Low phosphate in the blood is linked to the risk of heart attack and coronary artery disease, a study reports. Researchers from the University of Surrey found that insufficient levels of phosphate in the blood may pose a particular danger to cardiovascular health, contradicting previous research in this area, which suggested low volumes of the mineral was beneficial to the heart.
The study, using data from the RCGP Research and Surveillance Centre, examined phosphate levels of more than 100,000 patients, over five and nine-year intervals, and the impact on their cardiac health. The researchers found that those with low levels (below 0.75 mmol/L) of the mineral in their blood were at a similar risk of developing coronary problems as those with elevated levels (above 1.5 mmol/L). Instances of both conditions were high amongst those with low and excessive levels of phosphate in the blood, however cardiac events in those with mid-range (1-1.25 mmol/L) levels were significantly less.
Risks associated with high levels of phosphate in the blood have previously been proven by the scientific community, but this is the first time the dangers of low levels have been identified as potentially being just as dangerous.
Phosphate is an important mineral in the body and helps to regulate blood biochemistry, which can impact on the working of the heart. It plays a crucial role in enabling red blood cells to deliver oxygen to the body's tissues, and can be found in protein rich foods such as meat, poultry and fish.
Lead author Dr Nick Hayward, who conducted the research while at the University of Surrey, said: "The importance of phosphate in primary and secondary healthcare should be reviewed. It is often overlooked in blood tests yet phosphate may be a new risk factor for heart disease in adults."
Dr Andy McGovern from the University of Surrey said: "Our findings shed new light on the role of phosphate in the body and its relationship to cardiovascular health.
"In light of our findings we would suggest that clinicians consider people with low phosphate levels to be at higher cardiovascular risk and assess ways in which this can be reduced for each patient.
Abstract
Background: High serum phosphate is associated with coronary artery disease in patients with normal and impaired renal function. We asked: Does the serum phosphate range provide prediction of primary cardiac events? We extracted coded primary care data for over 100,000 patients from a database of 135 primary medical practices. Patients aged between 18 and 90 years without pre-existing cardiovascular diagnoses were included from a potential sample of over 1·2 million individuals.
Methods and findings: Binary logistic regression models were used to evaluate the contribution of QRISK factors and electrolytes, including serum phosphate, to cardiac outcomes at five and nine years following an initial phosphate measurement. At five-year review (n = 113,993), low serum phosphate (OR 1·75, 95%CI 1·36–2·23, p<0·001), high-normal (OR 1·50, 95%CI 1·29–1·74, p<0·001), and high serum phosphate (OR 1·74, 95%CI 1·06–2·70, p = 0·02) were long-term risk factors for primary cardiac disease events after adjusting for confounding variables. A similar pattern was seen at our nine-year review.
Conclusions: The extremes of serum phosphate may confer cardiac event risk with a U-shaped trend. In particular, we raise new cardiac concerns for low serum phosphate in the general population. Also, the normal range for phosphate may require redefinition among healthy adults.
Authors
Nicholas Hayward, Andrew McGovern, Simon de Lusignan, Nicholas Cole, William Hinton, Simon Jones
[link url="https://www.surrey.ac.uk/mediacentre/press/2017/heart-attacks-more-likely-those-low-blood-phosphate-levels"]University of Surrey material[/link]
[link url="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0184774"]PLOS One abstract[/link]