Prevalence of Vitamin D Depletion, and Associated Factors, among Patients Undergoing Bariatric Surgery in Southern Brazil.

BACKGROUND: Hypovitaminosis D is common, before and after gastric bypass surgery. The prevalence of hypovitaminosis D in a large group of candidates for bariatric surgery in Brazil and South America has not been studied. OBJECTIVE: To evaluate the prevalence of hypovitaminosis D and associated factors in patients undergoing bariatric surgery in Southern Brazil. MATERIALS AND METHODS: Cross-sectional study involving all patients presenting for bariatric surgery at Hospital de Clínicas de Porto Alegre, from January 2013 to June 2018. Data were extracted from the patients' electronic medical records. Patients who were taking multivitamin supplements or vitamin D supplements, who had renal insufficiency, or had missing data for 25(OH) vitamin D [25(OH)D] levels were excluded. RESULTS: A total of 291 patients were included. Mean subjects' age was 44.9 (SD 10.7) years, and BMI 49.3 (SD 8.3) kg/m2; 76.6% of the study patients were women, and 87.3% were white. More than half the patients (55.3%) were vitamin D deficient (serum 25(OH)D ≤ 19.9 ng/ml), and 37.1% had insufficient levels (20-29.9 ng/mL). Mean vitamin D level was 19.2 ng/mL (SD 7.6). An inverse correlation was found between 25(OH)D levels and BMI. Vitamin D deficiency was more prevalent in patients with higher BMI [PR 1.02; CI 95% (1.00-1.03)], higher fasting glucose [PR 1.01; CI 95% (1.00-1.01)], in nonwhite patients [PR 1.58; CI 95% (1.30-1.92)] and during autumn/winter season [PR 1.41; CI 95% (1.14-1.75)]. CONCLUSIONS: Prevalence of vitamin D insufficiency and deficiency is very high among patients presenting for bariatric surgery in Southern Brazil, and the known associated factors are confirmed in this population.

Effects of n-3 fatty acids and exercise on oxidative stress parameters in type 2 diabetic: a randomized clinical trial.

BACKGROUND: The relationship between diabetes and oxidative stress has been previously reported. Exercise represents a useful non-pharmacological strategy for the treatment in type 2 diabetic (T2DM) patients, but high intensity exercise can induce a transient inflammatory state and increase oxidative stress. Nutritional strategies that may contribute to the reduction of oxidative stress induced by acute exercise are necessary. The aim of this study was to examine if n-3 PUFA supplementation intervention can attenuate the inflammatory response and oxidative stress associated with high intensity exercise in this population. As a primary outcome, lipoperoxidation measurements (TBARS and F2-isoprostanes) were selected. METHODS: Thirty T2DM patients, without chronic complications, were randomly allocated into two groups: placebo (gelatin capsules) or n-3 PUFA (capsules containing 180 mg of eicosapentaenoic acid and 120 mg of docosahexaenoic acid). Blood samples were collected fasting before and after 8 weeks supplementation. In the beginning and at the end of protocol, an acute exercise was performed (treadmill), and new blood samples were collected before and immediately after the exercise for measurements of oxidative stress and high-sensitivity C-reactive protein (hs-CRP). RESULTS: After the supplementation period, a decrease in triglycerides levels was observed only in n-3 PUFA supplementation group (mean difference and 95% CI of 0.002 (0.000-0.004), p = 0.005). Supplementation also significantly reduced TRAP levels after exercise (mean difference and 95% CI to 9641 (- 20,068-39,351) for - 33,884 (- 56,976 - -10,793), p = 0.004, Cohen's d effect size = 1.12), but no significant difference was observed in n-3 PUFA supplementation group in lipoperoxidation parameters as TBARS (mean difference and 95% CI to - 3.8 (- 10-2.4) for - 2.9 (- 1.6-7.4) or F2-isoprostanes (mean difference and 95% CI -0.05 (- 0.19-0.10) for - 0.02 (- 0.19-0.16), p > 0.05 for both. CONCLUSION: PUFA n-3 supplementation reduced triglycerides as well as TRAP levels after exercise, without a significant effect on inflammatory and oxidative stress markers.This study is registered at ClinicalTrials.gov with the registration number of NCT03182712.

Effects of L-arginine supplementation on blood flow, oxidative stress status and exercise responses in young adults with uncomplicated type I diabetes.

BACKGROUND AND AIMS: Vascular disease is the principal cause of death and disability in patients with diabetes, and endothelial dysfunction seems to be the major cause in its pathogenesis. Since L-arginine levels are diminished in conditions such as type 1 and type 2 diabetes, in this work we aimed to verify the effects of L-arginine supplementation (7 g/day) over the endothelial function and oxidative stress markers in young male adults with uncomplicated type 1 diabetes. We also investigated the influences of L-arginine administration on vascular/oxidative stress responses to an acute bout of exercise. METHODS: Ten young adult male subjects with uncomplicated type 1 diabetes and twenty matched controls volunteered for this study. We analysed the influence of L-arginine supplementation (7 g/day during 1 week) over lower limb blood flow (using a venous occlusion plethysmography technique), oxidative stress marker (TBARS, Carbonyls), anti-oxidant parameters (uric acid and TRAP) and total tNOx in rest conditions and after a single bout of submaximal exercise (VO2 at 10 % below the second ventilatory threshold). Data described as mean ± standard error (SE). Alpha level was P < 0.05. RESULTS: Glycaemic control parameters were altered in type 1 diabetic subjects, such as HbA1c (5.5 ± 0.03 vs. 8.3 ± 0.4 %) and fasted glycaemia (94.8 ± 1.4 vs. 183 ± 19 mg/dL). Oxidative stress/damage markers (carbonyls and TBARS) were increased in the diabetic group, while uric acid was decreased. Rest lower limb blood flow was lower in type 1 diabetic subjects than in healthy controls (3.53 ± 0.35 vs. 2.66 ± 0.3 ml 100 ml⁻¹ min⁻¹). L-Arginine supplementation completely recovered basal blood flow to normal levels in type 1 diabetics' subjects (2.66 ± 0.3 to 4.74 ± 0.86 ml 100 ml⁻¹ min⁻¹) but did not interfere in any parameter of redox state or exercise. CONCLUSION: Our findings highlight the importance of L-arginine for the improvement of vascular function in subjects with diabetes, indicating that L-arginine supplementation could be an essential tool for the treatment for the disease complications, at least in non-complicated diabetes. However, based on our data, it is not possible to draw conclusions regarding the mechanisms by which L-arginine therapy is inducing improvements on cardiovascular function, but this important issue requires further investigations.

[Effect of L-arginine supplementation on secretion of human growth hormone and insulin-like growth factor in adults]. / Efeito da suplementação de L-arginina sobre a secreção de hormônio do crescimento e fator de crescimento semelhante à insulina em adultos.

Based on presumptions that the infusion of amino acids can augment the release of human growth hormone (hGH) and that this metabolism is related with secretion of insulin-like growth factor I (IGF-I), the purpose of this study was to verify the effect of L-arginine supplementation on GH and IGF-I in adults. Seventeen male individuals participated on the study and were randomized to receive L-arginine (n= 10) or placebo (n= 7), seven grams per day for seven days. Before and after the supplementation period, the volunteers realized blood collection in fasting to verify both GH and IGF-I levels, as well as urine collection to verify urea excretion. At the end of the experimental period, it was verified that the group that received L-arginine augmented the urea in urine excretion (to 2684.1 +/- 475.2 mg/dl from 2967.2 +/- 409.7 mg/dl, p= 0.002), therefore it did not alter significantly the release of hormones evaluated. The group which received placebo did not alter significantly any evaluated parameters. The L-arginine supplementation during seven days was ineffective to augment both GH and IGF-I release in individual male adults.

Efeito da suplementação de L-arginina sobre a secreção de hormônio do crescimento e fator de crescimento semelhante à insulina em adultos / Effect of L-arginine supplementation on secretion of human growth hormone and insuline-like growth factor in adults

Baseado nos pressupostos de que a infusão de aminoácidos pode aumentar a secreção de hormônio de crescimento (GH), e que o metabolismo deste hormônio está relacionado com a secreção do fator de crescimento semelhante à insulina (IGF-I), o objetivo deste estudo foi verificar o efeito da suplementação de L-arginina sobre o GH e IGF-I em adultos. Participaram do estudo 17 indivíduos do sexo masculino, que foram randomizados para receber L-arginina (n= 10) ou placebo (n= 7), sete gramas ao dia, durante um período de sete dias. Antes e após o período de suplementação, os voluntários realizaram coleta de sangue em jejum para verificação dos níveis séricos de GH e IGF-I, bem como coleta de urina para verificação da excreção de uréia. Ao final do período experimental, verificamos que o grupo que recebeu L-arginina aumentou a excreção de uréia na urina (de 2684,1 ± 475,2 mg/dl para 2967,2 ± 409,7 mg/dl, p= 0,002), entretanto não modificou significativamente a secreção dos hormônios avaliados. O grupo que recebeu placebo não alterou significativamente nenhum parâmetro avaliado. A suplementação de L-arginina durante sete dias mostrou-se ineficaz para aumentar a secreção de GH e IGF-I em indivíduos adultos do sexo masculino.

Based on presumptions that the infusion of amino acids can augment the release of human growth hormone (hGH) and that this metabolism is related with secretion of insulin-like growth factor I (IGF-I), the purpose of this study was to verify the effect of L-arginine supplementation on GH and IGF-I in adults. Seventeen male individuals participated on the study and were randomized to receive L-arginine (n= 10) or placebo (n= 7), seven grams per day for seven days. Before and after the supplementation period, the volunteers realized blood collection in fasting to verify both GH and IGF-I levels, as well as urine collection to verify urea excretion. At the end of the experimental period, it was verified that the group that received L-arginine augmented the urea in urine excretion (to 2684.1 ± 475.2 mg/dl from 2967.2 ± 409.7 mg/dl, p= 0.002), therefore it did not alter significantly the release of hormones evaluated. The group which received placebo did not alter significantly any evaluated parameters. The L-arginine supplementation during seven days was ineffective to augment both GH and IGF-I release in individual male adults.