Impact of the metabolic syndrome on prevalence and survival in motor neuron disease: a retrospective case series

Metabolic dysfunction is an important factor in the pathogenesis of motor neuron disease, but its prevalence and association with survival in this disorder is unknown. We hypothesized that patients with motor neuron disease would show a higher prevalence of metabolic syndrome compared to the general New Zealand population, and that metabolic syndrome would be associated with worsened survival. We undertook a retrospective analysis in 109 motor neuron disease patients diagnosed and treated at Waikato Hospital from 2013 to 2020. Demographic, clinical, and laboratory data were collected. Survival was defined as the date of initial symptom onset to the date of death. Of 104 eligible patients, 34 patients (33%) had metabolic syndrome (33% of Europeans, 46% of Māori). Mean survival in motor neuron disease patients with metabolic syndrome was significantly reduced compared to patients without metabolic syndrome (38 vs. 61 months, P = 0.044), with a 5-year survival rate of 21% for the former and 38% for the latter (P = 0.012). Compared with the general New Zealand population, metabolic syndrome is highly prevalent amongst motor neuron disease patients in the Waikato region and it is associated with worsened survival. Metabolic dysfunction may be a key factor underlying the pathogenesis of motor neuron disease.