THE INTERACTION OF FITNESS, FATNESS, AND CARDIOMETABOLIC RISK

Effects of Caffeine on Brown Adipose Tissue Thermogenesis and Metabolic Homeostasis: A Review

The impact of brown adipose tissue (BAT) metabolism on understanding energy balance in humans is a relatively new and exciting field of research. The pathogenesis of obesity can be largely explained by an imbalance between caloric intake and energy expenditure, but the underlying mechanisms are far more complex. Traditional non-selective sympathetic activators have been used to artificially elevate energy utilization, or suppress appetite, however undesirable side effects are apparent with the use of these pharmacological interventions. Understanding the role of BAT, in relation to human energy homeostasis has the potential to dramatically offset the energy imbalance associated with obesity. This review discusses paradoxical effects of caffeine on peripheral adenosine receptors and the possible role of adenosine in increasing metabolism is highlighted, with consideration to the potential of central rather than peripheral mechanisms for caffeine mediated BAT thermogenesis and energy expenditure. Research on the complex physiology of adipose tissue, the embryonic lineage and function of the different types of adipocytes is summarized. In addition, the effect of BAT on overall human metabolism and the extent of the associated increase in energy expenditure are discussed. The controversy surrounding the primary β-adrenoceptor involved in human BAT activation is examined, and suggestions as to the lack of translational findings from animal to human physiology and human in vitro to in vivo models are provided. This review compares and distinguishes human and rodent BAT effects, thus developing an understanding of human BAT thermogenesis to aid lifestyle interventions targeting obesity and metabolic syndrome. The focus of this review is on the effect of BAT thermogenesis on overall metabolism, and the potential therapeutic effects of caffeine in increasing metabolism via its effects on BAT.

The impact of obesity on haemodynamic profiles of pregnant women beyond 34 weeks' gestation

OBJECTIVE

We aimed to compare the haemodynamic profiles of obese and non-obese pregnant women, alongside describing the haemodynamic changes that occur in hypertensive disorders of pregnancies with an Appropriate for Gestational Age Fetus (HDP-AGA) beyond 34 weeks' gestation.

STUDY DESIGN

In this prospective case-control study, maternal haemodynamic assessment was carried out by a trained operator using an UltraSonic Cardiac Output Monitor during a routine clinical assessment after 34 weeks of gestation. Indexed and non-indexed parameters were evaluated.

MAIN OUTCOME MEASURES

Maternal hemodynamic parameters.

RESULTS

Obese and non-obese women did not differ for non-indexed parameters (Cardiac Output, Stroke Volume, Systemic Vascular Resistance). Using indexed parameters, corrected for Body Surface Area, obese women presented significantly lower Cardiac Index z-score (-0.23 ± 0.5 vs 0.26 ± 1.2; p = 0.004), Stroke Volume Index z-score (-0.27 ± 0.8 vs 0.31 ± 1.0; p < 0.0001) and significantly higher Systemic Vascular Resistance Index (0.16 ± 0.8 vs -0.36 ± 0.7; p < 0.0001). In obese women, HDP-AGA (n = 19) had significantly higher Systemic Vascular Resistance Index z-score (1.26 ± 1.7 vs 0.16 ± 0.8; P = 0.009) and significantly lower Stroke Volume Index (-0.68 ± 0.8 vs -0.27 ± 0.8; 0.049).

CONCLUSION

Using indexed parameters, differences in haemodynamic profiles between obese and non obese women can be highlighted. Obese women seem to present a cardiac maladapation to the pregnancy (reduced cardiac index and stroke volume and increased vascular resistance) that could explain the increased risk of complications in this subgroup.

Obesity with Comorbid Eating Disorders: Associated Health Risks and Treatment Approaches

Obesity and eating disorders are each associated with severe physical and mental health consequences, and individuals with obesity as well as comorbid eating disorders are at higher risk of these than individuals with either condition alone. Moreover, obesity can contribute to eating disorder behaviors and vice-versa. Here, we comment on the health complications and treatment options for individuals with obesity and comorbid eating disorder behaviors. It appears that in order to improve the healthcare provided to these individuals, there is a need for greater exchange of experiences and specialized knowledge between healthcare professionals working in the obesity field with those working in the field of eating disorders, and vice-versa. Additionally, nutritional and/or behavioral interventions simultaneously addressing weight management and reduction of eating disorder behaviors in individuals with obesity and comorbid eating disorders may be required. Future research investigating the effects of integrated medical, psychological and nutritional treatment programs addressing weight management and eating disorder psychopathology in individuals with obesity and comorbid eating disorder behaviors—such as binge eating—is necessary.

Obesity Epidemiology Worldwide

Obesity continues to be a public health concern across the globe. Obesity has a demonstrated association with health behaviors and health outcomes, such as diabetes, hypertension, and cancer. Over the past 2 decades, obesity has increased worldwide and remains highest in the United States. It is critical to understand the definition of obesity, using body mass index appropriately, recent estimates, and risk factors as a framework within which clinicians should work to help reduce the burden of obesity. This framework, including the Healthy People 2020 place-based approach to social determinants of health, is described in this article.