The Canadian Hypoglycaemia During Hospitalisation (HyDHo) Score is Externally Valid in the Australian DINGO Cohort of Adults with Diabetes.

OBJECTIVE: The Hypoglycaemia During Hospitalization (HyDHo) score predicts hypoglycaemia in a population of Canadian inpatients by assigning various weightings to five key clinical criteria known at the time of admission: age, recent presentation to an emergency department, insulin use, oral hypoglycaemic use, and chronic kidney disease. The aim of the present study is to externally validate the HyDHo score by applying this risk calculator to an Australian population of inpatients with diabetes. METHOD: This study was a retrospective data analysis of a subset of the Diabetes IN-hospital: Glucose & Outcomes cohort. The HyDHo score was applied based on clinical information known at the time of admission to stratify risk of inpatient hypoglycaemia. RESULTS: The HyDHo score was applied to 1,015 patients, generating a receiver operating characteristic c-statistic of 0.607. A threshold of ≥9, as per the original study, generated a sensitivity of 83% and specificity of 20%. A threshold of ≥10, to better suit this Australian population, generated a sensitivity of 90% and specificity of 34%. DISCUSSION: The HyDHo score is externally valid in a geographically different population, and in fact has outperformed the original study after accounting for local hypoglycaemia rates. CONCLUSION: This study supports the external validity of the HyDHo score in a geographically different population. This supports the application of a simple and accessible tool which can be used as an adjunct to predict an inpatient's risk of hypoglycaemia and therefore guide more appropriate glucose monitoring and diabetes management.

Glycaemic outcomes in hospital with IDegAsp versus BIAsp30 premixed insulins.

BACKGROUND AND AIMS: IDegAsp (Ryzodeg 70/30), a unique premixed formulation of long-acting insulin degludec and rapid-acting insulin aspart, is increasing in use. Management of IDegAsp during hospitalisation is challenging because of degludec's ultra-long duration of action. We investigated inpatient glycaemia in patients treated with IDegAsp compared to biphasic insulin aspart (BIAsp30; Novomix30). METHODS: We performed a retrospective observational study at two hospitals assessing inpatients with type 2 diabetes treated with IDegAsp or BIAsp30 prior to and during hospital admission. Standard inpatient glycaemic outcomes were analysed based on capillary blood glucose (BG) measurements. RESULTS: We assessed 88 individuals treated with IDegAsp and 88 HbA1c-matched individuals treated with BIAsp30. Patient characteristics, including insulin dose at admission, were well matched, but the IDegAsp group had less frequent twice-daily insulin dosing than the BIAsp30 group (49% vs 87%, P < 0.001). Patient-days with BG <4 mmol/L were not different (10.6% vs 9.9%, P = 0.7); however, the IDegAsp group had a higher patient-day mean BG (10.4 (SD 3.4) vs 10.0 (3.4) mmol/L, P < 0.001), and more patient-days with mean BG >10 mmol/L (48% vs 38%, P < 0.001) compared to the BIAsp30 group. Glucose was higher in the IDegAsp group in the evening (4 PM to midnight) (11.6 (SD 4.0) vs 10.9 (4.6) mmol/L, P = 0.004), but not different at other times during the day. CONCLUSIONS: Inpatients treated with IDegAsp compared to BIAsp30 had similar hypoglycaemia incidence, but higher hyperglycaemia incidence, potentially related to less frequent twice-daily dosing. With the increasing use of IDegAsp in the community, development of hospital management guidelines for this insulin formulation is needed.

Classification of type 1 diabetes: A pathogenic and treatment-based classification.

AIM: To improve the diagnosis and classification of patients who fail to satisfy current type 1 diabetes diagnostic criteria. METHODS: Review of the literature and current diagnostic guidelines. DISCUSSION: We propose a novel, clinically useful classification based on islet autoantibody status and non-fasting C-peptide levels. Notably, we discuss the subgroup of latent autoimmune diabetes in the young and propose a new subgroup classification of autoantibody negative type 1 diabetes in remission. CONCLUSION: A novel classification system is proposed. Further work is needed to accurately diagnose and manage minority type 1 diabetes subgroups.

Driving-related glucose patterns among older adults with type 1 diabetes.

Older adults with type 1 diabetes may face challenges driving safely. Glucose "above 5 to drive" is often recommended for insulin-treated diabetes to minimize hypoglycemia while driving. However, the effectiveness of this recommendation among older adults has not been evaluated. Older drivers with type 1 diabetes were assessed while using sensor-augmented insulin pumps during a 2-week clinical trial run-in. Twenty-three drivers (median age 69 years [IQR 65-72]; diabetes duration 37 years [20-45]) undertook 618 trips (duration 10 min [5-21]). Most trips (n = 535; 87%) were <30-min duration; nine trips (1.5%) exceeded 90 min and three trips (0.5%) exceeded 120 min. Pre-trip continuous glucose monitoring (CGM) was >5.0 mmol/L for 577 trips (93%) and none of these had CGM <3.9 mmol/L during driving (including eight trips >90 min and three trips >120 min). During 41 trips with pre-trip CGM ≤5.0 mmol/L, 11 trips had CGM <3.9 mmol/L. Seventy-one CGM alerts occurred during 60 trips (10%), of which 54/71 (76%) were unrelated to hypoglycemia. Our findings support a glucose "above-5-to-drive" recommendation to avoid CGM-detected hypoglycemia among older drivers, including for prolonged drives, and highlight the importance of active CGM low-glucose alerts to prevent hypoglycemia during driving. Driving-related CGM usability and alert functionality warrants investigation.

Bone Density and Trabecular Bone Score Decline Rapidly in the First Year After Bone Marrow Transplantation with a Marked Increase in 10-Year Fracture Risk.

As outcomes from allogeneic bone marrow transplantation (BMT) have improved, prevention of long-term complications, such as fragility fractures, has gained importance. We aimed to assess areal bone mineral density (aBMD) and trabecular bone score (TBS) changes post BMT, and determine their relationship with fracture prevalence. Patients who attended the Royal Melbourne Hospital (RMH) BMT clinic between 2005-2021 were included. Patient characteristics and dual-energy X-ray absorptiometry (DXA) values were collected from the electronic medical record and a survey. TBS iNsight™ was used to calculate TBS for DXA scans performed from 2019 onwards. 337 patients with sequential DXAs were eligible for inclusion. Patients were primarily male (60%) and mean age ± SD was 45.7 ± 13.4 years. The annualised decline in aBMD was greater at the femoral neck (0.066g/cm2 (0.0038-0.17)) and total hip (0.094g/cm2 (0.013-0.19)), compared to the lumbar spine (0.049g/cm2 (- 0.0032-0.16)), p < 0.0001. TBS declined independently of aBMD T-scores at all sites. Eighteen patients (5.3%) sustained 19 fractures over 3884 person-years of follow-up post-transplant (median follow-up 11 years (8.2-15)). This 5.3% fracture prevalence over the median 11-year follow-up period is higher than what would be predicted with FRAX® estimates. Twenty-two patients (6.5%) received antiresorptive therapy, and 9 of 18 (50%) who fractured received or were on antiresorptive therapy. In BMT patients, aBMD and TBS decline rapidly and independently in the first year post BMT. However, FRAX® fracture probability estimates incorporating these values significantly underestimate fracture rates, and antiresorptive treatment rates remain relatively low.

Treatment satisfaction with Omnipod DASH in adults with type 1 diabetes: A non-blinded 1:1 randomized controlled trial.

OBJECTIVE: We compared treatment satisfaction with a tubeless insulin pump (Omnipod DASH® Insulin Management System) to usual care (multiple daily injections [MDI] or tubed insulin pump therapy [IPT]) in adults with type 1 diabetes using self-monitoring blood glucose (SMBG). RESEARCH DESIGN AND METHODS: Adults with type 1 diabetes on MDI (n = 40) or IPT (n = 25) from four diabetes centers in Australia were randomized in a 1:1 non-blinded manner to Omnipod DASH System (Omnipod group) or continue usual care (Usual Care group) for 12 weeks, followed by a further 12-week extension where all participants used the device. The primary outcome was treatment satisfaction assessed by change in Diabetes Technology Questionnaire 'current' (ΔDTQ-current) score at 12-weeks (study-end). Secondary outcomes included ΔDTQ-current following extension and other participant-reported outcomes (PROs) measuring quality of life, burden of disease treatment, glycemic and device-related outcomes at 12-weeks (study-end) and 24-weeks (end-extension). RESULTS: Treatment satisfaction improved more in Omnipod group vs. Usual Care group (ΔDTQ-current score of 16.4 [21.2] vs. 0.0 [12.8]; p < 0.001) at study-end. Significantly greater improvements in other PROs and HbA1c were also observed. Improvements in DTQ-current and other PROs comparing study-end and end-extension were similar. While %TIR change from baseline did not differ at study-end (-2.0 [12.7] %), it was significantly greater at end-extension (5.6 [10.9] %; p = 0.016). CONCLUSIONS: Omnipod DASH System resulted in greater treatment satisfaction at 12 weeks in adults with type 1 diabetes using SMBG which was sustained after 24 weeks of device use without compromising sleep quality and fear of hypoglycemia. Improvements in glycemia were also observed.

"You can hide it if you want to, you can let it be seen if you want to": A qualitative study of the lived experiences of Australian adults with type 1 diabetes using the Omnipod DASH® system.

AIMS: Understanding the lived experience of using a tubeless insulin pump and how this differs compared to usual care (tubed insulin pump therapy (IPT) vs multiple daily injections (MDI)). METHODS: Interviews were conducted after 12-weeks of using the Omnipod DASH Insulin Management System (Insulet, Acton, MA) and analysed using thematic analysis. RESULTS: Fifty-eight adults (35 female; mean age 42;SD 13 years; 35 previous MDI) were interviewed. Most (84 %) wanted to continue using the device. Experiences fit two themes: 1. Taking back control of my diabetes: many previous MDI users perceived improved glycaemic control, explained by more "nuanced" control, with some reporting positive effects during exercise and sleep. Many previous MDI and IPT users endorsed positive experiences in concealing or disclosing their diabetes to others. However, some previous MDI users reported negative psychosocial experiences due to feeling continuously "attached" to their diabetes. 2. Barriers and facilitators of device acceptability: both MDI and IPT users cited wearability, alarms and the financial cost impacted their choice to continue device use. IPT users reported positive wearability experiences. CONCLUSIONS: The tubeless pump improved diabetes management perceptions for both MDI and tubed pump users. However, participants' prior glucose management affected perceptions of its advantages and disadvantages.

The Specialist Treatment of Inpatients: Caring for Diabetes in Surgery (STOIC-D Surgery) Trial: A Randomized Controlled Trial of Early Intervention With an Electronic Specialist-Led Model of Diabetes Care.

OBJECTIVE: To investigate the effect of early intervention with an electronic specialist-led "proactive" model of care on glycemic and clinical outcomes. RESEARCH DESIGN AND METHODS: The Specialist Treatment of Inpatients: Caring for Diabetes in Surgery (STOIC-D Surgery) randomized controlled trial was performed at the Royal Melbourne Hospital. Eligible participants were adults admitted to a surgical ward during the study with either known diabetes or newly detected hyperglycemia (at least one random blood glucose result ≥11.1 mmol/L). Participants were randomized 1:1 to standard diabetes care or the intervention consisting of an early consult by a specialist inpatient diabetes team using electronic tools for patient identification, communication of recommendations, and therapy intensification. The primary outcome was median patient-day mean glucose (PDMG). The key secondary outcome was incidence of healthcare-associated infection (HAI). RESULTS: Between 12 February 2021 and 17 December 2021, 1,371 admissions met inclusion criteria, with 680 assigned to early intervention and 691 to standard diabetes care. Baseline characteristics were similar between groups. The early intervention group achieved a lower median PDMG of 8.2 mmol/L (interquartile range [IQR] 6.9-10.0 mmol/L) compared with 8.6 mmol/L (IQR 7.2-10.3 mmol/L) in the control group for an estimated difference of -0.3 mmol/L (95% CI -0.4 to -0.2 mmol/L, P < 0.0001). The incidence of HAI was lower in the intervention group (77 [11%] vs. 110 [16%]), for an absolute risk difference of -4.6% (95% CI -8.2 to -1.0, P = 0.016). CONCLUSIONS: In surgical inpatients, early diabetes management intervention with an electronic specialist-led diabetes model of care reduces glucose and HAI.

Hyperglycemia in hospital: an independent marker of infection, acute kidney injury & stroke for hospital inpatients.

CONTEXT: Hyperglycemia in hospital inpatients without pre-existing diabetes is associated with increased mortality. However, the independent contribution of hyperglycemia to healthcare-associated infection (HAI), acute kidney injury (AKI), and stroke is unclear. OBJECTIVE: To investigate the relationship between hyperglycemia and adverse clinical outcomes in hospital for patients with and without diabetes. DESIGN: Diabetes IN-hospital: Glucose and Outcomes (DINGO) was a 26-week (October 2019 - March 2020) prospective cohort study. Clinical and glucose data were collected up to the 14th day of admission. Primary stratification was by hyperglycemia, defined as ≥2 random capillary blood glucose (BG) measurements ≥11.1 mmol/L (≥200 mg/dL). Propensity weighting for nine clinical characteristics, was performed to allow interrogation of causality. To maintain the positivity assumption, patients with HbA1c > 12.0% were excluded and pre-hospital treatment not adjusted for. SETTING: The Royal Melbourne Hospital, a quaternary referral hospital in Melbourne, Australia. PATIENTS: Admissions with at least two capillary glucose values and length of stay >24 hours were eligible, with half randomly sampled. OUTCOME MEASURES: HAI, AKI, stroke, and mortality. RESULTS: Of 2,558 included admissions, 1,147 (45%) experienced hyperglycemia in hospital. Following propensity-weighting and adjustment, hyperglycemia in hospital was found to, independently of nine covariables, contribute an increased risk of in-hospital HAI (130 [11.3%] vs.100 [7.1%], adjusted odds ratio [aOR] 1.03, 95% confidence interval [95%CI] 1.01-1.05, p = 0.003), AKI (120 [10.5%] vs. 59 [4.2%], aOR 1.07, 95%CI 1.05-1.09, p < 0.001), and stroke (10 [0.9%] vs. 1 [0.1%], aOR 1.05, 95%CI 1.04-1.06, p < 0.001). CONCLUSIONS: In hospital inpatients (HbA1c ≤ 12.0%), irrespective of diabetes status and pre-hospital glycaemia, hyperglycemia increases the risk of in-hospital HAI, AKI, and stroke compared with those not experiencing hyperglycemia.

Automated insulin delivery among adults with type 1 diabetes for up to 2 years: a real-world, multicentre study.

BACKGROUND AND AIMS: Automated insulin delivery (AID) improves glycaemia among people with type 1 diabetes in clinical trials and overseas real-world studies. Whether improvements are sustained beyond 12 months in the real world, and whether they occur in the Australian context, has not yet been established. We aimed to observe, up to 2 years, the effectiveness of initiating first-generation AID for type 1 diabetes management. METHODS: Retrospective, real-world, observational study using medical records, conducted across five sites in Australia. Adults with type 1 diabetes, who had AID initiated between February 2019 and December 2021, were observed for 6-24 months after initiation (until June 2022). Outcomes examined included glucose metrics assessed by glycated haemoglobin (HbA1c ) and continuous glucose monitoring (CGM), safety and therapy continuation. RESULTS: Ninety-four adults were studied (median age 39 years (interquartile range, IQR: 31-51); pre-initiation HbA1c 7.8% (7.2-8.6)). After AID initiation, HbA1c decreased by mean 0.5 percentage points (95% confidence interval (CI): -0.7 to -0.2) at 3 months (P < 0.001); CGM time in range 3.9-10.0 mmol/L increased by 11 percentage points (9-14) at 1 month (P < 0.001); these improvements were maintained up to 24 months (all P < 0.02). Median CGM time below 3.9 mmol/L was <1.5% pre- and post-AID initiation. The subgroup with pre-initiation HbA1c above 8.5% had the greatest HbA1c improvement (-1.4 percentage points (-1.8 to -1.1) at 3 months). Twelve individuals (13%) discontinued AID, predominantly citing difficulties with CGM. During the 150 person-years observed, four diabetes-related emergencies were documented: three severe hypoglycaemic events and one hyperglycaemic event without ketoacidosis. CONCLUSIONS: Early glucose improvements were observed after real-world AID initiation, sustained up to 2 years, without excess adverse events. The greatest benefits were observed among individuals with highest glycaemia before initiation. Future-generation systems with increased user-friendliness may enhance therapy continuation.

The Need to Prioritize Education and Resources to Support Exercise in Type 1 Diabetes: Results of an Australian Survey of Adults With Type 1 Diabetes and Health Providers.

OBJECTIVES: Regular exercise is recommended for people with type 1 diabetes (PWD) to improve their health, but many do not meet recommended exercise targets. Educational resources supporting PWD to exercise exist, but their value is unclear. To determine the need for improved exercise resources in Australia, we surveyed adult PWD and health providers (HPs) about their confidence in managing type 1 diabetes (T1D) around exercise, barriers to exercise, and the adequacy of current resources. METHODS: Australian adult PWD and HPs completed surveys to rate the importance of exercise in T1D management, confidence in managing T1D around exercise, barriers to giving and receiving education, resources used, and what form new resources should take. RESULTS: Responses were received from 128 PWD and 122 HPs. Both groups considered exercise to be important for diabetes management. PWD cited time constraints (57%) and concern about dysglycemia (43%) as barriers to exercise, and many lacked confidence in managing T1D around exercise. HPs were more confident, but experienced barriers to providing advice and PWD did not tend to rely on this advice. Instead, 72% of PWD found continuous glucose monitoring most helpful. Both groups desired better resources to support exercise in T1D, with PWD preferring to obtain information through a structured education program and HPs through eLearning. CONCLUSIONS: Australian HPs and PWD appreciate the importance of exercise in T1D management and express a clear desire for improved educational resources. Our findings provide a basis for developing a comprehensive package of resources for both adult PWD and HPs, to support PWD exercise.

Real-world lived experience of older adults with type 1 diabetes after an automated insulin delivery trial.

AIMS: First-generation closed-loop automated insulin delivery improves glycaemia and psychosocial outcomes among older adults with type 1 diabetes in clinical trials. However, no study has previously assessed real-world lived experience of older adults using closed-loop therapy outside a trial environment. METHODS: Semi-structured interviews were conducted with older adults who were pre-existing insulin pump users and previously completed the OldeR Adult Closed-Loop (ORACL) randomised trial. Interviews focused on perceptions of diabetes technology use, and factors influencing decisions regarding continuation. RESULTS: Twenty-eight participants, mean age 70 years (SD 5), were interviewed at median 650 days (IQR 608-694) after their final ORACL trial visit. At interview, 23 participants (82%) were still using a commercial closed-loop system (requiring manual input for prandial insulin bolus doses). Themes discussed in interviews relating to closed-loop system use included sustained psychosocial benefits, cost and retirement considerations and usability frustrations relating to sensor accuracy and system alarms. Of the five participants who had discontinued, reasons included cost, continuous glucose monitoring-associated difficulties and usability frustrations. Cost was the largest consideration regarding continued use; most participants considered the increased ease of diabetes management to be worth the associated costs, though cost was prohibitive for some. CONCLUSIONS: Almost 2 years after completing a closed-loop clinical trial, closed-loop automated insulin delivery remains the preferred type 1 diabetes therapy for the majority of older adult participants. Chronological age is not a barrier to real-world successful use of diabetes technology. Identifying age-related barriers, and solutions, to diabetes technology use among older adults is warranted.

A pilot randomised controlled parallel arm trial evaluating treatment satisfaction with the Omnipod DASH® Insulin Management System compared with usual care in adults with type 1 diabetes in Australia: rationale, study design and methodologies.

BACKGROUND: Insulin pump therapy (IPT) improves glucose control in people with type 1 diabetes (T1D) compared with multiple daily injections (MDI). However, their size, the tethered insulin infusion set, intrusiveness when operating the device and the need to disconnect during showering limit their acceptance to many who may benefit. The Omnipod DASH® Insulin Management System is a small waterproof tubeless device which is wirelessly controlled by a handheld device which may be an acceptable alternative. However, there are no randomised controlled trials focusing on the impact on user perceptions of tubeless insulin pump therapy. This pilot study aims to assess study feasibility and acceptability of patch pump therapy compared with usual care in adults with T1D in Australia to inform power calculations and progression to a large-scale multi-site randomised controlled study. METHODS: A pilot multi-site parallel randomised controlled study will be conducted in sixty-four adults with T1D who are managed on MDI or IPT and self-monitoring with finger-stick blood glucose from four specialist diabetes centres in Victoria, Australia. Following carbohydrate counting education, participants will be randomised to use Omnipod DASH® System (Omnipod group) or continue usual care (usual care group) for 12 weeks, followed by a 12-week extension phase where all participants will use Omnipod DASH® System. The primary outcome measure is feasibility determined by study completion rates with a threshold of 0.80. Acceptability of the intervention (Omnipod DASH® System) will be assessed by the difference in Diabetes Technology Questionnaire 'current' (DTQ-current) score at 12 weeks post-randomisation compared to baseline. Secondary outcomes will include other measures of user acceptance, process outcomes, resource outcomes, participant-centred outcomes, healthcare professional perceptions and glycaemic outcomes. DISCUSSION: This pilot study will provide insights regarding the feasibility of the study design and the first data regarding user acceptance of insulin patch pump technology in Australian T1D adults. We anticipate that this study will provide information informing the design of a larger study evaluating the impact of patch pumps on subjective outcomes that are of significance to the person living with T1D. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ( https://anzctr.org.au/ ) ACTRN12621001195842 (8th September 2021). Please refer to Additional file 1: Appendix 1 for full details.

Underutilisation of gastric emptying studies and underrecognition of gastroparesis in people with diabetes treated in a hospital setting.

Delayed gastric emptying occurs in up to 30% of patients with long-standing diabetes and causes significant morbidity. We performed a retrospective cohort study of 341 patients who had participated in a gastric emptying study from 2018 to 2021 in a large teaching hospital. Given the expected prevalence of gastroparesis in people with diabetes, there were fewer studies than anticipated, which could lead to gastroparesis underrecognition.

Reporting hypoglycaemia as a hospital-acquired complication: assessing biochemical and clinical validity.

BACKGROUND AND AIMS: Given treatment-related hypoglycaemia in hospitals can lead to adverse outcomes, the Australian Commission on Safety and Quality in Health Care has included hypoglycaemia as a reportable hospital-acquired complication (HAC) with financial disincentives. However, the designation of a hypoglycaemia HAC relies on clinical coding without a defined glucose threshold or clinical context. We assessed the biochemical validity and clinical relevance of a hypoglycaemia HAC. METHODS: We performed a retrospective review on patients discharged from the Northern Health hospitals between March and August 2021 who were designated as experiencing a hypoglycaemia HAC. We assessed cases for biochemical validity (glucose <4.0 mmol), clinical context and whether they were treatment-related (treatment with insulin or sulphonylurea). We then compared this cohort with a hospital-wide glucometric survey based on a point-prevalence study to determine the proportion of individuals with hypoglycaemic events that were designated as hypoglycaemia HAC. RESULTS: Two hundred fifty-six admissions were coded as hypoglycaemia HAC. Eleven (4%) did not have a biochemically valid episode. Of the valid cases, 34 (14%) were not treated with any glucose-lowering medication and 11 (4%) were treated with noninsulin, nonsulphonylurea glucose-lowering medication. Two hundred admissions (78%) were considered treatment-related HAC. Of 139 individuals with diabetes identified in the hospital-wide point-prevalence study, 25 (18%) had biochemical evidence for hypoglycaemia: 22 were treatment-related, of which 68% were not coded as HAC. CONCLUSION: Given safety and cost implications, the designation of hypoglycaemia HAC requires a standardised definition incorporating a biochemical threshold and clinical context. We propose a clinically relevant definition of hypoglycaemia HAC to promote safe diabetes care.

Contrast Increment and Decrement Processing in Individuals With and Without Diabetes.

Purpose: Animal models suggest that ON retinal ganglion cells (RGCs) may be more vulnerable to diabetic insult than OFF cells. Using three psychophysical tasks to infer the function of ON and OFF RGCs, we hypothesized that functional responses to contrast increments will be preferentially affected in early diabetes mellitus (DM) compared to contrast decrement responses. Methods: Fifty-two people with DM (type 1 or type 2) (mean age = 34.8 years, range = 18-60 years) and 48 age-matched controls (mean age = 35.4 years, range = 18-60 years) participated. Experiment 1 measured contrast sensitivity to increments and decrements at four visual field locations. Experiments 2 and 3 measured visual temporal processing using (i) a response time (RT) task, and (ii) a temporal order judgment task. Mean RT and accuracy were collected for experiment 2, whereas experiment 3 measured temporal thresholds. Results: For experiment 1, the DM group showed reduced increment and decrement contrast sensitivity (F (1, 97) = 4.04, P = 0.047) especially for the central location. For experiment 2, those with DM demonstrated slower RT and lower response accuracies to increments and decrements (increments: U = 780, P = 0.01, decrements: U = 749, P = 0.005). For experiment 3, performance was similar between groups (F (1, 91) = 2.52, P = 0.137). Conclusions: When assessed cross-sectionally, nonselective functional consequences of retinal neuron damage are present in early DM, particularly for foveal testing. Whether increment-decrement functional indices relate to diabetic retinopathy (DR) progression or poorer visual prognosis in DM requires further study.