Cause of death in mild cognitive impairment: a prospective study (NEDICES)

Abstract

BACKGROUND AND PURPOSE Previous studies have reported the occurrence of increased mortality rates among individuals with mild cognitive impairment (MCI), but possible links between MCI subtypes and cause-specific mortality need to be explored. To examine short-term mortality (5-years), long-term mortality (13-years) and cause-specific mortality of individuals over 65 years of age) suffering from mild cognitive impairment (MCI) compared to cognitively unimpaired individuals in the NEDICES (Neurological Disorders in Central Spain) cohort. METHODS MCI was classified using standardized psychometric and functional assessment in accordance with diagnostic convention. Cox's proportional hazards models, adjusted by sociodemographic and comorbidity, were used to assess the risk of death at 5 and 13 years of MCI subtypes compared with a reference group of elders without cognitive impairment (N = 2,329). Causes of death were obtained from the National Population Register of Spain. RESULTS There were 1,484 deceased individuals at 13 years. MCI subtypes were defined as amnestic-single domain (N = 259), amnestic-multiple domain (N = 197), and non-amnestic (N = 641). After adjusting for covariates, only amnestic-multiple domain MCI showed an increased hazard ratio (HR) for mortality at 5 years versus reference group. However, the HR for mortality at 13-years was increased for all MCI subtypes. The HR by MCI subtype was 1.19 in non-amnestic (95% CI: 1.05 to 1.36), 1.31 in amnestic-single domain (95% CI: 1.10 to 1.56) and 1.67 in amnestic multiple domain (95% CI: 1.38 to 2.02). In terms of cause specific mortality, the chance of death from dementia was statistically higher in all MCI subtypes. CONCLUSION Amnestic-multiple domain MCI showed the greatest risk of mortality in comparison with other MCI subtypes at different intervals. Dementia was the only cause-specific mortality that was increased in MCI individuals.

Mortality in Mild Cognitive Impairment Varies by Subtype, Sex, and Lifestyle Factors: The Mayo Clinic Study of Aging

“…Previous studies have also indicated an increased risk for mortality in persons with MCI compared to cognitively normal individuals [2–6]. A recent study reported an increased HR of death in naMCI (SD and MD combined) and for both SD aMCI and MD aMCI at 13 years of follow-up, with MD aMCI having the highest mortality rate compared to cognitively normal individuals [6]; only the MD aMCI had an increased HR for death compared to CN individuals at 5 years.…”

“…A recent study reported an increased HR of death in naMCI (SD and MD combined) and for both SD aMCI and MD aMCI at 13 years of follow-up, with MD aMCI having the highest mortality rate compared to cognitively normal individuals [6]; only the MD aMCI had an increased HR for death compared to CN individuals at 5 years. [6] By contrast, the present findings suggested higher mortality rates in general for naMCI than for aMCI (versus. the CN group).…”

“…It is an important clinical entity for the study of aging as both the incidence and prevalence of MCI are high in the elderly population [2]. Previous studies have demonstrated an increased risk of mortality in MCI cases compared to cognitively normal (CN) individuals [2–6]. However, only one of these studies [6] differentiated between mortality rates in amnestic MCI [aMCI; single (SD) and multiple domain (MD)] and non-amnestic MCI (naMCI), but provided no information on impact of number of domains affected on mortality for the naMCI.…”

Hypertension and aging

“…Importantly, MCI is associated with an increased risk of dementia (DeCarli, 2003; Gauthier et al, 2006; Ward et al, 2012) and is a strong predictor of excess mortality (i.e. premature death)(Bennett et al, 2002; Contador et al, 2014; Sachs et al, 2011). Recognition of these consequences has led to a growing awareness of the need to treat MCI among older adults (Eshkoor et al, 2015; Langa and Levine, 2014).…”

The co-occurrence of mental disorders in children and adolescents with intellectual disability/intellectual developmental disorder

“…Links between ID/IDD subtypes and cause-specific mortality rates need to be further explored. There is evidence that for individuals with mild cognitive impairment as part of the Neurological Disorders in Central Spain study, adjusted by socio-demographic factors, the risk of death at 13 years was increased for all mild cognitive impairment subtypes [41 ▪ ]. These outcomes reflect poor detection rates of cardiovascular and cancer, as well as co-occurring mental disorders in ID/IDD populations.…”