認知功能下降及失智症的危險因子 Risk factors for cognitive decline and dementia

造成認知功能下降及失智症的危險因子有非常多種. 藥物引起的失智症只是其中一種危險因子. 

Risk factors for cognitive decline and dementia
The Lancet Commission estimates that approximately 35 percent of dementia cases are attributable to a combination of nine potentially modifiable risk factors [1]:

●Low educational attainment

●Midlife hypertension

●Midlife obesity

●Hearing loss

●Late-life depression

●Diabetes

●Physical inactivity

●Smoking

●Social isolation

This topic will review the risk factors associated with cognitive decline and dementia. The risk factors for Alzheimer disease (AD) and the diagnosis, prevention, and treatment of dementia are discussed separately. 

Medications — Multiple studies have found an association between short-term use of certain medication classes (eg, benzodiazepines, anticholinergics, antihistamines, opioids) and cognitive impairment in older adults, but the effects have been presumed to be transient and reversible [228]. Several studies have observed a dose-response relationship between medication use and incident dementia and AD that persists despite adjustment for confounders, however, raising the possibility that adverse cognitive effects may not be reversible in some patients [229,230]. Potentially implicated classes of medications include benzodiazepines, anticholinergics, and proton pump inhibitors. (See "Epidemiology, pathology, and pathogenesis of Alzheimer disease", section on 'Medications'.)

It remains uncertain whether long-term use of medications such as benzodiazepines is associated with an increased risk of cognitive decline, however, and the data are conflicting. Interpretation of observational data is difficult in large part because benzodiazepines are prescribed to treat insomnia and anxiety, which can be prodromal symptoms of dementia. In studies that attempted to control for the prodromal phase and the potential for reverse causation, two found an increased risk of dementia with benzodiazepine use [229,231], while two others did not [232,233].

The case for anticholinergics increasing risk of irreversible effects is probably stronger [230,234] and makes more sense physiologically given the prominence of cholinergic deficits in AD.