Kidney dysfunction predicts long-term mortality in young stroke patients
MedWire News: The presence of kidney dysfunction warns of a high long-term mortality risk in young patients with ischemic stroke, shows research.
Both low and high estimated glomerular filtration rates (eGFRs) were associated with increased mortality rates in 958 patients over almost 9 years of follow-up.
"Multifactorial preventive strategies in these high-risk patients with either established or early-stage kidney disease are warranted, including aggressive glycemic and blood pressure control and a reduction in alcohol intake," say Jukka Putaala (Helsinki University Central Hospital, Finland) and colleagues.
As reported in the journal Stroke, the patients in the current study were aged between 15 and 49 years at the time of their first ever ischemic stroke.
At baseline, 84.4% of patients had normal eGFR (60-120 ml/min per 1.73 m2), 4.5% had low eGFR (<60 ml/min per 1.73 m2), and 11.1% had high eGFR (>120 ml/min per 1.73 m2).
A total of 922 patients survived at least 30 days after stroke. Among these patients, 53.5% of those with low eGFR died during the longer-term follow-up, as did 15.3% of those in the high eGFR group, and 10.8% of those in the normal eGFR group.
This equated to significant 5.73- and 1.78-fold increases in mortality risk associated with low and high eGFR, respectively, relative to normal eGFR, after accounting for age, gender, stroke severity, and stroke subtype.
Recurrent stroke rates were significantly higher in the low eGFR group than in the high and normal eGFR groups, at 25.6% versus 11.2% and 12.5%, respectively.
Relative to patients with normal eGFR, those with low eGFR were significantly more likely to have Type 1 diabetes, hypertension, and cardiovascular disease. In contrast, those with high eGFR were more likely to have Type 2 diabetes, and more likely to be male, heavy drinkers, and younger than patients with normal kidney function.
Putaala et al suggest that patients with Type 1 diabetes already had advanced kidney disease, whereas those with Type 2 diabetes had only the early stages of diabetic vascular damage, explaining why Type 1 and 2 diabetes were associated with low and high eGFR, respectively.
They also note that their analysis of the primary causes of death of the patients does not "support the view that the excess mortality risk in young patients with ischemic stroke with either low or high eGFR is due to cardiovascular causes."
But they caution: "Because of the relatively low number of events, our study cannot draw firm conclusions on this issue."
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By Eleanor McDermid