Implications and expectancies of the "Atahualpa Project": A population-based survey designed to reduce the burden of stroke and cardiovascular diseases in rural Ecuador

Validation of bedside manual versus automated measurements of brain arterial diameters from MR angiography

BACKGROUND AND PURPOSE

Brain arterial luminal diameters are reliably measured with automated imaging software. Nonautomated imaging software alternatives such as a Picture Archiving Communication System are more common bedside tools used for manual measurement. This study is aimed at validating manual measurements against automated methods.

METHODS

We randomly selected 600 participants from the Northern Manhattan Study (NOMAS) and 260 participants from the Atahualpa Project studied with 1.5 Tesla MR angiography. Using the Radiant measuring tool, three independent readers (general practitioner, neurology resident, and vascular neurologist) measured manually the diameter of arterial brain vessels. The same vessels were also measured by LKEB Automated Vessel Analysis (LAVA). We calculated the intraclass correlation coefficient (ICC) of each rater's diameters versus those obtained with LAVA.

RESULTS

The ICC between diameters obtained by the general practitioner or the neurology resident compared to LAVA was excellent for both internal carotid arteries (ICA) and Basilar Arteries (BA) (ICC > .80 in all comparisons) in NOMAS. In the Atahualpa Project, ICC between diameters obtained by a vascular neurologist and LAVA was good for both ICA and BA (ICC > .60 in all comparisons). The ICCs for the measurements of the remaining arteries were moderate to poor.

CONCLUSION

Results suggest that manual measurements of ICA and BA diameters, but not MCA or ACA, are valid and could be used to identify dilated brain arteries at the bedside and for eventual selection of patients with dolichoectasia into clinical trials.

Nonfatal Stroke and All-Cause Mortality among Community-Dwelling Older Adults Living in Rural Ecuador: A Population-Based, Prospective Study

Background

Stroke is a leading cause of disability in developing countries. However, there are no studies assessing the impact of nonfatal strokes on mortality in rural areas of Latin America. Using a population-based, prospective cohort study, we aimed to assess the influence of nonfatal strokes on all-cause mortality in older adults living in an underserved rural setting.

Methods

Deaths occurring during a 5-year period in Atahualpa residents aged ≥60 years were identified from overlapping sources. Tests for equality of survivor functions were used to estimate differences between observed and expected deaths for each covariate investigated. Cox proportional hazards models were used to estimate Kaplan-Meier survival curves of variables reaching significance in univariate analyses.

Results

Of 437 individuals enrolled over 5 years, follow-up was achieved in 417 (95%), contributing 1776 years of follow-up (average 4.3 ± 1.3 years). Fifty-one deaths were detected, for an overall cumulative 5-year mortality rate of 12.2% (8.9%-15.6%). Being older than 70 years of age, having poor physical activity, edentulism, and history of a nonfatal stroke were related to mortality in univariate analyses. A fully adjusted Cox proportional hazards model showed that having history of a nonfatal stroke (P = 0.024) and being older than 70 years of age (P = 0.031) independently predicted mortality. In contrast, obesity was inversely correlated with mortality (P = 0.047).

Conclusions

A nonfatal stroke and increasing age increase the risk of all-cause mortality in inhabitants of a remote rural village. The body mass index is inversely related to death (obesity paradox).

Basilar Artery Dolichoectasia: Prevalence and Correlates With Markers of Cerebral Small Vessel Disease in Community-Dwelling Older Adults

BACKGROUND

Basilar artery (BA) dolichoectasia has been associated with cerebral small vessel disease (SVD). However, studies have focused on stroke patients, and results cannot be extrapolated to the population at large. In this study, we aimed to assess prevalence of BA dolichoectasia and its association with SVD in community-dwelling older adults living in rural Ecuador.

METHODS

Atahualpa residents aged ≥60 years underwent brain magnetic resonance imaging and magnetic resonance angiography of intracranial vessels. Following Smoker's criteria, the mean BA diameter plus 2 standard deviation defined ectasia. In addition, a location lateral to the lateral margin of the clivus of dorsum sellae or a bifurcation at the third ventricle floor or higher defined dolichosis. Associations between BA abnormalities and imaging markers of SVD were assessed by the use of regression models adjusted for demographics and cardiovascular risk factors.

RESULTS

Of 346 participants, 11 (3.2%) had ectasia, 40 (11.6%) had dolichosis, and 47 (13.6%) had dolichoectasia (ectasia, dolichosis, or both). BA diameter was only associated with severity of white matter hyperintensities (P = .038). Dolichosis was associated with deep cerebral microbleeds (P = .002) but not with white matter hyperintensities. Dolichoectasia was associated with both white matter hyperintensities (P = .031) and cerebral microbleeds (P = .001). There were no associations with lacunar infarcts or enlarged perivascular spaces in any model.

CONCLUSIONS

Prevalence of BA dolichoectasia in this rural setting is similar to that reported in other populations. Associations with imaging markers of SVD differ according to whether the subject has ectasia or dolichosis.

The importance of people compliance (social desirability bias) in the assessment of epilepsy prevalence in rural areas of developing countries. Results of the Atahualpa Project

Epilepsy is a major health issue in rural areas of developing countries. However, heterogeneity of epilepsy prevalence in different studies precludes assessment of the magnitude of the problem. Using similar protocols, two population-based surveys were conducted 12 years apart (2003 and 2015) in a rural Ecuadorian village (Atahualpa). The only difference was a higher people compliance with interviewers during the second survey. Epilepsy prevalence in the 2003 survey was 13.5 per 1,000 (18/1,332) in villagers aged ≥20 years. This rate increased to 26.8 per 1,000 (41/1,530) in the 2015 survey. Thirty-three persons with epilepsy detected during the second survey lived in the village in 2003; six of them had seizures starting after 2003. Of the remaining 27 cases, 13 (48%) denied their problem during the first survey. Further interview revealed that denial was related to lack of confidence with unacquainted field personnel. Social Desirability Scale-17 scores were lower in those who admitted having epilepsy than in those who denied their condition (p = 0.048). Lack of confidence with interviewers and a social desirability bias account for a sizable proportion of epilepsy denial in the study population, and may explain heterogeneity of epilepsy prevalence reported in studies conducted in poor rural settings.

The burden of diabetes-related foot disorders in community-dwellers living in rural Ecuador: Results of the Atahualpa Project

BACKGROUND/OBJECTIVES

Prevalence of diabetes-related foot disorders (DRFD) in rural areas of developing countries is unknown. The burden of these conditions in Atahualpa, a rural Ecuadorian village, were assessed.

METHODS

Using a population-based design, Atahualpa residents aged ≥40 years with diabetes mellitus were identified. Ankle brachial index determinations were used to assess presence of peripheral arterial disease, and the Michigan Neuropathy Screening Instrument was used to estimate peripheral neuropathy. Ulcers in the foot/ankle as well as history of amputations were considered as evidence of active diabetic foot disease. Using a linear model of risk, factors that independently correlated with DRFD, were assessed.

RESULTS

Mean age of 110 participants was 64±12years (59% women). Peripheral arterial disease was diagnosed in 24% of cases and peripheral neuropathy in 59% (15% had both conditions). In the adjusted model, increasing age and being men increased the risk for DRFD. Active diabetic foot disease was noted in 7% of participants, and another 60% were at moderate-to-high risk for developing this complication (according to NHS Borders Foot Classification System).

CONCLUSIONS

The prevalence of DRFD is high in rural Ecuador, and most of the affected individuals are at risk for developing active diabetic foot disease.

Cognitive performance in community-dwelling older adults with stroke and the contribution of age and diffuse subcortical damage: a population-based study in rural Ecuador (The Atahualpa Project)

BACKGROUND

Cognitive impairment is common among stroke survivors. However, there is controversy on the role of the stroke itself or the associated subcortical damage in post-stroke cognitive decline.

AIM

To assess the independent contribution and the interaction of age, the stroke itself and diffuse subcortical damage in the poor cognitive performance observed in patients with stroke.

METHODS

Atahualpa residents aged ≥60 years were identified during a door-to-door survey and invited to undergo brain MRI for identification of stroke lesions and white matter hyperintensities (WMH) of presumed vascular origin. Cognitive performance was evaluated by the use of the Montreal Cognitive Assessment (MoCA). Using a generalized linear model, we examined the association between MoCA score, stroke and WMH, after adjusting for demographics, education, vascular risk factors, depression and edentulism.

RESULTS

Out of 311 persons aged ≥60 years, 242 (78 %) were enrolled. MRI showed strokes in 39 (16 %) and moderate-to-severe WMH in 52 (22 %) cases. Mean MoCA score was 18.5 ± 4.7 in the entire population. When participants were stratified according to the median age of the population (67 years), the generalized linear model showed that MoCA scores were not different in younger persons irrespective of the presence of stroke or WMH. In contrast, increased age associated with lower MoCA scores in persons with WMH (p = 0.002) or with both stroke and WMH (p = 0.003), but not in those with stroke without WMH (p = 0.087).

CONCLUSIONS

Interaction of age and diffuse subcortical damage are major determinants for poor cognitive performance among stroke patients.

Calcifications in the carotid siphon correlate with silent cerebral small vessel disease in community-dwelling older adults: A population-based study in rural Ecuador

AIM

Using a population-based, cross-sectional design, we aimed to assess whether the presence of calcifications in the carotid siphon (as seen on computed tomography) is associated with silent markers of cerebral small vessel disease (on magnetic resonance imaging) in apparently healthy older adults living in Atahualpa, a rural Ecuadorian village.

METHODS

Stroke-free Atahualpa residents aged ≥60 years identified during a door-to-door survey underwent head computed tomography for assessment of carotid siphon calcifications, and brain magnetic resonance imaging for identification of white matter hyperintensities and silent lacunar infarcts. We evaluated the association between calcifications and markers of small vessel disease using logistic regression models adjusted for demographics and cardiovascular risk factors.

RESULTS

The mean age of the 236 participants was 71 ± 8 years, and 139 (59%) were women. Computed tomography readings showed high calcium content in the carotid siphon in 64 individuals (27%), and magnetic resonance imaging showed moderate-to-severe white matter hyperintensities in 51 (30%) and lacunar infarcts in 28 (12%). In the univariate analysis, individuals with high calcium content were older and were more likely to have high fasting glucose levels than those with low calcium content. After adjusting for confounding variables, we found an independent association between high calcium content in the carotid siphon and moderate-to-severe white matter hyperintensities (OR 2.3, 95% CI 1.1-4.9, P = 0.035) as well as lacunar infarcts (OR 3.1, 95% CI 1.3-7.6, P = 0.013).

CONCLUSIONS

The present study shows a direct relationship between calcium content in the carotid siphon and silent small vessel disease in an indigenous Latin American population. Geriatr Gerontol Int 2016; 16: 1063-1067.

Intracranial arterial stenosis in Ecuadorian Natives/Mestizos. A population-based study in older adults (The Atahualpa Project)

BACKGROUND

Intracranial arterial stenosis (IAS) is more prevalent among Asians, Blacks and Caribbean Hispanics than in Whites. However, there is no information on the importance of this common cause of stroke among Mestizo/Native populations of Latin America. We aimed to assess prevalence and correlates of IAS in an indigenous Ecuadorian population of older adults.

METHODS

Atahualpa residents aged ≥60 years were identified during door-to-door surveys and invited to undergo brain magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) of intracranial vessels for identification of stroke lesions and arterial stenosis. Prevalence of IAS was assessed in patients with strokes as well as in stroke-free individuals. A logistic regression model was constructed with stroke as the outcome, IAS as the exposure, and confounders (demographics and cardiovascular risk factors) as independent variables.

RESULTS

Out of 267 participants (mean age 71 ± 8 years, 57% women), 15 (5.6%) had intracranial arterial stenosis, including 10 out of 52 (19.2%) persons with stroke and five out of 215 (2.3%) without. The multivariate logistic regression model showed significant association of IAS with stroke after adjusting for demographics and cardiovascular risk factors (OR: 7.9, 95% C.I.: 2.2-27.8, p=0.001). Mechanisms underlying stroke in patients with IAS included perforator occlusion, artery-to-artery embolism and hypoperfusion.

CONCLUSIONS

Prevalence of IAS in Ecuadorian Natives/Mestizos is similar to that in Asians. Individuals aged ≥60 years with IAS are almost eight times more likely to have a stroke after adjusting for confounding variables.

Technical difficulties due to poor acoustic insonation during transcranial Doppler recordings in Amerindians and individuals of European origin. A comparative study

BACKGROUND

There is no information on transcranial Doppler (TCD) failures due to poor insonation among native inhabitants of Latin America.

METHODS

Seventy Ecuadorian natives and 70 age- and sex-matched individuals of European origin underwent TCD. The same investigators performed all exams using the same equipment and protocol. Using the McNemar's test for correlated proportions, we compared TCD failures related to poor insonation across ethnic groups.

RESULTS

Out of 140 participants, 56 (40%) had one or more suboptimal/absent acoustic windows. These persons were older (p = 0.01) and were more often women (p < 0.0001) than those with all optimal windows (irrespective of race/ethnicity). In the matched-pair analysis, Amerindians were more likely to have suboptimal/absent acoustic windows than individuals of European origin (OR: 2.8, 95% CI: 1.3-6.5, p = 0.006).

CONCLUSION

Amerindians are almost three times more likely to have insonation failures related to poor acoustic windows than their European counterparts.

The association of ankle-brachial index with silent cerebral small vessel disease: results of the Atahualpa Project

BACKGROUND

An abnormal ankle-brachial index has been associated with overt stroke and coronary heart disease, but little is known about its relationship with silent cerebral small vessel disease.

AIM

To assess the value of ankle-brachial index as a predictor of silent small vessel disease in an Ecuadorian geriatric population.

METHODS

Stroke-free Atahualpa residents aged ≥60 years were identified during a door-to-door survey. Ankle-brachial index determinations and brain magnetic resonance imaging were performed in consented persons. Ankle-brachial index ≤0.9 and ≥1.4 were proxies of peripheral artery disease and noncompressible arteries, respectively. Using logistic regression models adjusted for age, gender, and cardiovascular health status, we evaluated the association between abnormal ankle-brachial index with silent lacunar infarcts, white matter hyperintensities, and cerebral microbleeds.

RESULTS

Mean age of the 224 participants was 70 ± 8 years, 60% were women, and 80% had poor cardiovascular health status. Ankle-brachial index was ≤0.90 in 37 persons and ≥1.4 in 17. Magnetic resonance imaging showed lacunar infarcts in 27 cases, moderate-to-severe white matter hyperintensities in 47, and cerebral microbleeds in 26. Adjusted models showed association of lacunar infarcts with ankle-brachial index ≤ 0.90 (OR: 3.72, 95% CI: 1.35-10.27, P = 0.01) and with ankle-brachial index ≥ 1.4 (OR: 3·85, 95% CI: 1.06-14.03, P = 0.04). White matter hyperintensities were associated with ankle-brachial index ≤ 0.90 (P = 0.03) and ankle-brachial index ≥ 1.4 (P = 0.02) in univariate analyses. There was no association between ankle-brachial index groups and cerebral microbleeds.

CONCLUSIONS

In this population-based study conducted in rural Ecuador, apparently healthy individuals aged ≥60 years with ankle-brachial index values ≤0.90 and ≥1.4 are almost four times more likely to have a silent lacunar infarct. Ankle-brachial index screening might allow recognition of asymptomatic people who need further investigation and preventive therapy.

Psychological distress in patients with restless legs syndrome (Willis-Ekbom disease): a population-based door-to-door survey in rural Ecuador

Background

Reported prevalence of restless legs syndrome (RLS), also known as Willis-Ekbom disease (WED), varies from country to country, and methodologic inconsistencies limit comparison of data. Impact of RLS on quality of life and health has been studied primarily in industrialized countries, particularly Europe and the United States. Many studies have relied exclusively on self-report of symptoms or have assessed only medical populations. Recently, interest has emerged on the impact of WED in rural, underserved populations globally.

Methods

In a population-based survey conducted in rural Ecuador, we assessed the relationship of psychological distress to WED, evaluated with the Depression Anxiety Stress Scales–21. WED was diagnosed through a 2-phase method in which all residents were screened with the International Restless Legs Syndrome Study Group (IRLSSG) questionnaire and all suspected cases were subsequently confirmed through expert medical examination. WED severity was assessed with the IRLSSG rating scale.

Results

Of 665 persons (mean [SD] age, 59.5 [12.6] years; women, 386 [58%]), 76 had depression, 93 had anxiety, and 60 reported stress. Forty persons (6%) had WED, with 15 (38%) having severe disease. In a regression model adjusted for age and sex, the prevalence of depression, anxiety, and stress was about 3 times greater among persons with WED than the general population.

Conclusions

Although cross-sectional data cannot establish causation, this study shows the large behavioral health burden associated with WED in an untreated, rural population.

Prevalence, correlates, and prognosis of peripheral artery disease in rural ecuador-rationale, protocol, and phase I results of a population-based survey: an atahualpa project-ancillary study

Background. Little is known on the prevalence of peripheral artery disease (PAD) in developing countries. Study design. Population-based study in Atahualpa. In Phase I, the Edinburgh claudication questionnaire (ECQ) was used for detection of suspected symptomatic PAD; persons with a negative ECQ but a pulse pressure ≥65 mmHg were suspected of asymptomatic PAD. In Phase II, the ankle-brachial index will be used to test reliability of screening instruments and to determine PAD prevalence. In Phase III, participants will be followed up to estimate the relevance of PAD as a predictor of vascular outcomes. Results. During Phase I, 665 Atahualpa residents aged ≥40 years were enrolled (mean age: 59.5 ± 12.6 years, 58% women). A poor cardiovascular health status was noticed in 464 (70%) persons of which 27 (4%) had a stroke and 14 (2%) had ischemic heart disease. Forty-four subjects (7%) had suspected symptomatic PAD and 170 (26%) had suspected asymptomatic PAD. Individuals with suspected PAD were older, more often women, and had a worse cardiovascular profile than those with nonsuspected PAD. Conclusions. Prevalence of suspected PAD in this underserved population is high. Subsequent phases of this study will determine whether prompt detection of PAD is useful to reduce the incidence of catastrophic vascular diseases in the region.

Global cortical atrophy (GCA) associates with worse performance in the Montreal Cognitive Assessment (MoCA). A population-based study in community-dwelling elders living in rural Ecuador

BACKGROUND/OBJECTIVE

Increasing numbers of individuals with cognitive impairment are posing economic threads to the developing world. Proper assessment of this condition may be complicated by illiteracy and cross-cultural factors. We conducted a population-based study in elders living in rural Ecuador to evaluate whether the MoCA associated with structural brain damage in less-educated populations.

METHODS

Atahualpa residents aged ≥60 years were identified during a door-to-door survey and invited to undergo MRI for grading GCA. Using a multivariate generalized linear model, we evaluated whether MoCA scores correlates with GCA, after adjusting for demographics, education, cardiovascular health (CVH) status, depression and edentulism.

RESULTS

Out of 311 eligible persons, 241 (78%) were enrolled. Mean age was 69.2±7.5 years, 141 (59%) were women, 199 (83%) had primary school education, 175 (73%) had poor CVH status, 30 (12%) had symptoms of depression and 104 (43%) had edentulism. Average MoCA scores were 18.5±4.7 points. GCA was mild in 108, moderate in 95, and severe in 26 persons. Total and most domain-specific MoCA scores were significantly worse in persons with moderate to severe GCA. In the multivariate model, mean MoCA score was associated with GCA severity (β=2.38, SE=1.07, p=0.027).

CONCLUSIONS

MoCA scores associate with severity of GCA after adjusting for potential confounders, and may be used as reliable estimates of structural brain damage. However, a lower cut-off than that recommended for developed countries, would be better for recognizing cognitive impairment in less educated populations.