Lifestyle and medical conditions in relation to ALS risk and progression-an introduction to the Swedish ALSrisc Study.

BACKGROUND: This study was an introduction to the Swedish ALSrisc Study and explored the association of lifestyle and medical conditions, with risk and progression of amyotrophic lateral sclerosis (ALS). METHODS: We included 265 newly diagnosed ALS patients during 2016-2022 in Stockholm and 207 ALS-free siblings and partners of the patients as controls. Information on body mass index (BMI), smoking, and history of head injuries, diabetes mellitus, hypercholesterolemia, and hypertension was obtained through the Euro-MOTOR questionnaire at recruitment. Patients were followed from diagnosis until death, invasive ventilation, or November 30, 2022. RESULTS: Higher BMI at recruitment was associated with lower risk for ALS (OR 0.89, 95%CI 0.83-0.95), especially among those diagnosed after 65 years. One unit increase in the average BMI during the 3 decades before diagnosis was associated with a lower risk for ALS (OR 0.94, 95%CI 0.89-0.99). Diabetes was associated with lower risk of ALS (OR 0.38, 95%CI 0.16-0.90), while hypercholesterolemia was associated with higher risk of ALS (OR 2.10, 95%CI 1.13-3.90). Higher BMI at diagnosis was associated with lower risk of death (HR 0.91, 95%CI 0.84-0.98), while the highest level of smoking exposure (in pack-years) (HR 1.90, 95%CI 1.20-3.00), hypercholesterolemia (HR 1.84, 95%CI 1.06-3.19), and hypertension (HR 1.76, 95%CI 1.03-3.01) were associated with higher risk of death, following ALS diagnosis. CONCLUSIONS: Higher BMI and diabetes were associated with lower risk of ALS. Higher BMI was associated with lower risk of death, whereas smoking (especially in high pack-years), hypercholesterolemia, and hypertension were associated with higher risk of death after ALS diagnosis.