Africa, burdened with the emerging chronic diseases, is home to one of the largest migrant Indian population, however, little data exists on the risk factors for non-communicable diseases in this population. The aim of this study was to determine the prevalence of yet undiagnosed selected intermediate risk factors for non-communicable diseases among the Indian population in KwaZulu-Natal. We randomly selected 250 apparently healthy Indians, aged 35-55 years, living in KwaDukuza to participate in this study. Clinical and anthropometric measurements were taken under prescribed clinical conditions using Asian cut-off points. Pearson correlations was used to detect associations between anthropometric and clinical risk markers. A large percentage of participants' systolic blood pressure fell within the normal range. Diastolic blood pressure was >85 mmHg for 61 % of the participants and triglyceride levels were >1.69 mmol/L for 89 % of the participants'; 94 % of the women and 87 % of the men were classified as centrally obese. Raised fasting blood glucose was seen in 39 % of participants'. Waist circumference and body mass index showed statistically significant associations with all clinical risk markers except for diastolic blood pressure. Our findings suggest that the use of ethno specific strategies in the management of the disease profile of South African Indians, will enable the South African health system to respond more positively towards the current trend of increased metabolic and physiological risk factors in this community. Moreover, key modifiable behaviours such as increased physical activity and weight reduction may improve most of these metabolic abnormalities.

Exploring reasons for ethnic disparities in diet- and lifestyle-related chronic disease for Asian sub-groups in New Zealand: a scoping exercise

OBJECTIVES

The current study aimed to explore if the impact of various risk factors for chronic disease differed for people of Chinese, Indian and New Zealand European and Other (NZEO) ethnicities.

DESIGN

Data analysed for this paper was extracted from the 2003-04 and the 2006-07 NZ Health surveys for adults aged 25-70 which used a cross-sectional survey design. Data from both the survey waves were combined and all statistical analysis was done using SAS version 9.2 or 9.3. Ethnicity of participants was coded using a priority-based classification system as (1) Indian, (2) Chinese, (3) Other Asian, (4) NZEO, (5) Maori and (6) Pacific. Only data for Indians, Chinese and NZEO were used for the current study. Prevalence estimates and 95% confidence intervals for chronic disease and the associated risk factors were generated to describe the sample. Logistic regression analysis was used to examine whether the difference in the change in risk of chronic disease with different exposures was different according to ethnicity.

RESULTS

Higher deprivation resulted in increased risk of chronic disease in Indian and Chinese males but not in NZEO males (p = .03). There was a weak evidence for a differing effect of physical activity (p = .10) on chronic disease with the protective effect not seen in Indian or Chinese participants.

CONCLUSION

The results of the current study indicate that some factors such as socio-economic deprivation and physical activity may impact differently on the prevalence of chronic disease according to ethnicity. The authors recommend further investigation of these factors using improved and innovative methodology and high-quality ethnicity data to better understand the factors underpinning ethnic disparities in disease prevalence among Asian sub-groups.

Fats & fatty acids in Indian diets: Time for serious introspection

Recommended dietary allowances for fat and fatty acid (FA) intakes are set on global standards aimed at prevention of lifestyle diseases. Yet, the fat composition of a diet is both ethnic/region specific as well as income dependent. Indian diets are predominantly vegetarian and relatively low in fat. Furthermore, the main sources of fat are of plant origin rather than animal origin. This results in a diet that is relatively low in saturated FA, high in n-6 polyunsaturated fatty acids (PUFA), and very low in n-3 PUFA. Though this appears as a good dietary composition as per global standards, the undeniable increase in the incidence of obesity, diabetes and cardiovascular diseases in India begs for an explanation. In this context, the current article is aimed at reopening the debate on fat intakes in Indian diets, with a focus on a balance between fats, carbohydrates and proteins, rather than an emphasis on individual macronutrients.

Pro: Heat stress as a potential etiology of Mesoamerican and Sri Lankan nephropathy: a late night consult with Sherlock Holmes

Epidemics of chronic kidney disease are now recognized in Central America, Mexico, India and Sri Lanka, and there is also some evidence that similar epidemics may be occurring in the USA, Thailand and elsewhere. A common denominator for each location is manually working outside in extremely hot environments. Here we review the evidence that the primary etiology may be heat stress related to repeated subclinical or clinical acute kidney injury that eventually manifests as chronic kidney disease. In some aspects, the disease may manifest as subclinical heat stroke, subclinical rhabdomyolysis or a subclinical tumor lysis syndrome. While toxins could be involved, it would be difficult to attribute this as a main mechanism, given the wide range of occupations and geographic regions manifesting this disease. While some of the epidemics may be due to better reporting, we believe the most important reasons are increasing heat extremes (heat waves) coupled with hydration with sugary or, less commonly, alcoholic beverages.

Body composition and metabolic outcomes after 96 weeks of treatment with ritonavir-boosted lopinavir plus either nucleoside or nucleotide reverse transcriptase inhibitors or raltegravir in patients with HIV with virological failure of a standard first-line antiretroviral therapy regimen: a substudy of the randomised, open-label, non-inferiority SECOND-LINE study

BACKGROUND

Lipoatrophy is one of the most feared complications associated with the use of nucleoside or nucleotide reverse transcriptase inhibitors (N[t]RTIs). We aimed to assess soft-tissue changes in participants with HIV who had virological failure of a first-line antiretroviral (ART) regimen containing a non-nucleoside reverse transcriptase inhibitor plus two N(t)RTIs and were randomly assigned to receive a second-line regimen containing a boosted protease inhibitor given with either N(t)RTIs or raltegravir.

METHODS

Of the 37 sites that participated in the randomised, open-label, non-inferiority SECOND-LINE study, eight sites from five countries (Argentina, India, Malaysia, South Africa, and Thailand) participated in the body composition substudy. All sites had a dual energy x-ray absorptiometry (DXA) scanner and all participants enrolled in SECOND-LINE were eligible for inclusion in the substudy. Participants were randomly assigned (1:1), via a computer-generated allocation schedule, to receive either ritonavir-boosted lopinavir plus raltegravir (raltegravir group) or ritonavir-boosted lopinavir plus two or three N(t)RTIs (N[t]RTI group). Randomisation was stratified by site and screening HIV-1 RNA. Participants and investigators were not masked to group assignment, but allocation was concealed until after interventions were assigned. DXA scans were done at weeks 0, 48, and 96. The primary endpoint was mean percentage and absolute change in peripheral limb fat from baseline to week 96. We did intention-to-treat analyses of available data. This substudy is registered with ClinicalTrials.gov, number NCT01513122.

FINDINGS

Between Aug 1, 2010, and July 10, 2011, we recruited 211 participants into the substudy. The intention-to-treat population comprised 102 participants in the N(t)RTI group and 108 participants in the raltegravir group, of whom 91 and 105 participants, respectively, reached 96 weeks. Mean percentage change in limb fat from baseline to week 96 was 16·8% (SD 32·6) in the N(t)RTI group and 28·0% (37·6) in the raltegravir group (mean difference 10·2%, 95% CI 0·1-20·4; p=0·048). Mean absolute change was 1·04 kg (SD 2·29) in the N(t)RTI group and 1·81 kg (2·50) in the raltegravir group (mean difference 0·6, 95% CI -0·1 to 1·3; p=0·10).

INTERPRETATION

Our findings suggest that for people with virological failure of a first-line regimen containing efavirenz plus tenofovir and lamivudine or emtricitabine, the WHO-recommended switch to a ritonavir-boosted protease inhibitor plus zidovudine (a thymidine analogue nucleoside reverse transcriptase inhibitor) and lamivudine might come at the cost of peripheral lipoatrophy. Further study could help to define specific groups of people who might benefit from a switch to an N(t)RTI-sparing second-line ART regimen.

FUNDING

The Kirby Institute and the Australian National Health and Medical Research Council.

Urbanized South Asians' susceptibility to coronary heart disease: The high-heat food preparation hypothesis

OBJECTIVE

Known risk factors do not fully explain the comparatively high susceptibility to coronary heart disease (CHD) in South Asians (Indian, Pakistani, Bangladeshi, and Sri Lankan populations in South Asia and overseas). The search for explanatory hypotheses and cofactors that raise susceptibility of South Asians to CHD continues. The aim of this study was to propose "the high-heat food preparation hypothesis," where neo-formed contaminants (NFCs) such as trans-fatty acids (TFAs) and advanced glycation end-products (AGEs) are the cofactors.

METHODS

We reviewed the actions of AGEs and TFAs, the burden of these products in tissues and blood in South Asians, the relationship between these products and CHD, the effects of preparing food and reheating oils at high temperatures on NFCs, and the foods and mode of preparation in South Asian and Chinese cuisines.

RESULTS

Animal and human studies show NFCs increase the risk for CHD. Evidence on the consumption and body burden of these products across ethnic groups is not available, and comparable data on the NFC content of the cuisine of South Asians and potential comparison populations (e.g., the Chinese with lower CHD rates) are limited. South Asians' cuisine is dominated by frying and roasting techniques that use high temperatures. South Asian foods have high TFA content primarily through the use of partially hydrogenated fats, reheated oils, and high-heat cooking. Reheating oils greatly increases the TFA content. In comparison, Chinese cuisine involves mostly braising, steaming, and boiling rather than frying.

CONCLUSION

We hypothesize that South Asians' susceptibility to CHD is partly attributable to high-heat treated foods producing high NFCs. Research to accrue direct evidence is proposed.

Ambient Air Pollution and Newborn Size and Adiposity at Birth: Differences by Maternal Ethnicity (the Born in Bradford Study Cohort)

BACKGROUND

Exposure to ambient air pollution has been associated with reduced size of newborns; however, the modifying effect of maternal ethnicity remains little explored among South Asians.

OBJECTIVES

We investigated ethnic differences in the association between ambient air pollution and newborn's size.

METHOD

Pregnant women were recruited between 2007 and 2010 for the Born in Bradford cohort study, in England. Exposures to particulate matter (≤ 10 μm, PM10; ≤ 2.5 μm, PM2.5), PM2.5 absorbance, and nitrogen oxides (NOx, NO2) were estimated using land-use regressions models. Using multivariate linear regression models, we evaluated effect modification by maternal ethnicity ("white British" or "Pakistani origin," self-reported) on the associations of air pollution and birth weight, head circumference, and triceps and subscapular skinfold thickness.

RESULTS

A 5-μg/m3 increase in mean third trimester PM2.5 was associated with significantly lower birth weight and smaller head circumference in children of white British mothers (-43 g; 95% CI: -76, -10 and -0.28 cm; 95% CI: -0.39, -0.17, respectively), but not in children of Pakistani origin (9 g; 95% CI: -17, 35 and -0.08 cm; 95% CI: -0.17, 0.01, respectively) (p(int) = 0.03 and < 0.001). In contrast, PM2.5 was associated with significantly larger triceps and subscapular skinfold thicknesses in children of Pakistani origin (0.17 mm; 95% CI: 0.08, 0.25 and 0.21 mm; 95% CI: 0.12, 0.29, respectively), but not in white British children (-0.02 mm; 95% CI: -0.14, 0.01 and 0.06 mm; 95% CI: -0.06, 0.18, respectively) (p(int) = 0.06 and 0.11). Patterns of associations for PM10 and PM2.5 absorbance according to ethnicity were similar to those for PM2.5, but associations of the outcomes with NO2 and NOx were mostly nonsignificant in both ethnic groups.

CONCLUSIONS

Our results suggest that associations of ambient PM exposures with newborn size and adiposity differ between white British and Pakistani origin infants.

CITATION

Schembari A, de Hoogh K, Pedersen M, Dadvand P, Martinez D, Hoek G, Petherick ES, Wright J, Nieuwenhuijsen MJ. 2015. Ambient air pollution and newborn size and adiposity at birth: differences by maternal ethnicity (the Born in Bradford study cohort). Environ Health Perspect 123:1208-1215; http://dx.doi.org/10.1289/ehp.1408675.

Overnutrition during lactation leads to impairment in insulin signaling, up-regulation of GLUT1 and increased mitochondrial carbohydrate oxidation in heart of weaned mice

Several studies have demonstrated that overnutrition during early postnatal period can increase the long-term risk of developing obesity and cardiac disorders, yet the short-term effects of postnatal overfeeding in cardiac metabolism remains unknown. The aim of our study was to investigate the cardiac metabolism of weaned mice submitted to overnutrition during lactation, particularly as to mitochondrial function, substrate preference and insulin signaling. Postnatal overfeeding was induced by litter size reduction in mice at postnatal day 3. At 21 days of age (weaning), mice in the overfed group (OG) presented biometric and biochemical parameters of obesity, including increased body weight, visceral fat, liver weight and increased left ventricle weight/tibia length ratio; indicating cardiac hypertrophy, hyperglycemia, hyperinsulinemia and increased liver glycogen content compared to control group. In the heart, we detected impaired insulin signaling, mainly due to decreased IRβ, pTyr-IRS1, PI3K, GLUT4 and pAkt/Akt and increased PTP1B, GLUT1 and pAMPKα/AMPKα content. Activities of lactate dehydrogenase and citrate synthase were increased, accompanied by enhanced carbohydrate oxidation, as observed by high-resolution respirometry. Moreover, OG hearts had lower CPT1, PPARα and increased UCP2 mRNA expression, associated with increased oxidative stress (4-HNE content), BAX/BCL2 ratio and cardiac fibrosis. Ultrastructural analysis of OG hearts demonstrated mild mitochondrial damage without alterations in OXPHOS complexes. In conclusion, overnutrition during early life induces short-term metabolic disturbances, impairment in heart insulin signaling, up-regulates GLUT-1 and switch cardiac fuel preference in juvenile mice.

Comparative mitochondrial genomics and phylogenetic relationships of the Crossoptilon species (Phasianidae, Galliformes)

BACKGROUND

Phasianidae is a family of Galliformes containing 38 genera and approximately 138 species, which is grouped into two tribes based on their morphological features, the Pheasants and Partridges. Several studies have attempted to reconstruct the phylogenetic relationships of the Phasianidae, but many questions still remain unaddressed, such as the taxonomic status and phylogenetic relationships among Crossoptilon species. The mitochondrial genome (mitogenome) has been extensively used to infer avian genetic diversification with reasonable resolution. Here, we sequenced the entire mitogenomes of three Crossoptilon species (C. harmani, C. mantchuricum and C. crossoptilon) to investigate their evolutionary relationship among Crossoptilon species.

RESULTS

The complete mitogenomes of C. harmani, C. mantchuricum and C. crossoptilon are 16682 bp, 16690 bp and 16680 bp in length, respectively, encoding a standard set of 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes, and a putative control region. C. auritum and C. mantchuricum are more closely related genetically, whereas C. harmani is more closely related to C. crossoptilon. Crossoptilon has a closer relationship with Lophura, and the following phylogenetic relationship was reconstructed: ((Crossoptilon + Lophura) + (Phasianus + Chrysolophus)). The divergence time between the clades C. harmani-C. crossoptilon and C. mantchuricum-C. auritum is consistent with the uplift of the Tibetan Plateau during the Tertiary Pliocene. The Ka/Ks analysis showed that atp8 gene in the Crossoptilon likely experienced a strong selective pressure in adaptation to the plateau environment.

CONCLUSIONS

C. auritum with C. mantchuricum and C. harmani with C. crossoptilon form two pairs of sister groups. The genetic distance between C. harmani and C. crossoptilon is far less than the interspecific distance and is close to the intraspecific distance of Crossoptilon, indicating that C. harmani is much more closely related to C. crossoptilon. Our mito-phylogenomic analysis supports the monophyly of Crossoptilon and its closer relationship with Lophura. The uplift of Tibetan Plateau is suggested to impact the divergence between C. harmani-C. crossoptilon clade and C. mantchuricum-C. auritum clade during the Tertiary Pliocene. Atp8 gene in the Crossoptilon species might have experienced a strong selective pressure for adaptation to the plateau environment.

Low immigrant mortality in England and Wales: a data artefact?

Previous research shows low mortality for most immigrants compared to natives in host countries. This advantage is often attributed to health selection processes in migration and to protective health behaviours. Little research has examined the role of data quality, especially the registration of moves. Registration errors relating to moves between origin and host countries can mismatch deaths and risk populations, leading to denominator bias and an under-estimation of migrant mortality (data artefact). The paper investigates the mortality of immigrants in England and Wales from 1971 to 2001 using the Office for National Statistics Longitudinal Study (ONS LS), a 1% sample of the population of England and Wales. We apply parametric survival models to study the mortality of 450,000 individuals. We conduct sensitivity analysis to assess the impact of entry and exit uncertainty on immigrant mortality rates. The analysis shows that most international migrants have lower mortality than natives in England and Wales. Differences largely persist when we adjust models to entry and exit uncertainty and they become pronounced once we control for individual socioeconomic characteristics. This study supports low mortality among immigrants and shows that results are not a data artefact.

Pathogenesis of type 2 diabetes in South Asians

The risk of developing type 2 diabetes mellitus (T2DM) is exceptionally high among both native and migrant South Asians. T2DM occurs more often and at a younger age and lower BMI, and the risk of coronary artery and cerebrovascular disease, and renal complications is higher for South Asians compared with people of White Caucasian descent. The high prevalence of T2DM and its related complications in South Asians, which comprise one-fifth of the total world's population, poses a major health and socioeconomic burden. The underlying cause of this excess risk, however, is still not completely understood. Therefore, gaining insight into the pathogenesis of T2DM in South Asians is of great importance. The predominant mechanism, in this ethnicity seems to be insulin resistance (IR) rather than an impaired β-cell function. In this systematic review, we describe several possible mechanisms that may underlie or contribute to the increased IR observed in South Asians.

Best-fitting prediction equations for basal metabolic rate: informing obesity interventions in diverse populations

Basal metabolic rate (BMR) represents the largest component of total energy expenditure and is a major contributor to energy balance. Therefore, accurately estimating BMR is critical for developing rigorous obesity prevention and control strategies. Over the past several decades, numerous BMR formulas have been developed targeted to different population groups. A comprehensive literature search revealed 248 BMR estimation equations developed using diverse ranges of age, gender, race, fat-free mass, fat mass, height, waist-to-hip ratio, body mass index and weight. A subset of 47 studies included enough detail to allow for development of meta-regression equations. Utilizing these studies, meta-equations were developed targeted to 20 specific population groups. This review provides a comprehensive summary of available BMR equations and an estimate of their accuracy. An accompanying online BMR prediction tool (available at http://www.sdl.ise.vt.edu/tutorials.html) was developed to automatically estimate BMR based on the most appropriate equation after user-entry of individual age, race, gender and weight.

Mitochondrial genome sequences of Artemia tibetiana and Artemia urmiana: assessing molecular changes for high plateau adaptation

Brine shrimps, Artemia (Crustacea, Anostraca), inhabit hypersaline environments and have a broad geographical distribution from sea level to high plateaus. Artemia therefore possess significant genetic diversity, which gives them their outstanding adaptability. To understand this remarkable plasticity, we sequenced the mitochondrial genomes of two Artemia tibetiana isolates from the Tibetan Plateau in China and one Artemia urmiana isolate from Lake Urmia in Iran and compared them with the genome of a low-altitude Artemia, A. franciscana. We compared the ratio of the rate of nonsynonymous (Ka) and synonymous (Ks) substitutions (Ka/Ks ratio) in the mitochondrial protein-coding gene sequences and found that atp8 had the highest Ka/Ks ratios in comparisons of A. franciscana with either A. tibetiana or A. urmiana and that atp6 had the highest Ka/Ks ratio between A. tibetiana and A. urmiana. Atp6 may have experienced strong selective pressure for high-altitude adaptation because although A. tibetiana and A. urmiana are closely related they live at different altitudes. We identified two extended termination-associated sequences and three conserved sequence blocks in the D-loop region of the mitochondrial genomes. We propose that sequence variations in the D-loop region and in the subunits of the respiratory chain complexes independently or collectively contribute to the adaptation of Artemia to different altitudes.

Factors determining the risk of the metabolic syndrome: is there a central role for adiponectin?

BACKGROUND AND OBJECTIVES

The pathogenesis of the metabolic syndrome (MetS) is not well understood. This review is based on the hypothesis that both traditional and emerging risk factors act through adiponectin.

SUBJECTS AND METHODS

We conducted a search of the literature using prominent electronic databases and search terms that included in combination: adiponectin, diet, dietary patterns, exercise, metabolic rate, MetS and testosterone. Articles were restricted to studies conducted on adult humans, reported in English and within the time period 2000-2012.

RESULTS AND CONCLUSIONS

Both traditional and emerging risk factors associated with the MetS show some evidence of exerting their influence through adiponectin. High-quality randomized controlled trials that alter adiponectin levels are required to further corroborate this hypothesis.

A four-stage model explaining the higher risk of Type 2 diabetes mellitus in South Asians compared with European populations

With approximately 1.5 billion people at risk, the staggeringly high risk of Type 2 diabetes in South Asians comprises a global problem. The causes of this high risk are complex, with 23 major risk factors identified in a Lancet seminar. This paper proposes a four-stage explanatory model: (1) the birth of a small, adipose, lowlean mass South Asian baby--the phenotype tracking through life; (2) in childhood and early adulthood, the deposition of any excess energy intake preferentially in upper body and ectopic fat stores rather than in the lower body or superficial subcutaneous fat stores; (3) as a consequence of points 1 and 2, and exacerbated by an environment of low physical activity and excess calories, the accelerated appearance of high levels of plasma insulin, triglycerides and glucose, and the fatty-liver vicious cycle; (4) β-cell failure as a result of fewer β-cells at birth, exposure to apoptotic triggers such as fat in the pancreas, and high demand from insulin resistance, which causes diabetes. Other risk factors--especially energy-dense hyperglycaemic diet and low physical activity--play into this pathway. The recommended behavioural changes fit with this model, which brings clarity to guide future research, policy, practice and health promotion.

Integration of cellular bioenergetics with mitochondrial quality control and autophagy

Bioenergetic dysfunction is emerging as a cornerstone for establishing a framework for understanding the pathophysiology of cardiovascular disease, diabetes,cancer and neurodegeneration. Recent advances in cellular bioenergetics have shown that many cells maintain a substantial bioenergetic reserve capacity, which is a prospective index of ‘ healthy ’ mitochondrial populations.The bioenergetics of the cell are likely regulated by energy requirements and substrate availability. Additionally,the overall quality of the mitochondrial population and the relative abundance of mitochondria in cells and tissues also impinge on overall bioenergetic capacity and resistance to stress. Because mitochondria are susceptible to damage mediated by reactive oxygen/nitrogen and lipid species, maintaining a ‘ healthy ’ population of mitochondria through quality control mechanisms appears to be essential for cell survival under conditions of pathological stress. Accumulating evidence suggest that mitophagy is particularly important for preventing amplification of initial oxidative insults, which otherwise would further impair the respiratory chain or promote mutations in mitochondrial DNA (mtDNA). The processes underlying the regulation of mitophagy depend on several factors, including the integrity of mtDNA, electron transport chain activity, and the interaction and regulation of the autophagic machinery. The integration and interpretation of cellular bioenergetics in the context of mitochondrial quality control and genetics is the theme of this review.

Polymorphisms of the UCP2 gene are associated with body fat distribution and risk of abdominal obesity in Spanish population

BACKGROUND

Increased accumulation of fat results from an imbalance between energy expenditure and intake, being modulated by different environmental and genetic factors. Uncoupling proteins (UCPs) are mitochondrial carrier proteins able to spend energy generating heat. Therefore, variations in these genes are good candidates as potential modulators of body fat accumulation. Our aim was to investigate the possible association of genetic variations of the gene codifying the UCP2 protein with obesity and fat distribution.

DESIGN

We performed a cross-sectional study in 2367 individuals from two population-based studies from different regions of Spain. The Hortega Study included 1436 individuals (693 women) 21-85 years old, and the Pizarra Study included 931 individuals (584 women) 18-65 years old. We evaluated three polymorphisms of the UCP2 gene.

RESULTS

The TT genotype of the rs660339 polymorphism and the AA genotype of the rs659366 polymorphism of the UCP2 gene were significantly associated with higher waist circumference in the Hortega Study. Furthermore, subjects carrying both genotypes (TT+AA) also showed higher central adiposity compared with other genotypes. This association was also present in the Pizarra Study. Moreover, in the pooled population, we found a stronger association with waist circumference. Even, we found association with BMI. Furthermore, rs659366 polymorphism was associated with the risk of abdominal obesity (P= 0·04: OR = 1·3; CI = 1·01-1·67).

CONCLUSIONS

Polymorphisms of the UCP2 gene (rs660339 and rs659366) were associated with central obesity. This study shows association between the UCP2 gene and the susceptibility to obesity and body fat distribution in a south European population.

Effects of telmisartan on glucose levels in people at high risk for cardiovascular disease but free from diabetes: the TRANSCEND study

OBJECTIVE

Several large clinical trials suggest that ACE inhibitors may reduce the incidence of diabetes. Less is known about the effects of angiotensin receptor blockers (ARBs) on reducing incident diabetes or leading to regression of impaired fasting glucose (IFG) or impaired glucose tolerance (IGT) to normoglycemia.

RESEARCH DESIGN AND METHODS

Participants were 3,488 adults at high risk for cardiovascular disease but free from diabetes (mean age 67 years; 61% male) in the Telmisartan Randomized Assessment Study in ACE Intolerant Subjects With Cardiovascular Disease (TRANSCEND) study. The participants were randomized to the ARB telmisartan 80 mg (n = 1,726) or placebo (n = 1,762) in addition to usual care.

RESULTS

During a median 56 months, 21.8% of participants treated with telmisartan and 22.4% of those on placebo developed diabetes (relative ratio 0.95 [95% CI 0.83-1.10]; P = 0.51). Participants originally diagnosed with IFG and/or IGT were equally likely to regress to normoglycemia (26.9 vs. 24.5%) or to progress to incident diabetes (20.1 vs. 21.1%; P = 0.59) on telmisartan or placebo.

CONCLUSIONS

There was no evidence that addition of the ARB telmisartan to usual care prevents incident diabetes or leads to regression of IFG or IGT in people at high risk for cardiovascular disease but free from diabetes.

The mitochondrial paradigm for cardiovascular disease susceptibility and cellular function: a complementary concept to Mendelian genetics

While there is general agreement that cardiovascular disease (CVD) development is influenced by a combination of genetic, environmental, and behavioral contributors, the actual mechanistic basis of how these factors initiate or promote CVD development in some individuals while others with identical risk profiles do not, is not clearly understood. This review considers the potential role for mitochondrial genetics and function in determining CVD susceptibility from the standpoint that the original features that molded cellular function were based upon mitochondrial-nuclear relationships established millions of years ago and were likely refined during prehistoric environmental selection events that today, are largely absent. Consequently, contemporary risk factors that influence our susceptibility to a variety of age-related diseases, including CVD were probably not part of the dynamics that defined the processes of mitochondrial-nuclear interaction, and thus, cell function. In this regard, the selective conditions that contributed to cellular functionality and evolution should be given more consideration when interpreting and designing experimental data and strategies. Finally, future studies that probe beyond epidemiologic associations are required. These studies will serve as the initial steps for addressing the provocative concept that contemporary human disease susceptibility is the result of selection events for mitochondrial function that increased chances for prehistoric human survival and reproductive success.

Energy metabolism and the metabolic syndrome: does a lower basal metabolic rate signal recovery following weight loss?

AIM

To determine whether basal metabolic rate (BMR) was causally related to MetS, and to study the role of gender in this relationship.

METHODS

Seventy-two Caucasian subjects (43 women, 29 men) had changes in basal metabolic rate (BMR), carbohydrate oxidation rate (COR), fat oxidation rate (FOR) and prevalence of the metabolic syndrome (MetS) assessed in response to weight loss.

RESULTS

There was a significant gender×MetS interaction in BMR at the start. Women with MetS had higher adjusted BMR, whilst men with MetS had lower adjusted BMR than their respective counterparts. Weight loss resulted in a significant decrease in fat mass (-5.2±0.31 kg, p=0.001), fat free mass (-2.3±0.27 kg, p=0.001), BMR (-549±58 kJ/d, p=0.001) and a decreased proportion of MetS (22/72, χ(2)=0.005). Subjects who recovered from MetS after weight loss (RMS) had ∼250 kJ/d significantly lower adjusted BMR compared to those who were never MetS (NMS, p=0.046) and those who still had MetS (MetS+, p=0.047). Regression analysis showed that change (Δ) in BMR was best determined by Δglucose×gender interaction (r(2)=23%), ΔFOR (r(2)=20.3%), ΔCOR (r(2)=19.4%) and Δtriglycerides (r(2)=7.8%).

CONCLUSIONS

There is a sexual dimorphism of BMR in MetS. Overall, the data support the notion that alterations in BMR may be central to the etiopathogenesis of MetS.

Diabetics on hemodialysis in El-Minia Governorate, Upper Egypt: five-year study

INTRODUCTION

The number of patients with end-stage renal disease (ESRD) due to diabetic nephropathy (DN) is increasing worldwide. In many countries, diabetes mellitus has become the most frequent cause of ESRD. The goal of this work is to critically evaluate the prevalence of DN among chronic regular hemodialysis (HD) patients in El-Minia Governorate, to evaluate changes over the course of 5 years, and to compare data of El-Minia Governorate with data from the United States and other countries, in an attempt to detect factors that might explain causes of the differences.

MATERIAL AND METHODS

Data of patients on HD enrolled in the annual registry of the causes of ESRD in El-Minia Governorate were evaluated during the period from 2004 to 2008 for prevalence of DN. ESRD related to diabetes was defined as people who were initiated on chronic regular HD with diabetes mellitus as the cause of ESRD.

RESULTS

The prevalence of DN among HD patients increased from 5% in 2004 to 16% in 2008. The mean age was significantly higher than that of ESRD patients on HD due to other etiologies. Furthermore, DN was more prevalent in urban areas than rural areas.

CONCLUSION

Diabetic nephropathy among HD patients in El-Minia Governorate is increasing but is less prevalent than in the United States and other Western countries, probably because of a higher incidence of other causes of ESRD in El-Minia governorate, or because of premature death of diabetic patients. Therefore, meticulous management of diabetic patients is mandatory.