diabetes mellitus is a global health problem and an important cause of mortality and morbidity in many countries .
the trend of increasing diabetes prevalence seems to prevail among developing countries . in brazil , diabetes affected 11.3 million people in 2011 , and this number is likely to triple by 2030 .
estimates suggest that the diabetes rate in less developed countries will increase by 69% between 2010 and 2030 .
diabetes imposes a burden for society such as high socioeconomic costs that have an impact on productivity as well as life and health quality .
this situation seems to be worse in developing countries , where the healthcare system often fails to meet demand .
studies have concluded that a western dietary pattern , sedentary lifestyle , and genetic factors play a central role in diabetes development .
the brazilian ministry of health has followed the world health organization 's recommendations and has taken some actions to monitor diabetes such as an annual telephone - based survey .
socioeconomic disparities might contribute to some degree of heterogeneity in measures of prevalence between regions .
a study demonstrated that diabetes prevalence across the brazilian states ranged from 11% to 25% , with an overall rate of 16% in 2001 .
brasilia , the capital of brazil , is located in the central - west region of the country .
the city has the highest human development index in brazil , but it has one of the highest levels of social inequality compared with other brazilian regions [ 11 , 12 ] . these characteristics of brasilia warrant further investigation in many aspects , including the health status of its population .
thus , the goal of this study was to estimate the prevalence of diabetes and its associated risk factors in adults of brasilia , brazil .
the present cross - sectional population - based study was conducted in brasilia , brazil , from february to may 2012 .
the sample size was calculated based on an estimation of 16% of self - reported diabetes cases . considering a 95% confidence interval ( ci ) , precision of 2.25% , and a design effect of 1.8 ,
we added 10% of the sample size to compensate for any eventual attrition , which resulted in a final sample of 2,019 individuals .
participants were selected by a two - stage probability sampling process by cluster and were stratified by sex and age .
a total of 220 census tracts were randomly selected from 3,886 urban tracts with more than 200 inhabitants .
up to 10 households were selected from each census tract . in total , one adult per household was selected following the predefined quotas of sex and age to answer the interview . trained professionals surveyed all of the participants in their homes using a semistructured questionnaire . to ensure reliability , 20% of the interviews were audited by telephone . to test the understanding and acceptability of the questionnaire ,
150 pilot interviews were held prior to data collection . the dependent variable was self - reported diabetes .
independent variables included demographic characteristics ( age group , sex , marital status , living arrangements , and household location ) , socioeconomic characteristics ( level of education , occupation , and social class ) , chronic health conditions ( self - reported hypertension , depression , respiratory diseases , cardiovascular diseases , and other chronic diseases ) , access to healthcare ( health insurance , medical consultation , and hospitalization ) , and perceived health status ( mobility , self - care , usual activities , pain / discomfort , and anxiety / depression ) .
the stratification was based on the brazilian criterion of economic classification , which defines five classes , with  a  being the wealthiest group and  e  being the poorest . in all of the analyses ,
self - reported diabetes prevalence in the population was then calculated at a 95% ci . to identify factors related to diabetes prevalence , we calculated prevalence ratios ( pr ) using bivariate analysis and calculated the adjusted pr by a poisson regression model with robust variance . in this model ,
we preferred to use this more conservative model that included all of the variables to allow for better confounding adjustment .
other models that included only the most significant variables were tested and did not change the significance of the variables .
associations were considered to be statistically significant when p < 0.05 . the stata software version 10.1 was used for all of the calculations .
approximately 60% of the participants were women , and 57% were aged between 35 and 60 years .
most of the participants belonged to economic class  c ,  had completed high school , were married or cohabitating , lived with at least one more person in the household , and dwelled in a satellite town .
diabetes was self - reported by 10.1% ( 95% ci : 8.5%11.6% ) of the adult population in brasilia .
table 1 depicts diabetes prevalence and prevalence ratios ( pr ) before and after adjustment by poisson regression .
the age group of 3565 years , hypertension , respiratory disease , cardiovascular disease , and pain / discomfort were significantly associated with diabetes .
sex , marital status , living arrangements , social class , education level , employability , living location , health insurance , medical consultation , hospitalization , physical mobility , self - care , usual activities , and anxiety / depression revealed no significant association . 

figure 2 illustrates differences in diabetes prevalence between all persons and the population with comorbidities .
diabetes prevalence in the age range 3065 years is higher among individuals with cardiovascular disease , followed by those with hypertension and those with respiratory diseases .
this result suggests that the likelihood of diabetes increases with age and is greater in persons with comorbidities .
an age of 35 years and over , presence of pain or discomfort , cardiovascular disease , hypertension , and respiratory disease were positively associated with diabetes in the adult population of brasilia
. the main limitations of our study were the self - reported assessments of the primary outcome and independent variables .
self - reported diabetes might be a source of bias because individuals need to be aware of the diagnosis prior to answering , which could result in disease underestimation .
however , performing a clinical test for diagnosing diabetes is not always possible in population - based studies .
thus , self - reported answers regarding diabetes have been a common practice according to the literature [ 17 , 18 ] .
another shortcoming was the cross - sectional design of the study , which hampers a causal relationship between diabetes and the significantly associated factors identified herein .
a previous population - based study developed in brazil in 2008 used telephone interviews to investigate self - reported diabetes prevalence and found low prevalence rates in brasilia .
another study found that brasilia was the region with the highest diabetes prevalence compared with other brazilian regions from 2002 to 2007 .
research identified a significant increase in self - reported diabetes in the brazilian population because it ascended from 3.3% in 1998 to 5.3% in 2008 . in south and central america ,
the estimated diabetes prevalence in 2013 was 8.0% ; brazil demonstrated the highest prevalence , followed by colombia and argentina .
the variability of diabetes prevalence may be due to a poorer diet and a lack of physical activity , or it could be related to better access to diagnostic testing . as expected , our results demonstrated that the likelihood of having diabetes increases with age . from a healthcare policy perspective , diabetes prevention and management programs should target young people and not only the elderly population .
diabetes prevalence was higher among individuals with cardiovascular disease , hypertension , and respiratory disease compared with the general population .
there is convincing evidence of the association between diabetes and hypertension , which increases the risk of a cardiovascular event .
a 2003 study conducted in so luis , a city located in one of the poorest areas of brazil , observed a positive association between diabetes and hypertension . a cross - sectional study conducted between 2004 and 2005 in so jose do rio preto , a city in the brazilian southeast region , revealed that the diabetes prevalence was almost threefold higher in a population of hypertensive individuals compared with the general population . a cohort study performed in women between 1988 and 1996 throughout 11 states in the united states found that chronic obstructive pulmonary disease was a diabetes risk factor . a retrospective cohort study conducted in northern
california reported that individuals with diabetes are at a greater risk of developing asthma , chronic obstructive pulmonary disease , fibrosis , and pneumonia .
in contrast , a systematic review of 10 studies suggests that growing up in a socioeconomically disadvantaged environment may contribute to diabetes in later life .
an australian study also described a positive association between socioeconomic variables and diabetes in adults aged 45 years and over .
the perceived health dimensions physical mobility , self - care , usual activities , and anxiety / depression were not associated with diabetes in our sample . in 2012 , a literature review found that diabetes was considered a potential risk factor for the poor performance of daily life activities among individuals aged 50 years and over . a study conducted with older adult
other than depression , this finding might depict an association between diabetes and activities of daily living , which may be developed at older ages .
diabetes is a common health condition in adults living in brasilia and is positively associated with older age , cardiovascular disease , hypertension , respiratory disease , and presence of pain or discomfort .
 
 aim . 
 the aim of this study was to estimate the prevalence of diabetes and its associated risk factors in adults from brasilia , brazil . methods . 
 the present cross - sectional population - based study consisted of interviews with individuals aged 1865 years . 
 participants were selected through two - stage probability sampling by clusters and stratified by sex and age . 
 demographic and clinical data were collected directly with participants from february to may 2012 . 
 self - reported diabetes prevalence was calculated at a 95% confidence interval ( ci ) . 
 prevalence ratios ( pr ) were adjusted by poisson regression with robust variance . 
 results . in all , 1,820 individuals were interviewed . 
 diabetes prevalence in the adult population of brasilia was 10.1% ( 95% ci , 8.5%11.6% ) . 
 variables associated with diabetes were an age between 35 and 49 years ( pr = 1.83 ; 95% ci , 1.192.82 ) or 50 and 65 years ( pr = 1.95 ; 95% ci , 1.173.23 ) , hypertension ( pr = 4.04 ; 95% ci , 2.666.13 ) , respiratory disease ( pr = 1.67 ; 95% ci , 1.112.50 ) , cardiovascular disease ( pr = 1.74 ; 95% ci , 1.152.63 ) , and pain / discomfort ( pr = 1.71 ; 95% ci , 1.212.41 ) . conclusion . 
 diabetes is a prevalent condition in adults living in brasilia , and disease risk increases with age and comorbidities . 
 future health policies should focus on screening programs and prevention for the more vulnerable groups . 
1. Introduction
2. Materials and Methods
3. Results
4. Discussion
5. Conclusion