Abstract
Introduction
Magnesium is essential for regulating cardiovascular, neuromuscular and respiratory functions. Hypomagnesemia in older adults is often overlooked and insufficiently managed. Inadequate monitoring and correction of hypomagnesemia may leave old and frail patients more vulnerable to acute cognitive decline which in some cases can be preventable.
This study assessed the current management of hypomagnesaemia in older adults admitted to the geriatric wards of an NHS Trust and its association with acute cognitive decline.
Methods
A retrospective review of old and frail patients admitted to geriatric wards across two hospital sites over a month was conducted. Patients aged 65 years or above and those aged between 55 to 64 with clinical frailty were included. Electronic records were used to compare acute cognitive outcomes in patients with hypomagnesaemia and those with normal magnesium levels. Multivariate analysis was performed to assess predictors of acute cognitive impairment.
Results
Of the 667 hospitalised older adult patients included in our study, 149 (22.3%) had hypomagnesaemia, while 518 (77.7%) had normal levels.
Among the 149 patients with low magnesium, 18 (12.2%) had moderate to severe deficiency (</= 0.5 mmol/L); of these, 27.8% received intravenous supplementation, 38.9% received oral supplementation and 33.3% received no treatment.
The remaining 131 patients had mild hypomagnesaemia (<0.7 mmol/L), 45 (34.4%) received some form of supplementation, while 86 (65.5%) had none.
Only 60 (40.3%) of all hypomagnesaemic patients had follow up magnesium levels checked.
In the multivariable logistic regression model, adjusting for age, sex and potential clinical confounders, patients with hypomagnesaemia had 2.35 times greater odds of developing acute cognitive deterioration (OR (Odds ratio) = 2.354; 95% CI ( Confidence interval) : 1.543–3.604; p < 0.001).
These findings suggest an independent association between hypomagnesaemia and cognitive decline, underscoring the need for improved recognition and management in clinical practice.
Conclusion
Hypomagnesaemia may be a significant contributor to acute cognitive impairment in old and frail patients.
Comments
Really interesting and…
Really interesting and something that is generally looked over on a busy ward round ! wonder if there is an optimum target for magnesium levels
Treatment
Did you look at frailty score?
Would a better measure be whether cognitive decline (delirium) could be reversed or prevented with adequate replacement?
In my service, detection of perturbed levels of calcium, magnesium and phosphate is part of delirium investigation (and correction, part of management).
HYPOMAGNESEMIA and DELIRIUM
As delirium in our elderly cohort is commonly multifactorial in nature, it is unlikely that optimum Magnesium replacement will prevent or reverse delirium in most frail patients with hypomagnesaemia, but it may reduce the severity of acute cognitive decline, the length of hospital stay and possibly result in a reduction in the overall incidence of delirium too,
It would be interesting to…
It would be interesting to see how long these patient had had low magnesium for, and whether acute changes in the levels are associated with onset of delirium. Probably difficult to check in patients who have presented with delirium and easier to assess in patients who develop delirium during their in patient stay. Equally, I wonder how much is it magnesium that contributes to delirium, compared to other acute factors, such as reduced oral intake, dehydration, and other electrolyte/nutritional abnormalities.
Hi, I completely agree with…
Hi, I completely agree with assessing whether acute hypomagnesaemia coincides with the onset of delirium as I believe it would potentially yield a greater accuracy in determining the independent association between the two! To address your second question, the OR of 2.35 was found from the multivariate analysis which we have used to adjust to 11 other acute confounders, including dehydration and other electrolyte abnormalities like you have proposed :)
Definition
It would be helpful to define hypomagnesaemia. Outside lower limit of reference range on blood testing? Corrected for albumin? Presence of associated hypokalaemia or hypocalcaemia (functional effects). The first definition alone is too loose a definition and maybe clinical deficiency should include the other factors?
Good effort by the authors…
Good effort by the authors. I have come across similar evidence that links magnesium levels with frailty, but there is very little to make a case for a magnesium supplementation in older people. Do you agree ? Do you think sarcopenia acts as a mediator in this ?