We conducted an epidemiological approach to identify the negative impact of the vascular risk factors (such as hypertension, diabetes and hypercholesterolemia) over cognition. The interesting aspect of this study was that the survey was conducted in all age groups through a voluntary call (
Alzheimer disease international (ADI) have issued three reports since 2009, creating awareness about the high prevalence and incidence of the Alzheimer Disease (AD), especially in the low-income countries (≥5% in Latin America on people over 65 years old), about the increase in the cost of dementia and about the importance of an early identification. Moreover, these reports mention the possibility of applying new preventing strategies, like exercise promotion and vascular risk factors (RFs) control [
The relationship between age and cognitive performance is well known. Even though it is debatable, according to recent investigation the beginning of such cognitive decline may be fixed in middle-aged people [
Based on this background, the aim of our study is to identify cognitive disorders, as well as their relationship with the RF and verify the utility of the Minimum Cognitive Examination (MCE) as a tool in inhabitants from Villa María, Córdoba, Argentina.
The screening was done from February 2010 to August 2011. This study was a part of the Program “Corazón Sano” (Healthy Heart) a Cardiovascular Prevention Program set up by the Health Council of Villa María, Córdoba, Argentina. In said study 22 out of 34 neighborhoods were surveyed randomly. Subjects ≥18 years old, both sexes who went voluntarily to the ambulatory attention on the day and time previously told on different media channels, were included. Participants who were previously diagnosed with psychiatric diseases, dementia and/or depression (based on Diagnostic and Statistical Manual of Mental Disorders, 4th edition criteria), and stroke as well as those who were not able to complete the required protocol tests since they had sensory, motor, or neurological disorders—that stopped these participants from doing the tests—were excluded. The sample was formed by 1460 participants voluntarily called. A closed-answers questionnaire was used (national survey of the risk factors for nontransmissible diseases) [
The variables we took into account were (1) blood pressure (diastolic and systolic) taking as an average value the last 2 out of 3 measurements of a seated subject using a validated digital sphygmomanometer with size cuff “ComFit” adjustable according to the arm circumference (OMRON HEM-714 INT); (2) anthropometric measurement was standardized: body weight (recorded to the nearest 0.1 kg), body height (m), and waist circumference (cm) measuring the midpoint between the lowest rib and the iliac crest in which the participants were standing with non-forced exhalation. In all cases the same weighting machine (Co.Ar.Mc. N.R. model E 1001 with range from 5 to 150 kg) and tape measure were used. Body mass index (BMI) was calculated according to Quetelet formula. Blood pressure and anthropometric values were measured without knowledge of the cognitive score and vice versa; And (3) the glucose, triglyceride, and lipoproteins concentrations were measured using enzymatic standard techniques in venous blood. Blood pressure was recorded according to national and international guidelines and HTN was defined according to the guidelines of the Argentine Society of Cardiology [
Anxious or depressive symptoms were assessed using the 14-item anxiety-depression scale [
Field work was done in the medical centers of each neighborhood. All interviewers were trained before the study began. The tests were blindlyexamined by two neuropsychologists.
The participants signed an informed consent before participating in the trial. The trial protocol and the informed consent were approved by an independent ethic committee. The trial was done pursuant to the GCP (good clinical Practice), the local regulations, and the Declaration of Helsinki and its amendments.
This is an epidemiological, cross-sectional, and observational study. While the relative frequencies of the categorical variables were expressed in percentages, the continuous variables were expressed with mean ± standard deviation (SD). For paired samples, an analysis using two variables per category using the
In this study 1365, ≥18-year-old participants from both sexes were included. Table
General characteristics of the participants in each of the studied variables and difference between sexes (values in mean ± SD).
Variables | Totals | Men | Women |
|
---|---|---|---|---|
Sample ( |
1365 | 332 | 1033 | |
Age (years) | 49 ± 15,6 | 48,6 ± 16,2 | 47,1 ± 15,7 | |
Sex |
|
|
||
Schooling level (%) | ||||
Level 1 | 50,4 | 51,8 | 49,9 | ns |
Level 2 | 35,7 | 35,2 | 35,3 | ns |
Level 3 | 14,3 | 12,9 | 14,8 | ns |
Anthropometry | ||||
Weight (kg) | 75,9 ± 17,9 | 83,7 ± 16,5 | 73,4 ± 17,6 | ns |
WC (cm) | 96 ± 15 | 99,3 ± 13,4 | 94,9 ± 15,3 | ns |
BMI (kg/m2) | 29,4 ± 6,5 | 28,7 ± 5,1 | 29,6 ± 6,9 | ns |
BP (mm Hg) | ||||
SBP | 135,2 ± 22,5 | 142,6 ± 20,9 | 132,7 ± 22,5 | <0,01 |
DBP | 80 ± 12,5 | 83,1 ± 12,6 | 78,9 ± 12,3 | ns |
Blood chemistry (mg/dL) | ||||
Glycemia | 90,2 ± 29,4 | 98,3 ± 37,3 | 90,2 ± 26,1 | ns |
Total cholesterol | 196,2 ± 44,1 | 198,8 ± 46,2 | 195,2 ± 43,4 | ns |
HDL | 49,9 ± 11,8 | 45,4 ± 0.9 | 51,2 ± 12 | ns |
LDL | 124,4 ± 35,2 | 127,5 ± 36,9 | 123,4 ± 24,7 | ns |
Triglycerides | 146,1 ± 96,8 | 180,3 ± 12,7 | 135,2 ± 85,2 |
<0,01 |
Level 1: (primary school finished/unfinished), Level 2: (secondary school finished/unfinished), and Level 3: (tertiary school/college); WC: waist circumference; BMI: body mass index; BP: blood pressure; SBP: systolic blood pressure; DBP: diastolic blood pressure; HDL: high density lipoprotein; LDL: low density lipoprotein.
Table
Prevalence of the RF related to the cognitive test results.
Cognitive |
Hypertension | Diabetes | Obesity | Dislipemia | ||||
---|---|---|---|---|---|---|---|---|
Yes | No | Yes | No | Yes | No | Yes | No |
|
Anxiety plus depression |
7,78 (33) | 10,86 (24) | 11,28**(22) | 6,87 (80) | 8,43 (71) | 6,14 (32) | 7,44 (32) | 7,49 (69) |
MMSE | 18,12 (77) | 13,57 (30) | 19,49**(38) | 13,71 (160) | 15,18 (128) | 13,41 (70) | 15,81 (68) | 13,98 (129) |
Clock drawing | 39,29** (167) | 30,77 (68) | 43,59*** (85) | 33,16 (387) | 36,54 (308) | 31,61 (165) | 37,67 (162) | 33,48 (309) |
Boston naming | 67,29* (286) | 57,92 (128) | 65,13 (127) | 60,89 (710) | 63,82** (538) | 57,97 (302) | 62,56 (269) | 61,28 (565) |
The values are percentages and absolute pathological findings frequencies.
*
Table
Results of the anxiety/depression scale and cognitive tests and differences between sexes (values in mean ± SD of the score of each test).
Variables | Totals | Men | Women |
|
---|---|---|---|---|
Behaviour | ||||
Anxiety | 6,52 ± 4,5 | 4,4 ± 3,7 | 7,1 ± 4,6 | <0,01 |
Depression | 4,37 ± 4,5 | 3,1 ± 3,3 | 4,7 ± 4,7 | ns |
Cognition | ||||
Global cognition | ||||
Minimental test | 27,3 ± 3,2 | 26,9 ± 3,4 | 27,4 ± 3,1 | ns |
Benton’s test | 20,7 ± 3,0 | 20,4 ± 3,3 | 20,8 ± 2,9 | ns |
Executive function | ||||
Clock drawing test | 5,5 ± 1,8 | 5,7 ± 1,6 | 5,5 ± 1,8 | ns |
Alternating series test | 1,6 ± 0,59 | 1,6 ± 0,6 | 1,6 ± 0,5 | ns |
Memory | ||||
Boston naming test | 8,22 ± 2,7 | 8,3 ± 2,9 | 8,1 ± 2,7 | ns |
Cognitive tests relative frequencies between hypertensive and non-hypertensive participants. HTN; hypertension, (*)
Cognitive tests relative frequencies between Diabetes and non-diabetes participants. MD; mellitus diabetes, (*)
As long as life expectancy increases, there will also be a correlative increase in cognitive impairment and dementia. This fact makes age the main RF for dementia. That is why, in most of the previous studies about this topic, the cohorts are 60–70 years old or older. However, some trials showed that patients may have cognitive impairment before that age (approximately 40 years old). Singh-Manoux et al. [
Together with these data, HTN, diabetes, and obesity, among others that were not considered in this study, may add to age a negative impact over cognition. In a 20 years followup, Elias et al. [
From the four studied RF (HTN, dyslipemia, diabetes, and abdominal obesity), the only one that was not related to cognitive impairment was dyslipemia. Even though this had a significant relationship using the three tests separately, in the grouped test on executive functions and semantic memory, a higher number of participants with impairment were found. The importance of using the MCE (which includes the MMSE, clock drawing test, Boston naming test, etc.) is to create a wider field for the cognitive cortical disorders, (e.g., Alzheimer’s type dementia). Clock drawing test (OR 2.23) and Boston naming test (OR 9.3) had a significant increase in identifying probable neurodegenerative cortical dementia compared to the MMSE (
From these new findings, we have to modify and improve future studies design using another model that let us clarify the covariability of the RF more precisely in cognitive test results. In this way, this can be a considered a limitation in our study.
In this way, RF control not only prevents heart and brain damages, but also cognitive disorders and especially dementia. Even though there are drugs that evidence their control over dementia symptoms (cognitive and/or behavior), the most accepted preventive strategy seems to be vascular RF control. If we could delay the beginning of dementia by 5 years, the cases of dementia would decrease in 1 million in 10 years [
The authors declare no conflict of interests.
Thanks are due to CERTUS Research Group for its invaluable assistance the neuropsychology group Jorgelina Milanesio, Jesica Milio, and Valentina Astrada the Cardiovascular Prevention Program “Corazón Sano” (Healthy Heart), the area of mental health, and the Health Council of the Villa María city, Córdoba, Argentina.