Abstract

Objective

To investigate the association between dementia and anthropometric indicators in the elderly from Florianópolis.

Method

This is a cross-sectional population-based survey performed with 1,197 elderly (≥ 60 years) in 2013/2014. Dementia was defined as the combined evidence of low MMSE (Mini-Mental State Examination) score and moderate/severe disability in the activities of daily living. The independent variables were body mass index (BMI), waist circumference (WC), conicity index and waist-to-height ratio (WHtR). Logistic regression (crude and adjusted) was performed to identify associated factors.

Results

Dementia prevalence was estimated at 15.1%. After adjustment for sociodemographic characteristics, lifestyle and depressive symptoms, dementia was positively associated with the upper tertiles of the BMI (OR: 2.32; CI95%: 1.26-4.25), WC (OR: 2.22; CI95%: 1.20-4.11) and WHtR (OR: 2.30; CI95%: 1.19-4.43).

Conclusion

Results have shown that both obesity and abdominal fat were associated with the outcome, suggesting that BMI, WC and WHtR should be considered in the investigation of this relationship.

Keywords
Anthropometry; Body mass index; Abdominal fat; Cognitive disorders

Introduction

Dementia is a progressive or chronic neurodegenerative syndrome, characterized by a sufficiently severe cognitive decline, to the point of negatively affecting social functions and the ability to perform activities of daily living¹1. Chertkow H, Feldman HH, Jacova C, Massoud F. Definitions of dementia and predementia states in Alzheimer’s disease and vascular cognitive impairment: consensus from the Canadian conference on diagnosis of dementia. Alzheimers Res Ther 2013; 5(Supl. 1):S2.. By 2015, 46.8 million individuals with dementia were estimated worldwide. Of these, 58% would be from low- and middle-income countries. Brazil estimated 1.6 million elderly with this characteristic²2. Prince M, Wimo A, Guerchet M, Ali GC, Wu YT, Prina M. World Alzheimer Report 2015. The global impact of dementia. An analysis of prevalence, incidence, cost & trends. London: Alzheimer’s Disease International; 2015.. It is believed that more people will develop dementia with life expectancy increase.

Although its association with age²2. Prince M, Wimo A, Guerchet M, Ali GC, Wu YT, Prina M. World Alzheimer Report 2015. The global impact of dementia. An analysis of prevalence, incidence, cost & trends. London: Alzheimer’s Disease International; 2015., lower income, educational level³3. Bottino CM, Azevedo-Júnior D, Tatsch M, Hototian SR, Moscoso MA, Folquitto J, Scalco AZ, Bazzarella MC, Lopes MA, Litvoc J. Estimate of dementia prevalence in a community sample from São Paulo, Brazil. Dement Geriatr Cogn Disord 2008; 26(4):291-299. and depression⁴4. Lugtenburg A, Zuidersma M, Voshaar RC, Schoevers RA. symptom dimensions of depression and 3-year incidence of dementia results from the Amsterdam Study of the Elderly. J Geriatr Psychiatry Neurol 2016; 29(2):99-107., dementia can be prevented since several modifiable risk factors such as tobacco use⁵5. Teipel S, Grothe MJ. Association between smoking and cholinergic basal forebrain volume in healthy aging and prodromal and dementia stages of Alzheimer’s disease. J Alzheimers Dis 2016; 52(4):1443-1451., alcohol consumption⁶6. Ormstad H, Rosness TA, Bergem AL, Bjertness E, Strand BH. Alcohol consumption in the elderly and risk of dementia related death-a Norwegian prospective study with a 17-year follow-up. Int J Neurosci 2016; 126(2):135-144. and physical inactivity⁷7. Willey JZ, Gardener H, Caunca MR, Moon YP, Dong C, Cheung YK, Sacco RL, Elkind MS, Wright CB. Leisure-time physical activity associates with cognitive decline: The Northern Manhattan Study. Neurology 86(20):1897-1903. contribute to its occurrence. In addition to these factors, overweight/obesity and abdominal (visceral) fat have been studied as potentially modifiable factors associated with dementia⁸8. Luchsinger JA, Patel B, Tang MX, Schupf N, Mayeux R. Measures of adiposity and dementia risk in elderly persons. Arch Neurol 2007; 64(3):392-398.,⁹9. West NA, Haan MN. Body adiposity in late life and risk of dementia or cognitive impairment in a longitudinal community-based study. J Gerontol A Biol Sci Med Sci 2009; 64(1):103-109.. Body mass index (BMI) and different anthropometric indicators of abdominal obesity are used in epidemiological surveillance¹⁰10. Finer N. Medical consequences of obesity. Medicine 2011; 39(1):18-23. and risk assessment of developing metabolic, cardiovascular, musculoskeletal diseases and certain types of cancer, and many of these diseases are risk factors for dementia¹¹11. Brasil. Ministério da Saúde (MS). Protocolos do sistema de vigilância alimentar e nutricional na assistência à saúde. Brasília: MS; 2008.. More recently, anthropometric indicators (BMI, waist circumference, waist-to-height ratio, conicity index) have been used in association with dementia and this relationship is not yet fully established⁸8. Luchsinger JA, Patel B, Tang MX, Schupf N, Mayeux R. Measures of adiposity and dementia risk in elderly persons. Arch Neurol 2007; 64(3):392-398.,⁹9. West NA, Haan MN. Body adiposity in late life and risk of dementia or cognitive impairment in a longitudinal community-based study. J Gerontol A Biol Sci Med Sci 2009; 64(1):103-109.,¹²12. Gorospe EC, Dave JK. The risk of dementia with increased body mass index. Age Ageing 2007; 36(1):23-29.

13. Qizilbash N, Gregson J, Johnson ME, Pearce N, Douglas I, Wing K, Evans SJ, Pocock SJ. BMI and risk of dementia in two million people over two decades: a retrospective cohort study. Lancet Diabetes Endocrinol 2015; 3(6):431-436.-¹⁴14. Brito WA, Mendes L, Sales MM, Neto J, Brito C, Silva Grigoletto M, Ferreira AP. Cognitive profile associated with functional and anthropometric aspects in elderly. Rev Andal Med Deporte 2016; 9(4):154-159.. In addition, there are ongoing discussions on whether overweight/obesity and abdominal fat play a similar role in the association with dementia¹⁵15. Ghaderpanahi M, Fakhrzadeh H, Sharifi F, Mirarefin M, Badamchizade Z, Larijani B. Association between late-life body mass index, waist circumference, and dementia: Kahrizak Elderly Study. J Am Geriatr Soc 2012; 60(1):173-174..

As with dementia, the prevalence of overweight/obesity has been increasing worldwide, with projections of increases in the coming decades¹⁶16. Prince M, Ali G-C, Guerchet M, Prina AM, Albanese E, Wu Y-T. Recent global trends in the prevalence and incidence of dementia, and survival with dementia. Alzheimers Res Ther 2016; 8(1):23.,¹⁷17. Kelly T, Yang W, Chen CS, Reynolds K, He J. Global burden of obesity in 2005 and projections to 2030. Int J Obes 2008; 32(9):1431-1437.. These conditions contribute to the increase of the expenses in the health system, and with implications in the individual, familiar and social scope¹⁸18. Yang Z, Zhang K, Lin PJ, Clevenger C, Atherly A. A longitudinal analysis of the lifetime cost of dementia. Health Serv Res 2012; 47(4):1660-1678.,¹⁹19. Canella DS, Novaes HM, Levy RB. Influência do excesso de peso e da obesidade nos gastos em saúde nos domicílios brasileiros. Cad Saude Publica 2015; 31(11):2331-2341.. The identification of health markers associated with dementia is important to the health system, since it allows establishing those at greater risk of developing dementia, preventing and/or treating risk factors, improving the quality of life and the autonomy of individuals. Thus, this study aimed to investigate the association between dementia and anthropometric indicators in the elderly from Florianópolis.

Methodology

This is a cross-sectional, population-based epidemiological survey performed with data from the second wave of the cohort study entitled EpiFloripa Ageing. This study investigates the health conditions of people 60 years of age or older living in the city of Florianópolis.

Population details, sample selection and site characterization have been previously published²⁰20. Confortin SC, Schneider IJC, Antes DL, Cembranel F, Ono LM, Marques LP, Borges LJ, Krug RR, d’Orsi E. Condições de vida e saúde de idosos: resultados do estudo de coorte EpiFloripa Idoso. Epidemiol Serv Saúde 2017; 26(2):305-317.. At the survey’s baseline (2009/2010), 1,702 individuals were interviewed (response rate of 89.1%). In the second wave of the study conducted in 2013/2014, 217 deaths were excluded, which resulted in 1,488 eligible elderly. The analytical sample of this study includes the 1,197 individuals that were part of the 2013/14 household interviews.

The Committee of Ethics in Research with Human Beings of the Federal University of Santa Catarina approved the project, and an Informed Consent Form was signed.

Dependent variable

Dementia

Dementia was investigated for the presence of low score in the Mini-Mental State Examination (MMSE) and moderate to severe activities of daily living (ADL) disability. The MMSE was categorized considering the educational level²¹21. Almeida OP. Mini exame do estado mental e o diagnóstico de demência no Brasil. Arq Neuropsiquiatr 1998; 56(3-B):605-612. (probable cognitive impairment – no cognitive impairment). ADL disability was assessed using the Brazilian Questionnaire for Multidimensional Functional Assessment, validated in Brazil²²22. Blay SL, Ramos LR, Mari JJ. Validity of a Brazilian version of the Older Americans Resources and Services (OARS) mental health screening questionnaire. J Am Geriatr Soc 1988; 36(8):687-692., using the following classification: no disability (difficulty/disability in zero to three activities) and with disability (difficulty/disability in four or more activities).

Independent variables

Body mass and height were measured using standardized procedures, and from these measurements body mass index (BMI) [BMI (kg/m²2. Prince M, Wimo A, Guerchet M, Ali GC, Wu YT, Prina M. World Alzheimer Report 2015. The global impact of dementia. An analysis of prevalence, incidence, cost & trends. London: Alzheimer’s Disease International; 2015.) = body mass (Kg)/height (m)²2. Prince M, Wimo A, Guerchet M, Ali GC, Wu YT, Prina M. World Alzheimer Report 2015. The global impact of dementia. An analysis of prevalence, incidence, cost & trends. London: Alzheimer’s Disease International; 2015.] was calculated. The waist circumference (WC) was measured according to the standardization of Callaway et al.²³23. Callaway CW, Chumlea CW, Bouchard C, Himes JH, Lohamn TG, Martin AD, Mitchell CD, Mueller WH, Roche AF, Seefeldt VD. Circumferences. In: Lohman TG, Roche AF, Martorell R, editors. Anthropometric Standardization Reference Manual. Champaign: Human Kinetics; 1988. p.39-54.. The waist-to-height ratio (WHtR) was calculated by dividing WC (cm) by height (cm). The conicity index (CI) was verified through the waist circumference (m) over 0.109 √weight (Kg) / height (m) [WC / 0.109√Weight (Kg) / height (m)]²⁴24. Valdez R. A simple model- based index of abdominal obesity. J Clin Epidemiol 1991; 44(9):955-056..

All independent variables were classified in tertiles (≤ lower tertile, medium tertile and ≥ upper tertile).

Adjustment variables

Adjustment variables were: sex; age group (60-69 years, 70-79 years and 80 years and older); educational level (no formal education, 1 to 4 years, 5 to 8 years, 9 to 11 years and 12 years and over); household income in minimum wages (≥ 1 MW, greater than <1 MW ≥ 3 MW, < 3 MW ≥ 5 MW, <5 MW ≥ 10 MW, <10 MW); smoking (never smoked, former smoker and current smoker) and alcohol consumption (non-consumption, non-abusive consumption and abusive consumption) verified through the first three questions in the AUDIT questionnaire (The Alcohol Use Disorders Identification Test)²⁵25. Lima CT, Freire ACC, Silva APB, Teixeira RM, Farrell M, Prince M. Concurrent and construct validity of the AUDIT in an urban Brazilian sample. Alcohol Alcohol 2005; 40(6):584-589.. Depressive symptoms were assessed using the Geriatric Depression Scale²⁶26. Almeida OP, Almeida SA. Confiabilidade da versão brasileira da Escala de Depressão em Geriatria (GDS) versão reduzida. Arq Neuropsiquiatr 1999; 57(2B):421-426. (normal < 6; suspected depression ≥ 6). Leisure physical activity was verified by means of the long version of International Physical Activity Questionnaire (IPAQ)²⁷27. Craig CL, Marshall AL, Sjostrom M, Bauman AE, Booth ML, Ainsworth BE, Pratt M, Ekelund U, Yngve A, Sallis JF, Oja P. International physical activity questionnaire: 12-country reliability and validity. Med Sci Sports Exerc 2003; 35(8):1381-1395., and categorized as: insufficiently active (< 150 minutes of physical activity in weekly leisure) and physically active (≥150 minutes of physical activity in the weekly leisure).

Statistical analysis

Descriptive analyses were performed using prevalence and confidence intervals (95% CI) (categorical variables) and mean, 95% CI, minimum and maximum values and tertile distribution (continuous variables).

The association between dementia and anthropometric indicators was identified through logistic regression models (crude and adjusted analyzes), in which odds ratios (OR) with their respective 95% CI were estimated. The statistical significance level considered was 5%.

Data analyses were conducted in the statistical program Stata SE 13.0 (Stata Corp. College Station, USA). All analyses took into account the effect of the study design, using the svy command.

Results

The sample of this study consisted of 1,197 individuals with mean age of 73.9 ± 7.3 years. Most individuals were female, aged between 70 and 79 years, with a household income of less than three MW, never smoked, no alcohol consumption, insufficiently active in leisure and without suspected depression (Table 1). The estimated prevalence of dementia was 15.1% (95% CI: 12.6-18.0).

Table 2 shows mean values, standard deviations, minimum and maximum values and the distribution of anthropometric indicators values in tertiles. The upper tertiles were: BMI ≥ 29.53; WC ≥100.00; WHtR ≥ 100.00 and CI > 1.36.

The crude and adjusted analyses of the association between anthropometric indicators and dementia are shown in Table 3. In the crude analysis, dementia was only associated with the upper tertiles of the WHtR and the conicity index. After adjustment, the WHtR maintained the association and dementia was also associated with BMI and WC. The probability of outcome was approximately two-fold higher in those in the upper tertile of BMI, WC and the WHtR, when compared to the lower tertile.

Discussion

This study verified the association of dementia with BMI, WC, conicity index and WHtR in the elderly from Florianópolis. According to results, dementia showed an independent association with the highest tertile of all anthropometric indicators, except the conicity index. The strength of association was similar for all three indicators.

In this study, the estimated prevalence of dementia (15.1%) and prevalence rates differ little from that reported in other studies³3. Bottino CM, Azevedo-Júnior D, Tatsch M, Hototian SR, Moscoso MA, Folquitto J, Scalco AZ, Bazzarella MC, Lopes MA, Litvoc J. Estimate of dementia prevalence in a community sample from São Paulo, Brazil. Dement Geriatr Cogn Disord 2008; 26(4):291-299.,²⁸28. Correa Ribeiro PC, Lopes CS, Lourenço RA. Prevalence of dementia in elderly clients of a private health care plan: a study of the FIBRA-RJ, Brazil. Dement Geriatr Cogn Disord 2013; 35(1-2):77-86.. In the study by Correa Ribeiro et al.²⁸28. Correa Ribeiro PC, Lopes CS, Lourenço RA. Prevalence of dementia in elderly clients of a private health care plan: a study of the FIBRA-RJ, Brazil. Dement Geriatr Cogn Disord 2013; 35(1-2):77-86. (Network for Research on Frailty of the Brazilian Elderly – Rio de Janeiro Section, FIBRA-RJ), carried out with 683 health insurance clients (≥ 67 years) of Rio de Janeiro, the estimated prevalence was 16.9%. However, in the study by Bottino et al.³3. Bottino CM, Azevedo-Júnior D, Tatsch M, Hototian SR, Moscoso MA, Folquitto J, Scalco AZ, Bazzarella MC, Lopes MA, Litvoc J. Estimate of dementia prevalence in a community sample from São Paulo, Brazil. Dement Geriatr Cogn Disord 2008; 26(4):291-299., conducted with a random sample of community-dwelling elderly living in 3 districts of the city of São Paulo (n=1,563), the prevalence adjusted for study design was 12.5% among people aged 60 and older. Differences in prevalence estimates may be related to the use of different instruments and/or categorization used to verify dementia in the studies, methods of sampling/data collection.

The results showed that dementia was positively associated with the upper tertile of BMI, as was identified in a systematic review study¹²12. Gorospe EC, Dave JK. The risk of dementia with increased body mass index. Age Ageing 2007; 36(1):23-29.. Data from prospective studies have shown controversial results¹³13. Qizilbash N, Gregson J, Johnson ME, Pearce N, Douglas I, Wing K, Evans SJ, Pocock SJ. BMI and risk of dementia in two million people over two decades: a retrospective cohort study. Lancet Diabetes Endocrinol 2015; 3(6):431-436.,²⁹29. Power BD, Alfonso H, Flicker L, Hankey GJ, Yeap BB, Almeida OP. Body adiposity in later life and the incidence of dementia: the health in men study. PloS One 2011; 6(3):e17902.,³⁰30. Jeong S-K, Nam H-S, Son M-H, Son E-J, Cho K-H. Interactive effect of obesity indexes on cognition. Dement Geriatr Cogn Disord 2005; 19(2-3):91-96.. In the follow-up study conducted by Qizilbash et al.¹³13. Qizilbash N, Gregson J, Johnson ME, Pearce N, Douglas I, Wing K, Evans SJ, Pocock SJ. BMI and risk of dementia in two million people over two decades: a retrospective cohort study. Lancet Diabetes Endocrinol 2015; 3(6):431-436., carried out with 1,958,191 individuals (40 years of age or older) receiving primary care in the United Kingdom, the risk of dementia was higher in those with low weight, while overweight had a protective role. However, unlike this study and as pointed out by Kivimäki et al.³¹31. Kivimäki M, Singh-Manoux A, Shipley MJ, Elbaz A. Does midlife obesity really lower dementia risk? Lancet Diabetes Endocrinol 2015; 3(7):498., Qizilbash et al.¹³13. Qizilbash N, Gregson J, Johnson ME, Pearce N, Douglas I, Wing K, Evans SJ, Pocock SJ. BMI and risk of dementia in two million people over two decades: a retrospective cohort study. Lancet Diabetes Endocrinol 2015; 3(6):431-436. did not consider the covariates related to the lifestyle and educational level of the participants. In addition, the same nutritional status score (BMI) was used for individuals of different age groups, both for those aged less than and over 60 years, including for the elderly aged 80 and older. In the study by Jeong et al.³⁰30. Jeong S-K, Nam H-S, Son M-H, Son E-J, Cho K-H. Interactive effect of obesity indexes on cognition. Dement Geriatr Cogn Disord 2005; 19(2-3):91-96. conducted with 467 elderly (≥ 65 years) from three rural communities in South Korea, authors found that high BMI was associated with dementia only in individuals with elevated WC. In people whose WC was normal, the BMI lost the association. Data from systematic review, meta-analysis, and prospective studies³²32. Tolppanen AM, Ngandu T, Kåreholt I, Laatikainen T, Rusanen M, Soininen H, Kivipelto M. Midlife and late-life body mass index and late-life dementia: results from a prospective population-based cohort. J Alzheimers Dis 2014; 38(1):201-209.

33. Loef M, Walach H. Midlife obesity and dementia: Meta-analysis and adjusted forecast of dementia prevalence in the United States and China. Obesity (Silver Spring) 2013; 21(1):E51-55.-³⁴34. Anstey KJ, Cherbuin N, Budge M, Young J. Body mass index in midlife and late-life as a risk factor for dementia: a meta-analysis of prospective studies. Obes Rev 2011; 12(5):e426-37. have shown that being overweight at middle age increases the risk of dementia at advanced age, which is in line with the results of this study, although BMI cutoff points values have been different.

The reason why overweight/obesity is associated with dementia is not yet fully understood, probably due to the complexity of its determinants, which involve environmental, behavioral, metabolic, genetic and hereditary factors³⁵35. Medic N, Ziauddeen H, Ersche KD, Farooqi IS, Bullmore ET, Nathan PJ, Ronan L, Fletcher PC. Increased body mass index is associated with specific regional alterations in brain structure. Int J Obes 2016; 40(7):1177-1182.. In addition to the effects mediated by chronic diseases that are risk factors for dementia (diabetes, high cholesterol, cardiovascular disease and hypertension), it is believed that overweight/obesity has a negative influence on the brain long before the onset of dementia symptoms³⁶36. Emmerzaal TL, Kiliaan AJ, Gustafson DR. 2003-2013: a decade of body mass index, Alzheimer’s disease, and dementia. J Alzheimers Dis 2015; 43(3):739-755.. In addition to changes in brain structure³⁵35. Medic N, Ziauddeen H, Ersche KD, Farooqi IS, Bullmore ET, Nathan PJ, Ronan L, Fletcher PC. Increased body mass index is associated with specific regional alterations in brain structure. Int J Obes 2016; 40(7):1177-1182., oxidative stress, deregulation in the hormones leptin and insulin³⁷37. Smith E, Hay P, Campbell L, Trollor JN. A review of the association between obesity and cognitive function across the lifespan: implications for novel approaches to prevention and treatment, Obes Rev 2011; 12(9):740-755. and a variety of metabolites bioavailable by adipose tissue affect the brain directly through the blood-brain barrier³⁶36. Emmerzaal TL, Kiliaan AJ, Gustafson DR. 2003-2013: a decade of body mass index, Alzheimer’s disease, and dementia. J Alzheimers Dis 2015; 43(3):739-755.. However, other authors postulate that the risk for dementia is related to visceral adiposity³⁸38. Whitmer R, Gustafson D, Barrett-Connor E, Haan M, Gunderson E, Yaffe K. Central obesity and increased risk of dementia more than three decades later. Neurology 2008; 71(14):1057-1064..

In this study, dementia was also associated with the highest tertile of two indicators of centralized fat, WC and WHtR, similar to other studies⁸8. Luchsinger JA, Patel B, Tang MX, Schupf N, Mayeux R. Measures of adiposity and dementia risk in elderly persons. Arch Neurol 2007; 64(3):392-398.,⁹9. West NA, Haan MN. Body adiposity in late life and risk of dementia or cognitive impairment in a longitudinal community-based study. J Gerontol A Biol Sci Med Sci 2009; 64(1):103-109.,¹⁴14. Brito WA, Mendes L, Sales MM, Neto J, Brito C, Silva Grigoletto M, Ferreira AP. Cognitive profile associated with functional and anthropometric aspects in elderly. Rev Andal Med Deporte 2016; 9(4):154-159.. The strength of association was similar for both indicators. Data from the Sacramento Area Latino Study on Aging (SALSA) study with 1,351 community-dwelling individuals (aged 60 to 101 years) showed that the largest WC in the baseline period (1998-99) was associated with a higher rate of dementia after about 7 years⁹9. West NA, Haan MN. Body adiposity in late life and risk of dementia or cognitive impairment in a longitudinal community-based study. J Gerontol A Biol Sci Med Sci 2009; 64(1):103-109..

In the follow-up study (1992-2003) by Luchsinger et al.⁸8. Luchsinger JA, Patel B, Tang MX, Schupf N, Mayeux R. Measures of adiposity and dementia risk in elderly persons. Arch Neurol 2007; 64(3):392-398., involving a random sample of subjects (≥ 65 years old) living in the northern part of New York City, attended by Medicare, the largest WC was associated with a higher risk of dementia in those aged under 76 years. Brito et al.¹⁴14. Brito WA, Mendes L, Sales MM, Neto J, Brito C, Silva Grigoletto M, Ferreira AP. Cognitive profile associated with functional and anthropometric aspects in elderly. Rev Andal Med Deporte 2016; 9(4):154-159. found an association between dementia and WHtR in the elderly (61 to 90 years) of the Federal District (Brazil), and found no association with CI, as in this study. However, it is noteworthy that this study was performed with only 84 elderly people living in the community.

There are some potential factors that explain the relationship between visceral fat and dementia, in addition to factors related to overweight/obesity. Visceral and subcutaneous fat secretion profiles are distinct, and the former is the more damaging one. Visceral fat is metabolically active and secretes proinflammatory cytokines that can affect tissues locally and systematically³⁸38. Whitmer R, Gustafson D, Barrett-Connor E, Haan M, Gunderson E, Yaffe K. Central obesity and increased risk of dementia more than three decades later. Neurology 2008; 71(14):1057-1064.. Systemic inflammation is related to metabolic syndrome, insulin resistance, diabetes, dyslipidemias and cardiovascular diseases, conditions that increase the risk of dementia³⁸38. Whitmer R, Gustafson D, Barrett-Connor E, Haan M, Gunderson E, Yaffe K. Central obesity and increased risk of dementia more than three decades later. Neurology 2008; 71(14):1057-1064.,³⁹39. Tchernof A, Després JP. Pathophysiology of human visceral obesity: an update. Physiol Rev 2013; 93(1):359-404..

Among the positive aspects of this research is the fact that the study is population-based, with a representative sample of elderly people, with a good response rate (89.1%), that is, without significant loss of participants between baseline and follow-up. The methodology used in data collection, training of interviewers, standardization of measures and the use of validated questionnaires for the target population also reinforce data quality of this study. The adjustment for characteristics that has an association with dementia and overweight/obesity is also highlighted. The use of respondent proxy in issues related to ADL disability and the use of self-reported questions are the limitations of this study.

In conclusion, according to the results, dementia was positively associated with the highest values (upper tertile) of BMI, WC and WHtR, that is, both obesity and abdominal fat were associated with the outcome. It is important to note that there is no consensus regarding the best BMI value for the elderly, however, the value of the upper tertile identified in this study is higher than the value used in Brazil by the Food and Nutrition Surveillance System¹¹11. Brasil. Ministério da Saúde (MS). Protocolos do sistema de vigilância alimentar e nutricional na assistência à saúde. Brasília: MS; 2008.. Regarding WC, there is still no consensus regarding the cutoff point value for the elderly and different populations⁴⁰40. Barbosa AR, Munaretti DB, Coqueiro RD, Borgatto AF. Anthropometric indexes of obesity and hypertension in elderly from Cuba and Barbados. J Nutr Health Aging 2011; 15(1):17-21.. Similarly, WHtR and conicity index are still poorly used in studies involving the elderly, especially in association with dementia. However, it should be noted that these are non-invasive, easy to apply and low cost indicators that can be used together in clinical practice, health surveillance and planning.

Since overweight/obesity prevalence is increasing worldwide¹⁶16. Prince M, Ali G-C, Guerchet M, Prina AM, Albanese E, Wu Y-T. Recent global trends in the prevalence and incidence of dementia, and survival with dementia. Alzheimers Res Ther 2016; 8(1):23.,¹⁷17. Kelly T, Yang W, Chen CS, Reynolds K, He J. Global burden of obesity in 2005 and projections to 2030. Int J Obes 2008; 32(9):1431-1437., the association of anthropometric indicators of overweight/abdominal obesity with dementia should be taken into account, although other studies, including follow-up studies, should investigate better this association.

Acknowledgements

Authors would like to thank study participants and the National Council for Scientific and Technological Development for funding the research.

References

Publication Dates

History