David O’Neal

Low-density lipoprotein size, high-density lipoprotein concentration, and endothelial dysfunction in non-insulin-dependent diabetes

We examined endothelial function (nitric‐oxide mediated) in 29 men with diet‐treated non‐insulin‐dependent (Type 2) diabetes mellitus (NIDDM) and 18 male age‐matched controls. Forearm blood flow was measured by venous occlusive plethysmography during intra‐arterial administration of acetylcholine (ACh, 7.5 and 15 μg min−1) and sodium nitroprusside (SNP, 3 and 10 μg min−1). LDL particle size was estimated by non‐denaturing gel electrophoresis. Serum lipids, blood pressure, and glycated haemoglobin were also measured. LDL particle size was smaller (p = 0.048) in the diabetic patients than controls. In the diabetic patients, LDL particle size was a significant positive predictor (p = 0.01) of the area under the dose–response curve for ACh, after adjusting for age, HbA1c, systolic BP, and cholesterol (R2 0.20). In stepwise regression including serum lipid and lipoprotein concentrations and LDL particle size, decreased HDL cholesterol was the best predictor of an impaired vasodilatory response to ACh. Vasodilatory responses to sodium nitroprusside were not significantly correlated with LDL particle size or serum lipid and lipoprotein concentrations. We conclude that in men with NIDDM, small, dense LDL particle size is associated with abnormal endogenous release of nitric oxide. The contribution of small, dense LDL particles to the development of endothelial dysfunction and early diabetic vasculopathy may not, however, be as great as decreased HDL cholesterol.

The role of continuous glucose monitoring in clinical decision‐making in diabetes in pregnancy

Background:  The continuous glucose monitoring system (CGMS) is a novel tool to assess 24‐h glucose fluctuations. In pregnancies complicated by diabetes, where excellent glucose control is desired to improve maternal and fetal outcomes, CGMS may have a role in fine‐tuning management.

Diabetic Dyslipidaemia Current Treatment Recommendations

Insulin deficiency and hyperglycaemia in type 1 (insulin-dependent) diabetes mellitus produce lipid abnormalities, which can be corrected by appropriate insulin therapy. Diabetic nephropathy, which is the main risk factor for coronary heart disease (CHD) in type 1 diabetes, causes pro-atherosclerotic changes in lipid metabolism. Detection and treatment of elevated cholesterol levels is likely to be of benefit in these patients.Type 2 (noninsulin-dependent) diabetes mellitus is associated with abnormal lipid metabolism, even when glycaemic control is good and nephropathy absent. Elevated triglyceride levels, reduced high density lipoprotein (HDL) cholesterol and a preponderance of small, dense low density lipoprotein (LDL) particles are the key abnormalities that constitute diabetic dyslipidaemia. The prevalence of hypercholesterolaemia is the same as for the nondiabetic population, but the relative risk of CHD is greatly increased at every level of cholesterol. Based on effectiveness, tolerability and clinical trial results, treatment with HMG-CoA reductase inhibitors to lower LDL cholesterol is recommended as primary therapy. These agents are also moderately effective at reducing triglyceride and increasing HDL cholesterol levels. If hypertriglyceridaemia predominates, treatment with fibric acid derivatives is appropriate, although there is currently only limited clinical trial evidence that the risk of CHD will be reduced.In type 1 diabetes, but particularly in type 2 diabetes, lipid disorders are likely to contribute significantly to the increased risk of macrovascular complications, especially CHD. Management of the disordered lipid metabolism should be given a high priority in the clinical care of all patients with diabetes.

Non-invasive measures of tissue autofluorescence are increased in Type 1 diabetes complications and correlate with a non-invasive measure of vascular dysfunction

Diabet. Med. 29, 726–733 (2012)

Australian Aboriginal people and Torres Strait Islanders have an atherogenic lipid profile that is characterised by low HDL-cholesterol level and small LDL particles

AIM To characterise lipid profiles for Australian Aboriginal people and Torres Strait Islanders. METHODS Community-based, cross-sectional surveys in 1995-1997 including: 407 female and 322 male Australian Aboriginal people and 207 female and 186 male Torres Strait Islanders over 15 years old. A comparator of 78 female (44 with diabetes) and 148 male (73 with diabetes) non-indigenous participants recruited to clinical epidemiological studies was used. Lipids were determined by standard assays and LDL diameter by gradient gel electrophoresis. RESULTS Diabetes prevalence was 14.8% and 22.6% among Aboriginal people and Torres Strait Islanders, respectively. LDL size (mean [95% CI (confidence interval)]) was smaller (P<0.05) in non-diabetic Aboriginal (26.02 [25.96-26.07] nm) and Torres Strait Islander women (26.01 [25.92-26.09] nm) than in non-diabetic non-indigenous women (26.29 [26.13-26.44] nm). LDL size correlated (P<0.0005) inversely with triglyceride, WHR, and fasting insulin and positively with HDL-cholesterol. HDL-cholesterol (mean [95% CI] mmol/L) was lower (P<0.0005) in indigenous Australians than in non-indigenous subjects, independent of age, sex, diabetes, WHR, insulin, triglyceride, and LDL size: Aboriginal (non-diabetic women, 0.86 [0.84-0.88]; diabetic women, 0.76 [0.72-0.80]; non-diabetic men, 0.79 [0.76-0.81]; diabetic men, 0.76 [0.71-0.82]); Torres Strait Islander (non-diabetic women, 1.00 [0.95-1.04]; diabetic women, 0.89 [0.83-0.96]; non-diabetic men, 1.00 [0.95-1.04]; diabetic men, 0.87 [0.79-0.96]); non-indigenous (non-diabetic women, 1.49 [1.33-1.67]; diabetic women, 1.12 [1.03-1.21]; non-diabetic men, 1.18 [1.11-1.25]; diabetic men, 1.05 [0.98-1.12]). CONCLUSIONS Indigenous Australians have a dyslipidaemia which includes small LDL and very low HDL-cholesterol levels. The dyslipidaemia was equally severe in both genders. Strategies aimed at increasing HDL-cholesterol and LDL size may reduce high CVD risk for indigenous populations.

Roles and relationships between health professionals involved in insulin initiation for people with type 2 diabetes in the general practice setting: a qualitative study drawing on relational coordination theory

BackgroundThe majority of care for people with type 2 diabetes occurs in general practice, however when insulin initiation is required it often does not occur in this setting or in a timely manner and this may have implications for the development of complications. Increased insulin initiation in general practice is an important goal given the increasing prevalence of type 2 diabetes and a relative shortage of specialists. Coordination between primary and secondary care, and between medical and nursing personnel, may be important in achieving this. Relational coordination theory identifies key concepts that underpin effective interprofessional work: communication which is problem solving, timely, accurate and frequent and relationships between professional roles which are characterized by shared goals, shared knowledge and mutual respect. This study explores roles and relationships between health professionals involved in insulin initiation in order to gain an understanding of factors which may impact on this task being carried out in the general practice setting.Method21 general practitioners, practice nurses, diabetes nurse educators and physicians were purposively sampled to participate in a semi-structured interview. Transcripts of the interviews were analysed using framework analysis.ResultsThere were four closely interlinked themes identified which impacted on how health professionals worked together to initiate people with type 2 diabetes on insulin: 1. Ambiguous roles; 2. Uncertain competency and capacity; 3. Varying relationships and communication; and 4. Developing trust and respect.ConclusionsThis study has shown that insulin initiation is generally recognised as acceptable in general practice. The role of the DNE and practice nurse in this space and improved communication and relationships between health professionals across organisations and levels of care are factors which need to be addressed to support this clinical work. Relational coordination provides a useful framework for exploring these issues.

An exploratory trial of basal and prandial insulin initiation and titration for type 2 diabetes in primary care with adjunct retrospective continuous glucose monitoring: INITIATION study

AIMS To evaluate basal and prandial insulin initiation and titration in people with type 2 diabetes mellitus (T2DM) in primary care and to explore the feasibility of retrospective-continuous glucose monitoring (r-CGM) in guiding insulin dosing. The new model of care features General Practitioners (GPs) and Practice Nurses (PNs) working in an expanded role, with Credentialed Diabetes Educator - Registered Nurse (CDE-RN) support. METHODS Insulin-naïve T2DM patients (HbA1c >7.5% [>58 mmol/mol] despite maximal oral therapy) from 22 general practices in Victoria, Australia commenced insulin glargine, with glulisine added as required. Each was randomised to receive r-CGM or self-monitoring of blood glucose (SMBG). Glycaemic control (HbA1c) was benchmarked against specialist ambulatory patients referred for insulin initiation. RESULTS Ninety-two patients mean age (range) 59 (28-77) years; 40% female; mean (SD) diabetes duration 10.5 (6.1) years participated. HbA1c decreased from (median (IQR)) 9.9 (8.8, 11.2)%; 85 (73, 99) mmol/mol to 7.3 (6.9, 7.8)%; 56 (52, 62) mmol/mol at 24 weeks (p < 0.0001). Comparing r-CGM (n = 46) with SMBG (n = 42), there were no differences in major hypoglycaemia (p=0.17) or ΔHbA1c (p = 0.31). More r-CGM than SMBG participants commenced glulisine (26/48 vs. 7/44; p < 0.001). Results were comparable to 82 benchmark patients, with similar low rates of major hypoglycaemia (2/89 vs. 0/82; p = 0.17) and less loss to follow up in the INITIATION group (3/92 vs. 14/82; p = 0.002). CONCLUSIONS Insulin initiation and titration for T2DM patients in primary care was safe and improved HbA1c with low rates of major hypoglycaemia. CDE-RNs were effective in a new consultant role. r-CGM use in primary care was feasible and enhanced post-prandial hyperglycaemia recognition. Trial registration ACTRN12610000797077.

Plasma 1,5 anhydroglucitol levels, a measure of short-term glycaemia: Assay assessment and lower levels in diabetic vs. non-diabetic subjects

An assay of plasma 1,5-anhydroglucitol was evaluated. Assay CVs, effects of four plasma freeze-thaw cycles, glucose up to 80 mmol/L and triglycerides up to 20 mmol/L were acceptable. 1,5-anhydroglucitol levels were significantly lower in diabetic vs. non-diabetic subjects and correlated inversely with renal function, but not with HbA1c.

Stepping up: a nurse-led model of care for insulin initiation for people with type 2 diabetes

BACKGROUND Most people with type 2 diabetes (T2D) have glycaemic levels outside of target. Insulin is effective in improving glycaemia and most people with T2D eventually need this. Despite this, transition to insulin therapy is often delayed in primary care. OBJECTIVE To develop a model of care (Stepping Up) for insulin initiation in routine diabetes care in Australian general practice. To evaluate the model for feasibility of integration within routine general practice care. METHODS Drawing on qualitative work and normalisation process theory, we developed a model of care that included clarification of roles, in-practice systems and simple clinical tools. The model was introduced in an educational and practice system change intervention for general practitioners (GPs) and practice nurses (PNs). Five practices (seven GPs and five PNs) and 18 patients formed the feasibility study. Evaluation at 3 and 12 months explored experiences of GPs, PNs and patients. RESULTS Fourteen patients commenced insulin, with average HbA1c falling from 8.4% (68.3 mmol/mol) to 7.5% (58.5 mmol/mol) at 3 months. Qualitative evaluation highlighted how the model of care supported integration of the technical work of insulin initiation within ongoing generalist GP care. Ensuring peer support for patients and issues of clinical accountability and flexibility, managing time and resources were highlighted as important. CONCLUSIONS The Stepping Up model allowed technical care to be embedded within generalist whole-person care, supported clinicians and practice system to overcome clinical inertia and supported patients to make the timely transition to insulin. Testing of the models effectiveness is now underway.

Can primary care team-based transition to insulin improve outcomes in adults with type 2 diabetes: the stepping up to insulin cluster randomized controlled trial protocol

BackgroundType 2 diabetes (T2D) brings significant human and healthcare costs. Its progressive nature means achieving normoglycaemia is increasingly difficult, yet critical to avoiding long term vascular complications. Nearly one-half of people with T2D have glycaemic levels out of target. Insulin is effective in achieving glycaemic targets, yet initiation of insulin is often delayed, particularly in primary care. Given limited access to specialist resources and the size of the diabetes epidemic, primary care is where insulin initiation must become part of routine practice. This would also support integrated holistic care for people with diabetes. Our Stepping Up Program is based on a general practitioner (GP) and practice nurse (PN) model of care supported appropriately by endocrinologists and credentialed diabetes educator-registered nurses. Pilot work suggests the model facilitates integration of the technical work of insulin initiation within ongoing generalist care.MethodsThis protocol is for a cluster randomized controlled trial to examine the effectiveness of the Stepping Up Program to enhance the role of the GP-PN team in initiating insulin and improving glycaemic outcomes for people with T2D. 224 patients between the ages of 18 and 80 years with T2D, on two or more oral hypoglycaemic agents and with an HbA1c ≥7.5% in the last six months will be recruited from 74 general practices. The unit of randomization is the practice.Primary outcome is change in glycated haemoglobin HbA1c (measured as a continuous variable). We hypothesize that the intervention arm will achieve an absolute HbA1c mean difference of 0.5% lower than control group at 12 months follow up. Secondary outcomes include the number of participants who successfully transfer to insulin and the proportion who achieve HbA1c measurement of <7.0%. We will also collect data on patient psychosocial outcomes and healthcare utilization and costs.DiscussionThe study is a pragmatic translational study with important potential implications for people with T2D, healthcare professionals and funders of healthcare though making better use of scarce healthcare resources, improving timely access to therapy that can improve disease outcomes.Trial registrationAustralian and New Zealand Clinical Trials Registry ACTRN12612001028897