Factors associated with the development of diabetes mellitus in older caregivers

Objective: evaluate the factors associated with the risk of diabetes mellitus in older caregivers. Method: this is a cross-sectional study conducted with 326 older caregivers enrolled in Family Health Units. Data were collected using a sociodemographic characterization questionnaire, clinical and care information, and the Finnish Diabetes Risk Score to assess the risk of developing diabetes . Results: 35.5% of the caregivers presented a high risk of developing diabetes. The factors associated with the risk of developing diabetes were: use of medication (OR = 3.88), satisfactory or poor health assessment (OR = 1.72), and the fact of being female (OR = 0.48). Conclusion: more than one third of older caregivers present high risk of developing diabetes. Therefore, being female, living with other people, using medication, and having a poor health assessment are factors associated with increased risk of developing diabetes.


INTRODUCTION
Brazil sees now a moment of demographic transition due to the fast and intense increase of the elderly population and changes in the epidemiology of the diseases from infectious to noncommunicable (or chronic) diseases (1) . Chronicity of health problems and longevity of the population help increase the number of elderly people with impaired function, who then require a caregiver (2) .
Most caregivers are family members, providing care in informal environments (3) , an intense task that causes several changes in the daily life of caregivers, especially if they are also elderly. Some studies highlight an increase in the number of older people who are informal caregivers of other elderly people with more serious health problems (2,4) .
The task of being a caregiver can bring benefits and positive results, but the literature highlights the prevalence of overload or burden due to emotional stress, physical exhaustion and health problems (5) . Extended care period associated with the degree of dependence of the elderly can have a negative impact on the health of caregivers, as they are overloaded with daily activities that imply greater risk of psychiatric and physical morbidity (5)(6)(7) .
In this sense, caregiver health care should focus on monitoring and control of risk factors for chronic diseases, such as diabetes mellitus (DM), which is one of the major public health problems (8) . According to estimates, DM cases in Brazil reach 14.3 million (9) . Among the elderly population, this prevalence increases with aging, affecting around 20% of the population aged 65 to 74 years, and more than 3.5 million people aged 75 years or more (10) .
Results of the National Health Survey show that female people, the elderly population, low level of school education, and low income generate greater diagnosis of DM and more access to medication and medical consultation (10)(11) . These data were reported in other national studies (12)(13)(14) .
Considering the above, having a better understanding of the factors associated with the risk of developing DM among caregivers enables essential indicators for the development of health policies for the prevention and control of these diseases. Because of the important role of caregivers, their health conditions should be preserved, allowing them to provide good quality care and promote their physical health.

OBJECTIVE
Evaluate the factors associated with the risk of diabetes mellitus in older caregivers.

Ethical aspects
The development of this study observed the ethical standards in research involving human beings. All participants signed an informed consent form before the interview. The research project was approved by the Human Research Ethics Committee of Universidade Federal de São Carlos.

Study design, site and period
This is a quantitative cross-sectional study conducted in 17 Family Health Units (FHUs) of a municipality in the State of São Paulo, from April to November 2014.

Sample, inclusion criteria and exclusion criteria
Participants were selected from lists offered by the USF teams, which contain information from homes with two or more elderly people. In total, 594 homes were visited; 26 older people were excluded due to death, 28 due to address changes, 69 were not found after three attempts, and 36 were considered fully independent according to functionality scales, resulting in 351 older caregivers interviewed. Of the 351 participants who filled the complete questionnaire, 25 were excluded because they did not accept to perform anthropometric measurements. Therefore, the final sample consisted of 326 older caregivers.
The inclusion criteria were: aged 60 years or over, enrolled in a municipal USF, and acting as the primary caregiver of a dependent elderly person (≥ 60 years old) living in the same house. The Katz Index of Independence in Activities of Daily Living (15) and the Lawton Instrumental Activities of Daily Living Scale (16) were used to distinguish the older caregivers from dependent elderly patients. The most independent elderly person in the household was considered the caregiver.

Study protocol
A questionnaire was used to collect sociodemographic data and clinical and care information about sex, age, marital status, school education level, family income, number of people living in the same home, subjective health assessment, use of medication, degree of relationship with the elderly patient, and daily care period.
The Finnish Diabetes Risk Score (Findrisc), developed in Finland and validated by the Department of Public Health of the University of Helsinki (17) , was used to assess the risk for developing DM. So far, this instrument has not been validated in Portuguese; however, it is an easy low-cost instrument that has been used in other Brazilian studies (18)(19)(20) .
BMI was calculated using the formula: BMI = kg/m 2 , with a mechanical scale of 150 kg capacity. Height was measured using anthropometric inelastic tape with barefoot participants, weight equally distributed between the feet, arms down next to the body, in an upright position, with the heels together and touching the wall. Abdominal circumference was measured using a measuring tape in centimeters placed between the iliac crest and the last rib. The other variables were self-reported by participants.

Analysis of results and statistics
Data were analyzed in the Statistical Package for the Social Sciences (SPSS for Windows), version 22.0. Calculations were made for the descriptive analysis of data. For the assessment of the factors associated with the outcome, a multiple logistic regression analysis was performed using the stepwise forward method (21) . For the selection of the variables, univariate regression analyses were performed, adopting p<0.20 as the critical level, and later in the multiple model, only those considered significant (p <0.05) or adjusted to the risk measure by at least 10%, were used.

RESULTS
Most caregivers were female (76.1%), mean age of 69.7 years (±7.0), and married (90.2%). Their mean school education level was 3.7 years (±3.4) with prevalence of elementary education (57.5%). Most of them (70.2%) lived with up to three people in the same house, their average income was BRL861.65, and 52.1% of them received one to two minimum wages.
Regarding the characteristics of care, most caregivers were the patient's spouse (84.7%) and provided care one to four hours a day (51.5%). In general, they self-declared their health as good (40.8%) and satisfactory (37.4%). Most of them were taking controlled medicines (89.3%). Table 1 shows the characteristics of elderly caregivers.  Table 2 shows the risk factors according to Findrisc, where 72.4% of caregivers were aged ≥65 years, the minority did not practice physical activity (39.3%) and reported no daily intake of fruits and/or vegetables (17.8% %). Among the caregivers, 36.2% were overweight, 52.2% had a history of DM, only 16.6% had prior hyperglycemia, and 67.8% were taking antihypertensive medication.
The Findrisc mean score was 13.5 (±4.1); therefore, considering the questionnaire categories, 35.5% presented high risk ( Table 2). Table 3 shows the results of multiple logistic regression analysis. The risk for DM was associated with the following factors: of advanced aging corresponds to 1.04 more risks for DM. All associations were controlled by income per capita (OR=1.000).

DISCUSSION
The sociodemographic data and care context information are similar to those found in the national and international literature (22)(23)(24)(25) . The predominance of female caregivers reflects the sociocultural role of women, who are assigned care tasks. Younger elderly are more likely to have living parents requiring care than older people (22) . When caregivers are the patient's spouse, there is a relation of matrimonial obligation to take care of the spouse, since the commitment to be together in sickness and in health was assumed when they got married (26) .
Negative outcomes such as frailty, mental health problems and chronic conditions may be associated with age (26) . Brazilian studies reported more frequent DM cases among older women of low school education level (10)(11) , indicating that unhealthy habits and lower levels of information can be an obstacle to health services early in the process, when seeking prevention of health complications.
Regarding the score of caregivers in the Findrisc questionnaire, one third of them presents a high risk of developing DM. A study conducted in Hungary (27) reported mean values of 10.45 (±5.09) using the same questionnaire, with 41.0% of interviewees presenting increased risk of developing DM.
The factors associated with the risk of developing DM among elderly caregivers included high use of medication, poor health assessment, high number of people living in the same house, and advanced age, all of which related to income. Being female was a protective factor.
With increasing longevity, there is a trend for growing number of elderly caregivers taking care of other elderly people (26) . This study found that advanced age contributes to increased risk of developing DM. In recent years, the number of elderly people with at least one chronic disease has increased significantly (28) ; besides, it constitutes a risk factor for functional disability. An epidemiological study (29) with 286 elderly people from primary health care found that functional disability is more prevalent among older (≥75 years old) female people who do not have a spouse. The presence of diseases such as DM, stroke and heart disease also influence the functional ability of elderly people.
Regarding the financial aspects, older caregivers are often unable to have a paid activity out of home because there is no other person available to take care of the elderly patient. This situation can impact the monthly income of the family (30) . In this sense, the retirement pension is the only source of income for these families, with the elderly person acting as a critical provider (31) . Limited financial resources place the elderly people in a situation of social vulnerability, exposing them to the risk of sickness, pre-existing diseases or a possibility to compromise a treatment, since many elderly people use medications not always provided by the government (Brazilian Health System -SUS) (30)(31) .
A poor health assessment may be related to the task of care provision. In the literature, older caregivers report fatigue, stress and overload (22,32) , which may contribute to impairment of mental, physical and psychological well-being (4) . In this perspective, a better understanding of modifiable risk factors that influence DM is critical to support the planning of actions for the promotion, prevention and early diagnosis (19) , since health care with the disease development would require time and attention, and can be perceived negatively by a caregiver who has several tasks linked with care provision.
Given the facts above, programs to monitor the health of older caregivers should be promoted, which include variables for the development of DM risk, thus contributing to prevention or delay of DM development, with influence on associated factors.

Study limitation
This study has some limitations. It is a cross-sectional study conduct3d with a specific sample of older caregivers and, therefore, data cannot be generalized. Also, it is not possible to establish a cause-and-effect relationship. Studies of different designs in this area are certainly necessary in basic health care, especially considering the increasing number of informal older caregivers.

Contributions to the area of nursing, health or public policy
A better understanding of risk factors for the development of diabetes mellitus among older caregivers allows the definition of health goals for this population and prevention strategies for other health problems. It is a critical aspect, since the number of elderly people who provide care to other elderly people in Brazil has grown in quantity and importance. The results of this study may be a warning for health professionals indicating a timely identification of modifiable risk factors for diabetes mellitus.

CONCLUSION
This study concluded that more than one third of older caregivers present a high risk of developing DM. Therefore, being female, living with other people, using medication, having a poor health assessment are factors associated with an increase of this risk.
In this sense, intervention measures in public health are required, such as training to health professionals for the promotion of healthy habits, prevention and treatment of chronic diseases, avoiding modifiable risk factors for the development of DM.