Study Protocol
“NUTRITION, DEPRESSION AND COGNITIVE IMPAIRMENT: A POPULATION-BASED APPROACH IN THE ELDERLY IN A GEOGRAPHICALLY DEFINED AREA OF CENTRAL GREECE (MAGNESIA)”
Introduction
A large number of chronic diseases such as depression (Carnethon MR et al, 2003), cognitive impairment (Morris MC et al, 2004), dementia (Luchsinger LA et al, 2004) and other diseases of aging are affected by nutritional preferences. The health burden of these diseases in the mortality and morbidity of the elderly is significant (Μeydani M, 2001). During the last years it has become clear enough that diseases of aging constitute a hidden and ignored epidemic due to both the adoption of western lifestyle changes and the extension of life-span.
Aim
a. To estimate the prevalence of depression and cognitive impairment in individuals over 60 years old in a geographically defined area of Central Greece (Velestino, Magnesia). b. To conduct research on the possible risk factors for depression and cognitive impairment in the aforementioned population through the study of the nutritional preferences with the help of the EPIC questionnaire (European Prospective Investigation into Cancer and Nutrition) and through the study of socio-demographic characteristics, personal health record, somatometric parameters, laboratory indicators and DNA polymorphisms. It is expected that this study will provide very useful conclusions that will allow us to speculate on possible intervention practices in order to adopt the necessary prevention strategies in the future.
Material – Methodology
This is a community-based, descriptive study of prevalence held in the town of Velestino, county of Magnesia, Thessaly, Central Greece. The population of Chloe (a village 5 miles far from Velestino) is also included in the study sample. Based on data derived from the National Statistical Service of Greece, 2001, the number of individuals over the age of 60 in this town is about 850 the total population is 3659, 389 of which reside in Chloe (www.statistics.gr).
Before the data collection begins, the region will be visited by our staff in order to investigate the geographical, transportational and residing properties of this area. Scheduled contacts with the local authorities and health representatives will also take place. The population will be educated about the purpose and the usefulness of this study through well-prepared lectures that will take place in busy public places. All individuals that will take part in this study will be asked to provide written informed consent. All individuals that will require hospitalization (in public or private hospitals) during the study period will also be recorded; in this case the closest relative will be our main source of information. Due to the nature of this study it is possible that a written consent may not be provided by some people (for example, people suffering from severe cognitive impairment); in this case the closest possible relative will be asked to provide the required written consent. All data collected will be safely stored in the Department of Hygiene and Epidemiology and Medical Statistics of the University of Athens, Medical School and no information relating to the specific identity of the individuals will be available; medical privacy in this study is of utmost importance and it will be a top-priority.
The questionnaire will include both non-specific (socio-demographic), as well as specific-type questions related to the nutritional preferences of the individual, the personal health record and somatometric parameters (Faxen-Irving G et al, 2002). In addition, all individuals will be asked to provide their answers to the shortened version of the GDS (Geriatric Depression Scale) questionnaire (GDS-15) (Sheikh and Yesavage, 1986) and to the MMSE (Mini Mental State Examination) (Folstein et al., 1975). Finally, venipunctures (Robertson RG et al, 2004) and saliva collection will be attempted in order to measure specific laboratory values that may be associated with depression and cognitive impairment.
All medical procedures, such as interviews, measurement of somatometric characteristics and venipunctures will be performed by specialized and experienced personnel familiar to the study population.
Data Analysis
Multiple logistic regression models will be used in order to neutralize the possible effect of confounding factors and all results will be shown in figures and tables. All results will be presented in summary reports and it will be ensured that no information leading to the identity of the individuals taking part in this study will be available.
Time schedule of the study
It is expected that this study will last 3 years. Preliminary preparations for this study will last 3 months, collection of data and biological samples will last 12 months, data input 3 months, statistical analysis 3 months, greek and worldwide literature study and thesis writing and editing 15 months.