- Both high blood pressure and chronic kidney disease are common complications of diabetes.
- If blood pressure is well controlled, this can help kidney slow the progression of diabetic disease.
- Several medications are used to control blood pressure, among them dihydropyridine calcium-channel-blockers (DCCBs).
- However, a new study suggests that this blood pressure treatment could speed up the progression of diabetic kidney disease in people with type 2 diabetes.
People with type 2 diabetes often also have hypertension (high kidney blood pressure), which increases their risk of developing chronic kidney disease and failure.
However, controlling blood pressure is effective in slowing the progression of kidney disease, as well as reducing the risk of cardiovascular events.
Now, a study presented at the 63rd European Renal Association Congress in Glasgow, United Kingdom, suggests that DCCBs could be associated with poorer kidney outcomes in people with type 2 diabetes.
The research found that DCCB use was associated with a 33% higher risk of major adverse kidney events, when compared with other hypertension treatments used with people with type 2 diabetes.
These findings are yet to appear in a peer-reviewed journal.
The Association of British Clinical Diabetologists (ABCD) told Medical News Today:
“Treatment of hypertension is crucial in the management of diabetic kidney disease (DKD). While treatment of hypertension with drugs that block the renin-angiotensin system (RAS) is of proven benefit in reducing progression of DKD, many patients require additional antihypertensive agents to achieve blood pressure targets. Dihydropyridine Calcium Channel Blockers (DCCB) are often used second or third line in many patients with DKD.”
“This data suggests that DCCBs may be associated (with) a more rapid progression of kidney disease in such patients. This is, of course, important and concerning. There may, however, be many confounders, and the findings need to be replicated in larger cohorts, ideally prospectively, before guidelines should be significantly changed,” they added.
High blood pressure and diabetic kidney disease
Diabetic kidney disease develops when persistently high blood glucose, which results from poorly controlled type 2 diabetes, damages small blood vessels in the kidneys, meaning that they cannot filter waste products from the blood effectively.
If people also have high blood pressure, this accelerates the condition, damaging the kidneys further.
People with type 2 diabetes are commonly treated with 2 medications to control blood pressure and help the functioning of the kidneys.
RASi are the first-line treatment for hypertension, and SGLT2i lower blood glucose and protect both the cardiovascular system and kidneys.
However, these two treatments are often not enough to control blood pressure, so clinicians prescribe additional blood pressure treatments, such as the widely used DCCBs.
Although DCCBs are highly effective in controlling kidney blood pressure, this new study suggests that they may actually increase risk of diabetic disease progression.
Benaya Rozen-Zvi, MD, principal investigator of this research and Director of the Nephrology Department at Rabin Medical Center, Petah Tikva, and Clinical Associate Professor, Tel Aviv University, Israel, told us that:
“These results are of significant clinical importance, given that more than 80% of patients with chronic kidney disease (CKD) also suffer from hypertension. Selecting the appropriate antihypertensive treatment is critical, as it can directly influence the rate of kidney disease progression.”
Possible increase in kidney disease risk
In this study, researchers analyzed data from 31,041 adults with type 2 diabetes between 2016 and 2021. All patients were being treated with RASi and SGLT2i to control their blood pressure and blood glucose levels, plus another medication for blood pressure control.
Of the group, 11,841 (38.1%) were also receiving DCCB, and 19,200 (61.9%) a non-DCCB anti-hypertensive therapy. During a median follow up of 3.5 years, 482 patients experienced a major adverse kidney event, and 2,066 patients died.
Rozen-Zvi explained that most of these deaths were not due to kidney disease: “Because mortality in this population is primarily driven by cardiovascular disease or infections, the number of deaths directly attributed to kidney disease itself is low. However, it is important to note that the risk of cardiovascular mortality is increased several-fold in diabetic patients who have concurrent kidney disease.”
A 2022 study comparing almost 10,000 patients with type 2 diabetes who took DCCBs to almost 10,000 non-DCCB users suggested that DCCBs could reduce the risk of advanced chronic kidney disease, or end stage renal disease.
However, this latest study found that those on DCCBs had a higher risk of their kidney disease progressing to a major adverse kidney event than those taking other blood pressure medications.
Timna Agur, lead author of the study, Nephrology Department at Rabin Medical Center, Petah Tikva, and Gray Faculty of Medical and Health Sciences, Tel Aviv University noted in a press release that the “findings raise important questions about whether these medications are always the best option for patients already receiving modern kidney-protective therapies.”
Further research needed to verify findings
ABCD cautioned that several unknowns still remain, and the findings of the study require rigorous replication and verification. Speaking to MNTthey said that “residual confounding cannot be controlled for, and indication bias may (still) be present.”
Rozen-Zvi also told us that, as this was an observational study, the authors could not make definitive clinical recommendations about whether DCCBs should be used for patients with type 2 diabetes.
He advised that “patients on these combined therapies should consult their treating physicians to determine the most optimal blood pressure management strategy for their specific case.”
The team is currently planning further studies to evaluate this research question within a non-diabetic population.
How can people with type 2 diabetes lower their blood pressure?
Type 2 diabetes and hypertension, which is twice as common in those with type 2 diabetes as in people without the condition, are risk factors for coronary artery disease, cerebrovascular disease, renal failure and congestive heart failure, so both need to be treated effectively to reduce the risks of these complications.
The first step in lowering blood pressure is lifestyle changes — weight loss, a high potassium and low sodium diet, such as the
However, if lifestyle changes are insufficient to attain healthy blood pressure, clinicians have a range of treatments at their disposal.
Rozen-Zvi said that thiazide diuretics were an alternative to DCCB that could be used alongside RASi and SGLT2i, telling MNT they are “safe and effective options that can be used in combination with these therapies. However, they sometimes require careful monitoring of the glomerular filtration rate (GFR) and serum electrolytes following the initiation of treatment.”
As with all medications, he stressed that patients should only change their treatment following advice from their physician.
