News studies regularly report that the risk of serious illness and death from COVID-19 increases with age. (This study finds a marked increase begins at age 50, although the highest fatality rates are for those over age 80.) We also know that certain co-morbidities--cardiovascular disease, chronic lung diseases (like emphysema, chronic bronchitis, and "moderate to severe" asthma), and diabetes--increase the risk of serious illness and death from COVID-19. Yet most of these co-morbidities also increase with age (chronic bronchitis and asthma may be the exceptions). Has there been any study that has disentangled age and the co-morbidities? This article explains that as people get older, their immune systems get weaker, but is that the primary explanation for the higher fatality rate among older patients, or is it the combination of weaker immune systems and co-morbidities? Links to studies or articles related to this question welcome.
UPDATE: Here's the latest report on co-morbidities: no real surprises and consistent with the comments above.
