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Ma R.C.W.,Chinese University of Hong Kong | Chan J.C.N.,Chinese University of Hong Kong | Tam W.H.,Chinese University of Hong Kong | Hanson M.A.,University of Southampton | And 2 more authors.
Clinical Obstetrics and Gynecology | Year: 2013

A greater proportion of women of reproductive age are now overweight or obese. Gestational diabetes mellitus and maternal obesity are associated with long-term adverse consequences in the offspring and subsequent generations, and are important drivers of the escalating global burden of diabetes and cardiovascular disease. We review the evidence linking gestational diabetes mellitus and maternal obesity with a greater risk of metabolic compromise in the offspring. We use an evolutionary perspective to elucidate the origins of gestational diabetes. Focusing efforts on maternal health is an important approach to combating the growing burden of diabetes and other noncommunicable diseases. © 2013, Lippincott Williams & Wilkins. Source


Hanson M.A.,University of Southampton | Gluckman P.D.,University of Auckland | Gluckman P.D.,Singapore Institute of Clinical Science | Ma R.C.W.,Chinese University of Hong Kong | And 3 more authors.
BMC Public Health | Year: 2012

Background: The global burden of diabetes and other non-communicable diseases is rising dramatically worldwide and is causing a double poor health burden in low- and middle-income countries. Early life influences play an important part in this scenario because maternal lifestyle and conditions such as gestational diabetes and obesity affect the risk of diabetes in the next generation. This indicates important periods during the lifecourse when interventions could have powerful affects in reducing incidence of non-communicable diseases. However, interventions to promote diet and lifestyle in prospective parents before conception have not received sufficient attention, especially in low- and middle-income countries undergoing socio-economic transition. Discussion. Interventions to produce weight loss in adults or to reduce weight gain in pregnancy have had limited success and might be too late to produce the largest effects on the health of the child and his/her later risk of non-communicable diseases. A very important factor in the prevention of the developmental component of diabetes risk is the physiological state in which the parents enter pregnancy. We argue that the most promising strategy to improve prospective parents' body composition and lifestyle is the promotion of health literacy in adolescents. Multiple but integrated forms of community-based interventions that focus on nutrition, physical activity, family planning, breastfeeding and infant feeding practices are needed. They need to address the wider social economic context in which adolescents live and to be linked with existing public health programmes in sexual and reproductive health and maternal and child health initiatives. Summary. Interventions aimed at ensuring a healthy body composition, diet and lifestyle before pregnancy offer a most effective solution in many settings, especially in low- and middle-income countries undergoing socio-economic transition. Preparing a mother, her partner and her future child for "the 1000 days", whether from planned or unplanned conception would break the cycle of risk and demonstrate benefit in the shortest possible time. Such interventions will be particularly important in adolescents and young women in disadvantaged groups and can improve the physiological status of the fetus as well as reduce the prevalence of pregnancy conditions such as gestational diabetes mellitus which both predispose to non-communicables diseases in both the mother and her child. Pre-conception interventions require equipping prospective parents with the necessary knowledge and skills to make healthy lifestyle choices for themselves and their children. Addressing the promotion of such health literacy in parents-to-be in low- and middle-income countries requires a wider social perspective. It requires a range of multisectoral agencies to work together and could be linked to the issues of women's empowerment, to reproductive health, to communicable disease prevention and to the Millennium Development Goals 4 and 5. © 2012 Hanson et al.; licensee BioMed Central Ltd. Source


Tai E.S.,National University of Singapore | Tan M.L.S.,Singapore Health Services | Stevens R.D.,Sarah edman Nutrition And Metabolism Center | Low Y.L.,Singapore Institute of Clinical Science | And 10 more authors.
Diabetologia | Year: 2010

Aims/hypothesis: Insulin resistance (IR) is associated with obesity, but can also develop in individuals with normal body weight. We employed comprehensive profiling methods to identify metabolic events associated with IR, while controlling for obesity. Methods: We selected 263 non-obese (BMI approximately 24 kg/m2) Asian-Indian and Chinese men from a large cross-sectional study carried out in Singapore. Individuals taking medication for diabetes or hyperlipidaemia were excluded. Participants were separated into lower and upper tertiles of IR based on HOMA indices of ≥1.06 or ≤1.93, respectively. MS-based metabolic profiling of acylcarnitines, amino acids and organic acids was combined with hormonal and cytokine profiling in all participants. Results: After controlling for BMI, commonly accepted risk factors for IR, including circulating fatty acids and inflammatory cytokines, did not discriminate the upper and lower quartiles of insulin sensitivity in either Asian-Indian or Chinese men. Instead, IR was correlated with increased levels of alanine, proline, valine, leucine/isoleucine, phenylalanine, tyrosine, glutamate/glutamine and ornithine, and a cluster of branched-chain and related amino acids identified by principal components analysis. These changes were not due to increased protein intake by individuals in the upper quartile of IR. Increased abdominal adiposity and leptin, and decreased adiponectin and IGF-binding protein 1 were also correlated with IR. Conclusions/interpretation: These findings demonstrate that perturbations in amino acid homeostasis, but not inflammatory markers or NEFAs, are associated with IR in individuals of relatively low body mass. © 2009 Springer-Verlag. Source


Sriram S.,Nanyang Technological University | Subramanian S.,Nanyang Technological University | Juvvuna P.K.,National University of Singapore | Ge X.,Singapore Institute of Clinical Science | And 6 more authors.
Molecular Endocrinology | Year: 2014

Smad (Sma and Mad-related protein) 2/3 are downstream signaling molecules for TGF-β and myostatin (Mstn). Recently, Mstn was shown to induce reactive oxygen species (ROS) in skeletal muscle via canonical Smad3, nuclear factor-κB, and TNF-α pathway. However, mice lacking Smad3 display skeletal muscle atrophy due to increased Mstn levels. Hence, our aims were first to investigate whether Mstn induced muscle atrophy in Smad3-/- mice by increasing ROS and second to delineate Smad3-independent signaling mechanism for Mstn-induced ROS. Herein we show that Smad3-/- mice have increased ROS levels in skeletal muscle, and inactivation of Mstn in these mice partially ablates the oxidative stress. Furthermore, ROS induction by Mstn in Smad3-/- muscle was not via nuclear factor-κB (p65) signaling but due to activated p38, ERK MAPK signaling and enhanced IL-6 levels. Consequently, TNF-α, nicotinamide adenine dinucleotide phosphate oxidase, and xanthine oxidase levels were up-regulated, which led to an increase in ROS production in Smad3-/- skeletal muscle. The exaggerated ROS in the Smad3-/- muscle potentiated binding of C/EBP homology protein transcription factor to MuRF1 promoter, resulting in enhanced MuRF1 levels leading to muscle atrophy. © 2014 by the Endocrine Society. Source


Sriram S.,Nanyang Technological University | Subramanian S.,Nanyang Technological University | Sathiakumar D.,Nanyang Technological University | Venkatesh R.,Nanyang Technological University | And 5 more authors.
Aging Cell | Year: 2011

Abnormal levels of reactive oxygen species (ROS) and inflammatory cytokines have been observed in the skeletal muscle during muscle wasting including sarcopenia. However, the mechanisms that signal ROS production and prolonged maintenance of ROS levels during muscle wasting are not fully understood. Here, we show that myostatin (Mstn) is a pro-oxidant and signals the generation of ROS in muscle cells. Myostatin, a transforming growth factor-β (TGF-β) family member, has been shown to play an important role in skeletal muscle wasting by increasing protein degradation. Our results here show that Mstn induces oxidative stress by producing ROS in skeletal muscle cells through tumor necrosis factor-α (TNF-α) signaling via NF-κB and NADPH oxidase. Aged Mstn null (Mstn -/-) muscles, which display reduced sarcopenia, also show an increased basal antioxidant enzyme (AOE) levels and lower NF-κB levels indicating efficient scavenging of excess ROS. Additionally, our results indicate that both TNF-α and hydrogen peroxide (H 2O 2) are potent inducers of Mstn and require NF-κB signaling for Mstn induction. These results demonstrate that Mstn and TNF-α are components of a feed forward loop in which Mstn triggers the generation of second messenger ROS, mediated by TNF-α and NADPH oxidase, and the elevated TNF-α in turn stimulates Mstn expression. Higher levels of Mstn in turn induce muscle wasting by activating proteasomal-mediated catabolism of intracellular proteins. Thus, we propose that inhibition of ROS induced by Mstn could lead to reduced muscle wasting during sarcopenia. © 2011 The Authors. Aging Cell © 2011 Blackwell Publishing Ltd/Anatomical Society of Great Britain and Ireland. Source

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