Annual decline in β-cell function in patients with type 2 diabetes in China

Initial Combination Therapy in Type 2 Diabetes

Type 2 diabetes (T2D) is a progressive disease in which it is challenging to achieve long-term durable glycemic control. However, intensive glycemic control is crucial for preventing diabetes-related complications. Previous studies showed that monotherapy with a stepwise add-on approach was seldom effective for long-term durable glycemic control. Combination therapy, which refers to the use of two or more drugs to control hyperglycemia, has multiple benefits, including the ability to target a variety of pathophysiological processes underlying hyperglycemia. In clinical trials, initial combination therapy showed better glycemic control than monotherapy or a stepwise approach. Emerging evidence indicates that initial combination therapy is associated with preserved β-cell function and fewer complications in T2D. However, cost-effectiveness and adverse events with combination therapy are issues that should be considered. Therefore, initial combination therapy is an important option for patients with T2D that clinicians should consider with a view toward balancing benefits and potential harms. In this review, we summarize the literature addressing initial combination therapy in T2D, and we suggest optimal strategies based on clinical situations and patient characteristics.

Impact of Type 2 Diabetes Duration on the Efficacy and Safety of Add-on Lixisenatide in Asian Individuals Receiving Basal Insulin: A Pooled Analysis

INTRODUCTION

This analysis investigated the efficacy and safety of add-on lixisenatide by disease duration in Asian people with type 2 diabetes inadequately controlled with basal insulin ± oral antidiabetic drugs.

METHODS

Data for Asian participants in the GetGoal-Duo 1, GetGoal-L, and GetGoal-L-C studies were pooled and categorized by diabetes duration: < 10 years (group 1), 10 to < 15 years (group 2), and ≥ 15 years (group 3). Efficacy and safety of lixisenatide versus placebo were evaluated by subgroup. The potential influence of diabetes duration on efficacy was examined using multivariable regression analyses.

RESULTS

A total of 555 participants were included (mean age 53.9 years, 52.4% male). No significant differences in treatment effect between the duration subgroups were observed for the changes from baseline to 24 weeks in glycated hemoglobin (HbA1c), fasting plasma glucose (FPG), postprandial glucose (PPG), PPG excursion, body weight or body mass index, or the proportion of participants with HbA1c < 7% at 24 weeks (all P values for interaction > 0.1). Change in insulin dosage (U/day) was significantly different between subgroups (P = 0.038). Multivariable regression analysis showed participants in group 1 had a smaller change in body weight and basal insulin dose over the 24-week treatment period than participants in group 3 (P = 0.014 and 0.030, respectively) and were less likely to achieve an HbA1c < 7% than participants in group 2 (P = 0.047). No severe hypoglycemia was reported. A higher proportion of participants in group 3 versus the other groups had symptomatic hypoglycemia, for both lixisenatide and placebo, and T2D duration had a significant effect on hypoglycemia risk (P = 0.001).

CONCLUSIONS

Lixisenatide improved glycemic control in Asian individuals regardless of diabetes duration, without increasing the risk of hypoglycemia. Individuals with longer disease duration had a greater risk of symptomatic hypoglycemia than individuals with shorter disease duration regardless of treatment. No additional safety concerns were observed.

CLINICAL TRIAL REGISTRATION

GetGoal-Duo 1, ClinicalTrials.gov record NCT00975286; GetGoal-L, ClinicalTrials.gov record NCT00715624; GetGoal-L-C, ClinicalTrials.gov record NCT01632163.

Clinical expert consensus on the assessment and protection of pancreatic islet β-cell function in type 2 diabetes mellitus

Islet β-cell dysfunction is a basic pathophysiological characteristic of type 2 diabetes mellitus (T2DM). Appropriate assessment of islet β-cell function is beneficial to better management of T2DM. Protecting islet β-cell function is vital to delay the progress of type 2 diabetes mellitus. Therefore, the Pancreatic Islet β-cell Expert Panel of the Chinese Diabetes Society and Endocrinology Society of Jiangsu Medical Association organized experts to draft the "Clinical expert consensus on the assessment and protection of pancreatic islet β-cell function in type 2 diabetes mellitus." This consensus suggests that β-cell function can be clinically assessed using blood glucose-based methods or methods that combine blood glucose and endogenous insulin or C-peptide levels. Some measures, including weight loss and early and sustained euglycemia control, could effectively protect islet β-cell function, and some newly developed drugs, such as Sodium-glucose cotransporter-2 inhibitor and Glucagon-like peptide-1 receptor agonists, could improve islet β-cell function, independent of glycemic control.

Insulin resistance and beta-cell dysfunction in newly diagnosed type 2 diabetes: Expression, aggregation and predominance. Verona Newly Diagnosed Type 2 Diabetes Study 10

AIMS

We investigated quantitative expression, mutual aggregation and relation with hyperglycemia of insulin resistance (IR) and beta-cell dysfunction (BCD) in newly diagnosed type 2 diabetes.

METHODS

We assessed IR with euglycemic hyperinsulinemic clamp and BCD with modelled glucose/C-peptide response to oral glucose in 729 mostly drug-naïve patients. We measured glycated hemoglobin, pre-prandial, post-prandial and meal-related excursion of blood glucose.

RESULTS

IR was found in 87.8% [95% confidence intervals 85.4-90.2] and BCD in 90.0% [87.8-92.2] of subjects, ranging from mild to moderate or severe. Approximately 20% of subjects had solely one defect: BCD 10.8% [8.6-13.1] or IR 8.6% [6.6-10.7]. Insulin resistance and BCD aggregated in most subjects (79.1% [76.2-82.1]). We arbitrarily set nine possible combinations of mild, moderate or severe IR and mild, moderate or severe BCD, finding that each had a similar frequency (∼10%). In multiple regression analyses parameters of glucose control were related more strongly with BCD than with IR.

CONCLUSIONS

In newly-diagnosed type 2 diabetes, IR and BCD are very common with a wide range of expression but no specific pattern of aggregation. Beta-cell dysfunction is likely to play a greater quantitative role than IR in causing/sustaining hyperglycemia in newly-diagnosed type 2 diabetes.

Basal Insulin Reduces Glucose Variability and Hypoglycaemia Compared to Premixed Insulin in Type 2 Diabetes Patients: A Study Based on Continuous Glucose Monitoring Systems

Aims

To examine the glycaemic variability and safety of basal and premixed insulin by using continuous glucose monitoring (CGM) systems.

Methods

393 patients with type 2 diabetes mellitus (T2DM) treated with basal or premixed insulin for more than 3 months were enrolled. Patients were classified into a basal insulin group or premixed insulin group according to their insulin regimens. CGMs were used for 72 h with their previous hypoglycaemic regimen unchanged. The following glycaemic parameters were calculated for each 24 h using CGM data.

Results

Despite similar HbA1c and fasting C-peptide concentrations, glycaemic variability (GV), including the mean amplitude of glycaemic excursion (MAGE), standard deviation (SD) and coefficient of variation (CV), and the time below range (TBR) were significantly lower in the basal insulin group than these in the premixed insulin group. Night-time hypoglycaemia was lower in the basal insulin group than that in the premixed insulin group (p<0.01). Among participants with haemoglobin A1c (HbA1c) < 7%, the GV and TBR were higher in the premixed insulin group than that in the basal insulin group.

Conclusion

Compared with basal insulin, the patients who use premixed insulin had higher GV, smaller TIR and an increased incidence of hypoglycaemia. For patients who use premixed insulin and with HbA1c < 7%, more attention needs to be given to hypoglycaemic events and asymptomatic hypoglycaemia.

Clinical Trial Registration

ClinicalTrials.gov, identifier NCT03566472.

Case Report: A Chinese Family of Woodhouse-Sakati Syndrome With Diabetes Mellitus, With a Novel Biallelic Deletion Mutation of the DCAF17 Gene

Woodhouse-Sakati syndrome (WSS) (OMIM#241080) is a rare multi-system autosomal recessive disease with homozygous mutation of the DCAF17 gene. The main features of WSS include diabetes, hypogonadism, alopecia, deafness, intellectual disability and progressive extrapyramidal syndrome. We identified a WSS family with a novel DCAF17 gene mutation type in China. Two unconsanguineous siblings from the Chinese Han family exhibiting signs and symptoms of Woodhouse-Sakati syndrome were presented for evaluation. Whole-exome sequencing revealed a homozygous deletion NM_025000.4:c.1488_1489delAG in the DCAF17 gene, which resulted in a frameshift mutation that led to stop codon formation. We found that the two patients exhibited low insulin and C-peptide release after glucose stimulation by insulin and C-peptide release tests. These findings indicate that the DCAF17 gene mutation may cause pancreatic β cell functional impairment and contribute to the development of diabetes.

Age at diagnosis, glycemic trajectories, and responses to oral glucose-lowering drugs in type 2 diabetes in Hong Kong: A population-based observational study

BACKGROUND

Lifetime glycemic exposure and its relationship with age at diagnosis in type 2 diabetes (T2D) are unknown. Pharmacologic glycemic management strategies for young-onset T2D (age at diagnosis <40 years) are poorly defined. We studied how age at diagnosis affects glycemic exposure, glycemic deterioration, and responses to oral glucose-lowering drugs (OGLDs).

METHODS AND FINDINGS

In a population-based cohort (n = 328,199; 47.2% women; mean age 34.6 and 59.3 years, respectively, for young-onset and usual-onset [age at diagnosis ≥40 years] T2D; 2002-2016), we used linear mixed-effects models to estimate the association between age at diagnosis and A1C slope (glycemic deterioration) and tested for an interaction between age at diagnosis and responses to various combinations of OGLDs during the first decade after diagnosis. In a register-based cohort (n = 21,016; 47.1% women; mean age 43.8 and 58.9 years, respectively, for young- and usual-onset T2D; 2000-2015), we estimated the glycemic exposure from diagnosis until age 75 years. People with young-onset T2D had a higher mean A1C (8.0% [standard deviation 0.15%]) versus usual-onset T2D (7.6% [0.03%]) throughout the life span (p < 0.001). The cumulative glycemic exposure was >3 times higher for young-onset versus usual-onset T2D (41.0 [95% confidence interval 39.1-42.8] versus 12.1 [11.8-12.3] A1C-years [1 A1C-year = 1 year with 8% average A1C]). Younger age at diagnosis was associated with faster glycemic deterioration (A1C slope over time +0.08% [0.078-0.084%] per year for age at diagnosis 20 years versus +0.02% [0.016-0.018%] per year for age at diagnosis 50 years; p-value for interaction <0.001). Age at diagnosis ≥60 years was associated with glycemic improvement (-0.004% [-0.005 to -0.004%] and -0.02% [-0.027 to -0.0244%] per year for ages 60 and 70 years at diagnosis, respectively; p-value for interaction <0.001). Responses to OGLDs differed by age at diagnosis (p-value for interaction <0.001). Those with young-onset T2D had smaller A1C decrements for metformin-based combinations versus usual-onset T2D (metformin alone: young-onset -0.15% [-0.105 to -0.080%], usual-onset -0.17% [-0.179 to -0.169%]; metformin, sulfonylurea, and dipeptidyl peptidase-4 inhibitor: young-onset -0.44% [-0.476 to -0.405%], usual-onset -0.48% [-0.498 to -0.459%]; metformin and α-glucosidase inhibitor: young-onset -0.40% [-0.660 to -0.144%], usual-onset -0.25% [-0.420 to -0.077%]) but greater responses to other combinations containing sulfonylureas (sulfonylurea alone: young-onset -0.08% [-0.099 to -0.065%], usual-onset +0.06% [+0.059 to +0.072%]; sulfonylurea and α-glucosidase inhibitor: young-onset -0.10% [-0.266 to 0.064%], usual-onset: 0.25% [+0.196% to +0.312%]). Limitations include possible residual confounding and unknown generalizability outside Hong Kong.

CONCLUSIONS

In this study, we observed excess glycemic exposure and rapid glycemic deterioration in young-onset T2D, indicating that improved treatment strategies are needed in this setting. The differential responses to OGLDs between young- and usual-onset T2D suggest that better disease classification could guide personalized therapy.