The UK Prospective Diabetes Study (UKPDS; UKPDS Group 1998a) provided convincing proof of the value of good glycaemic control in type 2 diabetes. This article summarises the options for managing glycaemia in the primary care setting–from nutritional and exercise approaches to the use of oral agents and insulin therapy.

There is high quality evidence from randomised controlled trials in both type 1 and type 2 diabetes to show that intensive control of blood glucose (giving Hb[A.sub.1c] measurements of 7% or less) reduces the risk of adverse outcomes. The evidence in type 1 diabetes comes from the Diabetes Control and Complications Trial (DCCT; DCCT Research Group, 1993), in which an intensively controlled group with an average Hb[A.sub.1c] of 7% had a 47% reduced risk of severe retinopathy, a 54% reduced risk of developing microalbuminuria and a 60% reduced risk of neuropathy compared with a standard treatment group who had an Hb[A.sub.1c] of 9%.

In type 2 diabetes, the United Kingdom Prospective Diabetes Study (UKPDS) provided convincing proof of the value of good glycaemic control (UKPDS Group, 1998a). In the study, 5102 people with newly diagnosed type 2 diabetes were initially managed with 3 months’ diet treatment. Then 4209 of these who were asymptomatic and had fasting plasma glucose levels between 6 and 15 mmol/l were randomised into an intensively treated group, who had an average Hb[A.sub.1c] of 7.9%, and a conventionally treated group, who had an average Hb[A.sub.1c] of 7%. Follow up was for 12 years on average. The intensive group had 12% less risk of any diabetes-related adverse endpoints, 25% fewer adverse microvascular endpoints and 16% fewer myocardial infarctions (this figure for major macrovascular outcomes did not reach statistical significance). Neither sulphonylurea nor insulin therapy showed any advantage over the other, but a group of obese patients randomised to metformin had substantially better macrovascular outcomes (UKPDS Group, 1998b).

This UKPDS glycaemic data has also been published in an epidemiological form in which it can be shown that adverse outcomes are reduced given any reduction in Hb[A.sub.1c] level even if a target of 7% is not reached, and thus a reduction of Hb[A.sub.1c] from 10% to 9% is of benefit (Stratton et al, 2000).

The diabetes section of the Quality and Outcomes Framework of the new General Medical Services (nGMS) contract for general practitioners recognises the importance of glycaemic control in diabetes by giving 30 points for glycaemic control: 3 for Hb[A.sub.1c] process measurements and 27 for reaching Hb[A.sub.1c] quality targets (British Medical Association, 2003).

Achieving good glycaemic control: The role of nutrition and exercise

The emphasis today in diabetes is away from the concept of diet, towards the concept of healthy eating. This concept of healthy eating is important for all people and its adoption by all members of the family will help in management.

A simple written guide can be used to reinforce healthy eating messages. A full assessment can be given by a dietitian for those who need more detailed advice.

Weight reduction in those who are overweight is a vital part of type 2 diabetes management. There is clear evidence that weight reduction and exercise can prevent the onset of diabetes in people who are especially at risk (i.e. those with impaired glucose tolerance; Tuomilehto et al, 2001). Regular weighing and encouragement of weight loss (in those who are overweight) at each practice diabetes visit can help in this difficult area. Some people also benefit from attendance at peer-support groups such as ‘Weight Watchers’ and similar groups.

Encouraging exercise in diabetes is another vital part of good glycaemic control, and has been shown to help prevent the onset of diabetes in susceptible individuals (Tuomilehto et al, 2001).

It is important that advice about exercise should be realistic, simple, individualised, and enjoyable. Gentle walking for 20 minutes a day is a realistic goal in self-management for many people with diabetes. In parts of the UK ‘walking for exercise’ schemes have been established where people are invited to join in set walks which are organised and led by local volunteers.

It is usual to give most overweight people newly diagnosed with type 2 diabetes initial nutrition and exercise advice and to review them at 3 months to see if it has been successful at reducing Hb[A.sub.1c] levels to target.

If nutrition and exercise alone are not successful in giving good glycaemic control, oral agents need to be added.

Initial oral agent monotherapy NICE guidance on initial monotherapy choice

For those overweight: Metformin as initial monotherapy

The National Institute for Health and Clinical Excellence (NICE; formerly the National Institute of Clincal Excellence) guideline on glycaemic control in type 2 diabetes (NICE, 2002) recommends that metformin be the initial monotherapy of choice in all people who are overweight (defined as a body mass index [BMI] greater than 25 kg/[m.sup.2]).