Metabolic dysregulation in obese women and the carcinogenesis of gynecological tumors: A review.

Obesity is a significant health issue associated with increased cancer risks, including gynecological malignancies. The worldwide rise in obesity rates is significantly impacting both cancer development and treatment outcomes. Adipose tissue plays a crucial role in metabolism, secreting various substances that can influence cancer formation. In obese individuals, dysfunctional adipose tissue can contribute to cancer development through inflammation, insulin resistance, hormonal changes, and abnormal cholesterol metabolism. Studies have shown a strong correlation between obesity and gynecological cancers, particularly endometrial and breast cancers. Obesity not only increases the risk of developing these cancers but is also associated with poorer outcomes. Additionally, obesity affects the perioperative management of gynecological cancers, requiring specialized care due to increased complications and resistance to therapy. Treatment strategies for managing metabolic dysregulation in patients with gynecological cancers include weight management, statin therapy, and insulin-sensitizing medications. Emerging studies suggest that interventions like intermittent fasting and caloric restriction may enhance the effectiveness of cancer treatments. Furthermore, targeting cholesterol metabolism, such as with statins or proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, shows potential in cancer therapy. In conclusion, addressing metabolic issues, particularly obesity, is crucial in preventing and treating gynecological malignancies. Personalized approaches focusing on weight management and metabolic reprogramming may improve outcomes in these patients.

The Effect of Recruitment Maneuver on Static Lung Compliance in Patients Undergoing General Anesthesia for Laparoscopic Cholecystectomy: A Single-Centre Prospective Clinical Intervention Study.

Background and Objectives: The aim of this study was to examine whether the use of an alveolar recruitment maneuver (RM) leads to a significant increase in static lung compliance (Cstat) and an improvement in gas exchange in patients undergoing laparoscopic cholecystectomy. Material and Methods: A clinical prospective intervention study was conducted. Patients were divided into two groups according to their body mass index (BMI): normal-weight (group I) and pre-obese and obese grade I (group II). Lung mechanics were monitored (Cstat, dynamic compliance-Cdin, peak pressure-Ppeak, plateau pressure-Pplat, driving pressure-DP) alongside gas exchange, and hemodynamic changes (heart rate-HR, mean arterial pressure-MAP) at six time points: T1 (induction of anesthesia), T2 (formation of pneumoperitoneum), T3 (RM with a PEEP of 5 cm H2O), T4 (RM with a PEEP of 7 cm H2O), T5 (desufflation), and T6 (RM at the end). The RM was performed by increasing the peak pressure by +5 cm of H2O at an equal inspiration-to-expiration ratio (I/E = 1:1) and applying a PEEP of 5 and 7 cm of H2O. Results: Out of 96 patients, 33 belonged to group I and 63 to group II. An increase in Cstat values occurred after all three RMs. At each time point, the Cstat value was measured higher in group I than in group II. A higher increase in Cstat was observed in group II after the second and third RM. Cstat values were higher at the end of the surgical procedure compared to values after the induction of anesthesia. The RM led to a significant increase in PaO2 in both groups without changes in HR or MAP. Conclusions: During laparoscopic cholecystectomy, the application of RM leads to a significant increase in Cstat and an improvement in gas exchange. The prevention of atelectasis during anesthesia should be initiated immediately after the induction of anesthesia, using protective mechanical ventilation and RM.

Potential health benefits of blueberry and raspberry pomace as functional food ingredients: Dietetic intervention study on healthy women volunteers.

The fruit juice industry generates pomace as a valuable by-product especially rich in polyphenols, dietary fibers, vitamins, minerals, and unsaturated fatty acids. In the cookies used in this study, 30% of the gluten-free flour was replaced with dried and ground blueberry and raspberry pomace, rich source of polyphenols, dietary fibers, linoleic and alpha-linolenic acid. In order to examine whether the addition of blueberry and raspberry pomace in cookie formulation can have beneficial effects on certain blood parameters and anthropometric measurements, the designed cookies were tested in 20 healthy, normally fed female subjects, aged 30-50 years (41.35 ± 8.58 years) over four-week dietetic intervention study. Significant changes in the composition of fatty acids serum phospholipids, decrease in LDL-cholesterol level (20.16%), increase in adiponectin level (25.52%) and decrease in ALT and AST values were observed, thus indicating that inclusion of cookies containing blueberry and raspberry dried and ground pomace to usual diet might have positive effects on certain cardiovascular risk factors and liver function indicators.

New Sub-Phenotyping of Subjects at High Risk of Type 2 Diabetes: What Are the Potential Clinical Implications?

Prediabetes is defined as a condition of abnormal glucose metabolism, characterised by plasma glucose above normal range but not as high as required for the diagnosis of diabetes mellitus (DM). It represents a heterogeneous entity of intermediate glucose metabolism, including impaired fasting glucose, impaired glucose tolerance, and borderline glycated haemoglobin. Prediabetes is being increasingly recognised as an important metabolic state not only predisposing to a higher probability of future progression to DM, but also to an increased risk of different micro- and macrovascular complications. The recently proposed sub-phenotyping of individuals at increased risk of type 2 DM, which distinguishes six different clusters, offers the opportunity for the improvement in screening, prevention, and treatment algorithms. Such progress should also enable more efficient and cost-effective strategies aimed at decreasing the disease burden associated with prediabetes.

Methods for algorithmic diagnosis of metabolic syndrome.

Metabolic Syndrome (MetS) is associated with the risk of developing chronic disease (atherosclerotic cardiovascular disease, type 2 diabetes, cancers and chronic kidney disease) and has an important role in early prevention. Previous research showed that an artificial neural network (ANN) is a suitable tool for algorithmic MetS diagnostics, that includes solely non-invasive, low-cost and easily-obtainabled (NI&LC&EO) diagnostic methods. This paper considers using four well-known machine learning methods (linear regression, artificial neural network, decision tree and random forest) for MetS predictions and provides their comparison, in order to induce and facilitate development of appropriate medical software by using these methods. Training, validation and testing are conducted on the large dataset that includes 3000 persons. Input vectors are very simple and contain the following parameters: gender, age, body mass index, waist-to-height ratio, systolic and diastolic blood pressures, while the output is MetS diagnosis in true/false form, made in accordance with International Diabetes Federation (IDF). Comparison leads to the conclusion that random forest achieves the highest specificity (SPC=0.9436), sensitivity (SNS=0.9154), positive (PPV=0.9379) and negative (NPV=0.9150) predictive values. Algorithmic diagnosis of MetS could be beneficial in everyday clinical practice since it can easily identify high risk patients.

AGING, HEART RATE VARIABILITY AND METABOLIC IMPACT OF OBESITY.

The relationship between aging and changes in heart rate variability (HRV) could depend on the metabolic profile of obese people, i.e. metabolically healthy obese (MHO) and metabolically unhealthy obese (MUO). We aimed to determine the age at which obesity related autonomic dysfunction becomes significant and whether it decreases differently according to metabolic profile. We analyzed HRV in 99 adults using Wildman's criteria for metabolic profile and 5-minute HRV for autonomic nervous system. In MHO, high frequency (HF) decreased in the 4th decade of life. In MUO, standard deviation of R-R intervals (SDNN), root mean square of successive differences of all R-R intervals (RMSSD), number of adjacent intervals differing by more than 50 ms expressed as percentage of all intervals in the collecting period (pNN50), HF, low frequency (LF), LF/HF (LF divided by HF) and total power (TP) decreased in the 4th decade of life (partial shared variance 28%-36%). In conclusion, an age dependent decrease of HRV occurs in MUO between the third and fifth decade of life. In MHO, HF significantly decreases around the age of 40 years. Cardiometabolic profile influences metabolic aging, altering the autonomic nervous system.

Febrile neutropenia induces changes in insulin sensitivity similar to obesity.

Background/aim: To determine insulin sensitivity before chemotherapy and during febrile neutropenia in patients with acute leukemia and to assess its effect on the number of documented infections, the severity of infection and the outcome of the first hospitalization. To compare insulin sensitivity in the study group to a group of patient with obesity. Materials and methods: The study group consisted of 30 (37% of the total number) patients with newly diagnosed acute leukemia. Testing of insulin sensitivity was done before chemotherapy and during febrile neutropenia. Parameters were compared to a group of 30 age, and sex matched patients with obesity. Results: Insulin sensitivity was normal before chemotherapy. Obese patients were characterized by insulin resistance. Febrile neutropenia led to the development of insulin resistance (t = -2.43, p = 0.021). The level of insulin resistance was in positive correlation with fibrinogen (r = 0.59, p < 0.05). Patients with a documented site of infection had higher fasting insulin and an insulin resistance before chemotherapy (t = -2.38, p = 0.024). Insulin sensitivity did not influence outcome of the first hospitalization. Conclusion: Patients with acute leukemia in febrile neutropenia developed changes in insulin sensitivity similar to those seen in obesity. Insulin resistance was present in patients with a documented site of infection, and it worsened with the extent of inflammation. The outcome of the first hospitalization was not affected.

Chronic Latent Magnesium Deficiency in Obesity Decreases Positive Effects of Vitamin D on Cardiometabolic Risk Indicators.

BACKGROUND: Obesity and micronutrient deficiencies contribute to the risk of cardiometabolic diseases such are type 2 diabetes mellitus and Cardiovascular Disease (CVD). OBJECTIVE: We examined the frequency of concomitant deficit of Magnesium (Mg) and vitamin D in obese patients and evaluated the connection of these combined deficiencies with indicators of cardiometabolic risk in non-diabetic subjects. METHODS: Non-diabetic middle aged adults (n = 80; mean age 36 ± 4 years, 52% women) were recruited based on weight/adiposity parameters [i.e. Body Mass Index (BMI) and body fat percentage (FAT%)]. Cardiometabolic risk indicators [insulin resistance (Homeostatic Model Assessment for Insulin Resistance (HOMA-IR)) and CVD risk (Framingham risk score for predicting 10-year CVD)], Mg status (i.e. total serum Mg concentration (TMg), Chronic Latent Mg Deficiency (CLMD) - 0.75-0.85 mmol/L), vitamin D status (i.e. serum concentration of 25-hydroxyvitamin D (25(OH)D), vitamin D deficiency <50 nmol/l) were assessed. RESULTS: Among obese subjects 36% presented a combination of vitamin D deficiency and CLMD. In all studied patients, 25(OH)D and TMg levels both, individually and combined, showed a negative linear correlation with HOMA-IR and CVD risk. In subjects with CLMD (TMg <0.85 mmol/L), a negative linear coefficient was found between 25(OH)D and, HOMA-IR and CVD risk, compared with subjects with normal TMg status (TMg ≥0.85 mmol/L). CONCLUSION: CLMD and vitamin D deficiency may commonly be present in obese non-diabetic subjects. Individually and combined, both deficiencies predispose non-diabetic patients to increased risk of cardiometabolic diseases. Maintaining normal Mg status may improve the beneficial effects of vitamin D on cardiometabolic risk indicators.

PCSK9 and Hypercholesterolemia: Therapeutic Approach.

Despite the intensive research and progress in modern pharmacotherapy, hypercholesterolemia and related cardiovascular complications remain one of the leading causes of mortality and disability in the modern world. A significant contribution to the treatment of hypercholesterolemia was made by the discovery of proprotein convertase subtilisin/kexin type 9 (PCSK9). This enzyme is responsible for the degradation of the low-density lipoprotein (LDL) receptor (LDLR) found at the surface of the plasma membrane in the liver and directly associated with serum LDL level. Limitations in standard therapy used in the treatment of lipid disorders have led to the development of new drugs, such as an inhibitor of PCSK9. Over the past years, the greatest achievement in discovering the PCSK9 inhibitor was made by designing monoclonal antibodies that disable PCSK9 to bind LDLR and RNA interference to reduce PCSK9 production, but one of the main disadvantages is costeffectiveness. In this review, we will summarize the most recent findings of basic and clinical studies which focus on PCSK9 function, regulation and therapeutic target for the treatment of hypercholesterolemia and associated cardiovascular diseases.

Association between Apolipoproteins AI and B and Ultrasound Indicators of Carotid Atherosclerosis.

BACKGROUND: Apolipoproteins A-I and B (apoA-I and apoB) may be better indicators of the risk of cardiovascular and cerebrovascular diseases than conventional risk factors (RFs). The onset of ischemic stroke (IS) may be preceded by the development of atherosclerotic changes in carotid arteries, which can be detected by ultrasound. Only a certain % of patients with IS have an (underlying) carotid etiology. OBJECTIVE: The aim of our study was to determine the association between ultrasound indicators of carotid atherosclerosis and the presence of apolipoproteins and other biomarkers in patients with IS. METHODS: The study included 120 patients with clinically first, non-cardioembolic ischemic stroke in the carotid circulation. For all patients the following data were recorded: risk factors (hypertension, diabetes, hyperlipoproteinemia, smoking, obesity, metabolic syndrome, (MetS) hyperhomocysteinemia and inflammation), and levels of blood pressure, glucose, glycosylated hemoglobin, lipids, apoA-I and apoB apolipoproteins, body mass index, homocysteine, and C-reactive protein (CRP). Carotid duplex ultrasound was used to measure carotid intima media thickness (cIMT) and determine the presence of an unstable (hypoechogenic) plaque. RESULTS: The most significant associations were found between cIMT and older age (ß=0.230; p=0.006), lower concentrations of apoA-I (ß=-0.244; p=0.008) and a higher apoB/apoA-I ratio (ß=0.247; p=0.007). The presence of a hypoechogenic plaque was most significantly associated with increased concentrations of apoB (OR=2.29; 95% CI=4.9-173.5; p<0.0001), the presence of MetS (OR=9.2; 95% CI=2.9-29.2; p<0.0001) and elevated CRP (OR=2.7; 95% CI=1.1-6.9; p = 0.046). CONCLUSION: Among RFs and their biomarkers, apoA-I, apoB and the apoB/apoA-I ratio showed strong association with ultrasound indicators of carotid atherosclerosis in IS patients.

Association between anthropometric measures of regional fat mass and heart rate variability in obese women.

AIM: Impaired autonomic function could be the mechanism for the development of cardiometabolic diseases in obesity. Hence, simple anthropometric measures of overall and central obesity could be screening markers for autonomic imbalance. We analysed the relationship between heart rate variability (HRV) parameters and obesity indicators. METHODS: Sixty-three obese women underwent blood pressure, lipids and anthropometric measurements, body composition assessment, HOMA (homeostasis model assessment) index calculation and short-term HRV analysis. RESULTS: The correlation between obesity indicators and HRV parameters was influenced by age. In the multiple regression model, sagittal abdominal diameter (SAD) was a significant negative predictor of lnLF/HF (logarithmically transformed ratio of low to high frequencies) and lnLFnorm, and positive predictor of HFnorm (normalized high frequencies); the significant relationship remained even after adjustment for age, HOMA, blood pressure, lipid profile, menopause, body mass index (BMI) and body fat percentage (FAT). Anterior forearm skinfold showed inverse association with HRV. Correlation between waist circumference and waist-to-height ratio (WHtR) with lnLF/HF, as well as between anterior thigh skinfold with lnLF/HF, LFnorm (normalised low frequencies) and HFnorm was lost after further adjustments. CONCLUSION: Among all anthropometric measures, SAD and anterior forearm skinfold thickness showed the highest predictive ability for HRV. Markers of lower sympathetic and higher cardiac parasympathetic activity corresponded with indicator of central obesity, while indicators of peripheral obesity showed completely opposite relationship with markers of cardiac autonomic activity.

The Wnt/ß-catenin Signalling Pathway Inhibitor Sclerostin is a Biomarker for Early Atherosclerosis in Obesity.

BACKGROUND: Sclerostin is an inhibitor of the wingless-type mouse mammary tumor virus integration site family/ß-catenin signalling pathway (WßcSP), which plays an important role in bone metabolism and in vascular biology. It could act protective regarding atherosclerosis development through its effect on WßcSP in vascular cells. Nevertheless, results of studies analyzing association between circulating sclerostin level (CSL) and atherosclerotic diseases (AD) are showing conflicting results. The aim of this study is to test the value of CSL as a biomarker of subclinical carotid atherosclerosis (SCA) in obese persons. METHODS: The cross-sectional study included 50 obese persons without previous history of diabetes and AD. Participants underwent adequate anthropometrical, ultrasound and laboratory examinations, including 2h 75 g oral glucose tolerance test (OGTT). RESULTS: Only the presence of SCA significantly indirectly correlated with CSL (p<0.05). Based on the median value of CSL, we formed two groups: low CSL (CSL<7.9 pmol/l) and high CSL (CSL>7.9 pmol/l). There were no statistically significant differences in general (gender, age and current smoking) and anthropometrical characteristics (body mass index, waist circumference, systolic and diastolic blood pressure), inflammatory (total white blood cell count, erythrocyte sedimentation rate, fibrinogen, C-reactive protein and uric acid), glucose metabolism (fasting and 2h OGTT blood glucose, glycated hemoglobin and presence of dysglycemia) and lipid metabolism (low density lipoprotein cholesterol, high density lipoprotein cholesterol, triglycerides, apolipoprotein A-I, apolipoprotein B and lipoprotein (a)) parameters between low and high CSL groups. Low CSL group had significantly higher incidence of SCA (p<0.05). CONCLUSION: CSL could serve as a useful biomarker of early atherosclerosis in obese persons without previous history of cardiometabolic disorders but the final conclusion requires further testing.

1h Post-load Blood Glucose in the Identification of Proatherogenic Cardiometabolic Profile in Obesity.

BACKGROUND AND AIM: Current data show that 1h oral glucose tolerance test (OGTT) blood glucose (1h-BG) might identify persons at increased risk of developing type 2 diabetes and cardiovascular diseases more precisely than fasting blood glucose (FBG) and 2h OGTT blood glucose (2h-BG). The aim of study was to determine whether is justified to use 1h-BG over traditional blood glucose measurements, in cardiometabolic profiling of obese individuals. METHOD: Cross-sectional study enrolled 60 obese individuals without previous history of diabetes and other cardiometabolic disorders. Anthropometrical, ultrasound and laboratory examinations were conducted. RESULTS: All three parameters significantly directly correlated with age, body mass index, waist circumference, erythrocyte sedimentation rate, C-reactive protein, triglycerides and glycated hemoglobin. FBG and 1h-BG significantly directly correlated with alanine transaminase, gammaglutamyltransferase and total cholesterol. FBG significantly directly correlated with fibrinogen and aspartate transaminase, 1h-BG with systolic blood pressure and 2h-BG with diastolic blood pressure. None of parameters significantly correlated with gender, total white blood cell count, uric acid, 25-hydroxyvitamin D, high density lipoprotein cholesterol, low density lipoprotein cholesterol, serum adiponectin and albuminuria. Differences in correlation coefficients were not statistically significant. Individuals with 1h-BG >8.6 mmol/l had much more proatherogenic cardiometabolic profile, as well as higher incidence of dysglycemia, metabolic syndrome (MetS) and non-alcoholic fatty liver disease (NAFLD) than ones with 1h-BG <8.6 mmol/l, but all differences were driven by the average value of glycemia. There were no statistically significant differences in ability of predicting MetS, NAFLD and pathologically increased carotid artery intima media thickness among analyzed glucose metabolism parameters. CONCLUSION: 1h-BG is not superior to FBG and 2h-BG in the identification of proatherogenic cardiometabolic profile in obesity.

Vitamin D status and circulating biomarkers of endothelial dysfunction and inflammation in non-diabetic obese individuals: a pilot study.

INTRODUCTION: Obesity and inadequate vitamin D status are associated with endothelial dysfunction and cardiovascular disease. We evaluated the associations between vitamin D status (i.e. serum levels of 25-hydroxyvitamin D (25(OH)D)), biomarkers of endothelial dysfunction (i.e. serum concentrations of soluble intercellular adhesion molecule 1 (sICAM-1) and soluble E-selectin (sE-selectin)), inflammatory markers (i.e. high-sensitivity C-reactive protein (hsCRP) and fibrinogen) and cardiometabolic risk factors. MATERIAL AND METHODS: Fifty obese (body mass index (BMI) ≥ 30 kg/m2) non-diabetic adults (mean age: 36.2 ±5.4 years) without pre-existing cardiovascular abnormalities and 25 clinically healthy, normal weight and age-matched individuals were included. Anthropometric parameters, markers of glucose and lipid metabolism, and serum levels of inflammatory and endothelial dysfunction biomarkers were assessed in all subjects. RESULTS: The mean serum 25(OH)D level was significantly lower in the obese group than in controls (33.5 ±15.2 vs. 60.1 ±23.1 nmol/l; p < 0.001). In the obese group, sE-selectin (36.4 (32.1-47.2) vs. 32.4 (24.6-35.5) ng/ml, p < 0.05) and hsCRP (6.0 ±3.4 vs. 3.5 ±1.0 mg/l, p < 0.05) were significantly higher in individuals with lower than median vitamin D levels (i.e. 31 nmol/l) compared with those with higher vitamin D levels. In multivariable linear regression analysis, hsCRP (ß = -0.43; p < 0.001) and sE-selectin (ß = -0.30; p = 0.03) were independently and significantly associated with serum 25(OH)D levels in the obese group. CONCLUSIONS: Vitamin D levels may be related to increased levels of biomarkers of endothelial dysfunction and inflammation in obese non-diabetic individuals.

Surrogates of Insulin Sensitivity and Indices of Cardiometabolic Profile in Obesity.

BACKGROUND AND OBJECTIVES: Obesity is often associated with insulin resistance (IR). We considered different IR indexes: the Homeostasis Model Assessment-Insulin Resistance (HOMA-IR) index, the two specimen (0 and 120 min) oral glucose tolerance test Matsuda Index (MI) and the Homeostasis Model Assessment-Adiponectin (HOMA-AD) index. These IR indexes were compared with indicators of the cardiometabolic profile. METHOD: This cross-sectional study enrolled 60 obese individuals without previous history of diabetes. Anthropometrical, ultrasound and laboratory examinations were conducted. RESULTS: All 3 indexes significantly correlated with indicators of central obesity, systolic and diastolic blood pressure, inflammation parameters, liver enzymes, HbA1c and some lipid parameters. The majority of correlation coefficients were the highest for HOMA-AD, but only the difference in correlation with waist circumference comparing with MI was statistically significant. HOMA-IR directly, and MI indirectly, significantly correlated with age, while HOMA-AD significantly directly correlated with the mean carotid artery intima media thickness (CAIMT). MI showed the best performances in predicting non-alcoholic fatty liver disease and pathologically increased CAIMT; HOMA-AD was the best in predicting metabolic syndrome, while HOMA-IR demonstrated the poorest performances in the prediction of all 3 conditions. There were no statistically significant differences in predicting performances of the analysed indexes. CONCLUSION: The HOMA-AD and MI are not superior compared with the HOMA-IR, in the identification of obese individuals with a proatherogenic cardiometabolic profile.

What kind of Relationship is Between Body Mass Index and Body Fat Percentage?

Although body mass index (BMI) and body fat percentage (B F %) are well known as indicators of nutritional status, there are insuficient data whether the relationship between them is linear or not. There are appropriate linear and quadratic formulas that are available to predict B F % from age, gender and BMI. On the other hand, our previous research has shown that artificial neural network (ANN) is a more accurate method for that. The aim of this study is to analyze relationship between BMI and B F % by using ANN and big dataset (3058 persons). Our results show that this relationship is rather quadratic than linear for both gender and all age groups. Comparing genders, quadratic relathionship is more pronounced in women, while linear relationship is more pronounced in men. Additionaly, our results show that quadratic relationship is more pronounced in old than in young and middle-age men and it is slightly more pronounced in young and middle-age than in old women.

ANN Prediction of Metabolic Syndrome: a Complex Puzzle that will be Completed.

The diagnosis of metabolic syndrome (MetS) has a leading role in the early prevention of chronic disease, such as cardiovascular disease, type 2 diabetes, cancers and chronic kidney disease. It would be very greatful that MetS diagnosis can be predicted in everyday clinical practice. This paper presents artificial neural network (ANN) prediction of the diagnosis of MetS that includes solely non-invasive, low-cost and easily-obtained diagnostic methods. This solution can extract the risky persons and suggests complete tests only on them by saving money and time. ANN input vectors are very simple and contain solely non-invasive, low-cost and easily-obtained parameters: gender, age, body mass index, waist-to-height ratio, systolic and diastolic blood pressures. ANN output is M e t S-coefficient in true/false form, obtained from MetS definition of International Diabetes Federation (IDF). ANN training, validation and testing are conducted on the large dataset that includes 2928 persons. Feed-forward ANNs with 1-100 hidden neurons were considered and an optimal architecture were determinated. Comparison with other authors leads to the conclusion that our solution achieves the highest positive predictive value P P V = 0.8579. Further, obtained negative predictive value N P V = 0.8319 is also high and close to PPV, which means that our ANN solution is suitable both for positive and negative MetS prediction.