Dietary Polyphenols and Glycation in Renal Insufficiency (PoGlyDRI)

NHS Trust

Status: Terminated

Conditions: Diabetes Mellitus, Type 2; Renal Insufficiency, Chronic

Treatments: Dietary Supplement: Chlorogenic Acid (CGA) enriched coffee; Dietary Supplement: Conventional coffee

Study type: Interventional

Funder types: Other

Identifiers

NCT02524938

GN15DI242

Details and patient eligibility

About

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.

Enrollment: 9 patients

Sex: All

Ages: 40 to 80 years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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9 participants in 2 patient groups

Treatment group

Experimental group

Description:

Chlorogenic Acid (CGA) 400mg/day (CGA-enriched coffee)

Treatment:

Dietary Supplement: Chlorogenic Acid (CGA) enriched coffee

Control group

Sham Comparator group

Description:

Conventional coffee (habitual diet)

Treatment:

Dietary Supplement: Conventional coffee