Diabetes carries increased seizure risk in elderly
Diabetes mellitus appears to be an independent risk factor for seizures in elderly individuals, with the risk of seizures increasing with the number of comorbidities, a study from Italy has found.
Researchers used administrative databases of the Lombardy region in Northern Italy to identify diabetic, seizure-free individuals aged ≥65 years in 2002. All individuals were followed until 2012 for incident seizures. Cox proportional hazards regression models were used in the analysis, with adjustments for age classes, sex, comorbidities and number of hospital admission.
The population at risk consisted of 1,494,071 individuals, including 136,941 who had diabetes. The cumulative time-dependent incidence of seizures at the end of follow-up was 3 percent in the diabetes group vs 1.9 percent in the no-diabetes group (hazard ratio [HR], 1.47; 95 percent CI, 1.41 to 1.53). In the subgroup of patients with no history of stroke, the HR was 1.45 (1.38 to 1.53).
The incidence of seizures in individuals with no diabetes and no cardiocerebrovascular comorbidities was 1.8 percent, which increased to 2.8 percent in diabetic individuals without comorbidities, to 3.2 percent in nondiabetic individuals with at least one comorbidity, to 4.1 percent in diabetic individuals with one comorbidity and to 4.9 percent in diabetic individuals with two or more comorbidities.
Researchers noted that the increase in seizure risk that occurs with increasing number of comorbidities among diabetic patients supports the role of vascular disease as a cause of epilepsy in the elderly.
Hyperglycaemia and hypoglycaemia commonly occur in elderly patients with diabetes. These metabolic imbalances are said to alter the balance between excitation and inhibition of neural networks, potentially exerting a damaging effect on the central nervous system, leading to electroencephalogram abnormalities and epileptic seizures. [PLoS One 2013;8:e83168; Eur J Neurosci 2006;23:1512–1522]