DXA, bioelectrical impedance, ultrasonography and biometry for the estimation of fat and lean mass in cats during weight loss

Background: Few equations have been developed in veterinary medicine compared to human medicine to predict body composition. The present study was done to evaluate the influence of weight loss on biometry (BIO), bioimpedance analysis (BIA) and ultrasonography (US) in cats, proposing equations to estimate fat (FM) and lean (LM) body mass, as compared to dual energy x-ray absorptiometry (DXA) as the referenced method. For this were used 16 gonadectomized obese cats (8 males and 8 females) in a weight loss program. DXA, BIO, BIA and US were performed in the obese state (T0; obese animals), after 10% of weight loss (T1) and after 20% of weight loss (T2). Stepwise regression was used to analyze the relationship between the dependent variables (FM, LM) determined by DXA and the independent variables obtained by BIO, BIA and US. The better models chosen were evaluated by a simple regression analysis and means predicted vs. determined by DXA were compared to verify the accuracy of the equations. Results: The independent variables determined by BIO, BIA and US that best correlated (p < 0.005) with the dependent variables (FM and LM) were BW (body weight), TC (thoracic circumference), PC (pelvic circumference), R (resistance) and SFLT (subcutaneous fat layer thickness). Using Mallows'Cp statistics, p value and r(2), 19 equations were selected (12 for FM, 7 for LM); however, only 7 equations accurately predicted FM and one LM of cats. Conclusions: The equations with two variables are better to use because they are effective and will be an alternative method to estimate body composition in the clinical routine. For estimated lean mass the equations using body weight associated with biometrics measures can be proposed. For estimated fat mass the equations using body weight associated with bioimpedance analysis can be proposed.

Effects of circuit-based exercise programs on the body composition of elderly obese women

Aim: The aim of this study was to investigate the impact of circuit-based exercise on the body composition in obese older women by focusing on physical exercise and body weight (BW) gain control in older people. Methods: Seventy older women (>60 years old) voluntarily took part in the study. Participants were randomized into six different groups according to body mass index (BMI): appropriate weight (AW) control (AWC) and trained (AWT) groups, overweight (OW) control (OWC) and trained (OWT) groups, and obesity (O) control (OC) and trained (OT) groups. The exercise program consisted of 50 minutes of exercise three times per week for 12 weeks. The exercises were alternated between upper and lower body using rest between sets for 40 seconds with intensity controlled by heart rate (70% of work). The contraction time established was 5 seconds to eccentric and concentric muscular action phase. The following anthropometric parameters were evaluated: height (m), body weight (BW, kg), body fat (BF, %), fat mass (FM, kg), lean mass (LM, kg), and BMI (kg/m(2)). Results: The values (mean +/- standard deviation [SD]) of relative changes to BW (-8.0% +/- 0.8%), BF (-21.4% +/- 2.1%), LM (3.0% +/- 0.3%), and FM (-31.2% +/- 3.0%) to the OT group were higher (P < .05) than in the AWT (BW: -2.0% +/- 1.1%; BF: -4.6% +/- 1.8%; FM: -7.0% +/- 2.8%; LM: 0.2% +/- 1.1%) and OWT (BW: -4.5% +/- 1.0%; BF: -11.0% +/- 2.2%; FM: -16.1% +/- 3.2%; LM: -0.2% +/- 1.0%) groups; additionally, no differences were found for C groups. While reduction (P < .03) in BMI according to absolute values was observed for all trained groups (AWT: 22 +/- 1 versus 21 +/- 1; OWT: 27 +/- 1 versus 25 +/- 1, OT: 34 +/- 1 versus 30 +/- 1) after training, no differences were found for C groups. Conclusion: In summary, circuit-based exercise is an effective method for promoting reduction in anthropometrics parameters in obese older women.

The influence of anthropometric factors on postural balance: the relationship between body composition and posturographic measurements in young adults

OBJECTIVE: The aim of the present study was to evaluate the influence of anthropometric characteristics and gender on postural balance in adults. One hundred individuals were examined (50 males, 50 females; age range 20-40 years). METHODS: The following body composition measurements were collected (using bone densitometry measurements): fat percentage (% fat), tissue (g), fat (g), lean mass (g), bone mineral content (g), and bone mineral density (g/cm(2)). In addition, the following anthropometric measurements were collected: body mass (kg), height (cm), length of the trunk-cephalic region (cm), length of the lower limbs (cm) and length of the upper limbs (cm). The following indices were calculated: body mass index (kg/m(2)), waist-hip ratio and the support base (cm 2). Also, a postural balance test was performed using posturography variables with open and closed eyes. RESULTS: The analysis revealed poor correlations between postural balance and the anthropometric variables. A multiple linear regression analysis demonstrated that the whole group (female and male) height explained 12% of the medial-lateral displacement, 10% of the speed of oscillation, and 11% of the displacement area. The length of the trunk-cephalic length explained 6% of the displacement in the anteroposterior direction. With eyes closed, the support base and height explained 18% of the medial displacement, and the lateral height explained 10% of the displacement speed and 5% of the scroll area. CONCLUSION: Measured using posturography, the postural balance was only slightly influenced by the anthropometric variables, both with open and closed eyes. Height was the anthropometric variable that most influenced postural balance, both in the whole group and separately for each gender. Postural balance was more influenced by anthropometric factors in males than females.

Juvenile onset systemic lupus erythematosus: a possible role for vitamin D in disease status and bone health

Purpose: In juvenile onset systemic lupus erythematosus (JoSLE), evidence for the association between vitamin D status, lupus activity, and bone health is very limited and not conclusive. The aim of this study was, therefore, to assess in JoSLE patients the possible relevance of vitamin D deficiency in disease and bone parameters. Methods: Fifty-seven JoSLE patients were initially compared to 37 age, race and body mass index (BMI) -matched healthy controls. The serum concentration of 25 hydroxyvitamin D (25OHD) was determined by radioimmunoassay. Patients with 25OHD deficiency (acurrency sign20 ng/mL) were compared to those with levels > 20 ng/mL. Disease activity was evaluated by SLE Disease Activity Index (SLEDAI). Bone mineral density (BMD) and body composition (BC) were measured using dual-energy X-ray absorptiometry (DXA). Results: 25OHD levels were similar in patients and controls (21.44 +/- 7.91 vs 22.54 +/- 8.25 ng/mL, p = 0.519), regardless of supplementation (65% of patients and none in controls). Thirty-one patients with 25OHD deficiency (acurrency sign20 ng/mL) were further compared to the 26 JoSLE patients with levels > 20 ng/mL. These two groups were well-balanced regarding vitamin D confounding variables: age (p = 0.100), ethnicity (p = 1.000), BMI (p = 0.911), season (p = 0.502), frequency of vitamin D supplementation (p = 0.587), creatinine (p = 0.751), renal involvement (p = 0.597), fat mass (p = 0.764), lean mass (p = 0.549), previous/current use of glucocorticoids(GC) (p = 1.0), immunosuppressors (p = 0.765), and mean current daily dose of GC (p = 0.345). Patients with vitamin D deficiency had higher SLEDAI (3.35 +/- 4.35 vs 1.00 +/- 2.48, p = 0.018), lower C4 levels (12.79 +/- 6.78 vs 18.38 +/- 12.24 mg/dL, p = 0.038), lower spine BMD (0.798 +/- 0.148 vs 0.880 +/- 0.127 g/cm2, p = 0.037) and whole body BMD (0.962 +/- 0.109 vs 1.027 +/- 0.098 g/cm2, p = 0.024). Conclusion: JoSLE vitamin D deficiency, in spite of conventional vitamin D supplementation, affects bone and disease activity status independent of therapy and fat mass reinforcing the recommendation to achieve adequate levels. Lupus (2012) 21, 1335-1342.

High frequency of osteoporosis and fractures in women with dermatomyositis/polymyositis

Bone mass was only previously studied in juvenile dermatomyositis/polymyositis (DM/PM) patients. Therefore, the objective this study was to evaluate the prevalence of osteoporosis and fractures in adult DM/PM. Forty female DM/PM and 78 age-, gender-, and BMI-matched healthy controls were studied. Medical charts and clinical interviews of all patients were evaluated for demographic and clinical data, including disease activity, cumulative doses of glucocorticoid, menarche and menopause age, and fractures. Bone mineral density (BMD) using dual X-ray absorptiometry (DXA) were measured at lumbar spine (L1-L4) and hip. A decreased BMD in lumbar spine [0.902 (0.136) vs. 0.965 (0.141) g/cm(2), P = 0.022] and femoral neck [0.729 (0.12) vs. 0.784 (0.127) g/cm(2), P = 0.027] was observed in patients compared to controls. In addition, osteoporosis was more frequent in patients than in controls in both lumbar spine (20 vs. 3.8%, P = 0.007) and the femoral neck (27.5 vs. 10.3%, P = 0.016). Moreover, a high prevalence of fractures was found in patients in comparison to healthy subjects (17.9 vs. 5.1%, P = 0.040; OR = 3.92; CI 95%: 1.07-14.33). Comparing DM/PM patients with (n = 17) and without (n = 23) osteoporosis/fractures, significant differences were observed regarding age [56.8 (11.9) vs. 48.3 (13.2) years, P = 0.042], weight [62.05 (13.56) vs. 71.51 (11.46) kg, P = 0.022] and frequency of post menopausal women (94.1 vs. 65.2%, P = 0.0002). No differences were observed concerning height, lean mass, total fat mass, disease activity, mean value of creatine kinase, cumulative glucocorticoid dose, or bisphosphonate use. Logistic regression analysis revealed a negative association between the presence of osteoporosis/fractures and weight (OR: 0.92, 95% CI: 0.85-0.98; P = 0.016). This is the first study that analyzed bone mass in adult DM/PM patients and it demonstrated that about one quarter of these patients have osteoporosis/fracture.

Bioelectrical impedance analysis and anthropometry for the determination of body composition in rats: effects of high-fat and high-sucrose diets

Objective The aim of the present study was to determine the impedance of Wistar rats treated with high-fat and high-sucrose diets and correlate their biochemical and anthropometric parameters with chemical analysis of the carcass. Methods Twenty-four male Wistar rats were fed a standard (AIN-93), high-fat (50% fat) or high-sucrose (59% of sucrose) diet for 4 weeks. Abdominal and thoracic circumference and body length were measured. Bioelectrical impedance analysis was used to determine resistance and reactance. Final body composition was determined by chemical analysis. Results Higher fat intake led to a high percentage of liver fat and cholesterol and low total body water in the High-Fat group, but these changes in the biochemical profile were not reflected by the anthropometric measurements or bioelectrical impedance analysis variables. Anthropometric and bioelectrical impedance analysis changes were not observed in the High-Sucrose group. However, a positive association was found between body fat and three anthropometric variables: body mass index, Lee index and abdominal circumference. Conclusion Bioelectrical impedance analysis did not prove to be sensitive for detecting changes in body composition, but body mass index, Lee index and abdominal circumference can be used for estimating the body composition of rats.