Metformin for the prevention of diabetes among people with HIV and either impaired fasting glucose or impaired glucose tolerance (prediabetes) in Tanzania: a Phase II randomised placebo-controlled trial

• Published in: Diabetologia 2023-10, Vol.66 (10), p.1882-1896
• Main Authors: Garrib, Anupam, Kivuyo, Sokoine, Bates, Katie, Ramaiya, Kaushik, Wang, Duolao, Majaliwa, Edna, Simbauranga, Rehema, Charles, Godbless, van Widenfelt, Erik, Luo, Huanyan, Alam, Uazman, Nyirenda, Moffat J., Jaffar, Shabbar, Mfinanga, Sayoki
• Format: Article
• Language: English
• Subjects: Acquired immune deficiency syndrome; Adolescent; Adult; Adverse events; AIDS; Antidiabetics; Blood glucose; Blood Glucose - analysis; Clinical trials; Controlled release; Coronaviruses; COVID-19; Diabetes; Diabetes mellitus (non-insulin dependent); Diabetes Mellitus, Type 2; Double-Blind Method; Fasting; Glucose; Glucose Intolerance - drug therapy; Glucose tolerance; HIV; HIV Infections - drug therapy; Human immunodeficiency virus; Human Physiology; Humans; Immunodeficiency; Internal Medicine; Medical research; Medicine; Medicine & Public Health; Metabolic Diseases; Metformin; Placebos; Prediabetic State - drug therapy; Public health; Tanzania
• ISSN: 0012-186X; 1432-0428; 1432-0428
• DOI: 10.1007/s00125-023-05968-7

Aims/hypothesis In sub-Saharan Africa (SSA), 5% of adults are living with type 2 diabetes and this is rising sharply, with a greater increase among people with HIV. Evidence on the efficacy of prevention strategies in this cohort is scarce. We conducted a Phase II double-blind placebo-controlled trial that aimed to determine the impact of metformin on blood glucose levels among people with prediabetes (defined as impaired fasting glucose [IFG] and/or impaired glucose tolerance [IGT]) and HIV in SSA. Methods Adults (≥18 years old) who were stable in HIV care and found to have prediabetes (IFG and/or IGT) and who were attending hospitals in Dar es Salaam, Tanzania, were randomised to receive sustained-release metformin, 2000 mg daily, or matching placebo between 4 November 2019 and 21 July 2020. Randomisation used permuted blocks. Allocation was concealed in the trial database and made visible only to the Chief Pharmacist after consent was taken. All participants, research and clinical staff remained blinded to the allocation. Participants were provided with information on diet and lifestyle and had access to various health information following the start of the coronavirus disease 2019 (COVID-19) pandemic. Participants were followed up for 12 months. The primary outcome measure was capillary blood glucose measured 2 h following a 75 g glucose load. Analyses were by intention-to-treat. Results In total, 364 participants (182 in each arm) were randomised to the metformin or placebo group. At enrolment, in the metformin and placebo arms, mean fasting glucose was 6.37 mmol/l (95% CI 6.23, 6.50) and 6.26 mmol/l (95% CI 6.15, 6.36), respectively, and mean 2 h glucose levels following a 75 g oral glucose load were 8.39 mmol/l (95% CI 8.22, 8.56) and 8.24 mmol/l (95% CI 8.07, 8.41), respectively. At the final assessment at 12 months, 145/182 (79.7%) individuals randomised to metformin compared with 158/182 (86.8%) randomised to placebo indicated that they had taken >95% of their medicines in the previous 28 days ( p =0.068). At this visit, in the metformin and placebo arms, mean fasting glucose levels were 6.17 mmol/l (95% CI 6.03, 6.30) and 6.30 mmol/l (95% CI 6.18, 6.42), respectively, and mean 2 h glucose levels following a 75 g oral glucose load were 7.88 mmol/l (95% CI 7.65, 8.12) and 7.71 mmol/l (95% CI 7.49, 7.94), respectively. Using a linear mixed model controlling for respective baseline values, the mean difference between the metformin and placebo group