An accurate calculation of energy expenditure (REE) is necessary for estimating energy needs in prostate cancer. The purpose of this research was to evaluate the accuracy of the established new equation for predicting REE in malign and benign prostate patients versus the accuracy of the previously used predictive equations based on REE measured by indirect calorimetry. In the present study findings demonstrated that the previous equations used to predict the REEs of adults with prostate cancer (over the age of 40) show a large disparity between the two, contain a large number of errors, and frequently result in over- or underestimating REE.
The factors of fat-free mass (FFM), body size, age, gender, and body fat, among others, are the most important in determining resting metabolic rate [41]. The study emphasized the importance of total body fat mass, fat free mass, and abdominal adiposity in determining RMR [42]. Table 2 was present the subjects' primary characteristics, but no statistical significance was found. This situation was thought to be related to the homogeneous distribution of the groups.
Many factors could contribute to errors in estimating REE in cancer patients. To begin, metabolic abnormalities that may occur in cancer patients (such as tumor energy demand, systemic inflammation, obesity, FFM, and fat mass (FM) metastases in advanced cancer stages can impact the performance of REE prediction equations [7, 43–45]. When making nutritional recommendations for cancer patients, it is important to first determine whether or not their metabolism and energy expenditure have been altered [46]. With so many equations involved in estimating energy expenditure, it's easy to see how mistakes can add up over time, which can reduce the impact of the intervention. Consequently, the best equation for estimating REE has not yet been determined [47, 48]. Evaluation of FitMate GS with canopy-hood REE with different predictive equations in malign and benign prostate group values was presented in Tables 3. An accurate prediction was defined as one that fell within the range of 90% and 110% of the actual REE. Under prediction was defined as a prediction of less than 90% and over prediction as a prediction of more than 110%. It was found that the percentage of adult hospital patients whose REE were correctly predicted was low, ranging from 8–49% across all equations in a study [48]. In another study, the acurate of correctly predicted REE was found to vary between 9.6% and 62% in all equations [49]. In the present study, the percentage of accurate prediction REE obtained from REE predictive equations varied between 2.4% and 60.9% in previous equations. The percentage of accurate prediction REE obtained from the new equations was found to be 80.9% in the maling prostate cancer group. This rate has the highest accurate prediction rate with 64.2% in the benign prostate group for new equation.
Bias was calculated as the percentage disparity between the predicted and measured REE. It was found in a study that the REE from FitMate GS exhibited a fanning effect, with smaller REE values exhibiting a narrower spread of biases, and a positive proportional bias being present. The FitMate GS showed little individual variation and high group precision because of its low bias [32]. As one study found in a sample of cancer patients, just over half had their REE predicted correctly using the Harris-Benedict, Owen et al., Mifflin et al., or 21 kcal/kg methods. Spread of bias was clearly visible for the group of cancer patients, with increasing REE values between measured REE and REE predicted by the equations of Cunningham et al. and Wang et al. The observed bias with REE predicted by the equation of Schofield showed a tendency toward underestimating measured REE with increasing REE values, but this trend was not statistically significant [46]. Using classical equations (Harris Benedict, Schofield, IretoneJones, and Mifflin-St.Jeor), researchers found that the mean of the measured REE was greater than the classical equations in a study of patients with digestive cancer [14].
Numerous studies have verified the Schofield Eq. (1985), making it one of the most widely used equations to date. When applied to critically ill patients and the majority of patients overall, it was deemed inadequate for estimating REEs [50, 51]. Although not statistically significant, the bias observed with REE predicted from the equation of Schofield showed a tendency toward underestimation of measured REE with increasing REE values in a study on the determination of resting energy expenditure in patients receiving anticancer treatment [46].
Except for men over the age of 60, Henry and equations gave lower values than Schofield equations. Henry's equations were the most reliable in males [52]. One study highlighted the fact that the Schofield equation most suitable for adults [53]. The relevance of measuring REE by indirect calorimetry in order to better adequately provide nutritional support to cancer patients is supported by the Barcellos Equations, allowing for less predictive and more accurate mean REE estimation in cancer patients [14]. The results of this research showed that the Barcellos II equation is more accurate than the existing equations for estimating REEs. Patients in hospitals were less likely to develop malnutrition when REE was accurately estimated and used to guide nutritional intervention [28]. Cunningham proposed an alternative equation that takes into account the correlation between resting metabolic rate (RMR) and fat-free mass (FFM). In a study involving both normal-weight and obese male subjects, served as the basis in equation [54]. In the study, Cunningham equation gave the last one in the estimation of REE of male individuals [55]. Similarly, the IOM equation, used for predicting the REEs was found to have low accuracy and high bias and RMSE value [23]. The result, related to the all equation was presented in Tables 3. This is widely assumed to have its roots in racial and genetic predispositions. Many studies, including those that provided funding for this one, have recommended that individual societies adopt the equations that have been tailored to their needs.
Since none of the existing prediction equations were appropriate for a population of men with prostate cancer, in this study was developed a new prediction equation. Consistent with expectations, the new equation found that WT, height, FFM, FM and PSA Total were the strongest predictors of REE, accounting for R2:54,8% of the variance in REE among men with malign prostate group and accounting for R2:37,5% of the variance in REE among men with benign prostate group in Table 5. The findings here corroborate those of other study. This study find was consistent with those of a previous one, which also founded that FM was a major factor in determining adults' REEs [56]. Genetics may also account for the variation in REE between populations, which is known to be linked to FM and WT. Since body composition equations are usually population-specific, they should be more appropriate for use as predictive equations for REE [57]. In our opinion, the information we gleaned from the outcomes of the malign and benign prostate group FitMate GS with canopy-hood multiple regression analysis will provide us more precision in predicting the REE particular to this group of PSAT value, which is incorporated into the malign prostate group equation.