Body Adiposity Index (BAI) as a predictor of body fat in an oldest old and independent Brazilian elderly cohort.

Background: Anthropometry and body mass index (BMI) do not assess body composition or its distribution in older adults; thus, individuals may have different fat percentages but similar BMI values. The body adiposity index (BAI) was recently proposed as a feasible and inexpensive method for estimating the percentage of body fat based on measurements of hip circumference and height. Objectives: The present study evaluated whether BAI and BMI are useful alternatives to dual-energy X-ray absorptiometry (DXA), which is rarely used in clinical practice, for predicting body fat in independent long-lived older adults. Methods: In this cross-sectional study, we used DXA to calculate the percentage of body fat, which was compared with BAI and BMI values. We performed Pearson correlation analyses and used Cronbach's alpha, described by Bland and Altman, to compare the reliability between the indexes. Results: Among 157 evaluated individuals (73.2% women, mean age 87 years, ± 3.57), men had a lower percentage of total fat, as assessed by DXA, and lower BAI indices than women. The correlation between BAI and DXA was moderate (r = 0.59 for men and r = 0.67 for women, p < 0.001). We confirmed the reliability based on Cronbach's alpha coefficients of 0.67 in men and 0.77 in women. We also observed that the BAI was strongly positively correlated with BMI in both men and women. Conclusion: The BAI, used in combination with BMI, can be an alternative to DXA for the assessment of body fat in the oldest old in clinical practice, mainly women, and can be used to add information to BMI.

Relationship of protein, calcium and vitamin D consumption with body composition and fractures in oldest-old independent people.

BACKGROUND & AIM: Some studies state that the protein intake has a protective effect against bone mass loss, while others show that the combination of low calcium intake and high protein consumption increases the risk of fractures. Perhaps this phenomenon is also altered by the consumption of vitamin D after the age 80 years. This study aimed to identify if there is an association of protein, calcium and vitamin D intake with body composition and fractures in community dwelling 80 years or older independent people. METHODS: This is a cross-sectional observational analytic study. We invited community dwelling 80 years or older independent people, with chronic diseases under control, according to the scientific guidelines. The food intake was obtained through a one-day food record (FR) and Avanutri software (4.1 version) was used to calculate the intake of total calories, calcium, protein, and other food nutrients. The body composition and bone densitometry were evaluated by whole-body Dual Energy X-ray Absorptiometry (DXA). The morphometric vertebral fractures were assessed through conventional X-ray of the vertebral, level T4 to L4, on side face position - semi quantitative technique. RESULTS: One hundred and fifty-nine 80 years or older independent people, mean age 87.0 ± 3.9 years old were studied. The mean calcium intake was 834.6 ± 374.7 mg/day and vitamin D was 6.1 ± 24.3 µg/day, in both cases they were complemented by supplements to reach the recommendations. The mean protein intake was 72.9 ± 26.8 g/day, we found that 48.4% had low muscle mass; there was a frequency of 45.3% of osteoporosis; and vertebral fractures in 24.7% of them. The estimates of the logistic regression model with the outcome variable obesity and low muscle mass with reference to "low muscle mass" showed that the 80 years or older independent people who have a fracture are more likely to be obese with low muscle mass compared to those with only low muscle mass. CONCLUSION: In the studied population of 80 years or older independent people, we observed that among all the nutrients studied, only dietary protein per g/kg/day was associated with body composition and bone mineral density, but not with fracture, although the elderly who have fracture are more likely to be obese with low muscle mass compared to those not obese with low muscle mass. More studies about nutrients intakes and its relationship with muscle and bone health in this population is necessary.

The influence of 25-hydroxyvitamin D and High-Density Lipoprotein Cholesterol on BIA Resistance results and aging on BIA Reactance results in elderly people.

BACKGROUND & AIMS: The use of Bioimpedance (BIA) as a bedside method of evaluation of body composition increased in the last years. However there are still some questions about correct interpretation of the raw data, reactance and resistance, as measures of body composition. This study investigated the relationship of age, physical activity practice, Body Mass Index (BMI), 25-hydroxyvitamin D and serum lipoproteins in BIA data of resistance and reactance. METHODS: A transversal study was performed with elderly women who practiced regular physical activity (Group 1) and community dwelling elderly women (Group 2). Blood test, antrophometric measures and BIA exam were performed. As some studies had suggested, the ones with a BMI superior to 34 Kg/m2 were excluded. Students T-test was applied to assess differences between both groups, and due to its results, it was performed a stepwise multiple regression analysis. RESULTS: The results of 320 elderly women with a BMI ≤34 Kg/m2 (Group 1 = 225; Group 2 = 95) were analyzed. At the blood test, there was a statistically significant difference for total-cholesterol, LDL-cholesterol, High-Density Lipoprotein Cholesterol and 25-hydroxyvitamin D. We observed an increase of 0.42 OHMS in BIA Resistance for each increment of 1 nmol/dL of 25-hydroxyvitamin D (p < 0.005), and an increase of 1 mg/dL of High-Density Lipoprotein Cholesterol led to an increase of 0.655 OHMS in BIA Resistance (p < 0.005). Also, it was observed that an increment of 1 year old have showed a reduction of 0.038 OHMS in BIA Reactance (p < 0.1). CONCLUSIONS: BIA Reactance was influenced by aging and BIA Resistance was influenced by High-Density Lipoprotein Cholesterol and 25-hydroxyvitamin D.