Taking its toll

The problem with getting diabetes - besides the actual disease itself - is that it leads to a whole range of other complications. Kidney disease, for example. New data from a comprehensive local study of 4,500 people shows that diabetes causes the bulk of kidney disease in Singapore. Singapore has seen a 50 per cent increase in type 2 diabetes in the last six years, in tandem with the rates of obesity. Now that there is a worldwide epidemic of diabetes - with one in nine adults under 70 years old having type 2 diabetes worldwide - doctors are advising early treatment to slow down the progress of diabetes' effect on resulting illness.

The key thing to realise is that once someone has diabetes, it will take its toll on the body, and it's important to manage diabetes to slow down the progression of complications, says Anthony Barnett, consultant physician, Heart of England NHS (National Health Service) Foundation Trust and Emeritus Professor of Medicine, University of Birmingham, UK. 'An estimated half of the people with diabetes have had it for years and they don't know it; until it is picked up late. There may be no significant symptoms in the early stages unless it is screened for,' says Prof Barnett, adding that by the time diabetes is detected, there could already be other complications.

'The earlier diabetes is detected, the less likelihood of long-term complications - that's certainly true for diabetes' effect on the kidneys. If controlled well, the risk of getting other damage is dramatically reduced,' he adds.

In the case of Singapore, where a majority of working professionals do get annual medical screenings, then it's also important to screen for kidney function particularly in people with diabetes. 'It's simple to do it - as a urine sample will show how much protein is excreted, and a blood test will show kidney function,' he says.

In the UK, diabetics are tested for their kidney function as part of their yearly review but it's not happening routinely in Singapore, Prof Barnett notes. He was in Singapore recently to introduce a new drug, linaglipin, which goes by the trade name Trajenta - a one-a-day oral drug for all type 2 diabetes patients, independent of their kidney or liver function.

The drug appeared to be safe for any stage of kidney disease, says Prof Barnett, who was involved in developing the drug. 'The problem with some classes of diabetes drugs is that they can cause hypoglycemia - which is caused by having more insulin in the body than required. It could happen when one is having insulin injections but not eating enough,' he explains. Some classes of oral drugs also improve glucose control in type 2 diabetes patients, but they work by making the pancreas secrete more insulin, and they're not glucose sensitive - this can also cause hypoglycaemia.

Managing diabetes

Managing diabetes includes having good glucose (sugar) control, which a lot of classes of drugs (such as insulin, sulfonylureas, glitazones ) can achieve but problems can arise because of side effects from these drugs - like weight gain and, for sulphonylureas and insulin, hypoglycaemia (sugar levels going too low which can be very distressing and even dangerous).

Linaglipin works by inhibiting an enzyme naturally produced in the body and this results in increased insulin production and reduction of another hormone called Glucagon which stimulates the liver to produce more glucose. The effect of linagliptin is seen only when sugar levels are high (that is, it is glucose sensitive) and therefore rarely causes any problems with hypoglycaemia (or indeed weight gain). 'By this means, it lowers glucose, with few side effects,' explains Prof Barnett.

High glucose levels damage blood vessels over time - the small vessels in the nerves, eyes and kidneys; and the larger vessels in the heart and brain. 'With good glucose control, the risk of getting small vessel problems can be reduced by nearly 40 per cent over a 10 year period and cardiovascular disease by around 20 per cent. Add this to good blood pressure and cholesterol control and not smoking, it is estimated that the risk of cardiovascular disease can be reduced by up to 70 per cent,' says Prof Barnett.

Another advantage of linaglipin is that it is excreted through bile and the gut and not through the kidneys, which is why it's safe for those who have impaired kidneys. One in three diabetic patients have reduced kidney functions, he highlights.

Because diabetes is a progressive disease, patients usually have to take drugs from different classes to manage it. Even detecting diabetes at an early stage and controlling it doesn't alter the natural history of the disease. 'Over time, it will progress as no drug will cure or prevent it. All we can do is to reduce the risk of complications,' Prof Barnett says, adding that's why one shouldn't get the disease to begin with.

'Natural history' refers to the beta cells in the pancreas, which produce insulin, becoming more dysfunctional over time. This process can't be changed with drugs, but glucose can be managed more effectively with these medicines and reduce the risks of complications. Critically, this means good sugar control and attention to other risk factors like not smoking, regular exercise and good blood pressure and cholesterol control.

The reason why there's an epidemic now is that people are putting on weight and not exercising enough. 'When I was a medical student, there were 30 million people with type 2 diabetes. Today, there are 300 million and it is getting worse! That's a tenfold increase in 30 years,' he underscores.

Among young people, there's also been a tenfold increase of those under 20 years old developing type 2 diabetes in the last 10 years. 'The real worry about the young developing diabetes is that they will lose more life years from the complications of diabetes,' says Prof Barnett.