Diabetic patients are at higher risk of kidney failure, but a new class of medication can help
Paula, 46, who has had Type 2 diabetes for nine years, recently came to consult me for her high blood sugar levels.
The mother of two wanted to exercise but her knees hurt when she walked due to her weight. She is 1.56m tall and weighed 78kg, giving her a body mass index of 32, which is in the obese range.
While going through the blood test results, she noticed the microalbumin reading was highlighted in red, indicating that it was "abnormal". She wanted to know what that meant. I paused for a moment to gather my thoughts.
Microalbumin refers to the presence of small amounts of protein in the urine. Normally, proteins are absent from urine. However, high blood sugar damages the kidney blood vessels and causes protein to seep out.
Gradually, more protein will leak and one's kidney function will deteriorate, ultimately causing the kidneys to fail.
Kidney failure is a much-feared complication of diabetes. Since 2015, diabetes has been the main cause of kidney failure, accounting for two-thirds of all new cases in Singapore.
There is a new class of medication for Type 2 diabetes called the SGLT2 inhibitors (sodium-glucose cotransporter 2 inhibitors). It allows more sugar to be passed out in the urine, decreasing the blood sugar in the body. It also helps the person shed weight.
To make matters worse, the presence of protein in the urine is also a sign that the blood vessels in the body are not healthy. This means that Paula has a much higher risk of heart disease and stroke.
In Singapore, half of patients with heart attacks, and 37 per cent of those with stroke, have diabetes.
Who would have thought that a single bad test result can mean such an ominous outcome? I had to be extremely careful about how much to tell the patient.
Of course, I should not hide the facts from my patients.
However, I have learnt that sometimes telling them the bare truth without giving them any hope can greatly demoralise them.
Therefore, when I tell them the truth, I also offer them a solution.
I said to Paula: "That means that your kidneys have been slightly damaged by the diabetes. While your kidney function is still normal, if we do not do anything, it can turn bad."
Her face darkened noticeably. In an anxious tone, she asked: "Can anything be done?"
"Sure. The most important thing is to have good control of your diabetes and blood pressure," I replied. "So you must be mindful of what you eat, and start exercising regularly. Plus, we have new medication that can help."
I could see that she was somewhat encouraged by this piece of information.
Previously, a class of medication called the ARBs (angiotensin-2 receptor blockers) had been shown to protect the kidneys of patients with diabetes.
However, Paula's blood pressure was normal and, thus, the drug was not suitable for her.
Fortunately, there is a new class of medication for Type 2 diabetes called the SGLT2 inhibitors (sodium-glucose cotransporter 2 inhibitors). It allows more sugar to be passed out in the urine, decreasing the blood sugar in the body. It also helps the person shed weight.
In July last year, the Agency for Care Effectiveness under the Ministry of Health (MOH) published a new set of guidelines on diabetic medication.
The guidelines encouraged the use of SGLT2 inhibitors in patients with low sugar levels, who are overweight or obese, or have heart disease or stroke.
MOH had deemed the class of medication cost-effective and now provides a subsidy for this relatively costly medication. Its price ranges from $90 to $120 a month.
A recently concluded international trial involving 26 countries showed that canagliflozin, one of the SGLT2 inhibitors, was able to preserve the patient's kidneys, sidestepping the need for dialysis and averting death. The study also showed that patients on canagliflozin had fewer complications from their heart disease and stroke.
So, I prescribed canagliflozin for Paula. As SGLT2 inhibitors can increase the amount of urine passed and may therefore cause dehydration, I told her to drink two litres of water daily to make sure she stays hydrated.
When she came to see me a few months later, her diabetes was under control, and there were fewer traces of protein in her urine.
She had also lost 8kg and found it much easier to walk around.
I continue to encourage her to be even more physically active, knowing that her kidneys and her heart were well protected.
•The writer is a consultant endocrinologist at Mount Elizabeth Hospital.
A version of this article appeared in the print edition of The Straits Times on January 09, 2018, with the headline 'Fighting protein leak in urine'. Print Edition | Subscribe
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