Cardiologia Croatica. 2017;12(7-8)

Ingrid Prkačin, Helena Zorko, Vesna Herceg-Čavrak

The progress in disease prevention and health care has prolonged life expectancy, thus increasing the global disease burden. The non-communicable diseases such as arterial hypertension, diabetes mellitus and dementia have been recognized as an inadequately clarified problem in the population all over the world. Senile dementia is an irreversible condition manifested by progressive decline of cognitive functions and considered as one of the leading health problems today. Proper care for this fragile population requires interdisciplinary approach because the pathophysiological events are underlain by hyperinsulinemia and oxidative stress at the whole body level rather than isolated to a single organ.

Vesna Herceg-Čavrak

The growing prevalence of arterial hypertension in children and adolescents is becoming an ever-greater public health problem. Longitudinal studies show that children and in particular adolescents with arterial hypertension are highly likely to become hypertensive adults, including the risk of cardiovascular disease. Although cardiovascular diseases are very rare in childhood, elevated arterial pressure can cause lesions of target organs already in childhood and adolescence. Left ventricular hypertrophy is a target organ lesion that is most frequently searched for in pediatric hypertension. Several studies have reported positive correlation between arterial pressure and left ventricular mass index, while the prevalence of left ventricular hypertrophy in children with hypertension was 8–41%. An association was found of arterial hypertension in children and adolescents with arterial stiffness, intima-media thickness, and other cardiovascular risks.

Mirsala Solak

Metabolic syndrome is a common clinical problem that encompasses interconnected conditions: hypertension, dyslipidemia, hyperglycemia, and central obesity. It is important because these patients have significantly increased cardiovascular risk and risk of developing Type 2 diabetes. These metabolic disorders more commonly manifest as a syndrome, and together they significantly increase risk in comparison with a single isolated metabolic disorder. Obesity and insulin resistance seem to play a major role in the pathogenesis of metabolic syndrome. Chronic proinflammatory state, endothelial dysfunction, and procoagulant condition contribute as well. Lifestyle modification is the initial intervention of choice, thereby improving all metabolic disorders that are part of this syndrome. Pharmacological treatment should be considered in order to reduce specific risk factors for cardiovascular disease when lifestyle measures fail. The ultimate goal of treatment is the reduction of the systemic effects of metabolic syndrome.

Ingrid Prkačin

In the last decade, we have witnessed a tendency of various medical professions to focus on an interdisciplinary approach, predominantly from the aspect of vascular health and based on advances in molecular physiology and genetics offering a translational approach not only in patient management but also for prevention of disease. The topical issue of obesity and the role of kidney in cardiovascular risk reduction have manifested through establishment of the Council on Kidney in Cardiovascular Disease at the American Heart Association to tackle the issue of obesity as part of translational medicine. Early recognition of the problem of obesity leads to reducing the sequels of not only kidney disease but also of the entire cardiovascular system, along with continuing treatment with interactive approach from pediatric through adult health care. It is crucial to change approach to the problem of obesity, especially because adipose cells are a hormonally active tissue secreting numerous cytokines that stimulate angiogenesis, thus causing systemic inflammatory event.

Dubravka Mihaljević

Obesity is a global problem and a serious chronic disease. Some non-communicablediseases, includingobesity are among the leadingcauses of morbidity and mortality globally. Obesity is associated with a variety of disorders and diseases that have direct impact on kidney function. This primarily refers to diabetes mellitus, elevated arterial pressure, and metabolic syndrome. Obesity, even without associated diseases, favors development of chronic kidney disease (CKD). Obesity is associated with a number of kidney diseases such as glomerulopathies and nephrolithiasis, and influences kidney graft survival. Metabolic syndrome and diabetes mellitus type 2 are classic risk factors for CKD and cardiovascular disease development. Inflammation is one of the most important CKD and obesity characteristics, contributing to the development of glomerulosclerosis and tubulointerstitial atrophy. Along with glomerulopathy associated with obesity, focal segmental glomerulosclerosis with significant proteinuria is directly related to obesity. Adipose patients with IgA nephropathy have poorer disease prognosis.

Ingrid Prkačin

Most of us have been committed to modern medicine as our life choice that gives true sense to our profession, aiming at continuing education and providing the best possible service and medical care on a daily basis. In Croatia, medicine is at a very high professional level, as revealed by the activities of particular branch societies, e.g., Croatian Cardiac Society, Croatian Society of Hypertension, and Croatian Society for Nephrology, Dialysis and Transplantation of Croatian Medical Association as examples of highly prolific societies that stimulate excellence in both routine work and scientific research through international collaboration and innovativeness. This in turn favors introduction of the latest achievements in medicine and integration of applied science in daily routine, to the benefit of our patients. Medicine has long ceased to be an isolated and strictly separated profession, so that an individually applicable model of integrated different medical professions is now one of the main characteristics of modern medicine. Therefore, continuous knowledge refreshment and life-long education should be adopted as a necessary segment of the development of medicine in Croatia, along with promotion of clinical practice based on empirical knowledge. Obesity is an omnipresent and topical problem all over the world; therefore, it is no surprise that obesity and kidney disease were the main topics of the World Kidney Day 2017 (1). Obesity is a condition of excessive accumulation of adipose tissue in the body with a number of adverse health sequels (2). In 2014, the World Health Organization reported alarming data pointing to the epidemic extent of obesity with more than 600 million adult persons facing this problem. In Europe, the prevalence of obesity is estimated to 4%-28% in male and 6.2%–36.5 % in female individuals. The Eurostat research published towards the end of 2016 has shown Croatia to rank eighth among the 28 European Union member countries according to the prevalence of obese persons (18.7%); the prevalence of obesity increases with age (25% of persons aged 45-72 are overweight) and shows male predominance (20.7% of men and 16.8% of women are obese). What is most disturbing is the high prevalence of obesity in young age groups, children in particular (8.8%) (3). Therefore, correct and timely recognition of the problem and ensuring appropriate treatment in childhood and adolescence is of utmost importance, along with follow up and necessary modifications in adulthood. Body mass index >25 kg/m2 is directly associated with the risk of developing chronic kidney disease (obesity induced glomerulosclerosis), while cardiovascular mortality and various comorbidities are also increased in obese individuals (4-7). One should not neglect the fact that obesity is a preventable risk factor for development of cardiovascular disease, diabetes mellitus, dyslipidemia, arterial hypertension, chronic kidney disease, etc.; therefore, professional debate and analysis of the issue, its causes, sequels and optimal therapies should remain in the focus of our professional interest and efforts. Promoting healthy lifestyle and habits, and continuing education for prevention and raising public awareness of the issue must be the key priorities in our daily work with patients. Considering the facts and circumstances mentioned above, and in continuation to the World Kidney Day held on March 9, 2017 (1), it is my great honor to be guest editor of this special issue of the *Cardiologia Croatica* journal. Our joint intention is to provide, through collaboration of various professions (pediatric and adult cardiologists and nephrologists, as well as public health professionals), a survey and latest concepts on the association between obesity and health of the brain, heart and kidney. A comprehensive and interdisciplinary approach to the prevention of renal and cardiovascular diseases is necessary from childhood to adult age. Accordingly, papers appearing in this issue have been chosen so as to point to the applicability of particular options in daily routine of not only cardiologic and nephrologic professions, but also in the work of family medicine, nurses and medical technicians, medical students, and all other healthcare workers. The contributions from the authors are greatly appreciated indeed. Special thanks go to the journal Editorial Board led by Assist Prof Ivanuša, PhD, for having recognized the topical importance of the issue of obesity and obesity related diseases, with special reference to the nephrologic-cardiologic association in childhood and adult age. I believe that all of us involved in the publication of this special issue of *Cardiologia Croatica* will be happy if this issue shows to be the preferred reading for medical students and medical professionals they will turn to all over again.

Višnja Nesek, Adam, Damir Važanić, Ingrid Prkačin

The treatment of obesity requires an interdisciplinary approach that includes a wide range of dietary measures, changes in life habits, physical activity, and the use of various medications. Most of these measures, however, only result in a limited and temporary loss of body mass, which is one of the reasons for an increasing tendency towards resorting to surgical treatment or bariatric surgery. Bariatric procedures change the capacity and anatomy of the digestive system and are recommended as treatment for obesity in persons with a BMI above 40 kg/m2 or persons with a BMI above 35 kg/m2 with concomitant diseases such as arterial hypertension, diabetes, or cardiorespiratory disorders.

Verica Kralj, Petra Čukelj

Currently, obesity is one of the leading public health problems worldwide, which has grown to a global epidemic. Overweight and obesity are among the most important modifiable risk factors for chronic non-communicable diseases, notably cardiovascular diseases, diabetes mellitus, certain malignant diseases, and chronic kidney disease (CKD). The role of obesity as a risk factor for CKD, as well as the public health relevance of CKD due to its ever growing prevalence and associated burden recorded at the international level in both industrialized and developing countries, has been increasingly recognized in recent years. ## Epidemiology of obesity An increase in the number of obese individuals has been recorded all over the industrialized world, while showing a progressive pattern also in developing countries. According to the latest data from 2015, there were more than 603 million obese adults and more than 107 million obese children in the world, the figures almost double those recorded in the 1980s (1). Body mass index (BMI, kg/m2) has been used as a measure to define obesity, whereby a BMI greater than 25 kg/m2 denotes overweight and BMI greater than 30 kg/m2 denotes obesity. Using BMI to define and study the prevalence of obesity is convenient and simple; however, the distribution of body fat, i.e. the amount of visceral fat, has been found to be a better indicator for assessment of the association of obesity and unfavorable health outcomes. There is visceral and subcutaneous body fat, and the waist to hip circumference ratio is the simplest indicator of visceral fat. Current research into the prevalence of obesity in European countries suffers from some methodological problems such as using non-representative samples, being conducted in only a few European countries, and employing non-standardized anthropometric measures that are difficult to interpret. A study carried out in 2010 in 16 European countries (2) was designed as a cross-sectional survey and included 14,685 subjects older than 18. The results obtained showed that 34.8 % of adults were overweight and 12.8 % were obese; accordingly, nearly half of the study subjects (47.6 %) were overweight or obese. Croatia is a country with with a very high prevalence of overweight and obese subjects (58.2 %), second only to Hungary. Croatia is the leading country in the prevalence of obesity of 21.5 %, as assessed on a study sample. The prevalence of obesity is lower in western and south Europe countries as compared with the central, eastern and north Europe countries (**Figure 1**). The prevalence of overweight and obesity increases with age and decreases with higher level of education. Figure 1. Percent prevalence of obesity (BMI ≥30kg/m2) and overweight/obesity (BMI ≥ 25kg/m2), overall and by country, in male and female adults from 16 European countries. Prevalence estimates for the overall population were computed weighing each country in proportion to the country specific adult population. In comparison with the United States of America (USA), the prevalence of obesity in Europe is less than half the prevalence recorded in the USA (14.0 % vs. 35.5 % in males and 11.5 % vs. 35.8 % in females). It should be noted that this was a survey in which the participants self-reported their body weight and height, and no measurements were performed. However, the potential biases and socially desirable answers probably did not differ considerably among various countries; even if absolute data on the prevalence of obesity are not precise enough, obesity in Croatia as compared with other European countries obviously poses a major public health problem. According to the recently published results of the European Health Interview Survey (EHIS) (3) conducted in 2014-2015 on the European Union (EU) population older than 15, in which Croatia also took part, 15.7 % and 34.5 % of the EU population are obese and overweight, respectively. Data on Croatia are even worse than this mean prevalence, i.e. 18.0 % of the Croatian population are obese and 37.7 % overweight, while 41.9 % have normal body weight. Overweight and obesity are more prevalent in males than in females (**Figure 2**) (4). It should be noted that the nutritional status was calculated according to anthropometric data reported by the participants. Figure 2. Percent prevalence of obesity (BMI ≥30kg/m2) and overweight/obesity (BMI ≥kg/m2), by gender, in Croatia and in EU. Prevalence estimates were computed by weighing using population weights. Based on the Croatian Health Survey conducted in 2003 on a representative sample of the population older than 18, more than half of women and two-thirds of men are overweight (BMI >25 kg/m2; 54.3 % of women and 63.2 % of men). Every fifth adult is obese (BMI >30 kg/m2; 20.6 % of women and 20.0 % of men); and one-third of women and nearly half of men are overweight (BMI 25-30 kg/m2; 33.7 % of women and 43.0 % of men) (5). Data derived from a sample of 3229 subjects included in the Croatian Health Survey 2003 and then in the CroHort study 2008 yielded the mean annual increase in the prevalence of obesity of 10.6 % in men and 11.08 % in women during the 5-year period between the 2 surveys. The cumulative incidence of obesity in this 5-year period was higher in women (20.5 %), whereas in men it was 8.7 % (6). Obesity in children is also increasing all over the world. In 2014, 41 million children younger than 5 years were obese or overweight (7). Overweight children are at an increased risk of developing cardiovascular disease, type 2 diabetes mellitus, sleep disorders and asthma, and they frequently have problems associated with being overweight in adulthood. The latest international survey of health behavior in schoolchildren (Health Behavior in School-aged Children 2013-2014) (8), also carried out in Croatia (9), included 42 countries and collected data on children aged 11, 13 and 15 years. In Croatia, the proportion of male schoolchildren with BMI exceeding the arithmetic mean value amplified by 1 standard deviation decreased with age, from 33 % in 11-year-old through 27 % in 13-year-old to 24 % in 15-year-old children, and this decrease was even more pronounced in female schoolchildren, with the respective figures of 20 %, 14 % and 9 % (**Figure 3**). Figure 3. Percentage of overweight (bodyweight at least one standard deviation above average) school children aged 11, 13 and 15, Croatia, 2013-2014. Concerning the group of 11-year-old children, Croatia ranks 11th country by the proportion of schoolchildren with BMI exceeding the arithmetic mean by 1 standard deviation. In case of the 13-year-old and 15-year-old children, Croatia ranks 14th and 20th country, respectively. Results recorded on the 11-year-old children according to gender in the selected countries included in the study are shown in **Figure 4**. Figure 4. Proportion of overweight or obese 11-year-olds, by gender, in European countries. ## Effect of obesity on chronic kidney disease According to the abovementioned study of the impact of obesity on the global disease burden, in 2015 there were 4 million deaths worldwide that were at least in part caused by high BMI, accounting for 7.1 % of all-cause deaths. In addition, obesity contributed as a causative agent to 120 million disability-adjusted life-years (DALY), another measure of the global disease burden. As many as 39 % of deaths associated with high BMI and 37 % of DALYs occurred in individuals with BMI lower than 30 (1). Cardiovascular diseases are the leading cause of deaths and DALYs associated with elevated BMI (52.4 %), while CKD ranks second as a cause of DALYs due to increased BMI (24.4 %) (1). Obesity is one of the major risk factors for development of CKD. Besides its indirect effects as the cause of diabetes mellitus and arterial hypertension that subsequently influence development of CKD, obesity has been demonstrated to act also as an independent risk factor for CKD. In overweight individuals, compensatory hyperfiltration occurs to enable the body to cope with the increased metabolic requirements. This in turn results in increased intraglomerular pressure, which may lead to kidney damage and at long term to the development of CKD. The amount of visceral fat in the body has been shown to be a risk factor for development and poorer outcome of CKD independently of BMI (10). Obesity doubles the risk of CKD relative to the normal nutritional status. Overweight is associated with an increased risk of renal calculi and kidney carcinoma (11). ## Epidemiology of chronic kidney disease Chronic kidney disease currently is a major public health problem due to its ever-growing prevalence, and consequentially for the increasing need of renal replacement therapy (RRT) with dialysis and transplantation. It is estimated that about 10 % of the European population suffer from CKD (12). Treatment by RRT is associated with lower quality of life and life expectancy in these patients, as well as great financial burden upon the society. In industrialized countries, dialysis and transplantation impose huge financial burden, which will become unsustainable considering the steady increase in the number of these patients. The increase in the prevalence of CKD certainly is caused by the population aging, increase in the prevalence of diabetes mellitus, as well as uncontrolled arterial hypertension, obesity, excessive and unreasonable use of nonsteroidal anti-inflammatory drugs, and exposure to various environmental toxins. Chronic kidney disease can be classified according to stages defined by the Kidney Disease Outcomes Quality Initiative (KDOQI). There are 5 stages as determined by the estimated glomerular filtration rate (eGFR) and indicators of the kidney structural changes (e.g., proteinuria) (13). CKD stages 3, 4 and 5 can be detected solely by eGFR determination, whereas detection of earlier CKD stages 1 and 2 also requires determination of urine albumin. CKD causes metabolic, endocrine, neurologic and cognitive disorders, as well as renal failure, and is a cardiovascular risk factor, whereas CKD complications involve all the organ systems in the body. In recent years, the association of CKD with cardiovascular morbidity and mortality has been ever better understood. Several large studies have shown that the risk of myocardial infarction or stroke in association with CKD outweighs the risk of initiating RRT. Unfortunately, the presence of CKD is frequently asymptomatic, and it is only recognized in advanced stages when the cardiovascular risk is even higher. According to some estimates, after control of other cardiovascular risk factors has been achieved, CKD increases this risk twofold to even fourfold (14). In addition, in CKD stages 1 and 2 the cardiovascular risk is identical to the risk associated with CKD stage 3, emphasizing the importance of early detection of the disease and increasing cost-effectiveness of the CKD screening programs (12). Chronic kidney disease in early stages is free from symptoms and therefore frequently unrecognized; that is why it is quite difficult to collect reliable data on its true prevalence. A recent meta-analysis aiming at assessment of the global prevalence of CKD included data from 100 studies conducted in 112 different populations. The estimated global prevalence of CKD in all studies was 13.5 % (based on data on 44 populations), whereas the estimated prevalence of CKD stages 3-5 was 10.6 % (based on data on 68 populations). Data on the CKD prevalence according to stages in all the studies involved in the analysis yielded a prevalence of 3.5 % for stage 1, 3.9 % for stage 2, 7.6 % for stage 3, 0.4 % for stage 4, and 0.1 % for stage 5 (13). Regression analysis of the correlation of CKD prevalence with age, arterial hypertension, diabetes mellitus, obesity, mean BMI and smoking habit showed positive correlation of CKD with older age, hypertension and diabetes mellitus in most of the study populations. Obesity and mean BMI were not significantly associated with CKD prevalence, whereas smoking habit showed negative correlation (however, the latter was annulled by excluding an outlier study where the low cut-off for defining smokers resulted in as many as 69.1 % of smokers in the sample) (13). Gender distribution shows the prevalence of CKD to be higher in women. In the studies involving all CKD stages, the prevalence was 12.8 % and 14.6 % in men and women, respectively. In the studies on CKD stages 3-5, the respective figures were 8.1 % and 12.1 % (13). ## Chronic kidney disease in Croatia There are no data on the prevalence of CKD in Croatia but the magnitude of the problem can be illustrated by use of indicators derived from routine healthcare and mortality statistics. Diseases of the urinary and sexual systems rank ninth by the number of deaths with 1072 dead patients in 2015, of which 494 patients died from renal failure (**Table 1**). The same group of diseases ranks seventh by the number of hospitalizations with 36,542 hospitalizations, of which 6605 hospitalizations were due to renal failure (**Table 2**). This group of diseases ranks fourth by the number of diseases and conditions recorded in family medicine offices with 597,997 cases, accounting for 5.3 % of the diseases and conditions established at primary healthcare level, of which 13,859 cases were diagnosed with renal failure (**Table 3**). It should be noted that data on diseases and conditions recorded at primary healthcare level cannot be used for determination of particular disease prevalence but only for providing an insight into the frequency of healthcare utilization at the primary healthcare level for a particular disease or condition. ### Table 1: Diseases of the genitourinary systems mortality of in Croatia, 2015 | Diseases and related health problems, ICD-10 | Code | Number | Ratio (%) | | --- | --- | --- | --- | | Renal failure | N17-N19 | 494 | 0.91% | | Diseases of the genitourinary systems | N00-N99 | 1072 | 1.98% | | *Total, diseases and conditions* | *A00-Z99* | *54205* | *100%* | [†] Source: Croatian Institute of Public Health, Croatian Central Bureau of Statistics. ### Table 2: Diseases of the genitourinary systems hospitalizations in Croatia, 2015. | Diseases and related health problems, ICD-10 | Code | Number | Ratio (%) | | --- | --- | --- | --- | | Renal failure | N17-N19 | 6605 | 1.1% | | Diseases of the genitourinary systems | N00-N99 | 36542 | 6.2% | | *Total, diseases and conditions* | *A00-Z99* | *589215* | *100%* | [†] Source: Croatian Institute of Public Health. ### Table 3: Diseases of the genitourinary systems diagnosed by the primary health care, Croatia, 2015. | Diseases and related health problems, ICD-10 | Code | 0-6 | 7-19 | 20-64 | 65 and older | Total | | --- | --- | --- | --- | --- | --- | --- | | Glomerular diseases | N00-N08 | 104 | 318 | 2693 | 1525 | 4640 | | Renal tubulo-interstitial diseases | N10-N16 | 2112 | 1172 | 7055 | 4813 | 15152 | | Renal failure | N17-N19 | 21 | 86 | 4123 | 9629 | 13859 | | Urolithiasis | N20-N23 | 16 | 678 | 26486 | 9621 | 36801 | | Cystitis | N30 | 8131 | 14894 | 126291 | 72835 | 222151 | | Other disorders of kidney and ureter (excluding N30) | N25-N39 | 5424 | 5778 | 48501 | 30189 | 89892 | | Hyperplasia of prostate | N40 | 0 | 0 | 25223 | 53415 | 78638 | | Other disorders of male genital organs | N41-N51 | 7655 | 4515 | 26190 | 10170 | 48530 | | Menopausal and other perimenopausal disorders | N95 | 0 | 0 | 1515 | 337 | 1852 | | Other disorders of female genital organs | | 1753 | 8109 | 60682 | 15938 | 86482 | | Diseases of the genitourinary systems | N00-N99 | 25216 | 35550 | 328759 | 208472 | 597997 | | *Total, diseases and conditions* | *A00-Z99* | *1129098* | *1315526* | *5613549* | *3209196* | *11267369* | [†] Source: Croatian Institute of Public Health. According to the results of EHIS (4) conducted in Croatia in 2014-2015 on a population older than 15, kidney problems were reported by 3.2 % of male and 5.6 % of female subjects. Data on renal diseases were collected from participant reports on having suffered from some of these diseases in the past 12 months. According to data from the Croatian Register of Renal Replacement Therapy, at the end of 2014 there were 4102 persons in Croatia on RRT, which was by 4.3 % less than the year before. The share of patients with kidney transplant has increased by 5.2 % as compared with previous year, whereas the percentage of hemodialysis patients has been on a decrease since 2007. The population on RRT is on increase because of the growing number of transplanted patients, despite reduction in the number of patients treated with hemodialysis and peritoneal dialysis (15). ## The possibilities of CKD prevention An alternative to the epidemic of CKD, advanced forms of renal insufficiency and increased mortality is early detection of CKD and use of preventive and therapeutic measures to slow down or halt progression of the disease. Detecting the disease in its early stages allows for its timely control while reducing the likelihood of chronic renal failure and the need for dialysis and kidney transplantation (12). Some European countries have developed programs of early CKD detection, but they vary in the diagnostic methods used, borderline eGFR values employed, and populations involved. In these programs, the most common target groups are diabetic patients, elderly, and those with hypertension. However, a pitfall of this approach is that, according to some estimates, per each individual diagnosed with hypertension or diabetes mellitus there is another one in whom hypertension or diabetes mellitus has not yet been diagnosed but has already caused damage to the organs (12). Employing eGFR as the only diagnostic method is of no use in detecting individuals in early stages of the disease when timely intervention is of crucial importance to prevent progression of the disease. In fact, the prevalence of CKD is highest in the first three stages of the disease, whereas eGFR determination can only detect ≥stage 3 CKD. Therefore, follow up determination of albuminuria should also be included in the CKD screening programs. According to the study that assessed the results of CKD screening programs in Norway, The Netherlands and Spain, the prevalence of pooled CKD stages 1 and 2 ranges from 5.1 % to 7 %, of stage 3 it is 4.5 %–5.3 %, and of stage 4 it is 0.1 %-0.4 % (12). It is also necessary to perform education and to increase population awareness of the CKD problem, as well as of the risk factors and possibilities of prevention, in particular among the groups at risk. Special emphasis should be put on education about healthy lifestyles as primary prevention, so that the disease would not develop at all. Overweight and obesity, as well as the disease they cause, are preventable to a great extent; however, favorable results in halting the epidemic of obesity are hard to achieve irrespective of the ever better knowledge and options currently available. The problem of obesity cannot be solved at the level of the individual and healthcare system but at the level of society as a whole, in particular food industry and environment sustaining healthy lifestyle. The countries where comprehensive and systematic programs of prevention of obesity and other risk factors have been implemented for years have lower morbidity and mortality rates of the most common chronic diseases. Systematic performance of the programs of prevention firstly requires legal and strategic healthcare policy documents. Concerning obesity, Croatia has passed a series of strategic documents; however, some crucial documents have not yet been enacted. Action plan for the prevention and reduction of overweight was passed for the 2010-2012 period, so currently there is no plan of prevention and control of obesity in Croatia. National guidelines for the nutrition of elementary school children were enacted in 2013, however, there is no surveillance of its implementation, whereas the planned national guidelines for the nutrition of working population are still in the preliminary phase. In 2014, the *Živjeti zdravo* (Living Healthy) national program was launched, consisting of the following components: health education; health tourism; health and diet; health and work place; health and environment; and a network of the Živjeti zdravo (Living Healthy) centers for health promotion, including those on appropriate diet and physical activity. A proposal of the action plan for prevention and surveillance of chronic non-communicable diseases has been designed, including control and prevention of the risk factors such as unfavorable dietary habits and obesity; however, this action plan has not yet been enacted. Studies of the prevalence of physical (in)activity conducted in Croatia indicate that about 60 % of the adult population are not involved in any form of physical activity. In spite of the great public health problem posed by physical inactivity in Croatia, no strategic documents to provide preconditions for efficient efforts and promotion in the area have been enacted so far. Accordingly, it is concluded that some relevant strategic documents to enable systematic implementation of the program of prevention and early detection of chronic diseases are lacking at the national level, and so are the respective human and financial resources to ensure necessary capacities for its implementation.

Bernardica Valent, Morić

The prevalence of chronic kidney disease increases in parallel with the growing prevalence of obesity, indicating an overt causal relationship of obesity and kidney disease. Nowadays, it is well known that prenatal factors, gestational age and birth mass, as well as dietary pattern from the earliest childhood have long-term effects on the individual’s susceptibility to develop obesity, diabetes mellitus, cardiovascular disease and chronic kidney disease. Obesity exerts unfavorable impact on primary kidney disease and is related to early onset of glomerulomegaly and renal hemodynamic changes due to glomerular hyperfiltration, albuminuria and elevated arterial pressure. Obese individuals with additional risk factors may develop obesity-related glomerulopathy. Recently, methods have been developed for early detection of kidney injury related to obesity, based on the fact that tubular lesions precede the onset of albuminuria, i.e. prior to glomerular injury. Body mass reduction, i.e. normalization, is the basic method in the treatment of renal complications of obesity.