Dementia Incidence in the Elderly Population of Greece

Abstract

Objectives: Recently a declining trend in dementia incidence rates has been reported in high-income countries. We investigated dementia incidence in a representative sample of the Greek population in the age group of 65 years and above. Methods: This research is part of the Hellenic Epidemiological Longitudinal Investigation of Aging and Diet (HELIAD). The incidence cohort consisted of 1072 participants who were reevaluated after a mean period of 3.09 years. Results: The incidence rate of dementia was 19.0 cases per 1000 person-years (age-standardized and sex-standardized incidence: 25.4/1000 person-years), of which 16.3 per 1000 person-years were attributable to Alzheimer disease. Each additional year of age increased dementia risk by 19.3% and each additional year of education decreased dementia risk by 12.1%. Apolipoprotein E (APOE)-ε4 homozygous participants were 18 times more likely to be diagnosed with dementia. A baseline diagnosis of mild cognitive decline (MCI) resulted in a risk for dementia increased by 3.7 times compared with the cognitively normal; in participants with MCI at baseline, APOE-ε4 carriage increased dementia risk by 4.5 times. Conclusions: The incidence rate of dementia in people 65 years and above in Greece is generally consistent with recently published rates in Europe and North America. Advancing age, baseline MCI, and APOE-ε4 homozygosity are risk factors, while higher educational attainment seems protective.

Genetic propensity for cerebral amyloidosis and risk of mild cognitive impairment and Alzheimer's disease within a cognitive reserve framework

“…The detailed information gathered by all participants allowed us to adjust for many potential confounders, including age and sex, that have been shown to be important risk factors for AD/MCI development. 71,72 The reported association of CR and PRS in continuous form and not only in binary form, with AD/aMCI risk, adds to the generalizability and the practicability of our findings since they become more useful for other populations and cohorts. In other words, the analyses presented here demonstrated that associations were significant on a continuous scale and throughout the whole CR range (for each oneunit standard deviation increase of PRS and for each 1-year increase of CR) and not only under a rather cohort-specific threshold of PRS and CR.…”

“…To help reduce reverse causality issues, we restricted our analyses to individuals not diagnosed with AD/aMCI at baseline. The detailed information gathered by all participants allowed us to adjust for many potential confounders, including age and sex, that have been shown to be important risk factors for AD/MCI development 71,72 . The reported association of CR and PRS in continuous form and not only in binary form, with AD/aMCI risk, adds to the generalizability and the practicability of our findings since they become more useful for other populations and cohorts.…”

“…As already described, we used a combined approach to diagnose AD/aMCI by integrating self‐ or informant‐derived medical history with current medications and brain scans or biochemistry results (where available) to form a complete assessment of the person's vascular burden and other comorbidities. More details on the exact methodology of diagnosis were provided in previous HELIAD publications reporting on the prevalence and incidence of dementias and AD 24,71 and MCI subtypes 23,72 . Rates are generally on par with those reported in other large population cohorts, indicating a low misdiagnosis rate.…”

“…More details on the exact methodology of diagnosis were provided in previous HELIAD publications reporting on the prevalence and incidence of dementias and AD 24,71 and MCI subtypes. 23,72 Rates are generally on par with those reported in other large population cohorts, indicating a low misdiagnosis rate.…”

Longitudinal Examination of Body Mass Index and Cognitive Function in Older Adults: The HELIAD Study

“…Participants’ caregivers were involved in providing information whenever needed. Extensive details of the study design and data collection have been published previously [ 20 , 21 , 22 , 23 , 24 , 25 ]. Based on participants’ preferences, sessions were carried out at day-care centers for older adults, the participants’ homes, or municipal public health clinics.…”