Type 2 is the most common form of diabetes mellitus and effects over 200,000 people in Ireland, mainly in people aged over 40 years at diagnosis. It consists of single or multiple dysfunctions resulting in hyperglycaemia, ie, a combination of resistance to insulin action, inadequate insulin secretion, and excessive or inappropriate glucagon secretion.
Glucose control remains the key outcome focus in the management of type 2 diabetes. However, this should always be in the context of a comprehensive cardiovascular risk factor reduction programme, to include smoking cessation and the adoption of other healthy lifestyle habits, blood pressure control, lipid management with priority to statin medications and, in some circumstances, antiplatelet therapy. Studies have conclusively determined that reducing hyperglycaemia decreases the onset and progression of microvascular complications. The impact of glucose control on cardiovascular complications remains unclear but there is some evidence that many years of improved control may have a modest benefit. Results from large trials have also suggested that overly aggressive control in older patients with more advanced disease may present different risk. Therefore, individualised target setting is necessary, balancing the benefits of glycaemic control with its potential risks, taking into account age, status, quality-of-life and living arrangements.
The first-line treatment for diabetes control is encouraging healthy dietary intake, weight control and increasing physical activity, with earlier introduction recommended of oral medications and injectable medications and/or insulin, as required in up to one-third of cases. Other treatments include reducing blood pressure if it is high, lowering high cholesterol levels and also other measures to reduce the risk of complications.
The diet for a person with diabetes is a healthy eating diet with emphasis on intake of high fiber, low saturated fat and low refined sugar foods. For most people, the best diet is one consisting of the foods that they are currently eating with attention to portion control and reduction in saturated fats and refined sugars. Weight loss may not result in improved glycaemic control, but should be sought for general health improvements. A weight loss of greater than 5 per cent appears necessary for beneficial effects on HbA1c, lipids, and blood pressure. Modest weight losses of 5-10 per cent have been associated with significant improvements in cardiovascular disease risk factors (ie, decreased HbA1c levels, reduced blood pressure, increase in HDL cholesterol, decreased plasma triglycerides) in type 2 diabetes. Risk factor reduction was even greater with losses of 10-15 per cent of body weight. In some instances, reports of diabetes reversals have been reported from following extreme low-calorie diets for a short period. Prof Roy Taylor, Professor of Medicine and Metabolism, Newcastle University in the UK, has shown that following such a diet can reduce liver fat content, increase or re-establish liver insulin sensitivity and attain normal fasting blood glucose levels. Achieving this level of weight loss requires intense interventions, including major dietary restriction, regular physical activity, and frequent contact with professionals not currently achievable in the public healthcare system.
<h3><strong>Physical activity </strong></h3>
Most people with type 2 diabetes can benefit from increased activity. Aerobic exercise improves insulin sensitivity and may improve glucose control markedly. Physical activity of more than 150 minutes per week is associated with better glycaemic control only when combined with dietary modifications. In order to achieve benefits, a minimum of 210 minutes per week of moderate-intensity exercise or 125 minutes per week of vigorous-intensity exercise with no more than two consecutive days without training is recommended. Vigorous-intensity exercise is more time efficient and may also result in greater benefits in appropriate individuals with consideration of complications and contraindications. It is further recommended that two or more resistance training sessions per week (two to four sets of eight to 10 repetitions) should be included as the inclusion of both aerobic and resistance training are necessary to achieve better lowering of HbA1c levels. Aerobic exercise alone or in combination with resistance training improves glycaemic control, circulating triglycerides, systolic blood pressure and waist circumference.
In order to sustain activity, the person should be encouraged to undertake an activity that she or he is likely to continue and preferably in the company of others to sustain momentum. Walking is accessible to nearly all people in terms of time, safety and financial expenditure.
Older people or patients with long-standing disease, multiple risk factors or with previous evidence of atherosclerotic disease should have a cardiovascular evaluation as part of their review to provide motivation and prove that an exercise regimen is possible and is safe for them.
<h3><strong>Bariatric surgery </strong></h3>
In morbidly obese patients, bariatric surgery has been shown to improve diabetes control and in some situations, normalise glucose tolerance. In 2016, the International Diabetes Federation Taskforce on Epidemiology and Prevention of Diabetes recommended bariatric surgery as an appropriate treatment for people with type 2 diabetes mellitus and obesity who have been unable to achieve recommended treatment targets using current medication options, particularly if other major comorbidities exist. In 60 patients with uncontrolled type 2 diabetes and moderate obesity, comparison of metabolic effects of the two types of bariatric surgery (Roux-en-Y gastric bypass or sleeve gastrectomy) combined with intensive medical therapy demonstrated that bariatric surgery improved glycaemic control overall, but the gastric bypass proved more effective in greater absolute reduction in truncal fat and improved insulin sensitivity.
Diabetes self-management education is the cornerstone of diabetes management and is an ongoing process of facilitating the knowledge, skill, motivation and ability necessary for diabetes self-care management. The overall objectives of diabetes education delivered individually or to groups are to support informed decision-making, improved self-management behaviors, problem-solving and active engagement with the diabetes team. There are three structured diabetes education programmes available free of charge for people with type 2 diabetes in Ireland approved and supported by the HSE.
Community Orientated Diabetes Education (CODE) for all people with type 2 diabetes or prediabetes facilitated by Diabetes Ireland nationwide through primary or secondary centres as demand dictates.
Diabetes Education and Self-Management for Ongoing and Newly Diagnosed (DESMOND) is for newly diagnosed type 2 diabetes delivered in some secondary centres nationwide and through community in the west.
X-PERT is for all people with diagnosed type 2 diabetes and is delivered at community level in 18 counties.
See www.hse.ie/eng/health/hl/living/diabetes for more information on available programmes. There is also an interactive online education programme for people with type 2 diabetes available on www.diabetes.ie/living-with-diabetes/living-with-type-2.
<h3><strong>Diabetes glucose targets</strong></h3>
Ideally, blood glucose should be maintained to achieve HbA1c levels of 53mmol/l or less. However, aggressive glucose lowering may not be the best strategy in all patients. Individual risk assessment and goal setting is highly recommended. Lowering HbA1c to 53mmol/l or lower may increase the risk of cardiovascular events in people who are at high-risk for cardiovascular disease. The ACCORD Study Group found that setting the treatment target for HbA1c below 6 per cent (40mmol/l) in high-risk patients resulted in reduced five-year non-fatal myocardial infarctions, but that people who did not achieve the treatment target experienced increased five-year mortality.
At each professional interaction, regardless of which healthcare professional they see, people with diabetes should be educated about and encouraged to follow their diabetes management plan and achieving goals should be discussed. Adherence to diet and exercise should continue to be stressed throughout the interaction because these lifestyle measures can have a large effect on the degree of diabetic control that patients can achieve. There is evidence that more frequent interaction with healthcare professionals where diabetes is discussed leads to improvements in serum glucose, HbA1c, and low-density lipoprotein (LDL) cholesterol levels.
<h3><strong>Pharmacologic therapy for hyperglycaemia</strong></h3>
Early initiation of pharmacologic therapy is associated with improved glycaemic control and reduced long-term complications in type 2 diabetes. There are multiple drug classes used for the treatment of type 2 diabetes.
Metformin lowers basal and postprandial plasma glucose levels by decreasing hepatic gluconeogenesis production, slowing intestinal absorption of glucose and improves insulin sensitivity by increasing peripheral glucose uptake and utilisation. Unlike oral sulfonylureas, metformin rarely causes hypoglycaemia and is the only oral diabetes drug that facilitates modest weight loss. In addition, the UK Prospective Diabetes Study (UKPDS) demonstrated that it was successful at reducing macrovascular disease in obese patients.
Sulfonylureas stimulate insulin release from pancreatic beta cells and enhance peripheral sensitivity to insulin secondary to an increase in insulin receptors or to changes in the events following insulin-receptor binding. Sulfonylureas are indicated for use as additional supports to diet and physical activity in adult patients with type 2 diabetes. They are generally well-tolerated, with hypoglycaemia the most common side effect.
Meglitinides (Repaglinide) are short-acting insulin secretagogues, with their shorter action time and preprandial dosing potentially achieving more normal insulin release and low risk of hypoglycaemia, provided adherence is maintained to the ‘no food/ no tablet’ regime.
Alpha-glucosidase inhibitors (Acarbose) delay sugar absorption and help to prevent postprandial glucose fluctuations by prolonging the absorption of carbohydrates. However, the side effect of increased flatulence greatly limits their use.
Thiazolidinediones (pioglitazone) act as insulin sensitisers and as such require the presence of insulin to work. They must be taken for 12-16 weeks to achieve maximal effect and are prescribed as monotherapy or in combination with sulfonylurea, metformin, meglitinide, DPP-4 inhibitors, GLP-1 receptor agonists, or insulin.
<strong><em>Glucagon-like peptide-1 agonists</em></strong>
GLP-1 agonists (ie, exenatide, liraglutide, dulaglutide) stimulate glucose-dependent insulin release, reduce glucagon, and slow gastric emptying by mimicking the endogenous incretin GLP-1. The use of a GLP-1 in addition to metformin and/or a sulfonylurea may result in modest weight loss.
<strong><em>Dipeptidyl peptidase-4 inhibitors</em></strong>
DPP-4 inhibitors (eg, sitagliptin, vildagliptin, saxagliptin, linagliptin) prolong the action of incretin hormones by blocking endogenous DPP-4 from degrading the endogenous glucagonlike peptide and glucose-dependent insulinotropic polypeptide. DPP-4 inhibitors can be used as a monotherapy or in combination with metformin or thiazolidinediones
<strong><em>Selective sodium-glucose transporter-2 inhibitors</em></strong>
SGLT-2 inhibition lowers the renal glucose threshold (ie, the plasma glucose concentration that exceeds the maximum glucose reabsorption capacity of the kidney), resulting in increased urinary glucose excretion at the expense of urinary symptoms/infection risk.
Ultimately, many people with type 2 diabetes will require insulin and if insulin resistant, small changes in insulin dosage may make no difference in glucose control, which requires individualised therapy in each patient. Long-acting insulin analogues are most effective for lowering fasting glucose whereas premixed analogues are more effective in lowering postprandial glucose but at the expense of increasing the incidence of hypoglycaemia and can be associated with weight gain.
<h3><strong>Blood pressure control</strong></h3>
More than 60 per cent of people diagnosed with type 2 diabetes have elevated blood pressure. Treatment should be initiated to a target of less than 140/80 mmHg for most people with type 2 diabetes but for younger individuals, a target of 130/80mmHg should be considered. For people with co-morbidity, eg, renal disease, a higher or lower systolic pressure may be appropriate. The individual should be encouraged to eat a low salt diet and reduce alcohol intake along with normal lifestyle recommendations.
High cholesterol levels are common among people with type 2 diabetes. Based on the LDL cholesterol target, lipid profiles should be checked every four months and medication titrated accordingly. Most people with diabetes have some kind of dyslipidaemia which combined with hyperglycaemia increase cardiovascular risk. Statins are very commonly used and they can reduce cardiovascular disease risk by up to 20 to 30 per cent. In diabetes, statins are indicated for all people with cardiovascular disease and primary prevention of cardiovascular disease in people over 40 years with one other cardiovascular risk factor (hypertension, albuminuria, etc) irrespective of lipid profile. The primary focus is on LDL cholesterol and using statins to achieve target levels unless contraindicated, eg, female planning a pregnancy.
<h3><strong>Complication surveillance </strong></h3>
Regular patient review is necessary to support self-management, review diabetes control and promote diabetes management with the focus on preventing diabetes complications, but equally there is a need for strong vigilance in the early detection of microvascular and macrovascular complications.
Current indications are that visual impairment due to retinopathy in Ireland has almost doubled whereas the rate of blindness from retinopathy has almost halved from 2004 to 2013. All people with diagnosed diabetes over 12 years of age are entitled to free retinal screening as part of Diabetic RetinaScreen (www.diabeticretinascreen.ie) and should be actively encouraged to attend all appointments as non-attendance is a risk factor for negative outcomes.
The majority of cases of diabetic nephropathy present with proteinuria, which progressively gets worse as the disease progresses, and is almost uniformly associated with hypertension. Up to 3 per cent of individuals will have overt nephropathy at diagnosis of type 2 diabetes and rates increase with duration of diabetes.
The results of the RENAAL trial underscore the importance of reducing dietary salt intake generally, but particularly in people with diabetes and angiotensin receptor blocker (ARB)-treated nephropathy, as sodium intake reduction enhances the renoprotective and cardioprotective effect of ARBs.
Type 2 diabetes is a major risk factor for cardiovascular disease, and the presence of both type 2 diabetes and cardiovascular disease increases the risk of death. A multifaceted approach of intensive glucose control, combined with blood pressure control and lipid lowering is necessary to make improvements in the rate of cardiovascular events.
Lower-limb ischaemia caused by peripheral arterial disease (PAD) is the major risk factor for foot ulceration and amputation, therefore, it is vital to control the risk factors of PAD – older age, cigarette smoking, poor glucose control, hypertension and hyperlipidaemia. Annual full foot assessment should be carried out with referral to the community diabetes podiatrist of all people with moderate to high-risk feet. See <strong>Diagram 1</strong> for a suggested template of what should be covered and frequency.
Type 2 diabetes is an epidemic in Ireland and is set to escalate in future years. Its long-term consequences result in enormous human suffering and economic costs and currently this is where the diabetes budget is being utilised. Based on best practice, this can change with early diagnosis and earlier education and pharmacological interventions to manage blood glucose, blood lipids and blood pressure rather than a unilateral focus on glycaemia. There are many new advances in diabetes management but the mainstay must remain lifestyle interventions with supportive interventions and ongoing surveillance through regular attendance for review. In order to maintain expert diabetes knowledge, regular attendance at study days offers the opportunity to hear from experts and view the latest technology by exhibitors.
<em>Diabetes Ireland is hosting a Paediatric Diabetes Study Day on 17 November 2017 at the Crowne Plaza Hotel, Santry. For further information contact Amanda Carrigan: </em><em>email@example.com</em><em> or call 01 842 8118.</em>