Modulation of Postprandial Plasma Concentrations of Digestive Hormones and Gut Microbiota by Foods Containing Oat ß-Glucans in Healthy Volunteers.

Cereal ß-glucans are beneficial health ingredients that reduce cholesterolemia and postprandial glycaemia. However, their impact on digestive hormones and gut microbiota is not yet fully established. Two randomized, double-blind, controlled studies were conducted. In the first study, 14 subjects ingested a breakfast with or without ß-glucan from oats (5.2 g). Compared to the control, ß-glucan increased orocecal transit time (p = 0.028) and decreased mean appetite score (p = 0.014) and postprandial plasma ghrelin (p = 0.030), C-peptide (p = 0.001), insulin (p = 0.06), and glucose (p = 0.0006). ß-glucan increased plasma GIP (p = 0.035) and PP (p = 0.018) without affecting leptin, GLP-1, PYY, glucagon, amylin, or 7α-hydroxy-4-cholesten-3-one, a biomarker of bile acid synthesis. In the second study, 32 subjects were distributed into 2 groups to ingest daily foods with (3 g/day) or without ß-glucan for 3 weeks; stools were collected before/after treatment. No changes in fecal microbiota composition/diversity (deep sequencing) were detected with ß-glucans. These results indicate that acute intake of 5 g ß-glucan slows transit time and decreases hunger sensation and postprandial glycaemia without affecting bile-acid synthesis, these changes being associated with decreased plasma insulin, C-peptide, and ghrelin, and increased plasma GIP and PP. However, regular daily intake of 3 g ß-glucan is not sufficient to have an effect on fecal microbiota composition.

Meal timing across the day modulates daily energy intake in adult patients with type 2 diabetes.

BACKGROUND/OBJECTIVES: We assessed the association between the timing of meals across the day with diet composition and metabolic parameters in patients with type-2 diabetes (T2D). SUBJECTS/METHODS: Eighty adults (55.2 ± 6.8 years, 45% males) patients with T2D (without insulin therapy) were included. Three non-consecutive dietary records assessed food intake. The onset time of each consumed meal/beverage was identified and assigned to one of three periods of the day: Period 1 (P1, 06:00-11:59 h), Period 2 (P2, 12:00-17:59 h), and Period 3 (P3, 18:00-00:30 h). RESULTS: Energy intake in P1 was lower compared to P2 and P3 (22.8 ± 7.9%, 37.5 ± 9.6%, and 39.7 ± 9.9%, respectively, P < 0.001). The same pattern was found for both total protein and fat intake, but carbohydrate intake was similar among periods. Patients with greater daily energy intake (as % of total energy) in P3 showed increased total food consumption, total energy, protein, and fat intake (all P < 0.05). The opposite pattern was observed in patients with greater daily energy intake in P1 (all P < 0.05). Regression analysis showed that daily energy intake was significantly reduced when a higher proportion of carbohydrates was eaten in P1 (vs. P3, P < 0.04). CONCLUSION: Increased energy intake late during the day is related to increased total food and daily energy intake in patients with T2D. A greater proportion of total carbohydrates eaten early during the day relates to lower total energy intake. Our results suggest that earlier food intake may be a nutritional tool for dietary and metabolic control in these patients.

Zinc absorption and zinc status are reduced after either sleeve gastrectomy or Roux-en-Y gastric bypass in premenopausal women with severe obesity studied prospectively over 24 postoperative months.

BACKGROUND: Roux-en-Y gastric bypass (RYGBP) is known to reduce zinc absorption; the effects of vertical sleeve gastrectomy (SG) and its long-term implications on zinc absorption have not yet been studied. OBJECTIVE: The aim was to evaluate the effects of SG and RYGBP on zinc absorption and zinc status in premenopausal women with severe obesity up to 24 mo after surgery. METHODS: Twenty-six premenopausal women undergoing SG [BMI (in kg/m2): 37.3 ± 3.2] and 32 undergoing RYGBP (BMI: 42.0 ± 4.2) were studied. A series of anthropometric, dietary, and zinc status parameters (plasma and hair zinc), and the size of the exchangeable zinc pool (EZP), as well as percentage zinc absorption from a standardized dose using a stable isotope methodology were evaluated in the patients before the surgical procedure and at 12 and 24 mo after SG or RYGBP. SG patients received 15 mg and RYGBP received 25 mg of supplemental Zn/d. RESULTS: In premenopausal women, zinc absorption was decreased by 71.9% and 52.0% in SG and RYGBP, respectively, 24 mo postsurgery, compared with initial values. According to 2-factor repeated-measures ANOVA, time effect was significant (P = <0.0001), but not time × group interaction (P = 0.470). Plasma zinc below the cutoff point of 70 µg/dL increased from 0 to 15.4% and 38.1% in SG and RYGBP, respectively. Mean EZP was significantly reduced 24 mo after surgery, although no time × group interactions were observed. Hair zinc did not change across time or between groups. CONCLUSIONS: Both SG and RYGBP have profound effects on zinc absorption capacity, which are not compensated for after 24 mo. Although zinc absorption reduction was similar in both types of surgeries, plasma zinc was more affected in RYGBP than SG, despite greater zinc supplementation in RYGBP.This trial was registered at http://www.isrctn.com as ISRCTN31937503.

Zinc Supplementation and Strength Exercise in Rats with Type 2 Diabetes: Akt and PTP1B Phosphorylation in Nonalcoholic Fatty Liver.

Type 2 diabetes mellitus (T2D) is a metabolic disorder caused by chronic hyperglycemia due to a deficiency in the secretion and/or action of insulin. Zinc (Zn) supplementation and strength exercise increases insulin signaling. We evaluate the effect of Zn supplementation and strength exercise on insulin resistance in the liver of rats with diet-induced T2D through the study of phosphorylation of Akt and protein tyrosine phosphatase 1B (PTP1B). Rats were fed with a high-fat diet (HFD) for 18 weeks to induce T2D and then assigned in four experimental groups: HFD, HFD-Zn (Zn), HFD-strength exercise (Ex), and HFD-Zn/strength exercise (ZnEx) and treated during 12 weeks. Serum Zn, lipid profile, transaminases, glucose, and insulin were measured. In the liver with/without insulin stimuli, total and phosphorylated Akt (pAktSer473) and PTP1B (pPTP1BSer50) were determined by western blot. Hepatic steatosis was evaluated by histological staining with red oil and intrahepatic triglyceride (IHTG) content. There were no differences in biochemical and body-related variables. The ZnEx group showed a higher level of pAkt, both with/without insulin. The ZnEx group also showed higher levels of pPTP1B with respect to HFD and Zn groups. The ZnEx group had higher levels of pPTP1B than groups treated with insulin. Liver histology showed a better integrity and less IHTG in Ex and ZnEx with respect to the HFD group. The Ex and ZnEx groups had lower IHTG with respect to the HFD group. Our results showed that Zn supplementation and strength exercise together improved insulin signaling and attenuated nonalcoholic liver disease in a T2D rat model.

La suplementación con zinc reduce la concentración de ácidos grasos libres en pacientes con diabetes tipo 2

RESUMEN Elevadas concentraciones de ácidos grasos libres (AGL) han sido asociadas con la patogénesis de resistencia a la insulina y diabetes tipo 2 (DT2), por lo que la regulación de la lipólisis resulta prioritaria en estos pacientes. El zinc mediante sus acciones insulinomiméticas e inducción de fosfodiesterasas podría regular la liberación de AGL desde el tejido adiposo. El objetivo de esta investigación fue evaluar en pacientes con DT2 el efecto de 24 meses de suplementación con zinc sobre las concentraciones séricas de AGL en ayuno. Para este propósito: se realizó la determinación de AGL en ayuno por colorimetría enzimática, zinc plasmático por espectrofotometría de absorción atómica, y parámetros bioquímicos y antropométricos de interés en 60 pacientes con DT2 que fueron asignados aleatoriamente para recibir suplementación con 30 mg/día de zinc (n= 30) o placebo (n= 30) por 24 meses. El grupo zinc presentó menor concentración sérica de AGL al mes 24 (p = 0,034). El cambio en el índice de masa corporal, el sexo y la suplementación con zinc contribuyeron significativamente como predictores de la concentración sérica de AGL al mes 24 (R= 0,493, R2= 0,243, p= 0,001). Conclusión: la suplementación con 30 mg/día de zinc en pacientes con DT2 tuvo un efecto significativo en reducir la concentración sérica de AGL en ayuno tras 24 meses de tratamiento. Estos resultados apoyan los beneficios del zinc como coadyuvante en el tratamiento de DT2.

ABSTRACT High concentrations of free fatty acids (FFA) have been associated with the pathogenesis of insulin resistance and type 2 diabetes (T2D), making lipolysis regulation a priority in these patients. Through its insulin-mimetic actions and phosphodiesterase induction, zinc could regulate FFA release from adipose tissue. The objective of this research was to evaluate the effect of 24 months of zinc supplementation on fasting serum FFA concentrations in patients with T2D. For this purpose: fasting FFA by enzymatic colorimetric, plasma zinc by atomic absorption spectrophotometry, and biochemical and anthropometric parameter of interest were determined in 60 T2D patients who were randomly assigned to 30 mg/day of zinc supplementation (n= 30) or placebo (n= 30) for 24 months. The zinc group had lower serum FFA concentration at month 24 (p= 0.034). Body mass index change, gender, and zinc supplementation contributed significantly as predictors of serum FFA concentration at month 24 (R= 0.493, R2= 0.243, p= 0.001). Conclusion: Supplementation with 30 mg/day of zinc in patients with T2D had a significant effect in reducing serum fasting FFA concentration after 24 months of treatment. These results support the benefits of zinc as coadjutant in T2D treatment.

Fatty acid desaturation in red blood cell membranes of patients with type 2 diabetes is improved by zinc supplementation.

BACKGROUND/OBJECTIVE: Membrane flexibility can be a determining factor in pathophysiological mechanisms of type 2 diabetes (T2D). As a cofactor of delta-5 desaturase (D5D) and delta-6 desaturase (D6D), and gene expression regulator, zinc may play a role modulating membrane flexibility by increasing membrane polyunsaturated fatty acids (PUFA) abundance. The objective of this study was to evaluate the effect of a 24-month zinc supplementation (30 mg elemental zinc) on membrane fatty acid composition in patients with T2D. SUBJECTS/METHODS: Sixty patients with T2D were evaluated. Thirty were randomly assigned to the zinc supplemented group and thirty to the placebo group. Fatty acid composition in red blood cell (RBC) membranes was determined by gas chromatography. Expression of gene encoding for D5D (FADS1), and D6D (FADS2) were evaluated in peripheral blood mononuclear cells by real-time polymerase chain reaction. RESULTS: After 24 months of supplementation, a greater abundance of docosapentaenoic acid (C22:5 n-3), arachidonic acid (C20:4 n-6), adrenic acid (C22:4 n-6), and total n-6 PUFA was found (p = 0.001, p = 0.007, p = 0.033, p = 0.048, respectively). The unsaturated fatty acids/saturated fatty acids ratio, and unsaturation index was increased in the zinc supplemented group at month 24 (p = 0.003 and p  = 0.000, respectively). FADS1 gene was upregulated in the zinc group in relation to placebo at month 12 (p = 0.020). CONCLUSIONS: Supplementation with 30 mg/d elemental zinc during 24 months in patients with T2D had an effect on the composition of RBC membranes increasing PUFA abundance and in turn, improving membrane flexibility. This effect may be mediated by induction of D5D gene expression.

Calcium absorption may be affected after either sleeve gastrectomy or Roux-en-Y gastric bypass in premenopausal women: a 2-y prospective study.

Background: Although Roux-en-Y gastric bypass (RYGBP) is known to reduce calcium absorption (CA), the effects of vertical sleeve gastrectomy (SG) and its long-term implications on CA have not yet been studied. Objective: The aim of this study was to evaluate changes in CA and its relation with modifications of bone mineral density (BMD), intakes of calcium and vitamin D, vitamin D status, and parathyroid hormone (PTH) concentrations ≤24 mo after SG and RYGBP, respectively. Design: Twenty-six premenopausal women undergoing SG [mean ± SD body mass index (BMI; kg/m2): 37.3 ± 3.2; age: 34.2 ± 10.2 y] and 32 undergoing RYGBP (BMI: 42.0 ± 4.2; age: 37.3 ± 8.1 y) were studied at baseline (presurgery) and followed up at 12 and 24 mo after surgery. BMD, bone alkaline phosphatase activity, and serum PTH, 25-hydroxyvitamin D [25(OH)D], calcium, magnesium, and phosphorus concentrations were determined. Food and supplement intakes were recorded. CA was measured by using a dual stable isotope method. Results: In premenopausal women, CA was significantly reduced from 36.5% ± 2.0% preoperatively to 21.0% ± 2.3% and 18.8% ± 3.4% at 12 and 24 mo post-SG surgery, respectively. CA also decreased significantly from 41.5% ± 2.8% preoperatively to 27.9% ± 3.8% and 18.5% ± 2.2% 12 and 24 mo after RYGBP, respectively. No difference was found between type of surgery (time × group interaction, P = 0.60). Considering both groups combined, 56.6% of the variance in CA at the 12-mo but not at the 24-mo follow-up was explained by serum PTH and 25(OH)D concentrations, together with vitamin D and calcium intakes. Conclusions: CA was similarly reduced in both SG and RYGBP compared with baseline, and it was not associated with changes in BMD or body weight loss. This reduction in CA could be explained only partially by calcium intake increase. This trial is registered at http://www.isrctn.com as ISRCTN31937503.

Association between zinc nutritional status and glycemic control in individuals with well-controlled type-2 diabetes.

BACKGROUND/OBJECTIVE: Interest in healthy properties of food and nutrients as co-adjuvant in type-2 diabetes therapy has increased in recent years. Zinc supplementation trials have shown improvements in glycemic control in these patients, although it seems dependent on zinc status of the individuals. The objective of this study was to evaluate the relationship between zinc nutritional status and glucose homeostasis in patients with type-2 diabetes. SUBJECTS/METHODS: Eighty patients with well controlled type-2 diabetes were recruited and clinical, anthropometric and dietary evaluations were performed. One week after, insulin sensitivity and beta cell function were assessed by a modified Frequently Sampled Intravenous Glucose Tolerance Test. Zinc status was assessed by plasma zinc and the size of rapidly Exchangeable Zinc Pool (EZP); zinc intake was also determined. Glucagon concentration was evaluated in a subsample of 36 patients. RESULTS: Patients presented a normal zinc status although zinc intake was lower than recommended. Overall, no associations were observed between zinc status and glycemic control markers. Nevertheless, positive correlations were observed between EZP and fasting insulin concentration (ρ = 0.393, p = 0.021) and HOMA-IR (ρ = 0.386, p = 0.024) in women, and between plasma zinc concentration and HbA1c (ρ = 0.342, p = 0.020) in men. CONCLUSIONS: No significant associations were found between zinc status and glycemic control parameters in patients with well-controlled type 2 diabetes and normal zinc status, although low-degree gender-dependent associations were observed. Further research is required to assess the role of zinc status in zinc deficient patients.

Zinc Supplementation Does Not Affect Glucagon Response to Intravenous Glucose and Insulin Infusion in Patients with Well-Controlled Type 2 Diabetes.

Glucagon dysregulation is an essential component in the pathophysiology of type 2 diabetes. Studies in vitro and in animal models have shown that zinc co-secreted with insulin suppresses glucagon secretion. Zinc supplementation improves blood glucose control in patients with type 2 diabetes, although there is little information about how zinc supplementation may affect glucagon secretion. The objective of this study was to evaluate the effect of 1-year zinc supplementation on fasting plasma glucagon concentration and in response to intravenous glucose and insulin infusion in patients with type 2 diabetes. A cross-sectional study was performed after 1-year of intervention with 30 mg/day zinc supplementation or a placebo on 28 patients with type 2 diabetes. Demographic, anthropometric, and biochemical parameters were determined. Fasting plasma glucagon and in response to intravenous glucose and insulin infusion were evaluated. Patients of both placebo and supplemented groups presented a well control of diabetes, with mean values of fasting blood glucose and glycated hemoglobin within the therapeutic goals established by ADA. No significant differences were observed in plasma glucagon concentration, glucagon/glucose ratio or glucagon/insulin ratio fasting, after glucose or after insulin infusions between placebo and supplemented groups. No significant effects of glucose or insulin infusions were observed on plasma glucagon concentration. One-year zinc supplementation did not affect fasting plasma glucagon nor response to intravenous glucose or insulin infusion in well-controlled type 2 diabetes patients with an adequate zinc status.

Micronutrient Deficiencies in Morbidly Obese Women Prior to Bariatric Surgery.

BACKGROUND: Although morbid obesity is related to excess of energy and macronutrient intake, it does not rule out the presence of micronutrient deficiencies. The aim of this study was to evaluate food intake and the prevalence of micronutrient deficiencies in a group of morbidly obese women seeking bariatric surgery. METHODS: A total of 103 morbidly obese women were studied prior to bariatric surgery. Anthropometry and body composition (dual-energy X-ray absorptiometry, DEXA) were performed on all subjects. Energy and nutrient intake was determined by food frequency questionnaire. Blood tests to assess micronutrients status, including plasma iron, ferritin, transferrin, zinc, copper, calcium, phosphorus, hemoglobin, hematocrit, mean corpuscular volume (MCV), and hair zinc, were performed. Folic acid, vitamin B12, vitamin D, and parathyroid hormone (PTH) were also assessed in 66 subjects. RESULTS: Mean energy intake was 2801 ± 970 kcal/day. Carbohydrate, protein, and lipid intake represented 55 ± 9.1, 13.9 ± 3.3, and 32.5 ± 8.2% of total energy intake, respectively. Iron, calcium, and vitamin D intake was below the recommended dietary allowance. The prevalence of nutritional deficiencies were as follows: plasma iron 12.6%, ferritin 8.7%, transferrin 14.6%, plasma zinc 2.9%, calcium 3.3%, phosphorus 2.3%, hemoglobin 7.7%, hematocrit 13.6%, MCV 6.8%, and hair zinc 15.7%. In the subsample, 10.6% had a vitamin B12 deficiency, 71.7% showed low concentrations of vitamin D, and 66% had high PTH levels. No folic acid or copper deficiencies were detected. CONCLUSIONS: Despite high daily energy intake and adequate macronutrient distribution, morbidly obese Chilean women seeking bariatric surgery present with deficient intake of some micronutrients and a high prevalence of micronutrient deficiencies.

[IMPACT OF DIETARY FATTY ACIDS ON LIPID PROFILE, INSULIN SENSITIVITY AND FUNCTIONALITY OF PANCREATIC ß CELLS IN TYPE 2 DIABETIC SUBJECTS]. / IMPACTO DE LOS ÁCIDOS GRASOS DE LA DIETA SOBRE EL PERFIL LIPÍDICO, LA SENSIBILIDAD A LA INSULINA Y LA FUNCIONALIDAD DE LAS CÉLULAS b PANCREÁTICAS EN SUJETOS DIABÉTICOS TIPO 2.

INTRODUCTION: the quality of fats could influence the metabolic control of patients with Type 2 Diabetes Mellitus (DM2). OBJECTIVES: to determine the relationship between intake and quality of dietary fatty acids to lipid profile, metabolic control, functionality of pancreatic cells and insulin sensivity in subjects with DM2. METHODS: we studied 54 subjects with DM2, anthropometric measurements were performed, body composition and dietary lipid intake, saturated fatty acids (SFA), trans, monounsaturated, polyunsaturated, omega 3, omega 6 and dietary cholesterol. Laboratory parameters related to their metabolic control were determined (fasting blood glucose, glycated hemoglobin, and lipid profile). The insulin secretion and insulin sensitivity was determined with the insulin-modified intravenous glucose tolerance test according to the Bergman's minimal model. RESULTS: 28 men and 26 women were studied (BMI of 29.5 ± 3.7 kg/m2; age 55.6 ± 6.8 y.), 48% had LDL-C < 100 mg/dL, 12.9% of men c-HDL > 40 mg/dL and 7.4% of women c-HDL > 50 mg/dL. 32% consumed > 10% of AGS and > 300 mg/day of dietary cholesterol. The SFA intake and percentage of calories from fat (G%) were significantly associated with insulin resistance and fasting plasma glucose concentration. The G% predicted 84% variability on c-VLDL. CONCLUSIONS: in patients with DM2 a greater intake of fat and saturated fatty acids it associated with greater fasting glycemia and insulin resistance.

Introducción: la calidad de las grasas podría influir en el control metabólico de los sujetos con diabetes mellitus tipo 2 (DM2). Objetivos: determinar la relación entre la ingesta y la calidad de los ácidos grasos de la dieta con el perfil lipídico, el control metabólico, la funcionalidad de las células pancreáticas y la sensibilidad a la insulina en sujetos con DM2. Métodos: se estudió a 54 sujetos con DM2, se realizaron determinaciones antropométricas, de composición corporal e ingesta dietética de lípidos, ácidos grasos saturados (AGS), trans, monoinsaturados, poliinsaturados, omega 3, omega 6 y colesterol dietario. Se determinaron los parámetros de laboratorio relacionados con el control metabólico (glicemia de ayuno, hemoglobina glicada, perfil lipídico). La secreción de insulina y la sensibilidad a la insulina se determinaron con el test intravenoso de tolerancia a la glucosa modificado con insulina, basado en el modelo mínimo de Bergman. Resultados: se estudió a 28 hombres y 26 mujeres (edad 55,6 ± 6,8 años; IMC 29,5 ± 3,7 kg/m2). Un 48% presentaba c-LDL < 100 mg/dl, el 12,9% de los hombres c-HDL > 40 mg/dl y el 7,4% de las mujeres c-HDL > 50 mg/dl. El 32% consumía > 10% de AGS y > 300 mg/día de colesterol dietario. La ingesta de AGS y el porcentaje de calorías grasas (G%) mostraron una asociación positiva significativa con la resistencia a la insulina y la glicemia. El G% predice en un 84% la variabilidad del c-VLDL. Conclusiones: en los sujetos con DM2, una mayor ingesta de AGS y de grasas se asocia con valores superiores de glicemia y de resistencia a la insulina.

Changes in bone mineral density after sleeve gastrectomy or gastric bypass: relationships with variations in vitamin D, ghrelin, and adiponectin levels.

BACKGROUND: A major long-term concern after gastric bypass (GBP) is the risk of osteoporosis; however, little is known about this complication in patients undergoing sleeve gastrectomy (SG). OBJECTIVE: To evaluate changes in bone mineral density (BMD) after GBP and SG, and its relationship with changes in vitamin D, parathyroid hormone (PTH), ghrelin, and adiponectin. METHODS: Twenty-three women undergoing GBP (BMI 42.0 ± 4.2 kg/m2; 37.3 ± 8.1 years) and 20 undergoing SG (BMI 37.3 ± 3.2 kg/m2; 34.2 ± 10.2 years) were studied before and 6 and 12 months after surgery. BMD was measured by dual-energy X-ray absorptiometry. Plasma PTH, 25-hydroxyvitamin D (25-OHD), ghrelin, and adiponectin concentrations were determined. Food as well as calcium and vitamin D supplement intake was recorded. RESULTS: Excess weight loss (mean ± SE), adjusted by baseline excess weight, was 79.1±3.8% and 74.9 ± 4.1% 1 year after GBP and SG, respectively (p = 0.481). Significant reduction in BMD for total body (TB), lumbar spine (LS), and femoral neck (FN) was observed after GBP. In the SG group, reduction in BMD was significant only for TB. Adjusted by baseline BMD, the difference between change in BMD for GBP vs. SG was not significant for TB, LS, or FN. Percent reduction in ghrelin concentration was a main factor related to total BMD loss (GBP group) and LS BMD loss (GBP and SG groups). CONCLUSIONS: One year after gastric bypass, bone mineral density was significantly affected, mainly at the femoral neck. Decreases in bone mineral density were more dramatic among patients who had greater baseline BMD and greater reduction in ghrelin concentrations.

Zinc as a potential coadjuvant in therapy for type 2 diabetes.

BACKGROUND: Type 2 diabetes is highly prevalent in populations having high rates of overweight and obesity. It is a chronic condition responsible for long-term severe dysfunction of several organs, including the kidneys, heart, blood vessels, and eyes. Although there are a number of pharmacologic products in the market to treat insulin resistance and impaired insulin secretion--the most prominent features of this disease--interventions directed at preserving the integrity and function of beta-cells in the long term are less available. The use of some nutrients with important cellular protective roles that may lead to a preservation of beta-cells has not been fully tested; among these, zinc may be an interesting candidate. OBJECTIVE: To assess the potential of zinc supplementation as coadjuvant to diabetes therapy. METHODS: This article reviews the available information on the use of zinc as part of diabetes therapy. RESULTS: Cellular and animal models provide information on the insulin mimetic action of zinc, as well as its role as a regulator of oxidative stress, inflammation, apoptosis, and insulin secretion. Zinc supplementation studies in humans are limited, although some positive effects have been reported; mainly, a modest but significant reduction in fasting glucose and a trend to decreased glycated hemoglobin (HbA1c). CONCLUSIONS: Zinc supplementation may have beneficial effects on glycemic control. Nevertheless, among the studies considered, the vast majority lasted for 6 months or less, suggesting the importance of conducting long-duration studies given the characteristics of type 2 diabetes as a chronic disease.

Heme- and nonheme-iron absorption and iron status 12 mo after sleeve gastrectomy and Roux-en-Y gastric bypass in morbidly obese women.

BACKGROUND: The effect of bariatric surgery on iron absorption is only partially known. OBJECTIVE: The objective was to study the effects of sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGBP) on heme- and nonheme-iron absorption and iron status. DESIGN: Fifty-eight menstruating women were enrolled in this prospective study [mean (±SD) age: 35.9 ± 9.1 y; weight: 101.7 ± 13.5 kg; BMI (in kg/m²): 39.9 ± 4.4]. Anthropometric, body-composition, dietary, and hematologic indexes and heme- and nonheme-iron absorption-using a standardized meal containing 3 mg Fe-were determined before and 12 mo after surgery. Forty-three subjects completed the 12-mo follow-up. Iron supplements were strictly controlled. RESULTS: Heme-iron absorption was 23.9% before and 6.2% 12 mo after surgery (P < 0.0001). Nonheme-iron absorption decreased from 11.1% to 4.7% (P < 0.0001). No differences were observed by type of surgery. Iron intakes from all sources of supplements were 27.9 ± 6.2 mg/d in the SG group and 63.2 ± 21.1 mg/d in the RYGBP group (P < 0.001). Serum ferritin and total-body iron decreased more after RYGBP than after SG. CONCLUSIONS: Iron (heme and nonheme) absorption is markedly reduced after SG and RYGBP. The magnitude of the decrease in heme-iron absorption is greater than that of nonheme iron. The amounts suggested as iron supplements may need to be increased to effectively prevent iron-status impairment.

Changes in ghrelin concentrations one year after resective and non-resective gastric bypass: associations with weight loss and energy and macronutrient intakes.

OBJECTIVE: Ghrelin is a potent stimulator of appetite and synthesized in the stomach. Its role in weight loss after gastric bypass (GBP) is still controversial. The aim of this study was to evaluate the relation between weight loss and food intake and between weight loss and changes in serum ghrelin concentrations 1 y after GBP with resection of the bypassed stomach (R-GBP) and without resection (NR-GBP). METHODS: Of 50 women (37.6 ± 10.2 y old, body mass index 43.8 ± 4.8 kg/m²) with GBP, 26 had R-GBP and 24 had NR-GBP. Body weight, body composition (dual energy x-ray absorptiometry), food intake, and serum ghrelin at baseline and 12 mo after GBP were measured. RESULTS: The percentage of excess weight loss was 68.9 ± 12.8% at 12 mo after GBP. At 12 mo, the decrease of serum ghrelin was greater in the R-GBP group (-25.3 ± 22.5%) compared with the NR-GBP group (+11.2 ± 50.9%, P < 0.005). After adjustment by the baseline excess of body weight, there was a greater percentage of excess weight loss in the R-GBP group only at 6 mo (61.8% versus 54.9%, P = 0.011). After controlling for the baseline intake, a significant lower carbohydrate intake was observed in the R-GBP group 6 mo after surgery (P < 0.05). CONCLUSION: A greater decrease in ghrelin levels was observed only in patients who underwent R-GBP at 12 mo after surgery. This difference was not associated with differences in dietary intakes or weight loss at the same time point. Therefore, the small gastric pouch is probably more important than decreased ghrelin levels in producing long-term weight loss after R-GBP.

[Quality of the diet of women with severe and morbid obesity undergoing gastric bypass and sleeve gastrectomy]. / Calidad de la alimentación de mujeres con obesidad severa y mórbida sometidas a bypass gastrico y gastrectomia vertical en manga.

The objective of this study was to evaluate the changes of dietary intake and quality of the diet in patients undergoing gastric bypass and sleeve surgery. In 36 women with severe and morbid obesity it was assessed their nutrient intakes and dietary quality before and 6 months after bariatric surgery through three-day food records. Vitamin and mineral intakes from supplements were strictly controlled. Energy and nutrient intakes were significantly decreased 6 months after surgery bypass compared to the pre-surgery period with the exceptions of calcium and vitamin C. No differences were observed between groups. The Dietary quality index was also similar in both groups. Dietary intakes of calcium, iron, zinc, copper, folic acid, vitamin C, and vitamin E were below 100% of adequacy from at the 6th month after the surgery. Nevertheless, by considering both diet and supplements supply, nutrient adequacy of all but calcium and folic acid was above 100% in both groups. Gastric bypass patients presented greater values. In conclusion, these patients present an important reduction of their energy and nutrient intakes, with no major impact of the type of surgery. Supplement characteristics are crucial to cover nutritional needs.

Zinc absorption and zinc status are reduced after Roux-en-Y gastric bypass: a randomized study using 2 supplements.

BACKGROUND: Micronutrient deficiencies are common in patients undergoing gastric bypass. The effect of this type of surgery on zinc absorption and zinc status is not well known. OBJECTIVE: The objective was to evaluate the effects of Roux-en-Y gastric bypass (RYGBP) on zinc status and zinc absorption at different stages after surgery. We hypothesized that zinc status would be significantly impaired after surgery and that this impairment would be less severe in subjects receiving increased supplemental zinc. We also hypothesized that zinc absorption would be lower after surgery. DESIGN: Anthropometric and body-composition variables and dietary and biochemical indexes of zinc status and zinc absorption were determined in 67 severe and morbidly obese women [mean (±SD) age: 36.9 ± 9.8 y; BMI (in kg/m(2)): 45.2 ± 4.7] who underwent RYGBP. The subjects were randomly assigned to 1 of 2 vitamin-mineral supplementation groups. Measurements were made before and 6, 12, and 18 mo after surgery. Fifty-six subjects completed the 18-mo follow-up. RESULTS: Mean plasma zinc, erythrocyte membrane alkaline phosphatase activity, and the size of the rapidly exchangeable zinc pool decreased after RYGBP. Percentage zinc absorption decreased significantly from 32.3% to 13.6% at 6 mo after RYGBP and to 21% at 18 mo after surgery. No effect of supplement type was observed. CONCLUSIONS: Zinc status is impaired after RYGBP, despite the finding that dietary plus supplemental zinc doubled recommended zinc intakes in healthy persons. Zinc absorption capacity is significantly reduced soon after RYGBP, with no major changes until 18 mo after surgery.

Trace element status and inflammation parameters after 6 months of Roux-en-Y gastric bypass.

BACKGROUND: Knowledge about the practical consequences of the nutritional status of Fe, Zn, and Cu and inflammation in obesity is limited. The objective of this study was to evaluate changes on trace element status and their potential associations with selected inflammation parameters in patients after Roux-en-Y gastric bypass (RYGBP). METHODS: Sixty-three women (mean age, 36.9 ± 9.2 years, body mass index, 43.8 ± 4.3 kg/m²) were evaluated at baseline and 6 months after RYGBP. Anthropometric (weight, waist circumference), body composition (fat mass and fat-free mass), dietary (nutrient intakes), and metabolic and inflammation (glucose, insulin, HOMA-IR, adiponectin, HDL-cholesterol, LDL-cholesterol, triglycerides, hs-CRP, leukocytes, polymorphonuclear neutrophils (PMN)) parameters were determined in addition to selected indices of Fe, Zn, and Cu status. RESULTS: All but one (HDL-cholesterol) metabolic and inflammation parameters had significant differences when compared before and after RYGBP. Hemoglobin, serum ferritin, the size of the rapidly exchangeable zinc pool, and plasma copper decreased after RYGBP. Plasma and hair zinc, as well as zinc protoporphyrin increased. The change in Hb was significantly associated (p < 0.05) to the change in leukocytes (r = 0.33) and adiponectin (r = -0.44). Zinc protoporphyrin change was associated to the change in PMN (r = 0.32) and HDL-cholesterol (r = -0.29). No other associations between the changes of the rest of Fe, Zn, and Cu parameters with the changes of any of the metabolic and inflammation parameters were observed. CONCLUSION: RYGBP produced significant weight and fat mass losses, with improvement of metabolic and inflammation parameters. Iron, zinc, and copper status were impaired after the surgery.

Calidad de la alimentación de mujeres con obesidad severa y mórbida sometidas a bypass gastrico y gastrectomia vertical en manga

El objetivo de este estudio fue comparar la ingesta de energía y nutrientes y la calidad de la alimentación, en pacientes sometidos a bypass gástrico en Y de Roux y (BPGYR) y gastrectomía vertical en manga (GVM). En 36 mujeres con obesidad severa y mórbida se estudió la alimentación previa y a los 6 meses posteriores a la cirugía, mediante encuesta de registro de tres días, se analizó el grado de adecuación e índice de calidad nutricional (ICN). Se controló estrictamente el consumo de suplementos de vitaminas y minerales. El consumo de energía y nutrientes fue significativamente menor al sexto mes post cirugía comparado con el preoperatorio, sin diferencias significativas entre grupos, excepto calcio y vitamina C. El ICN fue similar entre grupos. La ingesta dietética de calcio, hierro, zinc, cobre, ácido fólico, vitamina C y E fue menor al 100% de adecuación al 6º mes. Sin embargo, al considerar en conjunto el aporte de la dieta como de los suplementos, la adecuación de prácticamente todos los nutrientes estudiados sobrepasa el 100% en ambos grupos, logrando una mayor adecuación el grupo sometido a BPGYR. Las excepciones las constituyen el calcio, el cual no alcanza a cubrir el 100% en ningún grupo y el ácido fólico en el grupo sometido a GVM. En conclusión, estos pacientes presentan reducciones importantes de la ingesta dietética de energía y micronutrientes, sin mayores diferencias dependientes del tipo de cirugía. Las características de los suplementos son críticos para lograr la cobertura de las necesidades.

The objective of this study was to evaluate the changes of dietary intake and quality of the diet in patients undergoing gastric bypass and sleeve surgery. In 36 women with severe and morbid obesity it was assessed their nutrient intakes and dietary quality before and 6 months after bariatric surgery through three-day food records. Vitamin and mineral intakes from supplements were strictly controlled. Energy and nutrient intakes were significantly decreased 6 months after surgery bypass compared to the pre-surgery period, with the exceptions of calcium and vitamin C. No differences were observed between groups. The Dietary quality index was also similar in both groups. Dietary intakes of calcium, iron, zinc, copper, folic acid, vitamin C, and vitamin E were below 100% of adequacy from at the 6th month after the surgery. Nevertheless, by considering both diet and supplements supply, nutrient adequacy of all but calcium and folic acid was above 100% in both groups. Gastric bypass patients presented greater values. In conclusion, these patients present an important reduction of their energy and nutrient intakes, with no major impact of the type of surgery. Supplement characteristics are crucial to cover nutritional needs.

Iron absorption and iron status are reduced after Roux-en-Y gastric bypass.

BACKGROUND: Iron deficiency and iron deficiency anemia are common in patients who undergo gastric bypass. The magnitude of change in iron absorption is not well known. OBJECTIVE: The objective was to evaluate the effects of Roux-en-Y gastric bypass (RYGBP) on iron status and iron absorption at different stages after surgery. We hypothesized that iron absorption would be markedly impaired immediately after surgery and would not improve after such a procedure. DESIGN: Anthropometric, body-composition, dietary, hematologic, and iron-absorption measures were determined in 67 severe and morbidly obese women [mean age: 36.9 +/- 9.8 y; weight: 115.1 +/- 15.6 kg, body mass index (BMI: in kg/m(2)); 45.2 +/- 4.7] who underwent RYGBP. The Roux-en-Y loop length was 125-150 cm. Determinations were carried out before and 6, 12, and 18 mo after surgery. Fifty-one individuals completed all 4 evaluations. RESULTS: The hemoglobin concentration decreased significantly throughout the study (repeated-measures analysis of variance). The percentage of anemic subjects changed from 1.5% at the beginning of the study to 38.8% at 18 mo. The proportion of patients with low serum ferritin increased from 7.5% to 37.3%. The prevalence of iron deficiency anemia was 23.9% at the end of the experimental period. Iron absorption from both a standard diet and from a standard dose of ferrous ascorbate decreased significantly after 6 mo of RYGBP to 32.7% and 40.3% of their initial values, respectively. No further significant modifications were noted. CONCLUSION: Iron absorption is markedly reduced after RYGBP with no further modifications, at least until 18 mo after surgery.