Peyvand Amini

Food addiction: its prevalence and significant association with obesity in the general population.

Background ‘Food addiction’ shares a similar neurobiological and behavioral framework with substance addiction. However whether, and to what degree, ‘food addiction’ contributes to obesity in the general population is unknown. Objectives to assess 1) the prevalence of ‘food addiction’ in the Newfoundland population; 2) if clinical symptom counts of ‘food addiction’ were significantly correlated with the body composition measurements; 3) if food addicts were significantly more obese than controls, and 4) if macronutrient intakes are associated with ‘food addiction’. Design A total of 652 adults (415 women, 237 men) recruited from the general population participated in this study. Obesity was evaluated by Body Mass Index (BMI) and Body Fat percentage measured by dual-energy X-ray absorptiometry. ‘Food addiction’ was assessed using the Yale Food Addiction Scale and macronutrient intake was determined from the Willet Food Frequency Questionnaire. Results The prevalence of ‘food addiction’ was 5.4% (6.7% in females and 3.0% in males) and increased with obesity status. The clinical symptom counts of ‘food addiction’ were positively correlated with all body composition measurements across the entire sample (p<0.001). Obesity measurements were significantly higher in food addicts than controls; Food addicts were 11.7 (kg) heavier, 4.6 BMI units higher, and had 8.2% more body fat and 8.5% more trunk fat. Furthermore, food addicts consumed more calories from fat and protein compared with controls. Conclusion Our results demonstrated that ‘food addiction’ contributes to severity of obesity and body composition measurements from normal weight to obese individuals in the general population with higher rate in women as compared to men.

A randomized, placebo-controlled trial of selenium supplementation in patients with type 2 diabetes: effects on glucose homeostasis, oxidative stress, and lipid profile.

Selenium is an antioxidant trace element. Patients with diabetes are shown to have increased oxidative stress together with decreased selenium concentrations. Whether raising serum selenium will improve blood glucose management in diabetes is largely unknown. In this randomized, double-blind placebo-controlled trial, we assessed the effects of selenium on blood glucose, lipid profile, and oxidative stress in 60 patients with type 2 diabetes. Selenium 200 µg/d or placebo was administered orally for 3 months. Serum concentrations of fasting plasma glucose, glycosylated hemoglobin A1c (HbA1c), insulin, and lipid profile, as well as ferric-reducing ability of plasma and thiobarbituric acid–reactive substances were determined in the fasting state at baseline and after 3 months. Mean (SD) serum selenium at baseline was 42.69 (29.47) µg/L and 47.11 (42.86) µg/L in selenium and placebo groups, respectively. At endpoint, selenium concentration reached to 71.98 (45.08) µg/L in selenium recipients compared with 45.38 (46.45) µg/L in placebo recipients (P < 0.01). Between-group comparison showed that fasting plasma glucose, glycosylated hemoglobin A1c, and high-density lipoprotein cholesterol were statistically significantly higher in the selenium recipient arm. Other endpoints changes during the course of trial were not statistically different across the 2 treatment arms. This study suggests that selenium supplementation in patients with type 2 diabetes may be associated with adverse effects on blood glucose homeostasis, even when plasma selenium concentration is raised from deficient status to the optimal concentration of antioxidant activity. Until results of further studies become available, indiscriminate use of selenium supplements in patients with type 2 diabetes warrants caution.

Serum Acylated Ghrelin Concentrations in Response to Short-Term Overfeeding in Normal Weight, Overweight, and Obese Men

BACKGROUND Ghrelin, an orexigenic gut hormone secreted primarily from the stomach, is involved in energy homeostasis. However, little data is available regarding its response to energy surplus and the development of human obesity. OBJECTIVE The present study investigated the response of circulating acylated ghrelin to a 7-day positive energy challenge. DESIGN A total of 68 healthy young men were overfed 70% more calories than required, for 1-week. Subjects were classified based on percent body fat (measured by dual-energy X-ray absorptiometry) as normal weight, overweight, and obese. Serum acylated ghrelin concentration was measured before and after the positive energy challenge. Additionally, the relationship between acylated ghrelin and obesity-related phenotypes including weight, body mass index, percent body fat, cholesterol, HDL-c, LDL-c, glucose, insulin and homeostasis model assessment of insulin resistance and β-cell function at baseline and change due to overfeeding, were assessed. RESULTS Contrary to our expectations, serum acylated ghrelin was significantly increased in response to overfeeding and the increase was independent of obesity status. There was no significant difference in fasting acylated ghrelin between normal weight, overweight, and obese men at baseline. Acylated ghrelin was negatively correlated with weight and BMI for normal weight and with BMI in overweight men. Also ghrelin was correlated with change in weight and BMI in overweight (negative relationship) and obese (positive relationship) groups. CONCLUSION Our results showed that circulating acylated ghrelin was increased after a 7-day positive energy challenge regardless of adiposity status. However, acylated ghrelin was correlated with change in weight and BMI in opposing directions, in overweight and obese subjects respectively, thus dependent on obesity status.

Serum Acylated Ghrelin Is Negatively Correlated with the Insulin Resistance In the CODING study

Objective Ghrelin is a 28-amino acid orexigenic peptide synthesized mainly in the stomach. Acute administration of ghrelin has been found to decrease insulin secretion. However, little data is available regarding whether ghrelin contributes to the long-term regulation of insulin resistance at the population level. The aim of this study is to investigate the association between circulating ghrelin and insulin resistance in a large population based study. Design A total of 2082 CODING study (Complex Diseases in the Newfoundland population: Environment and Genetics) subjects were assessed. Subjects were of at least third generation Newfoundland descent, between the ages of 20 and 79 years, and had no serious metabolic, cardiovascular, or endocrine diseases. Ghrelin was measured with an Enzyme Immunoassay method. Insulin and fasting glucose were measured by Immulite 2500 autoanalyzer and Lx20 clinical chemistry analyzer, respectively. Homeostatic Model Assessment of β cell function (HOMA-β) and Insulin Resistance (HOMA-IR) and Quantitative Insulin-sensitivity Check Index (QUICKI) were used for measurement of insulin resistance. Results Partial correlation analyses showed a significant negative correlation between circulating ghrelin and insulin level and insulin resistance in the entire cohort and also in men and women separately. The aforementioned correlation was independent of age, percentage of trunk fat and HDL-cholesterol. According to menopausal status, only pre-menopausal women revealed negative correlations. Conclusion Our results suggest that except for postmenopausal women, high circulating ghrelin level is associated with lower insulin resistance in the general population.

Short-Term Overfeeding Increases Circulating Adiponectin Independent of Obesity Status

Background Adiponectin is an adipose tissue derived hormone which strengthens insulin sensitivity. However, there is little data available regarding the influence of a positive energy challenge (PEC) on circulating adiponectin and the role of obesity status on this response. Objective The purpose of this study was to investigate how circulating adiponectin will respond to a short-term PEC and whether or not this response will differ among normal-weight(NW), overweight(OW) and obese(OB). Design We examined adiponectin among 64 young men (19-29 yr) before and after a 7-day overfeeding (70% above normal energy requirements). The relationship between adiponectin and obesity related phenotypes including; weight, percent body fat (%BF), percent trunk fat (%TF), percent android fat (%AF), body mass index (BMI), total cholesterol, HDLc, LDLc, glucose, insulin, homeostatic model assessment insulin resistance (HOMA-IR) and β-cell function (HOMA-β) were analyzed before and after overfeeding. Results Analysis of variance (ANOVA) and partial correlations were used to compute the effect of overfeeding on adiponectin and its association with adiposity measurements, respectively. Circulating Adiponectin levels significantly increased after the 7-day overfeeding in all three adiposity groups. Moreover, adiponectin at baseline was not significantly different among NW, OW and OB subjects defined by either %BF or BMI. Baseline adiponectin was negatively correlated with weight and BMI for the entire cohort and %TF, glucose, insulin and HOMA-IR in OB. However, after controlling for insulin resistance the correlation of adiponectin with weight, BMI and %TF were nullified. Conclusion Our study provides evidence that the protective response of adiponectin is preserved during a PEC regardless of adiposity. Baseline adiponectin level is not directly associated with obesity status and weight gain in response to short-term overfeeding. However, the significant increase of adiponectin in response to overfeeding indicates the physiological potential for adiponectin to attenuate insulin resistance during the development of obesity.

Beneficial association of serum ghrelin and peptide YY with bone mineral density in the Newfoundland population

BackgroundGhrelin and peptide YY (PYY) are appetite regulating hormones secreted from the gastrointestinal tract (gut). Aside from their known effect on energy homeostasis, accumulating data indicates that these gut hormones also affect bone metabolism. However, data regarding the influence of ghrelin and PYY on bone density in humans is very limited, and the results are inconclusive. Therefore, this study was designed to investigate the potential association between circulating ghrelin and PYY with bone density indices in the general population.MethodsA total of 2257 adult subjects from the CODING (Complex Diseases in the Newfoundland Population: Environment and Genetics) study participated in this investigation. Acylated ghrelin and total PYY were measured in serum after a 12-hour fasting, with the Enzyme- Linked Immunosorbent Assay (ELISA) method. Bone mineral density was measured by dual-energy X-ray absorptiometry at the spine, femoral neck, and total hip. Multiple regression analyses adjusting for age, BMI, physical activity, smoking, and alcohol consumption were employed to analyze the association between serum ghrelin and PYY with bone mineral density parameters.ResultsSignificant positive associations of ghrelin concentration with L2-L4 BMD, L2-L4 Z-score, femoral neck BMD, femoral neck Z-score, total hip BMD, and total hip Z-score were found in women. No significant correlations between ghrelin and bone density indices were present in men. After dividing the female group into pre-menopausal and post-menopausal, ghrelin was positively correlated with femoral neck Z-score, and total hip Z-score in pre-menopausal women and L2-L4 BMD, and Z-score in post-menopausal group. Moreover, no significant association was discovered between serum PYY and bone density at any site.ConclusionOur results suggest a beneficial association of circulating ghrelin concentration with bone density in women at the population level. This association is independent of major confounding factors including BMI, physical activity, age, alcohol consumption, and smoking. Effect of menopause on this association seemed to be site specific. However, PYY does not seem to be associated with bone density parameters.

The Association of Serum Total Peptide YY (PYY) with Obesity and Body Fat Measures in the CODING Study.

Background PYY is an appetite suppressing hormone. Low circulating PYY has been linked to greater BMI. However data is controversial and this association has not been verified in large human populations. Objective The purpose of this study was to investigate if fasting serum total PYY is associated with obesity status and/or adiposity at the population level. Design A total of 2094 subjects (Male-523, Female-1571) participated in this investigation. Total PYY was measured in fasting serum by enzyme-linked immunosorbent assay. Obesity status (NW-normal-weight, OW-overweight and OB-obese) was determined by the Bray Criteria according to body fat percentage measured by dual-energy x-ray absorptiometry and the WHO criteria according to BMI. One-way ANOVA and multiple regression was used to assess the adiposity-specific association between PYY and the following; weight, BMI, waist-circumference, hip-circumference, waist-hip ratio, percent body fat (%BF), trunk fat (%TF), android fat (%AF) and gynoid fat (%GF). Results PYY was not significantly different among NW, OW and OB groups defined by neither %BF nor BMI for both men and women. However among women, fasting PYY was positively associated with adiposity measures. Women with the highest (Top 33%) waist-circumference, %BF and %TF had significantly higher PYY (10.5%, 8.3% and 9.2% respectively) than women with the lowest (Bottom 33%). Age, smoking, medication use and menopause were all positively associated with PYY levels in women but not in men. Conclusion To our knowledge this is the largest population based study, with the most comprehensive analysis and measures of confounding factors, to explore the relationship of circulating PYY with obesity. Contrary to initial findings in the literature we discovered that PYY was positively associated with body fat measures (waist-circumference, %BF and %TF) in women. Although the effect size of the positive association of PYY with obesity in women is small, and potentially negligible, it may in fact represent a protective response against significant weight gain.

Effect of treatment of iron deficiency anemia onhemoglobin A1c in type 2 diabetic patients

Background/aim: Iron deficiency anemia (IDA) affects hemoglobin A1c (HbA1c) levels. This study aimed to evaluate the effect of treatment of iron deficiency anemia on hemoglobin A1c in type 2 diabetic patients.Materials and methods: Ninety type 2 diabetes mellitus (T2DM) patients with IDA were included in a randomized, placebo-controlled, single-blind clinical trial. The intervention group (n = 45) received 200 mg/day oral iron for 3 months and the control group (n = 45) received an oral placebo for the same period. Fasting blood sugar, complete blood count, and HbA1c were measured for all subjects at the beginning and the end of the trial.Results: The mean age of the treatment and control group was 51.47 ± 1.05 and 52 ± 1.1 years, respectively. The two groups were not statistically significantly different with regard to diabetes duration (P = 0.436) and age (P = 0.617). Hemoglobin, mean corpuscular volume, mean corpuscular hemoglobin, serum iron, ferritin, total iron-binding capacity, and HbA1c were significantly improved in the intervention group in comparison with the control group (P = 0.005).Conclusion: Iron status should be considered during the interpretation of the HbA1c concentrations in diabetes mellitus. Iron replacement therapy can decrease HbA1c in anemic patients with IDA and T2DM.