Protect your kidneys, save your heart
Dr Kevin Fernando, GP Partner and Educational Supervisor, North Berwick Health Centre, and Scottish Lead of the Primary Care Diabetes Society, gave a masterclass in managing chronic kidney disease with type 2 diabetes in primary care at the Society’s recent conference. Dr Susan Aldridge reports.
If someone with type 2 diabetes has an estimated glomerular filtration rate (eGFR) of less than 60, they are more at risk of ischaemic heart disease, cardiovascular disease and peripheral vascular disease and they also have higher cardiovascular mortality. People with chronic kidney disease (CKD) will also find it harder to reach their blood pressure target and be prone to ankle swelling and fluid retention, as well as having an increased risk of hip fracture. Finally, CKD is also an independent risk factor for hypoglycaemia, because insulin and other diabetes drugs are cleared from the body by the kidneys. When the kidneys aren’t working properly, these drugs stay in the body for longer. “Chronic kidney disease is very much the ‘canary in the coal mine’ and a harbinger of poor outcomes,” Kevin said. “So, the key message for us as healthcare professionals and our patients is: protect your kidneys, save your heart.”
This protection starts with the annual tests that all people with type 1 and type 2 diabetes should have – namely, eGFR, albumin:creatinine ratio (ACR) and a check for albuminuria.
CKD is classified by both eGFR (G1 to G5) and ACR (A1 to A3). “Increasing ACR and decreasing eGFR multiplies the risk of adverse outcomes,” Kevin said. “And, unfortunately, that combination of CKD and diabetes is like having had a heart attack previously – it’s a cardiovascular risk equivalent.”
Given how serious CKD can be, how often should we be checking eGFR? “That’s an individual decision, as it’s not progressive in many people. It should be done with respect to the stage of the disease,” Kevin advised. “My rule of thumb is that if someone has an eGFR below 60, check six monthly, if below 50, every five months, below 40, every four months and so on. I find this is a pragmatic approach to monitoring CKD in primary care.”
Delaying progression of CKD
An ACE inhibitor or an angiotensin receptor blocker should be offered to people with CKD stage A2 or A3 and diabetes, to people with hypertension and CKD stage A3, and to anyone with an ACR of more than 70 mg/mmol. This all comes from the updated NICE guidelines (the UK’s National Institute for Health and Care Excellence). These medications should be titrated to the maximum tolerated dose, but should not be offered as a combination as this comes with a high risk of acute kidney injury.
Besides these medications, what more can be done? “Our main role is the active detection and management cardiovascular risk factors, such as smoking. Statins should be prescribed according to NICE guidelines. And aim for blood pressure less than 130/80. Check blood pressure when the person is standing and lying down, and use the standing measurement,” said Kevin. “Aspirin and clopidogrel can be used for secondary prevention, but opinion varies for primary prevention. My own practice is not to offer aspirin for primary prevention but absolutely to do so for secondary prevention.”
When it comes to HbA1c targets in CKD, there is little evidence that tight control of less than 53 mmol/mol reduces progression. And there is potential harm – as this might risk hypoglycaemia. “As always, we need to individualise targets for HbA1c when it comes to CKD,” said Kevin.
Kevin finished his masterclass by talking about one of the big new changes in the management of CKD in people with, and without, type 2 diabetes. The new NICE guideline on CKD recommends suggests adding an SGLT-2 inhibitor if the ACR is over 30 mg/mmol.
“We have had compelling data published suggesting that SGLT-2 inhibitors can directly reduce the progression of CKD. They can directly reduce the risk of major adverse renal outcomes, including the requirement for renal replacement therapy,” said Kevin. Pivotal studies, like CREDENCE and DAPA-CKD, have compellingly demonstrated the renal protective effects of SGLT-2. “Also the ADA/EASD guidelines tell me that for my patients with type 2 diabetes living with CKD, I should consider SGLT-2 inhibitors with their proven renal benefits, irrespective of their HbA1c. So, this is a big change in approach in how we’ve been managing CKD in those living with type 2 diabetes.”
The DAPA-CKD trial also showed benefits in people without type 2 diabetes, so NICE might update their guidelines accordingly. Kidney Disease: Improving Global Outcomes has also adopted a similar approach, so guidelines are changing around the world. “This is a big change in practice for us,” Kevin concluded. “The SGLT-2 inhibitors have the potential to improve both quality and quantity of life for people living with type 2 diabetes and CKD and, indeed, for people with CKD without diabetes too.”
Any opinions expressed in this article are the responsibility of the EASD e-Learning Programme Director, Dr Eleanor D Kennedy.