People with type 1 diabetes whose blood pressure is low are less likely to develop chronic kidney disease, new research has found.
The long term study led by a team at UC San Francisco in the United States compared blood pressure control and kidney health in almost 1,500 people with type 1 diabetes over more than two decades.
The researchers pointed out that chronic kidney disease is one of the leading causes of increased mortality for people with type 1 diabetes. And according to the National Kidney Foundation 30% of people with type 1 diabetes and 10% to 40% of those with type 2 diabetes typically developing kidney problems as some point in their lives.
While the researchers said further study would be needed to prove causation, the finding is an important first step in exploring the issue said senior study author Chi-Yuan Hsu, a professor of medicine and chief of the Nephrology Division at UCSF Medical Centre. The research also questions whether current guidelines on blood pressure for diabetics are strict enough.
Hsu pointed out that the new findings contrast sharply with the recent relaxation of aggressive blood pressure targets for diabetes patients recommended by the American Diabetes Association (ADA) and NIH Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC).
In 2014, these groups relaxed acceptable blood pressure targets for patients with diabetes, replacing the relatively conservative recommendation to maintain blood pressure below 130/80 mm Hg with a more permissive target of keeping blood pressure below 140/90 mm Hg, citing a lack of evidence that more intensive blood pressure control improved health outcomes in diabetics.
However, nephrologist Elaine Ku, an assistant professor of medicine at UCSF and lead author on the new study, is wary of these recommendations, which she says ignore the crucial difference between type 1 and type 2 diabetes.
Among other factors, Ku said, patients with type 1 diabetes, who are typically diagnosed in childhood or as young adults, may have a longer time to suffer potential kidney damage as a result of long term high blood pressure.
However, most of the existing studies of high blood pressure and diabetes focused on the more common type 2 diabetes, she said, and these are the studies upon which the ADA and JNC primarily based their recent recommendations.
‘We felt it was critical to better understand how blood pressure affects those with type 1 diabetes over the long term,’ said Ku who also directs the UCSF Nephrology Transition Clinic for adolescents and young adults with kidney disease.
She explained that the current study can only show a correlation between higher blood pressure and increased risk of kidney disease in those with type 1 diabetes. ‘It will take a long term randomised clinical trial to prove causation, but right now, this cohort is the best dataset I am aware of that allows us to even ask this question. The data suggest the current guidelines are not as strict as they should be for these patients,’ she added.
According to Ku the new research should be a wake-up call to conduct more long term studies of the effects of blood pressure on kidney health. ‘There’s been a lot of research focused on blood pressure, which makes us think we know what we’re doing. But in my practice as a nephrologist who sees both children and adults with chronic illnesses, I realise we don’t understand how blood pressure impacts people’s health in the long term nearly as well as we should,’ she pointed out.
The opinions expressed in this article do not necessarily reflect the views of the DiabetesForum.com Community and should not be interpreted as medical advice. Please see your doctor before making any changes to your diabetes management plan.