Non-Classical Aspects of Obesity Pathogenesis and Their Relative Clinical Importance for Obesity Treatment.

Obesity is a chronic disease and a major public health problem due to its association with non-communicable diseases and all-cause mortality. An increased energy intake and decreased physical activity have been long recognized as the classical parameters that contribute to the development of obesity. However, several other, non-classical factors have also been associated with obesity through various complex mechanisms. Some of them are diet related, such as diet quality, dietary habits and speed of eating. Other factors are non-dietary, such as endocrine-disrupting chemicals, sleep quality and quantity, psychotropic medications and light at night. The scope of the present narrative review is to address these non-classical factors that are implicated in the pathogenesis of obesity, to clarify their potential role in the management of obesity and, where possible, to provide some practical clinical recommendations.

Ketone bodies and the heart.

Ketone bodies are low chain organic substances with four carbon atoms, with ß-hydroxybutyric acid and acetone being the main ketone bodies in blood circulation. Under physiological conditions their levels are low while during conditions of oxidative stress, such as exercise, fasting state and acute illness, ketone body levels are increased. Recent findings have shown that in patients with heart failure their plasma concentration is increased. There is a positive correlation between increased energy metabolism of myocardial cells and the levels of ß-hydroxybutyric acid and acetone. Furthermore, it has been hypothesized that the mild ketosis caused by sodium glucose cotransporter 2 inhibitors is one of the possible pathogenetic mechanisms explaining the significant cardiovascular and renal benefits observed in patients with type 2 diabetes treated with these agents. The aim of the present review is to summarize the role of ketone bodies in both normal and pathological conditions, such as heart failure.

"Is obesity linked to aging?": adipose tissue and the role of telomeres.

Obesity is a condition in which excess or abnormal fat accumulation may present with adverse effects on health and decreased life expectancy. Increased body weight and adipose tissue accumulation amplifies the risk of developing various age-related diseases, such as cardiovascular disease, type 2 diabetes mellitus, musculoskeletal disorders, respiratory diseases and certain types of cancer. This imbalance in body composition and body weight is now recognized as a state of increased oxidative stress and inflammation for the organism. Increasing oxidative stress and inflammation affect telomeres. Telomeres are specialized DNA-protein structures found at the ends of eukaryotic chromosomes and serve as markers of biological aging rate. They also play a critical role in maintaining genomic integrity and are involved in age-related metabolic dysfunction. Erosion of telomeres is hazardous to healthy cells, as it is a known mechanism of premature cellular senescence and loss of longevity. The association of telomeres and oxidative stress is evident in cultured somatic cells in vitro, where oxidative stress enhances the process of erosion with each cycle of replication. Shorter telomeres have been associated with increasing body mass index, increased adiposity, and more recently with increasing waist to hip ratio and visceral excess fat accumulation. Furthermore, many of the metabolic imbalances of obesity (e.g. glycemic, lipidemic, etc.) give rise to organ dysfunction in a way that resembles the accelerated aging process. This article is a non-systematic review of the evidence linking obesity and accelerated aging processes as they are regulated by telomeres.

Dietary fat intake as risk factor for the development of diabetes: multinational, multicenter study of the Mediterranean Group for the Study of Diabetes (MGSD).

OBJECTIVE: To investigate the role of dietary factors in the development of type 2 diabetes. RESEARCH DESIGN AND METHODS: In the context of the Multinational MGSD Nutrition Study, three groups of subjects were studied: 204 subjects with recently diagnosed diabetes (RDM), 42 subjects with undiagnosed diabetes (UDM) (American Diabetes Association criteria-fasting plasma glucose [FPG] > or =126 mg/dl), and 55 subjects with impaired fasting glucose (IFG) (FPG > or =110 and <126 mg/dl). Each group was compared with a control group of nondiabetic subjects, matched one by one for center, sex, age, and BMI. Nutritional habits were evaluated by a dietary history method, validated against the 3-day diet diary. In RDM, the questionnaire referred to the nutritional habits before the diagnosis of diabetes. Demographic data were collected, and anthropometrical and biochemical measurements were taken. RESULTS: Compared with control subjects, RDM more frequently had a family history of diabetes (49.0 vs. 14.2%; P < 0.001), exercised less (exercise index 53.5 vs. 64.4; P < 0.01), and more frequently had sedentary professions (47.5 vs. 27.4%; P < 0.001). Carbohydrates contributed less to their energy intake (53.5 vs. 55.1%; P < 0.05), whereas total fat (30.2 +/- 0.5 vs. 27.8 +/- 0.5%; P < 0.001) and animal fat (12.2 +/- 0.3 vs. 10.8 +/- 0.3%; P < 0.01) contributed more and the plant-to-animal fat ratio was lower (1.5 +/- 0.1 vs. 1.8 +/- 0.1; P < 0.01). UDM more frequently had a family history of diabetes (38.1 vs. 19.0%; P < 0.05) and sedentary professions (58.5 vs. 34.1%; P < 0.05), carbohydrates contributed less to their energy intake (47.6 +/- 1.7 vs. 52.8 +/- 1.4%; P < 0.05), total fat (34.7 +/- 1.5 vs. 30.4 +/- 1.2%; P < 0.05) and animal fat (14.2 +/- 0.9 vs. 10.6 +/- 0.7%; P < 0.05) contributed more, and the plant-to-animal fat ratio was lower (1.6 +/- 0.2 vs. 2.3 +/- 0.4; P < 0.05). IFG differed only in the prevalence of family history of diabetes (32.7 vs. 16.4%; P < 0.05). CONCLUSIONS: Our data support the view that increased animal fat intake is associated with the presence of diabetes.