Comparison of bioelectrical impedance analysis-derived phase angle in individuals with different weight status

OBJECTIVE

Obesity is characterized not only by an increase of fat mass but also by alterations in skeletal muscle. Bioimpedance analysis (BIA)-derived phase angle (PhA) may provide specific information on the inherent characteristics of fat-free mass, and is widely used as an index of poor nutritional status. The aim of this study was to describe whether and to what extent PhA varies depending on age, sex, and body mass index (BMI) in individuals with different weight status.

METHODS

We selected 1877 participants for this retrospective study (two weight status groups): 983 individuals with obesity (age 40 ± 13.9 y; BMI 39.5 ± 7.2 kg/m²) and 894 controls (age 40 ± 13.3 y; BMI 24.6 ± 2.7 kg/m²). Anthropometry and PhA at 50 kHz for the whole body were performed in all participants.

RESULTS

PhA was greater in men than in women, although a decline of PhA was observed with age, which was linear in women and occurred in men after 40 y of age. On the other hand, no significant differences were observed with increasing BMI in either sex; lower values might be observed when BMI >50 kg/m².

CONCLUSIONS

A more detailed appraisal of BIA-derived PhA in obesity is reported in the present study, providing basic data that might be taken into consideration in prevention and clinical nutrition. Further studies are needed to explore differences of PhA in individuals with different weight status.

Evaluation of the Nutritional Status of Gaucher Disease Type I Patients under Enzyme Replacement Treatment

(1) Background: Gaucher disease (GD) is a rare lysosomal storage disease. The few studies analyzing Resting Energy Expenditure (REE) in GD involved mainly untreated patients and supported a hypermetabolic condition possibly due to the associated inflammatory state. Definitive conclusions could not be drawn also because of the heterogeneity and the small size of the samples investigated. In order to expand current knowledge concerning, in particular the condition of patients under Enzyme Replacement Therapy (ERT), we evaluated the nutritional status of a relatively large sample of GD patients followed at Federico II University Hospital in Naples, Italy. (2) Methods: The study, having a cross-sectional design and involving 26 patients on ERT, included routine biochemical analyses, bioelectrical impedance analysis, indirect calorimetry, and administration of food frequency and physical activity questionnaires. The results in GD patients were compared with those from an appropriate control group. (3) Results: GD patients had normal biochemical parameters in 80% of cases, except for HDL-cholesterol, consumed a hyper-lipidic diet, and had a 60% prevalence of overweight/obesity. Body composition did not differ between patients and controls; however, measured REE was significantly lower than predicted and was reduced in comparison with the healthy controls. (4) Conclusions: This study provided novel elements to the present knowledge about REE and the nutritional status of GD patients under ERT. Its results warrant confirmation in even larger GD population samples and a more in-depth investigation of the long-term effects of treatment superimposed on the basic pathophysiological disease condition.

Resting energy expenditure in elite athletes: development of new predictive equations based on anthropometric variables and bioelectrical impedance analysis derived phase angle

Background

An accurate estimation of athletes’ energy needs is crucial in diet planning to improve sport performance and to maintain an appropriate body composition. This study aimed to develop and validate in elite athletes new equations for estimating resting energy expenditure (REE) based on anthropometric parameters as well as bioimpedance analysis (BIA)-derived raw variables and to validate the accuracy of selected predictive equations.

Methods

Adult elite athletes aged 18–40 yrs were studied. Anthropometry, indirect calorimetry and BIA were performed in all subjects. The new predictive equations were generated using different regression models. The accuracy of the new equations was assessed at the group level (bias) and at the individual level (precision accuracy), and then compared with the one of five equations used in the general population or three athletes-specific formulas.

Results

One-hundred and twenty-six male athletes (age 26.9 ± 9.1 yrs; weight 71.3 ± 10.9 kg; BMI 22.8 ± 2.7 kg/m²) from different sport specialties were randomly assigned to the calibration (n = 75) or validation group (n = 51). REE was directly correlated with individual characteristics, except for age, and raw BIA variables. Most of the equations from the literature were reasonably accurate at the population level (bias within ±5%). The new equations showed a mean bias −0.3% (Eq. A based on anthropometric parameters) and −0.6% (Eq. B based on BIA-derived raw variables). Precision accuracy (individual predicted-measured differences within ±5%) was ~75% in six out of eight of the selected equations and even higher for Eq. A (82.4%) and Eq. B (92.2%).

Conclusion

In elite athletes, BIA-derived phase angle is a significant predictor of REE. The new equations have a very good prediction accuracy at both group and individual levels. The use of phase angle as predictor of REE requires further research with respect to different sport specialties, training programs and training level.

A proposal for reference values of hand grip strength in women with different body mass indexes

OBJECTIVE

Hand grip strength (HGS) is frequently used in clinical practice, resulting in a potential marker of nutritional status. This study aimed to develop reference values of HGS in Italian women with different categories of body mass index (BMI). Additionally, the main predictors of HGS were identified.

METHODS

A cross-sectional study was conducted in Italian women between ages 16 and 55 y with different categories of BMI at the Department of Clinical Medicine and Surgery, Federico II University Hospital, Naples Italy. The whole sample was divided into tertiles according to BMI: 15 to 17.29 kg/m² (T1), 17.3 to 19.9 kg/m² (T2), and 20 to 25 kg/m² (T3). Anthropometry, bioimpedance analysis, and muscle strength by an HGS test were evaluated. The cut-off values for HGS were developed for all participants and stratified by age group. Finally, a multivariate linear regression analysis was performed to assess the main predictors of HGS.

RESULTS

A total of 529 women with a mean age of 23.2 ± 7.0 y and an average BMI of 18.9 ± 2.5 kg/m² were analyzed. HGS was higher for the dominant hand than for the non-dominant hand in all BMI tertiles. On both sides, according to age groups, HGS increased with increasing age in T1 and T3, whereas it increased in the women between ages 20 and 30 y in T2 only. Multivariate linear regression analysis showed that predictors of HGS varied according to tertiles. Specifically, we found that body weight (R² = 0.252) was the main predictor in T1, whereas phase angle (PhA) was the main determinant in both T2 (R² = 0.240) and T3 (R² = 0.216).

CONCLUSION

This study defined the normal reference values of HGS in Italian women with different BMI ranges, stratifying the sample group by age. Additionally, the main predictors of HGS were assessed for each BMI tertile. In primary malnutrition (T1), the main predictor of HGS was body weight, whereas in the other two tertiles (T2, T3), the PhA was the main predictor of HGS.

Bioimpedance phase angle in elite male athletes: a segmental approach

OBJECTIVE

Phase angle (PA), a bioelectrical impedance analysis (BIA) parameter, has proven to be a proxy of body cell mass in athletes, but very few data are available on its segmental evaluation (upper and lower limbs). Therefore, we aimed to assess whether whole-body and segmental PA varied among elite male athletes of different sports and compared these to control groups. Additionally, we investigated its relationship with anthropometric and body composition parameters.

APPROACH

Elite athletes practicing cycling, water polo and ballet dance aged 18-40 years underwent anthropometric and BIA measurements. PA (whole-body and upper and lower limbs) was considered as raw BIA variable. Data were also compared with healthy subjects with similar characteristics who served as control groups.

MAIN RESULTS

Participants included three groups of male athletes: 18 cyclists (age 28.6 ± 3.4 years; weight 70.6 ± 5.4 kg; BMI 21.5 ± 1.4 kg m²), 20 water polo players (age 23.9 ± 4 years; weight 89.0 ± 5.2 kg; BMI 25.9 ± 1.9 kg m²) and 18 ballet dancers (age 19.2 ± 1.3 years; weight 63.3 ± 5.8 kg; BMI 20.8 ± 1.0 kg m²) and three groups of healthy control subjects each of which similar for general characteristics (one to one) to the previous ones. Both whole-body and limb PAs were significantly higher in athletes compared to their respective controls, whereas no differences were found among sport groups. PA was positively correlated with BMI and fat-free mass (FFM) more in athletes than in controls and FFM was the main determinant.

SIGNIFICANCE

PA may represent a useful proxy parameter of soft tissue mass quality, directly related to physical activity level. Furthermore, the direct evaluation of segmental PA among athletes practicing different sports may be useful for assessing and monitoring the differences among athletes and changes due to training.

New predictive equations for estimating resting energy expenditure in subjects with normal weight and overweight

OBJECTIVE

The aim of this study was to develop and validate new predictive equations for estimating resting energy expenditure (REE) in subjects with normal weight and overweight, considering anthropometric parameters as well as raw variables from bioimpedance analysis (BIA).

METHODS

Adult participants with normal weight and overweight were recruited and randomly split into calibration and validation groups. Indirect calorimetry (IC) and BIA were performed in all subjects. New predictive equations were developed using the following models: model 1 with age, weight, stature, and body mass index (BMI) as predictors; and model 2: model 1 + raw BIA variables (bioimpedance index and phase angle). The accuracy of the new equations at both the group (bias) and individual (within ±10%) levels was tested in the validation group. Three published predictive equations were also compared, with the REE values measured by IC.

RESULTS

A total of 2483 adults were included for developing and validating the new equations. All selected formulas, including the new ones, showed a bias of <5% in estimating REE at the group level. Accuracy at the individual level was slightly higher for the new equations, especially for the equation based on raw BIA variables (men = 70.3%; women = 72.3%).

CONCLUSIONS

Compared to the equations in the literature, the new equations showed good accuracy at both the group and individual levels, with a slight improvement in individual accuracy for the formula including raw BIA variables. However, future research is required to verify the role of the raw BIA variables in predicting REE in subjects with normal weight and overweight.

Resting Energy Expenditure, Body Composition and Phase Angle in Anorectic, Ballet Dancers and Constitutionally Lean Males

Background: The prevalence of anorexia nervosa among males is increasing but few data are available in the literature. This cross sectional study aims to evaluate resting energy expenditure (REE) and phase angle as a marker of qualitative changes of fat free mass (FFM) in three leanness groups as compared with control subjects. Methods: 17 anorectic (AN) males, 15 constitutionally lean (CL) individuals, 12 ballet dancers (DC), and 18 control (CTR) subjects were evaluated. REE was measured by indirect calorimetry (V max29- Sensormedics), and body composition was evaluated by bioimpedance analysis (BIA) at 50 kHz (DS Medica). Phase angle (a bioimpedance variable related to nutritional status) was used to evaluate differences in FFM characteristics between these three types of leanness. Results: REE, adjusted for FFM and fat mass (FM), were significantly higher in CL and lower in AN individuals (1783 ± 47 vs. 1291 ± 58 kcal, p < 0.05) compared to the other groups. Body composition was similar in AN and CL whereas dancers had the highest FFM (58.9 ± 4.8 kg, p < 0.05); anorectic males showed the lowest phase angle (5.8 ± 1.2 degrees vs. other groups, p < 0.05) and dancers the highest phase angle (7.9 ± 0.7 degree vs. other group, p < 0.05). Conclusions: Our findings confirm that phase angle could be a useful marker of qualitative changes, above all in the field of sport activities. On the other hand, there is the need to further evaluate the relationship between resting energy expenditure, body composition and endocrine status in different conditions of physical activity and dietary intake.

Prediction of body composition in anorexia nervosa: Results from a retrospective study

BACKGROUND & AIMS

The assessment of body composition is crucial in evaluating nutritional status in female subjects with anorexia nervosa (AN) and improving their clinical management. The aim of this retrospective study was to assess the accuracy of selected BIA (bioimpedance analysis) equations for fat-free mass (FFM) in female AN subjects and to formulate a specific equation for these subjects.

METHODS

Eighty-two restrictive female AN subjects (age 20.5 ± 3.7 yrs, BMI 15.7 ± 1.7 kg/m²) were studied. Body composition was determined with dual-energy X-ray absorptiometry (DXA) and estimated by BIA using five different equations. Linear correlation analysis was carried out to evaluate the association of FFM with selected variables. Multiple regression analysis was used to formulate specific equations to predict FFM in AN.

RESULTS

All predictive equations underestimated FFM at the population level with a bias from -5.6 to -11.7%, while the percentage of accurate predictions varied from 12.2% to 35.4%. More interestingly, multiple regression analysis clearly indicates that, in addition to weight, ZI₁₀₀ or RI also emerged as independent predictors of DXA-derived FFM, increasing the prediction power of the equation well above that observed with anthropometric characteristics only.

CONCLUSIONS

This study shows that the selected predictive BIA equations considered exhibit an insufficient accuracy at the population and the individual level. Predictive formulas based on body weight plus BIA parameters such as RI and ZI₁₀₀ offer a rather accurate prediction of FFM (with high R squared).

Adequacy of nutrient intake in women with restrictive anorexia nervosa

OBJECTIVE

The aim of the present study was to assess energy and nutrient intake in a group of women with restrictive AN (r-AN) compared with a control group.

METHODS

Thirteen r-AN patients and 13 healthy female controls completed 7-d food records. Intake of macro- and micronutrients was compared between the two groups as well as to the Dietary Reference Intake for the Italian Population (LARN) for specific ages. Additionally, the r-AN patients underwent indirect calorimetry for measuring resting energy expenditure (REE).

RESULTS

Total energy intake was significantly lower in the r-AN group than in controls (906 ± 224 vs 1660 ± 139, respectively; P < 0.01). Nutrient composition significantly differed, as well. Mean intake of sodium, phosphorus, and zinc was higher in controls than in the women with r-AN (P < 0.01), but neither group of women met LARN recommendations for potassium, calcium, or iron intake. With respect to vitamins, no significant differences were found for riboflavin or vitamins A, B₁₂, or C between groups, whereas levels of other vitamins differed (P < 0.01). Both groups failed to meet the LARN recommendation for vitamin D intake; moreover, none of the r-AN patients met recommended intake levels of vitamin E, thiamine, niacin, and folate.

CONCLUSIONS

Intakes reported by r-AN patients did not meet requirements for most micronutrients evaluated in this study and, as expected, both energy needs and specific dietary patterns differed between groups. Therefore, a careful evaluation of food consumption should be recommended to reduce nutritional gaps in these patients. According to these preliminary observations, nutritional counseling, mainly focused on calcium and vitamin D intake, should be suggested for healthy women, as well.

Evaluation of Hypocaloric Diet With Protein Supplementation in Middle-Aged Sarcopenic Obese Women: A Pilot Study

OBJECTIVE

The aim of this study was to evaluate the efficacy of a nutritional program, which is characterized by a different modulation of proteins, in adult patients with sarcopenic obesity.

METHODS

We studied 18 obese women aged 41-74 years. Obesity was diagnosed as fat mass > 34.8% and sarcopenia was defined when lean body mass was <90% of the subject's ideal fat free mass. All subjects were randomly assigned to different nutritional interventions: Hypocaloric diet plus placebo (A) and hypocaloric high-protein diet (1.2-1.4 g / kg body weight reference / day) (B). Anthropometric measurements, body composition, resting energy expenditure, handgrip test, Short Physical Performance Battery (SPPB), and SF-36 questionnaire were evaluated at baseline and after 4 months.

RESULTS

Weight significantly decreased in both groups. Women with high-protein diet preserved lean body mass compared to low-calorie diet and improved significantly muscle strength; SPPB score did not change in both groups. SF-36 test showed a significant change for general health after 4 months in group B.

CONCLUSIONS

In our study, sarcopenic obese patients with high-protein diet showed an improvement in muscle strength. Furthermore, dietary protein enrichment may represent a protection from the risk of sarcopenia following a hypocaloric diet.

Resting energy expenditure in adult patients with Crohn's disease

BACKGROUND & AIMS

Crohn's disease (CD) is a chronic intestinal disorder of unknown etiology involving any section of the gastrointestinal tract often associated with protein-energy malnutrition (PEM). Increased resting energy expenditure (REE) unmatched by adequate dietary intake is amongst the pathogenetic mechanisms proposed for PEM. Aim of this study was to evaluate REE in CD patients receiving or not immuno-suppressive therapy as compared to controls.

METHODS

36 CD patients (22 M and 14 F, age range 18-55 years) clinically stable and without complications since at least 6 month were studied. REE was evaluated by indirect calorimetry and body composition by BIA. Full biochemistry was performed. Patients were divided into two groups: Group 1 (G1 = 12 patients) without and Group 2 (G2 = 24 patients) with immuno-suppressive therapy.

RESULTS

The two groups were similar for age, height and BMI whereas significantly differed for weight (G1 vs G2: 56.9 ± 7.44 vs 62.3 ± 8.34 kg), fat free mass (FFM: 40.4 ± 5.73 vs 48.2 ± 7.06 kg), fat mass (FM: 17.0 ± 3.55 vs 13.9 ± 5.54 kg) and phase angle (PA: 5.6 ± 1.4 vs 6.5 ± 1.0°). Serum inflammation parameters were significantly higher in G1 than in G2: hs-PCR: 7.76 ± 14.2 vs 7.16 ± 13.4 mg/dl; alfa 2-protein: 11.7 ± 3.69 vs 9.74 ± 2.08 mg/dl; fibrinogen: 424 ± 174 vs 334 ± 118 mg/dl (p < 0.05). REE was higher in G2 vs G1: 1383 ± 267 vs 1582 ± 253kcal/die (p < 0.05) both in men: 1579 ± 314 vs 1640 ± 203 and women: 1267 ± 140 vs 1380 ± 132. Nevertheless, when corrected for FFM, REE resulted higher in G1 than G2 (34.8 ± 4.89 vs 33.0 ± 4.35 kcal/kg, p < 0.05) group, also higher compared to our, age and sex matched, control population (REE/FFM: 30.9 ± 4.5 kcal/kg).

CONCLUSIONS

Our preliminary results show that REE when adjusted for FFM is increased in clinically stable CD patients and mildly reduced by immunosuppressive therapy possibly through a direct action on inflammation and on body composition characteristics.

Accuracy of predictive equations for estimating resting energy expenditure in obese adolescents

OBJECTIVE

To compare resting energy expenditure (REE) measured by indirect calorimetry with REE predicted using different equations in obese adolescents.

STUDY DESIGN

We recruited 264 obese patients (body mass index ranging from 30.0-70.0 kg/m(2)) between 14 and 18 years of age. Data were obtained comparing measured and predicted REE derived from published equations for normal weight and obese adolescents. The average differences between measured and predicted REE, as well as the accuracy at ± 10% level, were evaluated.

RESULTS

Evaluating the mean REE in 109 males (1938 ± 271 kcal/d) and 155 females (2569 ± 459 kcal/d), we found that the Lazzer equation in males had the smallest difference between measured and predicted REE; in females the Henry-1, Food and Agriculture Organization/World Health Organization/United Nations University, Schmelze, and Lazzer equations were the most accurate. The prediction accuracy was considered adequate within ± 10%.

CONCLUSIONS

REE predictive equations developed in obese patients and for specific age groups are more suitable than those for the general population. Inaccuracy of predicted REE could affect dietary prescription appropriateness and, consequently, dietary compliance in this age group.

Preliminary evaluation of the prevalence of sarcopenia in obese patients from Southern Italy

OBJECTIVES

Sarcopenic obesity has not yet been widely defined. The aim of this study was to evaluate the prevalence of sarcopenia in a group of severely obese adults from southern Italy by using two different indexes: percentage of skeletal muscle mass (SMP) and skeletal muscle mass normalized for height (SMI); and to determine SMP and SMI cutoff points in a southern Italy reference population.

METHODS

Skeletal muscle mass of 131 consecutive obese adult outpatients (51 men and 80 women; ages 45-67 y; body mass index 44.6 ± 7.7 kg/m(2)), was assessed by bioimpedance analysis. SMP and SMI cutoff points to identify moderate and severe sarcopenia were calculated in a reference group of 500 young southern Italy adults (100 men and 400 women; ages 18-40 y; body mass index 25.2 ± 5.6 kg/m(2)) and applied to assess the prevalence of sarcopenia in the study population.

RESULTS

SMP cutoff points to identify moderate and severe sarcopenia were, 28.8% to 35.6% and ≤ 28.7% in men and 23.1% to 28.4% and ≤ 23% in women, respectively. The corresponding values for SMI were 8.44 to 9.53 kg/m(2) and ≤ 8.43 kg/m(2) in men, 6.49 to 7.32 kg/m(2) and ≤ 6.48 kg/m(2) in women. According to SMP, 23 of 51 (45.1%) men and 19 of 80 (23.8%) women were moderately sarcopenic; 28 of 51 (54.9%) men and 61 of 80 (76.3%) women met the definition of severe sarcopenia. Based on SMI, only 2 of 51 (3.9%) men were moderately sarcopenic.

CONCLUSIONS

This study confirms that sarcopenia rates vary widely in obese patients depending on the criteria used. SMP as a screening tool to identify a sarcopenia at-risk population.