The Effect of Metformin on Adolescents with Type 1 Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Effect of metformin adjunct therapy on cardiometabolic parameters in Indian adolescents with type 1 diabetes: a randomized controlled trial

Introduction

Insulin resistance is being increasingly reported in type-1 Diabetes (T1D) and is known to accelerate microvascular complications. The Asian Indian population has a higher risk of double diabetes development compared to Caucasians. Hence, we studied the effect of adding Metformin to standard insulin therapy on glycemic control, insulin sensitivity (IS), cardiometabolic parameters and body composition in Indian adolescents with T1D.

Methods

A Randomized controlled trial was conducted spanning 9 months (Registration number:CTRI/2019/11/022126). Inclusion: Age 10-19 years, T1D duration>1year, HbA1c>8% Exclusion: Uncontrolled vascular complications/comorbidities, Metformin intolerance, concomitant drugs affecting insulin sensitivity. Participants were randomized to Metformin/Placebo (n=41 each) groups and age, sex, duration-matched. Assessments were performed at baseline, 3 and 9 months.

Results

82 participants aged 14.7 ± 3years (40 females) were enrolled, with a mean diabetes duration of 5.2 ± 2.3 years. Over 9 months, HbA1c decreased significantly by 0.8 (95% confidence interval: -1.2 to -0.3) from 9.8 ± 1.8% to 9.1 ± 1.7% on Metformin but remained largely unchanged (difference of 0.2, 95% confidence interval: -0.7 to 0.2) i.e. 9.9 ± 1.6% and 9.7 ± 2.2% on placebo. HbA1c improvement correlated negatively with baseline IS (EGDR:r= -0.3;SEARCH:r = -0.24, p<0.05) implying better HbA1c-lowering in those with decreased initial IS. CGM-based glycemic variability (standard deviation) reduced by 6.3 mg/dL (95% confidence interval: -12.9 to 0.2) from 100.2 ± 19.1 mg/dL to 93.7 ± 19.9 mg/dL in those on Metformin (p=0.05) but not placebo (94.0 ± 20.5; 90.0 ± 22.6 mg/dL). Insulin sensitivity: CACTIexa & SEARCH scores demonstrated no change with Metformin but significant worsening on placebo. Significant increase in LDL-C(42%), total cholesterol(133.6 to 151.1 mg/dL), triglyceride (60.0 to 88.0 mg/dL) and carotid intima-media thickness was noted on placebo but not Metformin. Weight, BMI, fat Z-scores increased significantly on placebo but not Metformin. Adverse events (AE) were minor; AE, compliance and safety parameters were similar between the two groups.

Conclusion

Metformin as an adjunct to insulin in Asian Indian adolescents with T1D demonstrated beneficial effect on glycemic control, glycemic variability, IS, lipid profile, vascular function, weight and body fat, with a good safety profile when administered for 9 months.

Insulin Resistance in Adolescents and Youth With Type 1 Diabetes: A Review of Problems and Solutions

Though insulin resistance (IR) was previously considered a feature of only type 2 Diabetes (T2DM), its development in type 1 Diabetes (T1DM) is not an uncommon occurrence, the causes of which are multifactorial (gender, pubertal status, diabetes duration, ethnicity, genetics, adiposity, glycemic control, chronic inflammation). Despite improvements in glucose, blood pressure and lipid profile, vascular complications (coronary artery disease and nephropathy) continue to remain common causes of morbidity and mortality in T1DM. Aggressive glycemic control reduces but does not eliminate the risk of IR. IR accelerates the development of micro and macrovascular complications, many of which can be potentially reversed if diagnosed and managed early. Lack of endogenous insulin production makes estimation of insulin sensitivity in T1DM difficult. As hyperinsulinemic-euglycemic clamp studies are cumbersome and invasive, the use of prediction equations for calculating estimated insulin sensitivity may prove to be useful. Along with intensive insulin therapy, dietary modifications and increasing physical activity, the role of Metformin in managing IR in T1DM is becoming increasingly popular. Metformin adjunct therapy in T1DM has been shown to improve insulin sensitivity, glycemic control, lipid profile, body composition, vascular smooth muscle function, thereby reducing the risk of vascular complications, as well as reversal of early vascular dysfunction. However, further studies to assess long-term efficacy and safety of Metformin use in adolescents and youth with T1DM are needed. This review aims at revisiting the pathophysiology of IR in T1DM and techniques of identifying those at risk so as to put into action various strategies for management of the same.

Metformin: A Review of Potential Mechanism and Therapeutic Utility Beyond Diabetes

Metformin has been designated as one of the most crucial first-line therapeutic agents in the management of type 2 diabetes mellitus. Primarily being an antihyperglycemic agent, metformin also has a plethora of pleiotropic effects on various systems and processes. It acts majorly by activating AMPK (Adenosine Monophosphate-Activated Protein Kinase) in the cells and reducing glucose output from the liver. It also decreases advanced glycation end products and reactive oxygen species production in the endothelium apart from regulating the glucose and lipid metabolism in the cardiomyocytes, hence minimizing the cardiovascular risks. Its anticancer, antiproliferative and apoptosis-inducing effects on malignant cells might prove instrumental in the malignancy of organs like the breast, kidney, brain, ovary, lung, and endometrium. Preclinical studies have also shown some evidence of metformin's neuroprotective role in Parkinson's disease, Alzheimer's disease, multiple sclerosis and Huntington's disease. Metformin exerts its pleiotropic effects through varied pathways of intracellular signalling and exact mechanism in the majority of them remains yet to be clearly defined. This article has extensively reviewed the therapeutic benefits of metformin and the details of its mechanism for a molecule of boon in various conditions like diabetes, prediabetes, obesity, polycystic ovarian disease, metabolic derangement in HIV, various cancers and aging.

A Pilot Study to Assess Effect of Metformin Therapy on Prevention of Double Diabetes in Indian Adolescents with Type-1 Diabetes

Introduction

Increased prevalence of metabolic syndrome in Indian adolescents owing to the obesity epidemic leads to double diabetes (DD), which is associated with an increased risk of complications in type-1 diabetes (T1D). Metformin may be a useful intervention for the prevention and treatment of insulin resistance in T1D. We conducted this pilot randomized controlled trial with the objective of investigating the effect of metformin on insulin sensitivity in Indian adolescents with T1D.

Method

This pilot randomized controlled trial was performed on 59 participants with T1D aged 10-19 years distributed uniformly by gender and puberty across two groups with a 3-month intervention period. The intervention group received metformin (weight less than 60 kg received 500 mg twice daily and more than 60 kg received 1 gm twice daily) and non-metformin group received standard of care for diabetes. Anthropometric, clinical details, biochemistry and insulin sensitivity indices (ISI) were evaluated using standard protocols at baseline and endline.

Result

22.2% of subjects from non-metformin group and 12.5% from metformin group were at the risk of the development of DD. The odds ratio and relative risk for the development of DD in non-metformin subjects were 2.0 and 1.4, respectively, as compared to participants in metformin group. The mean improvement in ISI ranged from 1.4% to 4.6% in participants on metformin as opposed to deterioration of -2% to -14.1% in non-metformin group. On performing the paired sample t-test, the reduction in ISI in non-metformin group was significant.

Conclusion

Metformin may prevent deterioration in insulin sensitivity in Indian adolescents with T1D.

A combination of metformin and insulin improve cardiovascular and cerebrovascular risk factors in individuals with type 1 diabetes mellitus

BACKGROUND

This study aims to further clarify whether the addition of metformin to insulin treatment improve cardiovascular and cerebrovascular risk factors in individuals with T1DM.

METHODS

Electronic databases were searched for randomized controlled trials in which the efficacy and safety of metformin were compared with those of a placebo for risk factors of cardiovascular and cerebrovascular disease among individuals with T1DM, and a meta-analysis was conducted.

RESULTS

Thirteen cardiovascular studies were identified. In the metformin group, mean carotid intimal media thickness was significantly reduced by 0.03 mm, ascending aortic pulse wave velocity by 6.3 m/s, descending aortic wall shear stress by 1.77 dyn/cm² (P = 0.02), insulin daily dose by 0.05 U/kg/d, body weight by 2.27 kg, fat-free mass by 1.32 kg, body mass index by 0.58 kg/m², hip circumference by 0.29 m, and low-density lipoprotein by 0.16 mmol/L, all above are P < 0.05. In the metformin group, flow-mediated dilation was increased by 1.29 %, glucose infusion rate/insulin by 18.22 mg/(kg⋅min)/μIU/μL, and waist-to-hip ratio by 0.02, all above are P < 0.00001. The metformin group showed no differences in blood pressure, reactive hyperemia index, waist circumference, triglyceride, total cholesterol, high-density lipoprotein cholesterol, or body mass index Z score. For cerebrovascular studies were identified. But none of them had a risk factor assessment.

CONCLUSIONS

Metformin can ameliorate cardiovascular and cerebrovascular risk factors through non-hypoglycemic multiple pathways in individuals with T1DM.

Effect and Safety of Adding Metformin to Insulin Therapy in Treating Adolescents With Type 1 Diabetes Mellitus: An Updated Meta-Analysis of 10 Randomized Controlled Trials

BACKGROUND

The role of metformin in the treatment of adolescents with type 1 diabetes mellitus (T1DM) remains controversial. We conducted this updated meta-analysis to generate a comprehensive assessment regarding the effect and safety of metformin in treating adolescents with T1DM.

METHODS

We systematically searched PubMed, Embase, and the Cochrane Central Registry of Controlled Trials (CENTRAL) from their inception to November 2021 to identify randomized controlled trials evaluating the efficacy of metformin in the treatment of adolescents with T1DM. The primary outcome was the HbA1c level, and secondary outcomes included the body mass index (BMI), total insulin daily dose (TIDD) (unit/kg/d), hypoglycemia events, diabetes ketoacidosis (DKA) events, and gastrointestinal adverse events (GIAEs). Statistical analysis was conducted using RevMan 5.4 and STATA 14.0.

RESULTS

Ten studies enrolling 539 T1DM adolescents were included. Results suggested that metformin significantly decreased the HbA1c level at 12 months (mean difference [MD])=-0.50, 95% confidence interval [CI]=-0.61 to -0.39, P < 0.01); BMI (kg/m2) at 3 months (MD=-1.05, 95%CI=-2.05 to -0.05, P=0.04); BMI z-score at 6 months (MD=-0.10, 95%CI=-0.14 to -0.06, P<0.01); and TIDD at 3 (MD=-0.13, 95%CI=-0.20 to -0.06, P<0.01), 6 (MD=-0.18, 95%CI=-0.25 to -0.11, P<0.01), and 12 (MD=-0.42, 95%CI=-0.49 to -0.35, P<0.01) months but significantly increased the risk of hypoglycemia events (risk ratio [RR]=3.13, 95%CI=1.05 to 9.32, P=0.04) and GIAEs (RR=1.64, 95%CI=1.28 to 2.10, P<0.01). For remaining outcomes at other time points, no statistical difference was identified. Sensitivity analysis confirmed the robustness of all pooled results.

CONCLUSIONS

The use of metformin might result in decreased BMI (kg/m2), BMI z-score, and TIDD and increased risk of hypoglycemia events and GIAEs in adolescents with T1DM. However, future studies are required to further confirm the optimal dose and duration of metformin therapy.

Benefits of metformin add-on insulin therapy (MAIT) for HbA1c and lipid profile in adolescents with type 1 diabetes mellitus: preliminary report from a double-blinded, placebo-controlled, randomized clinical trial

OBJECTIVES

Metabolic control during puberty is impaired in Type 1 Diabetes Mellitus (T1DM) patients due to increased insulin resistance. Metformin is one of the oral medications typically used in type 2 diabetes mellitus to reduce insulin resistance. We aimed to examine the effect of metformin on glycemic indices and insulin daily dosage in adolescents with T1DM.

METHODS

The present clinical trial was carried out on 50 adolescents aged 10-20 years with T1DM referred to the Endocrinology Clinic of Mofid Children's Hospital in Tehran for nine months. The patients were randomly divided into two groups. In the first group, metformin was added to insulin therapy, while the second group continued routine insulin therapy combined with placebo. Hemoglobin A1c (HbA1c), weight, BMI, insulin dosage, and blood pressure were measured at the beginning of the study and repeated every three months. Serum lipid profile, creatinine, blood urea nitrogen, and liver enzymes were also measured twice: At the beginning and end of the study (after nine months).

RESULTS

The HbA1c level (p<0.001) and insulin dosage (p=0.04) were lower in the metformin group than in the placebo group after nine months. Daily insulin dosage variability was significantly lower in the metformin recipient group (p=0.041). Serum triglyceride, cholesterol, and creatinine were significantly lower in the metformin arm than in the placebo arm (p<0.05). However, metformin did not affect LDL, HDL, liver enzymes, and BUN.

CONCLUSIONS

Adjunctive metformin therapy reduces insulin dosage by inhibiting insulin resistance and weight gain. It helps decrease daily insulin dosage variability, which may prevent hypoglycemia. Also, metformin reduces creatinine, preventing renal failure in the long term.

Differences in insulin sensitivity in the partial remission phase of childhood type 1 diabetes; a longitudinal cohort study

AIMS

Studies suggest that type 1 diabetes (T1D) contributes to impaired insulin sensitivity (IS). Most children with T1D experience partial remission but the knowledge regarding the magnitude and implications of impaired IS in this phase is limited. Therefore, we investigate the impact of IS on the partial remission phase.

METHODS

In a longitudinal study of children and adolescents, participants were seen at three clinical visits during the first 14.5 months after diagnosis of T1D. Partial remission was defined as IDAA_1c (HbA_1c (%) + 4*daily insulin dose) ≤ 9. Beta-cell function was considered significant by a stimulated c-peptide > 300 pmol/L. Participants were characterized by (i) remission or non-remission and (ii) stimulated c-peptide levels above or below 300 pmol/L. IS, body mass index (BMI), total body fat, sex, age, pubertal status and ketoacidosis at onset were compared.

RESULTS

Seventy-eight children and adolescents aged 3.3-17.7 years were included. At 14.5 months post-diagnosis, 54.5% of the participants with stimulated c-peptide > 300 pmol/L were not in partial remission. Participants not in remission had significant lower IS 2.5 (p = 0.032), and 14.5 (p = 0.022) months after diagnosis compared to participants in partial remission with similar c-peptide levels. IS did not fluctuate during the remission phase.

CONCLUSIONS

A number of children and adolescents have impaired IS in the remission phase of paediatric T1D and are not in remission 14.5 months after diagnosis despite stimulated c-peptide > 300 pmol/L.

The clinical application of metformin in children and adolescents: A short update

Metformin is a widely used drug that results in clear benefits in relation to glucose metabolism and diabetes-related complications. The global increase in the prevalence of obesity among children and adolescents is accompanied by the appearance and increasing prevalence of insulin resistance, prediabetes, and type 2 diabetes mellitus (T2DM). In addition, children, and adolescents with premature pubarche and polycystic ovary have considerable degree of insulin resistance. The insulin sensitizing actions of metformin encouraged many investigators and physician to use it as the key drug in these conditions for both prevention and treatment. However, long term-controlled studies are still required to assess the degree and duration of effectiveness and safety of using metformin. This review tries to update physicians about the main and the new therapeutic perspectives of this drug.

Medication use for the treatment of diabetes in obese individuals

Obesity is a major cause of type 2 diabetes and may complicate type 1 diabetes. Weight loss for obese individuals with diabetes has many health benefits, often leads to improvement in glucose control and sometimes, in type 2 diabetes, near normalisation of abnormal glucose metabolism. Weight loss is difficult to maintain and attempts to lose weight may be undermined by some diabetes treatments such as sulfonylureas, thiazolidinediones and insulin. Whilst lifestyle support should be the primary approach to aid individuals who wish to lose weight, pharmacological approaches can also be considered. These include choosing glucose-lowering drugs or drug combinations that are weight neutral or result in weight loss or prescribing drugs that are specifically approved as anti-obesity medication. Given that some of the newer glucose-lowering medications that cause weight loss, such as glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and sodium-glucose cotransporter 2 inhibitors (SGLT2i), are also being used or considered for use as anti-obesity drugs, it seems that the distinction between glucose-lowering medication and weight loss medication is becoming blurred. This review discusses the main pharmacological approaches that can be used to support weight loss in individuals with diabetes.

Effect of Metformin on Vascular Function in Children With Type 1 Diabetes: A 12-Month Randomized Controlled Trial

CONTEXT

Children with type 1 diabetes have vascular dysfunction preceding atherosclerosis. Early interventions are needed to reduce cardiovascular disease.

OBJECTIVE

To evaluate the effect of metformin on vascular function in children with type 1 diabetes.

DESIGN

Twelve-month double-blind, randomized, placebo-controlled trial.

SETTING

Tertiary pediatric diabetes clinic.

PARTICIPANTS

Ninety children (8 to 18 years of age), >50th percentile body mass index (BMI), with type 1 diabetes.

INTERVENTION

Metformin (up to 1 g twice a day) or placebo.

MAIN OUTCOME MEASURE

Vascular function measured by brachial artery ultrasound [flow-mediated dilatation/glyceryl trinitrate-mediated dilatation (GTN)].

RESULTS

Ninety participants were enrolled [41 boys, 13.6 (2.5) years of age, 45 per group], 10 discontinued intervention, and 1 was lost to follow-up. On metformin, GTN improved, independent of glycosylated hemoglobin (HbA1c), by 3.3 percentage units [95% confidence interval (CI) 0.3, 6.3, P = 0.03] and insulin dose reduced by 0.2 U/kg/d (95% CI 0.1, 0.3, P = 0.001) during 12 months, with effects from 3 months. Metformin had a beneficial effect on HbA1c at 3 months (P = 0.001) and difference in adjusted HbA1c between groups during 12 months was 1.0%; 95% CI 0.4, 1.5 (10.9 mmol/mol; 95% CI 4.4, 16.4), P = 0.001. There were no effects on carotid/aortic intima media thickness, BMI, lipids, blood pressure, or other cardiovascular risk factors. Median (95% CI) adherence, evaluated by electronic monitoring, was 75.5% (65.7, 81.5), without group differences. More gastrointestinal side effects were reported on metformin (incidence rate ratio 1.65, 95% CI 1.08, 2.52, P = 0.02), with no difference in hypoglycemia or diabetic ketoacidosis.

CONCLUSIONS

Metformin improved vascular smooth muscle function and HbA1c, and lowered insulin dose in type 1 diabetes children. These benefits and good safety profile warrant further consideration of its use.

FAM3C activates HSF1 to suppress hepatic gluconeogenesis and attenuate hyperglycemia of type 1 diabetic mice

FAM3C, a member of FAM3 gene family, has been shown to improve insulin resistance and hyperglycemia in obese mice. This study further determined whether FAM3C functions as a hepatokine to suppress hepatic gluconeogenesis of type 1 diabetic mice. In STZ-induced type 1 diabetic mouse liver, the FAM3C-HSF1-CaM signaling axis was repressed. Hepatic FAM3C overexpression activated HSF1-CaM-Akt pathway to repress gluconeogenic gene expression and ameliorate hyperglycemia of type 1 diabetic mice. Moreover, hepatic HSF1 overexpression also activated CaM-Akt pathway to repress gluconeogenic gene expression and improve hyperglycemia of type 1 diabetic mice. Hepatic FAM3C and HSF1 overexpression had little effect on serum insulin levels in type 1 diabetic mice. In cultured hepatocytes, conditioned medium of Ad-FAM3C-infected cells induced Akt phosphorylation. Moreover, Akt activation and gluconeogenesis repression induced by FAM3C overexpression were reversed by the treatment with anti-FAM3C antibodies. Treatment with recombinant FAM3C protein induced Akt activation in a HSF1- and CaM-dependent manner in cultured hepatocytes. Furthermore, recombinant FAM3C protein repressed gluconeogenic gene expression and gluconeogenesis by inactivating FOXO1 in a HSF1-dependent manner in cultured hepatocytes. In conclusion, FAM3C is a new hepatokine that suppresses hepatic gluconeogenic gene expression and gluconeogenesis independent of insulin by activating HSF1-CaM-Akt pathway.