Dietary carbohydrate intake, insulin resistance and gastro-oesophageal reflux disease: a pilot study in European- and African-American obese women.

BACKGROUND: Although obesity rates are higher in African-American than European-American women, gastro-oesophageal reflux disease (GERD) and its comorbidities are more prevalent in European-American women. A common denominator for increased adiposity, and consequent insulin resistance, is excess dietary macronutrient intake - which may promote greater prevalence and severity of GERD in women. AIM: To investigate whether GERD is more robustly associated with dietary carbohydrate intake, particularly dietary simple carbohydrate intake, and insulin resistance in European-American women. METHODS: About 144 obese women were assessed at baseline and 16 weeks after consuming a high-fat/low-carbohydrate diet. GERD diagnosis and medication usage was confirmed in medical records with symptoms and medications assessed weekly. RESULTS: About 33.3% (N = 33) of European-American and 20.0% (N = 9) of African-American women had GERD at baseline. Total carbohydrate (r = 0.34, P < 0.001), sugars (r = 0.30, P = 0.005), glycaemic load (r = 0.34, P = 0.001) and HOMAIR (r = 0.30, P = 0.004) were associated with GERD, but only in European-American women. In response to high-fat/low-carbohydrate diet, reduced intake of sugars was associated with reduced insulin resistance. By the end of diet week 10, all GERD symptoms and medication usage had resolved in all women. CONCLUSIONS: GERD symptoms and medication usage was more prevalent in European-American women, for whom the relationships between dietary carbohydrate intake, insulin resistance and GERD were most significant. Nevertheless, high-fat/low-carbohydrate diet benefited all women with regard to reducing GERD symptoms and frequency of medication use.

DXA-measured visceral adipose tissue predicts impaired glucose tolerance and metabolic syndrome in obese Caucasian and African-American women.

BACKGROUND/OBJECTIVES: New methods to measure visceral adipose tissue (VAT) by dual-energy X-ray absorptiometry (DXA) may help discern sex, race and phenotype differences in the role of VAT in cardiometabolic risk. This study was designed (1) to compare relationships of DXA-VAT, anthropometric and body composition variables with cardiometabolic risk factors in obese women; (2) to determine which variables most robustly predict impaired glucose tolerance (IGT) and metabolic syndrome (MetSx); and (3) to determine thresholds for DXA-VAT by race. SUBJECTS/METHODS: VAT mass (g) and volume (cm(3)) were measured in 229 obese (body mass index (BMI), 30-49.9) women aged 21-69 years of European-American (EA=123) and African-American (AA=106) descent using the CoreScan algorithm on a Lunar iDXA scanner. Linear regression modeling and areas under the curve (AUC of ROC (receiver operating characteristic) curves) compared relationships with cardiometabolic risk. Bootstrapping with LASSO (least absolute shrinkage and selection operator) regression modeling determined thresholds and predictors of IGT and MetSx. RESULTS: DXA-VAT explained more of the variance in triglycerides, blood pressure, glucose and homeostatic model assessment-insulin resistance (HOMA-IR) compared with anthropometric and other body composition variables. DXA-VAT also had the highest AUC for IGT (0.767) and MetSx (0.749). Including race as a variable and the interaction between VAT and race in modeling did not significantly change the results. Thresholds at which the probability of developing IGT or MetSx was⩾50% were determined separately for AA women (IGT: 2120 cm(3); MetSx: 1320 cm(3)) and EA women (IGT: 2550 cm(3); MetSx: 1713 cm(3)). The odds for IGT or MetSx were fourfold greater with each standard deviation increase in DXA-VAT. CONCLUSIONS: DXA-VAT provides robust clinical information regarding cardiometabolic risk in AA and EA obese women and offers potential utility in the risk reduction interventions.

Simple kcal/kg formula is comparable to prediction equations for estimating resting energy expenditure in older cognitively impaired long term care residents.

OBJECTIVE: Assessment of energy needs is a critical step in developing the nutrition care plan, especially for individuals unable to modulate their own energy intakes. The purpose of this study was to assess precision and accuracy of commonly used prediction equations in comparison to measured resting energy expenditure in a sample of "oldest old" adults residing in long term care (LTC). SUBJECTS AND DESIGN: Resting energy expenditure (mREE) was measured by indirect calorimetry in 45 residents aged 86.1 ± 7.3 years, and compared to frequently used prediction equations (pREE): Mifflin St.Jeor, Harris Benedict, World Health Organization and Owen. Precision and accuracy were determined by concordance correlation coefficients and number of individuals within ± 10% of mREE. Bland Altman plots with linear dependence trends were constructed to visualize agreement. To complete analyses, the common 25 kcal/kg formula was assessed and alternative formulas were determined for best fit by regressing adjusted mREE on body weight. RESULTS: mREE averaged 976.2 ± 190.3 kcal/day for females and 1260.0 ± 275.9 kcal/d for males. The strength of the relationships between pREE and mREE were only moderate (r = 0.41 - 0.72). In examining linear trends in the Bland Altman plots, significant systematic deviation from mREE was detected for all pREE. Two kcal/kg formulas were generated: 20.6 kcal/kg for females and 22.7 kcal/kg for males, which were not significantly different. CONCLUSION: None of the prediction equations adequately estimated energy needs in this sample of the "oldest old." A simple formula using 21-23 kcal/kg may be a more practical and reliable method to determine energy needs in the LTC setting.

Nutritional complications and management of intestinal transplant.

Advances in intestinal transplantation provide a promising alternative to patients with intestinal failure and chronic dependence on total parenteral nutrition. However, many physiologic complications arising from the surgical procedure and high-dose immunosuppression, along with potential for rejection and infection, make successful graft function after transplantation a challenge. Nutrition issues unique to this patient population include recovery of normal intestinal motility and absorptive capacity. Diarrhea and high stomal output, which are common postoperatively, lead to deficits in macronutrients and micronutrients, especially electrolytes. Impaired gastrointestinal function affects ability to wean patients off hyperalimentation and enable them to tolerate nutrients enterally. In pediatric recipients of intestinal transplant, lack of experience with food or prior food aversions can lead to refusal to eat after transplant--additional challenges to achieving oral intake. Early and aggressive nutrition intervention is necessary for resolution of nutritional deficits and health of donor small bowel. This article presents an overview of the surgical procedure of intestinal transplantation and describes the physiologic adaptations that occur after the process. A case study demonstrates the clinical and nutritional hurdles associated with an intestinal transplant in a child and how dietitians can provide nutrition management. The potential role of individual nutrients in recovery of the transplanted bowel is also discussed.