The current issue of “Postępy Nauk Medycznych” – similarly to the last one – is devoted to obesity which one of the most common health issues related to life style. We present several review papers pointing the readers’ attention to the fact that obesity is related to an increased risk for metabolic syndromes, many diseases, and even earlier death. This knowledge may be helpful for doctors of many specializations, especially in their daily clinical work; namely, we hope that the current publication will help the doctors understand how to prevent and treat obesity as well as how to choose most appropriate intervention (dietetic, pharmacological, surgical) for an individual patient.

The first article written by Walicka et al. “Metabolic Syndrome – does it exist?” revealed controversies concerning diagnosis of metabolic syndrome and its usefulness in every day practice (1). The authors discuss problems arising from changes of definition, and as a consequence, difficulties derived from the lack of one binding criteria of diagnosis. The authors presented four principal outcomes causing that diagnosis of metabolic syndrome should be an individual decision of the practitioner.

In the article by Kuźmińska et al. “Obstructive sleep apnea (OSA)” the authors state that obesity is a major risk factor of OSA (2). They emphasize that in assessment of the disease, in addition to BMI, adjusted neck circumference plays an important role. The authors present hormones that are responsible for obesity and the impact of reduction of obesity in the treatment of OSA and reduction of the severity of the disease.

In the article “Obesity and osteoarthritis” written by Jasik et al. it is emphasized that obesity is a well-known risk factor for the development of knee, hip, and perhaps hand OA (3). They authors stress additionally that pathogenesis of osteoarthritis is still unclear and that future studies are required to fully understand the molecular mechanisms responsible for pathogenesis of OA.

In the next article Bogołowska-Stieblich et al. analyzed changes in cardio-vascular system in obesity and emphasized that obesity is a significant risk factor for the development of cardiovascular diseases, and it also increases the risk of sudden cardiac death (4). The authors presents results of several studies indicating a positive influence of obesity on the prognosis in patients with preexisting cardio-vascular diseases. This phenomenon is called the „obesity paradox”.

In the article „Obesity and kidney diseases” Tałałaj explained why obese persons manifest an increased the risk of renal function impairment and why glomerulopathy develops (5). He considered why in the population of patients treated with hemodialysis, higher BMI values correlate with a lower mortality rate and why in patients with past kidney transplantation obesity goes together with an increased frequency of infective complications in post-surgical wounds, an increased risk of graft loss and a higher risk of death. However, excess body weight does not eliminate benefits resulting from transplantation, because the mortality rate and the incidence of circulatorysystem diseases in transplant recipients are significantly lower than they are in patients undergoing dialysis.

The paper by Habior concentreated on nonalcoholic fatty liver disease (NAFLD) which due to its high incidence is a worldwide health concern (6). This review presents definitions, epidemiology, diagnosis and a new concept of pathogenesis of NAFLD, NAFL and NASH. The association of obesity with NAFLD was also discussed.

The next several article focus on the treatment of obesity. The first article written by Białkowska concentrated on the well-established methods of obesity treatment which is a combination of low energy diet with an increased physical activity (7). She emphasized that the effects of diet based treatment of obesity are still disappointing. Thus, it is necessary to search for new and individually-designed therapies.

The paper written by Kusz-Rynkun et al. focuses on possibilities of a pharmacological treatment of obesity (8). There were shown trials of pharmacotherapy used in the past, however those drugs were withdrawn because of the dangerous side effects. The review presented also drugs currently used in Poland, and drugs which are still in a trial stage but their efficiency gives a hope to have a new weapon in the struggle with obesity.

Surgical treatment of obesity presented by Binda et al. emphases that bariatric surgery currently seems to be the most effective method for durable weight loss (9). In contrast to conservative treatment it allows for complete resolution of the majority of co-morbidities in a large number of cases. This paper presents a general comment on the surgical treatment of obesity taking into account the most common and novel surgical methods. In the treatment of obesity, in addition to a bariatric surgeon, a multidisciplinary team plays an important role. It should consist of an experienced general practitioner, an endocrinologist, a psychologist and a dietician. In order to increase the effectiveness of treatment it is necessary to modify eating habits and daily physical activity.