Changes in Iron Absorption and Availability Before and After Weight Loss in Obese Pre-menopausal Women and Men.
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 43
- 试验地点
- 1
- 主要终点
- Fractional iron absorption before and after weight loss, based on 57Fe and 58Fe isotope concentrations in erythrocytes.
研究概览
简要总结
The objective of this study is to investigate if weight loss, in particular due to adipose tissue loss, in obese patients will reverse the obesity-related reduction of iron absorption, and if this is due to a decrease in hepcidin concentrations. Additionally, the investigators will investigate changes in iron incorporation into erythrocytes due to a reduction of iron sequestration by the adipose tissue and reticuloendothelial system. The investigators expect that by decreasing adiposity, circulating hepcidin levels will decrease, iron absorption and incorporation into erythrocytes will increase and as a result iron status will be improved.
详细描述
Until now adiposity has been associated with low iron status and with higher hepcidin levels. Moreover, weight loss and thereby loss of fat mass, has been associated with decreased hepcidin levels and improved iron status. However, until now no direct measures of iron absorption or incorporation into erythrocytes have been assessed before and after losing weight/fat mass.
We hypothesize that:
- body fat loss in obese women and men will improve iron absorption, corrected for iron status, from a labeled test meal measured by using a stable isotopes technique by on average 30%.
- body fat loss in obese women and men will decrease the related inflammatory state.
- greater subclinical inflammation in obese women and men will be correlated with a decreased incorporation of iron into erythrocytes, and that this will improve after loss of body fat.
The study is a prospective cohort in which iron bioavailability will be assessed in obese women and men before and after weight loss and associated loss of body fat over a period of 6 months.
Iron absorption will be estimated using stable-isotope techniques where incorporation of 57Fe and 58Fe into erythrocytes is measured 14 days after administration. Preparation of isotopically labelled iron will be done at the Laboratory of Human Nutrition of the Swiss Federal Institute of Technology Zurich (ETH Zürich).
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Prospective
入排标准
- 年龄范围
- 18 Years 至 50 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Women and men
- •aged 18 to 50 years
- •Premenopausal (had no absence of menstrual cycle in the past 12 months)
- •BMI ≥35<45
- •Indication for laparoscopic Sleeve Gastrectomy (LSG) or Laparoscopic Adjustable Gastric Band (LAGB).
- •Subjects are eligible for this surgery if they:
- •have BMI ≥35<45 and one of the following two conditions:
- •Medical, physical or psychosocial problems associated with their obesity.
- •A history of prolonged attempts at weight loss by other means.
- •have been adequately informed and understood and accepted the potential -- risks and benefits of the procedure, and expressed a commitment to follow the rules regarding eating and exercise permanently after the procedure.
- •No postoperative complications after the surgery
- •Apparently healthy: no significant medical conditions that could influence iron or inflammatory status other than obesity (i.e., cancer, HIV/AIDS, inflammatory bowel disease, gastrointestinal bleeding, and rheumatoid arthritis, renal disease or hemochromatosis) (judged by study physician).
- •No use of medication which interferes with study measurements (as judged by the study physician)
- •Willing to not change their intake of dietary iron and not take additional iron supplements, other than provided by the study team, between baseline and study end.
- •Not being pregnant during the study period or in the six months prior to the study and not planning to become pregnant until at least 3 months after the last study visit.
- •Non-lactating in the 6 weeks prior to the study and for the duration of the study
- •No reported weight loss ≥ 10 % of bodyweight during a period of six months before pre-surgery examination.
- •No full or partial hysterectomy in the past 3 months
- •Informed consent signed
- •Agreeing to be informed about medically relevant personal test-results by a physician.
- •Agreeing to be informed about medically relevant personal test-results by a physician.
- •No reported participation in night shift work two weeks prior to pre-study investigation and during the study. Night work is defined as working between midnight and 6.00 AM.
- •Consumption of =< 14 alcoholic drinks in a typical week
- •Strenuous exercise =< 10 hours per week
排除标准
- •Reported excessive blood loss at surgery (> 500 ml) and/or moderate/severe anemic (Hb < 100 g/L)
- •Complications during restrictive bariatric surgery defined as either:
- •Surgery duration of > 3 hours
- •Blood loss of > 500 ml
- •Perforation of the gastrointestinal tract
- •Inability to adjust lapband
- •Women and men with diagnosed abnormalities in iron metabolism (diagnosed from routine pre-surgery blood sample)
结局指标
主要结局
Fractional iron absorption before and after weight loss, based on 57Fe and 58Fe isotope concentrations in erythrocytes.
时间窗: 6 months
次要结局
- Iron status and regulatory markers (Hb, serum ferritin, transferrin receptor, hepcidin),(pro)inflammatory markers (CRP, AGP, TNF-α, IL-6, leptin), blood volume, body composition (DXA).(6 months)