In this free-living sample of 2063 Brazilian adults with known diabetes, HbA1c was controlled in more than half of the sample (66.1%), as were blood pressure (77.4%) and LDL-c (52.6%). However, only 28.6% of participants had all three factors controlled. Several indicators of greater social privilege (white ethnicity, higher income, and access to private health insurance) are associated with meeting targets.
The fraction of individuals reaching glycemic, blood pressure, and LDL-c goals in the ELSA-Brasil cohort was greater than that seen in the 2013 Brazilian National Health Survey (6): 66.1% in ELSA-Brasil vs 46% in the national survey when using identical control cutoffs for targets. Attainment of all three ABC goals in ELSA-Brasil participants was also greater than in this Brazilian National Health Survey (28.6% vs 12.5%). Consonant with the high estimates of non-smoking in Brazilian adults in general, achievement of the non-smoking target was similar in both studies (92.3% vs 90.3%) and higher than those found in other surveys (25) (12). This achievement results from the long-term implementation of multiple, strong public policies against tobacco (13) in Brazil,
In studies in diverse countries, attainment of all ABC goals was always low. In the US NHANES, 22.2% of individuals simultaneously achieved all three targets (HbA1c < 7%, blood pressure < 140/90 mmHg, and non–high-density lipoprotein cholesterol < 130 mg/dl) (14). In the Korean NHANES, with a more stringent target for glycemic control (HbA1c < 6.5%), and with targets of blood pressure < 140/85 mmHg, and LDL-C below 100 mg/dl, only 8.4% of subjects reached all three targets (15). In a study in nine Latin American countries, glycemic control was also lower (43.5%) than that described here (16). Our findings thus complement those already present in the literature, showing the current difficulty faced by diabetic patients in achieving desired levels of the principal factors affecting their prognosis which are modifiable at the individual level.
We found several characteristics that identified those not reaching targets for hyperglycemia and the ABC goals. As expected, a greater duration of diabetes was one. A higher BMI was marginally associated with a lesser frequency of control. Women were more frequently in glycemic control and achieved greater ABC control. The additional factors associated with worse control – being non-white, with lower income, and not having private health insurance, all point to better control being in part the result of social privilege.
Similarly, a representative survey of adults with diabetes showed that private health insurance led to their receiving better quality primary care, as measured by the cardinal attributes of quality primary care, especially access. Greater access to care provides a logical pathway linking this insurance to better control (17). A multicenter Brazilian study of hospital outpatients showed that multi-professional care and having had diabetes education as well as disease of lesser duration significantly associated with improved glycemic control (18). Morães et al., evaluating only glycemic control at the baseline ELSA-Brasil visit, demonstrated similar associations with socioeconomic factors (19) as those we found here for overall ABC target achievement.
Our study has limitations, principally that our sample is composed of active or retired civil servants, a socially privileged sample when compared to the general Brazilian population in terms of educational achievement, income, and job stability among other factors. That we found major socioeconomic determinants of control in this more privileged population only emphasizes the likelihood of greater health disparities in achieving ABC targets in the general diabetic population.
Strengths of our study include its free-living sample of participants obtained in multiple cities across Brazil, different from many other studies which investigated less representative inpatient or outpatient samples which will have both more comorbidities and, by their entry criteria, better access to care. Additional strengths include ELSA´s careful and extensive collection of factors examined, its standardized and centralized laboratory measurements, and its sample size permitting adequate investigation of epidemiologically relevant associations.
As has been shown for health outcomes in general (20), the correlates of control we found demonstrate the major role of social determinants of health in the ABCs of diabetes control. As put forth by the American Heart Association, clinical care and treatment account for 10–20% of the modifiable contributors to health outcomes. The other 80–90% are the social determinants of health, which include health-related behaviors, socioeconomic factors, environmental factors, and racism, all recognized to have a profound impact on cardiovascular disease and diabetes and their outcomes (21). The ADA also recently summarized what is known about the importance of social determinants (22). One implication from these findings is clear: though better control across the board is necessary, improvement and greater resources for the care for people with diabetes in the SUS, Brazil´s national health system should be a major goal if the aim is to improve control in the overall population of those with diabetes in Brazil. The SUS covers the bulk of the population and the majority of its underprivileged citizens. It also presents the advantage of providing cost-effective, evidence-based protocols to achieve treatment goals.
These findings are particularly relevant now, as actions aimed to achieve greater control at the health system level, supported by greater tracking and feedback of care, are now feasible given advances in information technology. The implementation and expansion of a diabetes registry orienting patient care in several Asian countries produced improvement in control of all the ABCs. In Hong Kong, a setting for which longer follow-up is available, the implementation of the registry was accompanied by a 40% decrease in CVD or microvascular complications and a 66% decrease in all-cause mortality, (23) and was additionally estimated to be cost-saving. (24) In Brazil, advances in the integration of databases within the national health system, which favors primary care and focuses resources on underprivileged communities, offer great hope in this regard. In this scenario, our study, by expanding knowledge of control of diabetes in Brazil and demonstrating the major role of socioeconomic factors, contributes to future strategies for better control and health promotion of Brazilians with diabetes. Future research can refine questions related to the relative benefit of greater control across the board as opposed to focus on better control among those with worst baseline levels.
Additionally, issues of relaxed control, especially of HbA1c, in older patients and those with greater morbidity and thus greater difficulty in managing multiple medications, are also important (25). The American Heart Association currently emphasizes a comprehensive approach to the management of all cardiovascular risk factors in patients with diabetes, including glycemic, blood pressure, lipid abnormalities, thrombotic risk, obesity, and smoking through applying lifestyle and pharmacological approaches with proven benefit using a patient-centered approach. This latter implies reframing clinical encounters to approach patients as people who live in families, communities, and societies that must be considered in their cardiovascular risk management. (5) While the ideal fraction of the diabetes population in control of all the ABCs, given these issues, is a question that remains open for debate, certainly it is much greater than the current fraction.
In conclusion, we have found a poor overall level of control of treatable factors associated with diabetes complications. This poor control was accompanied by large disparities in control across major social indicators, reinforcing the role of social factors in the multicausal context of risk factor control in diabetes. With due attention to social determinants and focusing on improving the integration of health system data to evaluate and orient patient care, health systems and clinicians can and should strive to implement a better level of care for people with diabetes.