Obesity is the result of an interplay between genetic and environmental factors which interact with energy metabolism and fat tissue. Obesity is defined as excessive accumulation of body fat due to high energy intake that may impair health. It is a complex and multifactorial metabolic disorder that affects not only adults but children as well. The prevalence of childhood obesity is rising in all pediatric age groups especially in developed countries but also in developing countries, and is an increasing health concern across the world
11-13. Childhood obesity should be taken seriously by parents to prevent the development of serious health problems now and in the future.
Increased prevalence of obesity is associated with increased prevalence of obesity-related disorders. Many health issues are associated with obesity, including cardiovascular disease, hypertension, type 2 diabetes and hepatosteatosis14. The liver is an important site for the synthesis of acute phase proteins. Monokines IL-1, IL-6 and TNF-α, which are synthesized and released by stimulated monocytes are considered as me-diators of acute phase proteins in the liver15. Inflammatory cytokines are secreted by the adipose tissue and cause liver disease. After being synthesized in a local lesion at the initial stage of inflammation, IL-6 moves to the liver via bloodstream, leading to a rapid induction of several acute phase proteins (16). Hepatosteatosis is a well-known complication of obesity and the most common liver disease across the globe. Hepatosteatosis is defined as steatosis affecting more than 5% of the liver weight in the absence of excessive alcohol intake, medication use or a genetic disorder4. Hepatosteatosis is of significance because 25% of affected patients develop steatohepatitis and 25% of them develop liver cirrhosis. While the incidence of fatty liver disease ranges from 10 to 77% in obese children, 38% of children with fatty liver disease are obese. In line with previous reports, hepatosteatosis was identified in 50.7% of the obese patients in the current study. Hepatosteatosis is infrequent in children under 8 years of age, and the mean age at presentation is 12 years17. Consistently, the mean age of the patients with hepatosteatosis was 136 months in our study. Children with hepatosteatosis are mostly obese and asymptomatic. Hepatosteatosis has gained significance worldwide due to its common occurrence in the general population and its progression to liver cirrhosis and liver failure. With an alarmingly increasing prevalence across the globe, obesity is a major nutritional problem that affects 25-30% of children18,19.
In obesity, leptin and other chemokines are involved in the transmigration of bone marrow-derived monocytes into fat tissue, resulting in increases in IL-6, TNF-α and many other cytokines. In turn, this leads to an elevation of acute phase proteins such as CRP. All of these events explain the chronic low-grade inflammation that actively contributes to changes in hematologic parameters 2. In obese individuals, inflammatory cells infiltrate into adipose tissue and inflammatory cells and adipocytes induce chronic systemic inflammation by producing cytokines20,21. Neutrophils, lymphocytes and platelets are major components of blood that are involved in inflammatory process 22. In recent years, it has been shown that NLR and PLR are mark-ers of systemic inflammation and may be correlated with prognosis in a number of cardiovascular diseases, malignancies and chronic inflammatory conditions. Both NLR and PLR can be easily measured and have emerged as practical markers that can provide valuable information for the diagnosis and prognosis of various diseases. Increased neutrophil count and elevated NLR have been demonstrated in obese patients in a study by Atmaca et al.23. In a study by Aydın et al. involving obese adolescents, greater NLR was found in obese patients with hepatosteatosis than in healthy controls24. In a study by Furuncuoğlu et al.25 in 223 obese patients aged 18 to 65 years, higher white blood cell and neutrophil counts were detected in obese individuals versus control group. Similarly, neutrophil count and NLR were found to be higher in obese patients with hepatosteatosis compared to patients without hepatosteatosis and the difference between the two groups was significant. Platelets interact with endothelial cells, leukocytes and progenitor cells, thereby triggering migration of inflammatory cells into the site of injury and release of inflammatory cytokines in abundance and eventually, creating an inflammatory environment in the lesion area. İn inflammatory events, the platelet count increases and lymphocyte count decreases, resulting in an increase in the platelet/lymphocyte ratio26. NLR and PLR can be easily obtained through peripheral blood count to identify inflammation. Both NLR and PLR measurements cost less and are more valuable compared to some other markers including IL-6, IL-8 and TNF-alpha. In this study, obese patients with steatosis showed higher neutrophil and platelet counts and lower lymphocyte count compared to obese patients without steatosis.
A number of limitations should be noted for this study. First, this was a single-center study with a limited sample size. Secondly, due to the retrospective design of the study, we cannot exclude the possibility that potential preanalytical errors in routine evaluation of hemogram analysis may have been overlooked. Nevertheless, preanalytical process for hemogram analysis is thoroughly followed at our center.