During the last few decades, there is a new demographic behavior in the elderly, in which there is a progressive increase in the prevalence of the elderly population due to improvements in life expectancy and the increase in the proportion of elderly in the world's population. However, the search for strategies that seek to prolong the life expectancy free of functional and cognitive impairment is relevant. The elderly population is a group characterized by heterogeneity, so that we can find in the same age group, elderly with preserved functional capacity and the ones with memory impairment levels in an advanced state. 1

The aging is a continuous process in which there is a progressive decline in physiological processes. Among the most apparent physiological changes during aging, there is a decrease in height by about 1 cm per decade and structural and functional changes in the nervous system, due to reduction in the number of neurons. It is also usual to have increased arterial stiffness, increased blood pressure, a decreased cardiac output at rest and during exercise, and reduced bone mineral density. 2–4

Specifically, regarding the changes that affect the central nervous system with the course of the aging process, there is the ventriculomegaly and reduced cortical mantle, usually accompanied by progressive cognitive impairment. However, regardless of degenerative diseases, cognitive dysfunction and dementia were observed. Dementia is the progressive reduction or loss of cognitive abilities, partial or complete, permanent or momentary form, enough to cause a loss of autonomy and functional decline. 2

For Pedrosa and Holland, 5 loss of independence and low levels of cardiorespiratory fitness are associated with risk of morbidity and mortality from chronic diseases, on the other hand the performance of daily activities of life and the maintenance of independence are linked to improved general health. In this sense, low levels of muscular strength and obesity are associated with functional decline and cognitive impairment. 3,6 In addition, important measures related to functional capacity and maintenance of daily activities as the amount of motor units, the contraction speed, neurons driving speed, the reaction time, and volume of brain matter show worsening over the decrease in walk velocity. 1,4,7

Accordingly, it appears that functional capacity, maintaining the autonomy are associated with a lower incidence of chronic degenerative diseases. Thus, there is a constant need for assessments and maintaining physical fitness, since it features associated with general health in the elderly, particularly in relation to cardiovascular disease, cognitive response and hospitalization. 2 In this light, the aim of this study was to evaluate the cognitive profile of the elderly and its association with anthropometric and functional aspects.

Tables 1 and 2 presented the characteristics of the sample, with anthropometric data, hemodynamics performance and results of the MMSE test as well as the percentages of dementia and other chronic diseases.

There was a statistically significant difference for the variables: body weight, height, WHR, neck circumference and WC, in which men showed higher values when compared to women.

Table 3 shows the cutoffs and their sensitivity and specificity of anthropometric indicators and tests that measured the functional capacity in predicting dementia.

According to Table 3, the WC and the waist/height ratio (WHeR) were considered predictors of dementia, since the lower limit of the confidence interval was above 0.50 (Li-IC > 0.5). Already body mass index (BMI), taper index, waist/hip ratio (WHR) and performance tests, as carried out in our methodology, showed no reliable values of sensitivity and specificity (Li-CI < 0.5). Fig. 1 shows the ROC curves of the key variables tested.

Fig. 1.

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ROC curves for the anthropometric indicators and functional tests as predictors of dementia. Abbreviations: BMI, body mass index; DH strength, dominant hand palmar pinch strength; NDH strength, nondominant hand palmar pinch strength; ROC, receiver operating characteristic; WHtR, waist-to-height ratio.

Table 4 presented the odds ratio of anthropometric measures and functional performance for dementia for the total sample.

Initially the sex was tested as modifier effect; however, it showed no change in capacity, and we chose to analyze only the total sample without stratification by sex. Among the anthropometric and functional variables analyzed, only WHeR and the equilibrium showed risk/protection, respectively as significant. Seniors with above 0.67 cm WHeR were 5.63 times more at risk of presenting dementia while older people who have balance were 15% less likely to have dementia.

The main results of this study showed that the prevalence of dementia verified by the results of the MMSE in the elderly was 7%, and that among the anthropometric and functional variables tested, only WC and WHeR showed predictive capacity to dementia. When analyzed the odds ratio, it was found that the maker of the top WHeR to 0.67 cm is 5.6 times more likely to have dementia, while the balance of the presence means protection factor by 15%. It is important to understand that the MMSE results only suggest the presence of dementia, and despite having high correlation with the same, more specific tests are necessary for the diagnosis to be confirmed.

We believe that the highest amount of abdominal fat was verified by WC and WHeR. According to Matsudo et al., 16 the anthropometric measures (greater deposition of fat in the central region) are associated with lower levels of physical fitness and a less active lifestyle. The gain in body weight as well as body fat accumulation particularly in the central region appears to result from a standard genetically programmed, changes in diet and physical activity level, age-related or an interaction between these factors. Lower levels of muscle strength, as well as obesity (BMI ≥ 30), higher waist circumference and percentages of fat are associated with functional declinel. 3

The grip strength is the only muscle strength measurement recommended for clinical practice, so that it is increasingly used for clinical diagnosis in elderly. 17 Lower strength scores can be considered an independent predictor of overall mortality in the elderly over 85 years noninstitutionalized. 18 The lower level physical fitness, lifestyle and excess weight are closely related to social isolation and physical mobility, and in some cases lead to loss of functional independence and neurological disorders, affecting performance cognitive test, as observed in this study. With increasing age, people become less active, their physical capabilities diminish and psychological changes appear as a feeling of old age, stress and depression. Concurrently, there is the appearance of chronic diseases that contribute to deteriorate the aging process; however, it seems that the disuse of physiological functions creates more problems than most of the effects of aging. 16

In this sense, our study found that the balance was considered a protective factor for dementia. Since subjects with higher performance, in the balance of capacity, possibly present greater physical mobility and functional autonomy, which corroborates Borges et al., 19 appointed that the practice of physical activity and functional autonomy both promote rehabilitation, as maintaining the overall health of the elderly maintaining physical fitness, independence and autonomy in activities of daily living. Currently there are various methods for measuring body stability, which is an important component in maintaining the standing position of equilibrium and during daily activities and movements, especially for elderly people, since they are considered to fall-risk population. 20 The system postural control depends on an intact ability (unharmed) to correctly perceive the environment by peripheral sensory system, as well as the processing and integration of proprioceptive pathways, visual and vestibular in the central nervous system. 20

The risk of falls increases with aging, and can have a devastating effect on the independence and quality of life. Often it leads to a vicious cycle of inactivity with future decline in functionality, increased risk of falls, and more likely to need an attendant. Balance tests are useful tools to diagnose the loss of this physical ability. Encouraging seniors to improve physical feature can help them maintain independence and reduce the need for live assistance. 21 Corroborating the findings of this study, Hanna et al., 22 indicated that the moderately active people presented a lower risk by mental disorders than those sedentary, showing that participation in physical exercise programs exerts benefits in the physical domain. Furthermore, psychologically and physically active people probably have a faster cognitive processing. This can be explained in part by a direct and indirect effect of exercise on cognitive function, such that the mechanisms that act directly increase the speed of cognitive processing, leading to an improvement in cerebral circulation and changes in the synthesis and degradation neurotransmitters.

In addition, direct mechanisms, such as low blood pressure, decrease in LDL and triglyceride in the blood plasma and inhibition of platelet aggregation appear to act indirectly by enhancing these functions and the overall functional capacity, reflecting in this way on mental health in the elderly. 23 The prevalence data of our study were similar to those presented by Oliveira et al., 24 which also show that cognitive impairments in the elderly detected by the MMSE were not associated with the mobility test assessed by TSW. These results coincide with the literature and can be explained by the fact that some cases of dementia, patients have exessiva movement and unrest for much of the day. What they are not perceived in Alzheimer's dementia due to lack of extrapyramidal signs and motor slowness.

One limitation of the present data is the sample size and the disproportion between male and female elderly; however, the literature still lacks investigations like this, making relevant the results of this study. Another limitation was the instrument used since the MMSE despite being a widely used test, still lacks studies to better determine its use, as well as the adoption of appropriate points of cuts in the Brazilian population. Applicable, the present study showed low prevalence of dementia in the elderly; however, it is important to keep the concern for variables related to functional capacity, as well as the anthropometric profile, as they present relationship with the cognitive deficits. 25–27 In this sense, health professionals should provide an environment that encourages physical activity safely, maintenance of functional capacity and avoidance of excess weight, particularly in the central part of the body.

In conclusion, the prevalence of dementia in the elderly was considered lower, however similar between male and female. Waist circumference and waist/height ratio showed predictive ability for dementia verified by MMSE, and seniors with greater deposition of fat in the central region of the body showed 5.6 times more likely to have dementia, while those with more balanced presence of a protective factor, with 15%, were less likely to have dementia.

The authors have no conflicts of interest to declare.