Phase Angle and Impedance Ratio: Reference Cut-Points From the United States National Health and Nutrition Examination Survey 1999-2004 From Bioimpedance Spectroscopy Data.

Background: Raw bioimpedance parameters (eg, 50-kHz phase angle [PA] and 200-kHz/5-kHz impedance ratio [IR]) have been investigated as predictors of nutrition status and/or clinical outcomes. However, their validity as prognostic measures depends on the availability of appropriate reference data. Using a large and ethnically diverse data set, we aimed to determine if ethnicity influences these measures and provide expanded bioimpedance reference data for the U.

Long-Term Body Composition Changes in Women Following Roux-en-Y Gastric Bypass Surgery.

Background: Although most individuals experience successful weight loss following Roux-en-Y gastric bypass (RYGB), weight regain is a concern, the composition of which is not well documented. Our aim was to evaluate changes in body composition and handgrip strength as a measure of functional status in participants from a previous 1-year post-RYGB longitudinal study who had undergone RYGB approximately 9 years prior.

Methods: Five women from an original larger cohort were monitored pre-RYGB and 1.

The Influence of Bariatric Surgery on Serum Bile Acids in Humans and Potential Metabolic and Hormonal Implications: a Systematic Review.

Recent research suggests a mechanistic role for bile acids (BA) in the metabolic improvement following bariatric surgery. It is believed that the hormonal and metabolic effects associated with changes in systemic BAs may be related to the farnesoid X receptor (FXR) and a G-protein coupled receptor (TGR5). This systematic review examines changes in systemic BAs following bariatric procedures.

Bioimpedance at the bedside: current applications, limitations, and opportunities.

The loss of muscle mass is a defining characteristic of malnutrition, and there is ongoing interest in the assessment of lean tissue at the bedside. Globally, bioimpedance techniques have been widely appreciated for their noninvasiveness, safety, ease of use, portability, and relatively low cost compared with other clinically available methods. In this brief update, we review the 3 primary types of commercially available bioimpedance devices (single- and multiple-frequency and spectroscopy) and differentiate the underlying theory and current applications of each.

Vitamin D status following bariatric surgery: implications and recommendations.

Individuals with extreme obesity who qualify for bariatric surgery are frequently vitamin D deficient before and after surgery. The anatomical changes that occur during some bariatric procedures may lead to decreased absorption of vitamin D, although vitamin D absorption and metabolism has not been quantified or compared across surgeries, and multiple other factors could influence vitamin D status in these individuals. Vitamin D treatment and dosing studies show that there is variability in how individuals respond to supplementation regimens regardless of the bariatric procedure.