The Relation Between Adiposity, Inflammation, Glycaemia and Iron Absorption
Condition: Iron Absorption
MeSH terms: Obesity; Inflammation
Study type: Interventional

Summary: 
      A total of 126 premenopausal women (42 lean, 42 obese with central obesity, 42 obese with
      peripheral obesity) will be recruited. Anthropometric measurements and body composition using
      DEXA will be collected. Overnight fasted subjects will be asked to give baseline blood
      samples before consuming a meal containing 6 mg 57Fe in the form of FeSO4. Subjects will
      return after 14 days and a blood sample will be collected for measurement of isotopic
      enrichment into red blood cells, serving as well as a baseline for the OGTT. Subjects will
      then be asked to ingest a solution of glucose (50g) containing 100 mg of iron in the form of
      sodium ferrous citrate (SFC), after which blood samples will be collected 2 hours post iron
      and glucose load. All three blood samples collected at baseline, 2 weeks post labeled iron
      load, and 2 hours post glucose/iron load will be analyzed for their levels of iron, glycaemia
      and inflammatory parameters.
    

Detailed description: 
      1. Obese subjects with central and peripheral obesity

           During the first phase, overweight/obese subjects with a BMI 28-35 Kg/m2 will be invited
           to a screening. At the screening, anthropometrics (weight, height, waist circumference)
           and body composition (using BIA and DEXA) will be measured. Based on the subject's
           distribution of body fat, those who have a predefined % body fat between 45-55% will be
           invited to join the study and they would fall into one of the following two groups:

             -  42 subjects with >43% fat in the android sector (area from the pelvis to 20% of the
                distance between the pelvis and the neck cuts) according to the DEXA results
                (central adiposity) would be recruited

             -  42 subjects with <43% fat in the android sector according to DEXA (peripheral
                adiposity) would be recruited.

        2. Lean subjects At the same time, anthropometric (weight, height, waist circumference) and
           body composition (using BIA and DEXA) measurement will be conducted on interested lean
           subjects (BMI 20-25).

      Overnight fasted subjects:

      At T0:

      There will be a determination of the type and degree of obesity through the measurement of
      weight, height, BMI, and WC, followed by both BIA screening and DEXA scan to obtain a more
      detailed image about the status of the participant.

      At T1:

      A fasting blood sample of 10 ml (4 ml EDTA coated tubes, 6 ml uncoated tubes) will be drawn
      to measure the inflammatory status, glycaemia, and iron levels of the participant by
      determining CRP, alpha-glycoprotein, hepcidin, ferritin, TfR, TIBC, HbA1c, insulin, FPG,
      serum iron, CBC and lipid profile.

      After this blood test, the subject will be given a meal including 57Fe (6 mg iron as FeSO4).

      At T2:

      A second venous blood sample of 10 ml (4 ml EDTA coated tubes, 6 ml uncoated tubes) will be
      drawn for analysis of hemoglobin and erythrocyte isotopic composition as well as for the
      determination of serum ferritin, transferrin receptor, C-reactive protein, alpha-glycoprotein
      and hepcidin.

      At T3:

      A third venous blood sample of 10 ml (4 ml EDTA coated tubes, 6 ml uncoated tubes) will be
      drawn to measure the level of glucose, insulin, TG, FFA, TIBC and serum iron. This blood test
      will be an indicator of the level of glycaemia and iron appearance in the blood of the
      subject through the earlier ingestion of OGTT and oral iron load.
    

Intervention name(s): Iron
Intervention type(s): Diagnostic Test
Intervention description(s): Labelled iron
Other intervention name(s): OGTT
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Basic Science