Type 1 diabetes in adults: diagnosis and management

Diagnosis: classification of late-onset type 1 diabetes

New evidence and stakeholder comments indicate that people with late-onset type 1 diabetes may be at risk of misclassification of diabetes and that clinical characteristics such as age at diagnosis and body mass index (currently mentioned in recommendation 1.1.1) may not be as accurate as C-peptide tests when distinguishing between diabetes types in people aged over 35 years.

Blood glucose management: telemedicine, smartphone applications and online platforms; flash glucose monitoring; continuous glucose monitoring (CGM)

Evidence indicates that the use of smartphone applications to enhance self-monitoring and telemedicine interventions (such as remote monitoring devices, online education platforms and teleconference sessions) help people to significantly reduce their HbA1c levels.

Flash glucose monitoring measures glucose levels from a sensor applied to the skin as an alternative to routine finger-prick blood glucose testing and can produce a near-continuous record of measurements which can be accessed on demand. It can also indicate glucose level trends over time. Evidence was identified to support the use of flash glucose monitoring in people with well-controlled diabetes, which is not currently recommended in the guideline.

Evidence was also identified which supports the use of CGM in people having multiple daily injection therapy with sub-optimal glucose control. Many stakeholders also raised concerns in this area, calling for CGM eligibility criteria in the guideline to be reconsidered.

Insulin therapy: long-acting insulin; biosimilar insulins; adjuncts to insulin; closed-loop systems

Evidence was identified which supports the use of the ultra-long-lasting insulin degludec. This was also an area raised by topic experts. The safety profiles and dosage conversions will also need careful consideration, given the advice in the corresponding drug safety update.

Evidence was identified to suggest that various biosimilar insulins may be non-inferior to original insulin formulations such as lispro and glargine. The guideline currently recommends offering insulin detemir or insulin glargine in adults with type 1 diabetes (recommendation 1.7.4). This was also an area raised by topic experts, who highlighted the potential cost savings available when switching to cheaper (but clinically comparable) insulins.

Several trials examined the effect of SGLT-2 inhibitors as an adjunct to insulin therapy; however many of the studies were related to NICE technology appraisals currently in development, so were not considered in this surveillance review. There was some evidence to suggest that canagliflozin (a SGLT-2 inhibitor currently licensed for use in type 2, but not type 1 diabetes) significantly improved HbA1c levels and body weight compared to placebo. Topic experts also highlighted this as a possible area for update. Given that the guideline does not currently have any recommendations on offering SGLT-2 inhibitors, we propose that the impact of the NICE technology appraisals is assessed when the decisions are finalised.

New evidence was identified to suggest a benefit of closed-loop insulin delivery systems, particularly in people with a high risk of hypoglycaemia and those with sub-optimally controlled diabetes. NICE has produced both diagnostics guidance and a medtech innovation briefing on these devices, however there are currently no recommendations on the use of closed-loop systems in the guideline. This was also an area raised by stakeholders, who highlighted recent evidence in this area as well as ongoing trials.

Managing complications: eye disease

New evidence was identified on the treatment of diabetic eye disease, including retinopathy and macular oedema. The evidence supports the use of anti-VEGF treatment for diabetic retinopathy and laser therapy for diabetic macular oedema. Currently the guideline has recommendations on screening and referral, but no recommendations on specific treatments. However, there are many treatments covered in NICE technology appraisal guidance, suggesting that there may be a gap in the recommendations in NICE's guideline on type 1 diabetes in adults.

For further details and a summary of all evidence identified in surveillance, see appendix A1.

Blood glucose management: first and second intensification

Evidence indicates the role of clinical characteristics in informing the choice of first intensification medication (treatment with 2 non‑insulin blood glucose lowering therapies in combination: dual therapy) after failure to control blood glucose with metformin and lifestyle interventions. These include the presence of established atherosclerotic cardiovascular disease (CVD), for which there is now evidence to support the use of SGLT-2 inhibitors and GLP-1 agonist classes. Evidence was also identified indicating that other comorbidities such as heart failure or chronic kidney disease; age and frailty; safety and tolerability of medication are also important in informing the choice of first intensification medication. Many stakeholders agreed with the surveillance proposal to review the antidiabetic drug pathway with a focus on CVD, renal and other relevant clinical characteristics.

Data from key cardiovascular outcome trials on SGLT-2 inhibitors and GLP-1 agonists have now been published. This evidence can be used to inform cost-effectiveness analysis of these drugs compared to other available antidiabetic drug options in people with type 2 diabetes for first or second intensification of drug treatment (treatment with either 3 non-insulin blood glucose lowering therapies in combination [triple therapy] or any treatment combination containing insulin). It is therefore proposed that this section of the guideline is updated to consider individual drugs within classes as well as class level comparisons in terms of cardiovascular outcomes, safety, tolerability and acquisition costs. Stakeholders were very supportive of the need for an update in this area including highlighting additional ongoing trials and anticipated publication dates.

NICE's guideline on type 2 diabetes in adults stipulates a body mass index (BMI) threshold of 35 kg/m² prior to being able to receive a GLP-1 analogue but stakeholder comments suggested that this is not evidence-based. Evidence was identified for different BMI cut-offs for ethnic groups for medications such as GLP-1 analogues. Other inequalities in treatment, metabolic control and use of healthcare services among ethnic groups was also raised by stakeholders and should be considered in the update of the antidiabetic drug pathway.

Insulin therapy: long-acting insulins – glargine biosimilars, degludec

The guideline recommends that when insulin therapy is necessary, it should be started from a choice of insulin types and regimens: Neutral Protamine Hagedorn (NPH) insulin injected once or twice daily according to need is the preferred option; insulin detemir or insulin glargine can be considered as an alternative in certain circumstances. There are several insulin glargine products available and new evidence indicates that biosimilars are non-inferior to glargine in reducing HbA1c and have similar safety profiles.

The price reduction of the long-acting insulin Tresiba (degludec) and evidence indicating its cost-effectiveness, in addition to the emergence of cheaper biosimilars, have implications for the health economics of insulin-based treatments. Further biosimilars are also in development. Stakeholders also highlighted evidence and were supportive of an update in this area.

Managing complications: eye disease

New evidence was identified on the treatment of diabetic eye disease, including retinopathy and macular oedema, which supports the use of anti-VEGF treatment and intravitreous injection of aflibercept for diabetic retinopathy and laser therapy for diabetic macular oedema. Currently the guideline has no recommendations on specific treatments for eye disease and stakeholders were in agreement that this area should be considered in the update.

For further details and a summary of all evidence identified in surveillance, see appendix A2.

Diabetic retinopathy in children and young people with type 1 or type 2 diabetes

Evidence was identified indicating that compared with usual care, quality improvement initiatives incorporating behaviour change techniques such as goal-setting and additional social support lead to a substantial increase in diabetic retinopathy screening attendance and are likely to be cost effective.

Flash glucose monitoring

Currently the NICE guideline does not contain any recommendations on flash glucose monitoring, however a number of topic experts and stakeholders highlighted UK guidance on its use, which indicate that children aged 4 years and older may receive a monitor (if other conditions are met): NHS England guidance on Flash Glucose Monitors for Type 1 diabetes patients, the Regional Medicines Optimisation Committee FreeStyle Libre Position Statement and Diabetes UK Type 1 diabetes technology: A consensus guideline. Stakeholders also reported that it is currently being prescribed to some children and young people on the NHS.

Fluid and insulin therapy for diabetic ketoacidosis

Evidence was identified which indicates that rapid fluid infusion at volumes higher than those currently recommended is not associated with an increased risk of cerebral oedema in children and young people with diabetic ketoacidosis; and that in the case of severe diabetic ketoacidosis, more rapid fluid infusion rates may be associated with faster improvements in mental status. This evidence, along with international guidance from the International Society for Pediatric and Adolescent Diabetes (ISPAD) and topic expert opinion, indicates that this should be an area for review.

For further details and a summary of all evidence identified in surveillance, see appendix A3.