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Dietary Polyphenols and Glycation in Renal Insufficiency

Not Applicable
Terminated
Conditions
Diabetes Mellitus, Type 2
Renal Insufficiency, Chronic
Interventions
Dietary Supplement: Chlorogenic Acid (CGA) enriched coffee
Dietary Supplement: Conventional coffee
Registration Number
NCT02524938
Lead Sponsor
NHS Greater Glasgow and Clyde
Brief Summary

Type 2 diabetes mellitus (T2DM) is associated with an increased risk of kidney failure, with high levels of glycohaemoglobin (HbA1c) presenting a sharper decline in renal function and an increase in the risk of mortality and end-stage renal disease (ESRD). Polyphenols may improve renal insufficiency in patients with diabetes with chlorogenic acids (CGA) one of the principle polyphenol groups in the diet - coffee/tea, stone fruits (especially plums/prunes) and some vegetables (artichoke, chicory). CGA (3-4 cups of coffee) has been associated with 25% lower risk of T2DM and a favourable reduction of HbA1c, blood pressure, and oxidative stress levels. This randomised controlled trial, therefore, aims to evaluate the effect of high CGA food on glycation and oxidative stress in T2DM subjects with early renal insufficiency (glomerular filtration rate of 35-60 mL/min) as well as progression of renal insufficiency and the risk of cardiovascular diseases.

The study will have two phases - phase I, an interventional study of 3 months followed by phase II, an observational study of 21 months.

In phase I, subjects will be randomized into 2 groups: CGA-enriched diet group, or control (habitual) diet group. The treatment group will be provided with a chlorogenic acid-rich food (coffee) with instructions to achieve an intake of 400 mg per day (equivalent to 3-4 coffee cups per day) for 12 weeks. The control group will receive a conventional coffee low in chlorogenic acid.

Participants will attend three sessions during phase I; baseline, 6 weeks, and 12 weeks. At baseline, general information, medical history, dietary habits and medication use will be recorded and a Food Frequency Questionnaire completed. Urine and blood samples will be collected and blood pressure, waist circumference, height and weight recorded. Participants' diet over the previous 3 days will be assessed by estimated food diary analysis.

In phase II, written dietary recommendations will be provided at three time points (months 6, 12 and 24) - treatment group to achieve a CGA-rich diet (total polyphenol intake of at least 1g per day, and at least 400mg per day of CGA) and standard dietary advice for the control group. Anthropometric/dietary data will be collected as well as blood and urine samples to assess markers of renal function, glycation and oxidative stress, and proteomic markers of cardiovascular disease, coronary artery disease and diabetes.

Detailed Description

Not available

Recruitment & Eligibility

Status
TERMINATED
Sex
All
Target Recruitment
9
Inclusion Criteria
  • type 2 Diabetes Mellitus
  • chronic renal insufficiency with persistent eGFR of 35-60mL/min for at least three months
  • fluent in English
Exclusion Criteria
  • dialysis therapy (current or previous)
  • malignancy
  • transplant recipient
  • hyperthyroidism
  • hypothyroidism
  • high dose glucocorticoids (≥250 mg)
  • body mass index (BMI) ≥ 45 kg/m2
  • special dietary requirements
  • take creatine, antioxidants or vitamin supplements
  • smoker
  • pregnant
  • consume >4 cups of tea/coffee per day
  • consume >5 portion of fruits and vegetables per day

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Treatment groupChlorogenic Acid (CGA) enriched coffeeChlorogenic Acid (CGA) 400mg/day (CGA-enriched coffee)
Control groupConventional coffeeConventional coffee (habitual diet)
Primary Outcome Measures
NameTimeMethod
Change in estimated glomerular filtration rate (eGFR)21 months
Change in glycohaemoglobin (HbA1c)3 months
Secondary Outcome Measures
NameTimeMethod
Change in fasting glucose3 months
Change in fructosamine3 months
Change in creatinine21 months
Change in soluble receptor for AGE (sRAGE)3 months
Change in F2-isoprostane3 months
Change in cholesterol21 months
Change in 8hydroxy 2'deoxyguanoside (8OhdG)21 months
Change in advanced glycation end product (AGE)3 months
Change in thiobarbituric acid reactive substances (TBARS)21 months
Change in malondialdehyde (MDA)3 months
Change in Interleukin-621 months
Change in Urinary Albumin Excretion21 months
Change in blood pressure21 months
Change in crystatin C21 months
Change in fibrinogen21 months
Change in C-reactive protein21 months
Change in advanced oxidation protein products (AOPP)21 months

Trial Locations

Locations (2)

University of Glasgow

🇬🇧

Glasgow, United Kingdom

NHS Greater Glasgow and Clyde

🇬🇧

Glasgow, United Kingdom

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