Neurodegenerative Disorders Tendency in Adult Cuban Population

Context and Classification of the Study

Longitudinal descriptive observational study was carried out, which classifies as chronological or temporal series, on the trend of 3 neurodegenerative diseases; Amyotrophic Lateral Sclerosis, Alzheimer’s dementia and Parkinson’s disease in Cuba during the period 2015 to 2020. First, the method of documentary analysis and bibliographic review was used. In a second moment, a time series or chronological analysis was carried out with the mortality statistics of each of the diseases included in the study.

For the selection of the sample of the first objective, the following criteria were taken into account: Inclusion criteria: full-text articles, related to the topic of the work (Dementia and/Alzheimer, Parkinson’s disease and Amyotrophic Lateral Sclerosis), date of publication between 2015 and 2020 and documents written in English and/or Spanish. Exclusion Criteria: final degree, master’s and doctoral theses.

Statistical Processing of the Data

During the search process, MEDLINE (via PubMed), Cochrane Library, Scielo, UpToDaTe, Dialnet and academic Google were used as databases, in order to ensure a wide and effective search. First, the search in the different databases is limited by combining the search terms DeCS and MeSH, using the Boolean operator AND and applying the inclusion criterion: publication date between 2015 and 2020.

Analysis of the Information

For the analysis of time series, the mortality statistics of Alzheimer’s dementia, Parkinson’s disease and Amyotrophic Lateral Sclerosis in Cuba from 2015 to 2020 were used, the control variables requested were age group, sex, skin color and provinces.

Sources of Information Used

Statistical Yearbook of Cuba for the years 2015, 2016, 2017, 2018, 2019 and 2020. Cuban Mortality Database available at the National Directorate of Statistics of the Ministry of Public Health and made up with the outputs of the Statistical Information System of deaths that are available at the National Directorate of Statistics of the Ministry of Public Health.

Statistical Processing

Mortality statistics have been processed in accordance with the provisions of ICD-10. The series of data collected from the different neurological diseases under study from 2015 to 2020, was stored in a database that were statistically processed. The trend analysis was carried out for each disease. Time series were built and percentage indicators, general and sex-specific rates were calculated.

Seasonal decomposition methods were used to decompose the series, the moving average method was used. To forecast, an adjustment of the trend of the series was made. A linear adjustment was used, with a p less than 0.05. The adjusted coefficients were determined. This analysis made it possible to evaluate the percentage of variability of the data explained by the model so that the closer to 1 is the

Ethical Considerations

The research was carried out in accordance with the ethical principles of the research.

The information requested from the Directorate of Medical Records and Health Statistics was used only for the purpose of the thesis.

Limit and Scope of the Investigation

The present study presents some limitations that are specific to the characteristics of this type of descriptive analysis and that would be associated with the quality and quantity of health records. In addition, it must be taken into account that the data comes from several sources, there may be no recorded information or initial inaccuracies. However, this is a limitation attributable to most of the studies published in this field.

Source: Database. National Directorate of Health Statistics, Cuba, 2015-2020. Table 1: Deaths in Alzheimer’s disease as a direct cause of death according to provinces, Cuba, 2015-2020.

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Source: Database. National Directorate of Health Statistics. Cuba. 2015-2020 Graph 1: Deaths in Alzheimer’s disease according to sex in Cuba during the years 2015 to 2020.

Source: Database, National Directorate of Health Statistics, Cuba, 2015-2020. Table 2: Behavior of deaths in Parkinson’s disease as a direct cause of death according to provinces, Cuba, 2015-2020.

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Source: Database. National Directorate of Health Statistics. Cuba. 2015-2020 Graph 2: Behavior of deaths in Parkinson’s disease as a direct cause of death according to skin color. Cuba. 2015-2020.

Source: Database. National Directorate of Health Statistics, Cuba, 2015-2020. Table 3: Deaths in amyotrophic lateral sclerosis as a direct cause of death according to age group. Cuba. 2015-2020.

Source: Database. National Directorate of Health Statistics, Cuba, 2015-2020. Table 4: Amyotrophic lateral sclerosis as a direct cause of death according to provinces. Cuba. 2015-2020.

Alzheimer’s Ddisease (AD)

It is the most frequent of dementias and contributes in 60 - 70% of cases. It is an anatomical-clinical entity of a degenerative nature and progressive course [6]. In 2018, 50 million people suffered from dementia worldwide and, of these, about 60 to 80% have Alzheimer’s disease. The prevalence of this pathology increases markedly with age, with an increase of more than 15 times between the ages of 65 and 85 [7]. Mortality from Alzheimer’s disease between 2000 and 2019 has doubled, increasing by 145%, that is, 1 in 3 older people dies from this pathology [8].

WHO mentions that women are disproportionately affected, globally, 65% of deaths are due to Alzheimer’s [9, 10, 11]. All of the above could be justified according to the years of survival, where women survive more than men about 9 years. In the provinces classified as the oldest, the proportional values of their population aged 60 and over exceed 20%, such as Villa Clara, Sancti Spiritus and Havana, where deaths from Alzheimer’s disease presented irregular behavior during the period of time contemplated by this research Table 1 & Graph 1.

According to a meta-analysis of 157 epidemiological studies carried out around the world, the prevalence of dementia is, depending on the geographical area, between 58% for people over 60 years of age, showing an exponential growth pattern with age, doubling approximately every five years, and a predominance of the female sex [12, 13]. Another meta-analysis shows similar results, with a point prevalence of 4.8% and a prevalence of 6.9% in the community population aged 60 years and over [14]. This work also analyzed the causes of heterogeneity between studies such as age, diagnostic criteria and geographical scope.

In Latin America, a recent collaborative study based on population studies carried out in urban areas of six countries (Brazil, Chile, Cuba, Peru, Uruguay and Venezuela) indicates an overall prevalence of dementia of 7.1% in those over 65 years of age. However, there is a significant variability in the estimates, since, among the three studies carried out in Brazil, the prevalence was 2%, 7.1% and 8.8%, respectively, while in Uruguay it was 3.1%, and in Venezuela it was 13.1% (14.5). Another study, based on the 10/66 Dementia Research Group protocol, obtained estimates of the prevalence of dementia in the population aged 65 and over in different more homogeneous Latin American countries, with values ranging from 6.2% to 7.3% for an urban area of Venezuela and a rural area of Mexico, respectively, and between 9.8% and 12.6% for urban areas of the Dominican Republic and Cuba [15].

Parkinson’s Disease (PE)

Is the second most common neurodegenerative disease after Alzheimer’s disease. When analyzing the yearbooks of Cuba, it was observed that the greatest involvement by Parkinson’s disease occurred in the 75-79 age groups, followed by the ages between 80 and 84 years, data that coincide with the study by Condor et al. where the average age was 72.93 [16]; with that of Solís who found that PE occurs at 71 years [17, 18]. Rong S, et al. [19] states that The data obtained in the present study show that there is currently a tendency in both men and women to increase PE, with a predominance of deaths in male patients as well as the work of Condor in which the male sex predominated 58.3%. [16, 17, 18, 19, 20] Table 2 &Graph 2.

Moreira-Díaz LR, et al. [21] says that the Cuban population has an aging trend, so it is predicted that the prevalence of PE will increase. Hence, the number of patients with this pathology can be increased to 29,000 in two decades, indicating that in 2018 there were 665 deaths from this condition, with a crude rate for men of 7.4% and for women of 4.4%. All of the above could be explained by the hormonal protective factor against nerve-like conditions that women have, because it decreases the loss of dopaminergic neurons, which shows the male sex to be more likely to suffer.

In 2016, it was estimated that 6.1 million people in the world suffered from the disease, which more than doubled compared to the 1990 figure (2.5 million). In 2040 it is estimated that there will be about 17 million people affected. This makes Parkinson’s disease one of all neurological diseases, the fastest growing worldwide according to the global burden study of the disease [17]. This increase can be explained by several factors, including the aging of the population, exposure to environmental risk factors (such as certain toxins and the global decrease in smoking) and improvements in the diagnosis and reporting of cases of the disease, in addition to increased survival of patients due to the availability of effective treatments [18].

The risk of the disease seems to be determined by complex interactions between individual factors (such as age and the presence of certain genetic polymorphisms or mutations) and environmental factors. As for genetic risk factors, the one with the most robust evidence is the presence of mutations in the GBA gene (which codes for the lysosomal enzyme beta- glucocerebroxidase). Other genes identified are related to monogenic forms of the disease (such as LRRK-2 and SNCA) [20]. Age is the risk factor most consistently associated with Parkinson’s disease. There is a peak prevalence between 85 and 89 years of age (1.7% in men and 1.2% in women) and a decrease from this age. It is more common in men, with a male-female ratio of 1:4, with a prevalence that has doubled in the last 26 years [21, 22]. The age-standardized prevalence rate in Colombia was recently estimated at between 60 and 70 per 100,000 inhabitants (which in 2016 would represent 25,930 patients) [23]. However, in the Epineuro population study, carried out through two-phase, door-to-door surveys between 1995 and 1996, a prevalence of 470 per 100,000 inhabitants was found [24].

Amyotrophic Lateral Sclerosis (ALS) or Charcot Disease

It represents the third neurodegenerative disease in frequency, surpassed by AD and PE. In the present study, the incidence rates of Amyotrophic Lateral Sclerosis increased steadily by 3% per year for 22 years, from 1.6 to 3.3 X 100,000 per year. Older age, bulbar symptoms and men negatively affected survival. The median survival since diagnosis was 17.6 months and from the onset of symptoms it was 27.6 months [25]. The incidence rates of ALS in Europe and North America range from 1.5 to 2.7 X 100,000 person-years, while prevalence rates range from 2.7 to 7.4 X 100,000 person- years. The incidence of ALS increased with each decade, especially after the age of 40 [26, 27].

The incidence rates of Amyotrophic Lateral Sclerosis (ALS) in Europe and North America range from 1.5 to 2.7 per 100,000 person-years, while prevalence rates range from 2.7 to 7.4 per 100,000 person-years [28]. According to Castro and Colbs, in their study, it obtained a prevalence of 6.1 million inhabitants in 2017. Annual incidence between 1.2 cases/100,000 inhabitants/year in 2012 and 3.5 cases/100,000 inhabitants/year in 2016 [29, 30].

The highest number of patients who died from this pathology ranged from 65 to 74 years old, similar to studies by Maragakis who demonstrates an abrupt increase in ALS in the seventh decade, but the incidence in the elderly is uncertain [25, 31] Tables 3&4.

Lara et al. in their study of this entity, carried out in 2 stages (2005 - 2011) and (2012-2017), showed that this pathology predominated in patients with white skin color 63.9% and 66.7% respectively, followed by the mestizo race [32]. In relation to the distribution by sex, men predominated in both groups, with 54.14% in the first stage and 53.3% in the second [32, 33].

The male-female ratio is approximately 1.3 to 1.5 for sporadic ALS, although the ratio is close to unity in the age group over 70 years [25]. Studies carried out in Italy and Latin America bring differences. Thus, in Italy the male-to-female ratio is practically 1:1, in the population of Latin America the disease predominates in women [34]. The incidence of ALS increases with each decade, especially after the age of 40, and peaks at 74 years, then gradually decreases [35, 36].

It is estimated that half a million people are affected in the world. Due to its low prevalence due to its high and rapid mortality, ALS is considered a rare or “invisible” disease. Every year, 120,000 new cases of ALS are diagnosed worldwide, 17 every hour, and a 69% increase in the number of cases is expected by 2040 [25].