Efficacy of ascorbic acid in improving glycaemic control in type 2 diabetes

Phase 2

Completed

• Conditions: Type 2 diabetes; Metabolic and Endocrine - Diabetes

• Registration Number: ACTRN12616000276459
• Lead Sponsor: Dr Glenn Wadley

Brief Summary

The main aim of this study was to investigate whether ascorbic acid (AA) supplementation improves glycaemic control under free-living conditions in individuals with type 2 diabetes. We also investigated effects of AA supplementation on blood pressure. Thirty-one individuals with type 2 diabetes (26 males and 5 females; average age 62 years; average duration of diabetes 5.6 years) and moderate glucose control (average HbA1c 7.6%) were enrolled in a randomized cross-over study involving 4 months of supplementation with oral AA (2 × 500 mg/day) or placebo. Participants took both AA and placebo, however the order of each 4-month period was randomized and blinded to both participants and researchers. AA supplementation significantly decreased the average daily post-meal glucose response, the duration of day spent in hyperglycaemia, the average 24-hour glucose concentration, blood pressure, and a marker of oxidative stress in blood as compared to placebo. Overall, individuals with type 2 diabetes experienced improved post-meal and 24-hour glucose levels and decreased blood pressure after 4 months of AA supplementation as compared to placebo. These findings offer evidence for the proposed use of AA as an adjunct therapy to improve glycaemic and blood pressure control in individuals with type 2 diabetes.

Detailed Description

Not available

Study Timeline

• Results First Posted: 1900-01-01
• Study Start: 2016-03-02
• Study Completion: 2017-11-05
• Last Update Posted: 13 January 2020

Recruitment & Eligibility

• Status: Completed
• Sex: All
• Target Recruitment: 29

Inclusion Criteria

(i) Type 2 diabetes with glycaemic control that is modest (HbA1c between 7.0% and 9.0%); (ii) aged 45-75 years; (iii) body mass index < 35 kg/m2; (iv) blood pressure <160/90 mmHg.

Exclusion Criteria

(i) Having a major medical illness in addition to Type 2 diabetes; (ii) taking >2000 mg metformin per day) or more than 2 different diabetes medications or on insulin therapy; (iii) smokers; (iv) taking vitamin supplements other than those provided by us during the trial

Study & Design

• Study Type: Interventional
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Postprandial incremental glucose area under the curve from data obtained through use of a continuous blood glucose monitor[For a continuous 48-hour period immediately before and immediately after both 4-month interventions]

Secondary Outcome Measures

Name	Time	Method
HbA1c by whole blood assay[Immediately before and immediately after both 4-month interventions];Time spent in hyperglycaemia and hypoglycaemia (hrs/day) from data obtained through use of a continuous blood glucose monitor [For a continuous 48-hour period immediately before and immediately after both 4-month interventions];Fasting insulin by radioimmunoassay[Immediately before and immediately after both 4-month interventions]