دانلود رایگان مقاله انگلیسی سنجش ترکیب بدن با استفاده از شاخص توده بدنی و آنالیز بردار امپدانس بیوالکتریک - الزویر 2018

Abstract

Background: Rheumatoid arthritis (RA) is a complex inflammatory disease that modifies body composition. Although body mass index (BMI) is one of the clinical 48 nutrition tools widely used to assess indirectly nutritional status, it is not able to identify these body alterations. Bioelectrical Vector Analysis (BIVA) is an alternative method to assess hydration and body cell mass of patients with wasting conditions. Objective: To investigate the differences in nutrition status according to BMI groups (normal, overweight and obesity) and BIVA classification (cachectic and non-cachectic) in women with RA. Methods: Women with confirmed diagnosis of RA were included from January 2015 to June 2016. Whole-body bioelectrical impedance was measured using a tetrapolar and mono-frequency equipment. Patients were classified according to BMI as: low body weight (n=6, 2.7%), normal (n=59, 26.3%), overweight (n=88, 39.3%) and obese (n=71, 31.7%), and each 58 group was divided into BIVA groups (cachectic 51.8% and non-cachectic 48.2%). Results: A total of 224 RA patients were included, with mean age 52.7 years and 60 median disease duration of 12 years. Significant differences were found in weight, 61arm circumference, waist, hip, resistance/height, reactance/height and erythrocyte sedimentation rate among all BMI groups. However, serum albumin levels were significantly different between cachectic and non-cachectic patients independently of BMI. In all BMI categories, cachectic groups had lower reactance and phase angle than non-cachectic subjects. Conclusion: RA patients with normal or even high BMI have a significantly lower muscle component. Evaluation of body composition with BIVA in RA patients could be an option for cachexia detection.

Discussion

In the present study, we observed that although patients were classified as normal, overweight or obese according to their BMI, BIVA detected cachectic patients within all BMI categories. In addition, serum albumin levels were lower in cachectic subjects independently of BMI categories; this could be explained because hypoalbuminemia is a consequence of inflammation due to suppression of albumin synthesis and transfer of albumin from the vascular to the extravascular space. Moreover, patients with RA have increased whole-body protein breakdown associated with higher TNF-α levels. It has been reported that in patients with RA, serum albumin is lower than in controls, and statistically associated with RA functional class, while a negative correlation exists with clinical, functional, and laboratory markers of disease activity [25]. Our results are similar to previous descriptions. Van Bokhorst-de van der Schueren et al reported high prevalence of overweight and obesity in RA patients, in combination with a reduced FFM and an increase of the FM. This explains why despite their classification as normal weight, overweight or obese, cachectic patients can be detected by the BIVA method [26]. Elkan et al evaluated body composition by DXA and found that 52% of women and 30% of men with RA were malnourished according to FFM determined by this method even if they were classified as normal, overweight or obese by BMI. Thus, the authors concluded that neither the BMI nor the nutritional assessment and screening tools could detect the low FFM with sufficient sensitivity and specificity to be used to assess cachexia [27]. Also, Konijn et al studied the differences between BMI and BIA and found that 44% of the studied women with a normal BMI had low FFM and 75% of men and 40% women had high FM. [5] These results are similar to our findings, demonstrating the low value of the BMI measurement in RA patients [27] because is only able to reflect abundance of adipose tissue in very high BMI or a reduction of fat and lean mass in very low BMIs. The problem of sarcopenic obesity, which can occur in RA, is most certainly not reflected by the BMI.