It is estimated that type 2 diabetes (T2DM) affects 463 million people worldwide (1). T2DM increases with age and also depends on social factors, such as education, income, neighborhood, or socioeconomic status (SES) (2). Patients with T2DM have an increased risk of mortality for all other conditions in comparison to patients without diabetes (3), especially in women (4).

To achieve optimal control of this condition, clinical guidelines recommend maintaining HbA1c of < 7%, blood pressure of ≤ 140/90 mmHg (BP), and a body mass index of < 30 kg/m² (BMI). The weight goal differs among the guidelines, but it is recommended to avoid obesity and lose weight if overweight (5, 6). The LDL cholesterol target has changed over the years based on studies that addressed it in the cardiovascular risk factor context. Although the objectives are clear, only two-thirds of patients can reach the HbA1c goal (7, 8). Some studies found that patients whose HbA1c is outside the range of 6–8% have more cardiovascular complications (9), more visits to the family doctor (likely a proxy for more complex disease) (10), more admissions to the hospital resulting from complications (11), and higher mortality than those with HbA1c levels inside this range (12).

In the past, glycemic control was focused on achieving a single target defined by HbA1c <7%. Recently, some studies have described not only glycemic control but also the cardiovascular multifactorial control targets of HbA1c <7%, BP ≤140/90 mmHg, and LDL <100 mg/dl (multifactorial control targets) (13–16). Less information is known to determine which single target could help T2DM management. Wan et al. have suggested that LDL targets alone could decrease cardiovascular disease risk among patients with T2DM (16). In the past years, patient demographics such as sex and SES have been added to this approach because both determinants influence both healthy behaviors and access to the health system (17–19). Health inequalities have been observed in those living in more socioeconomically deprived areas as they were less likely to attain glycemic control and had more T2DM complications (18).

The Spanish National Health System (NHS) provides first-contact, comprehensive, continuous, and coordinated care, which is free at the point of care for a defined population served by primary care centers. Every citizen in Spain is assigned a family physician. The T2DM is managed by the family physicians who are responsible for delivering and coordinating patient care. Electronic health record has been used in the country for over 20 years in the public sector and the private sector. The Spanish NHS provides care through 17 counties; each county has its own electronic health record. All the counties share data with the NHS to elaborate on national data.

This study aimed to analyze glycemic control and multifactorial cardiovascular control targets regarding sex and socioeconomic status (SES) in type 2 diabetes in primary care.

The glycemic control was achieved by 63% of primary care diabetic patients aged 40–75 years in the HHH study. However, only 10.3% achieved the 3-factor control target (HbA1c, BP, and LDL), and 6.6% achieved the BMI <30 kg/m² (4-factor control). Women had better glycemic control (HbA1c) but worst 3-factor and 4-factor control targets regardless of the SES.

In our population, we found that 60.5% of our patients had had their HbA1c checked in the last year. Our results are lower than in Canada, where 68.9% of patients had a baseline HbA1c assessment at a 1-year follow-up (23), or in the United Kingdom, where 69% had all the annual measures during the 5 years (19). In our study, high-SES participants were less likely to have an HbA1c measure, which could be explained by patients in that quintile of SES receiving care outside of the public health system. This contrasts with the UK study where patients belonging to the SES 5th quintile group were more likely not to have annual HbA1c monitoring. Perhaps, due to challenges concerning access to healthcare, this needs additional investigation. In this study, we compared those patients who had at least one measure of HbA1c in the 1-year follow-up and those who did not. Although we have a large sample size, many patients were excluded as they did not meet the inclusion criteria. This study collected information from the clinical practice as information was recorded during the clinical encounter. This approach to using real-world data has limitations as not all the variables were recorded, in contrast to a randomized clinical trial where missing data can be assessed more tightly (24). Other studies with the same aim and size population decided not to impute data (13, 14, 17), although they considered the missing data as a limitation. We focused on analyzing data from the clinical practice to capture how care was delivered, but the quality of the real-world data still has to improve to generate real-world evidence (25).

The glycemic target was achieved in 63.2% of our patients, which is consistent with other studies where only one-half or one-third of cohorts achieved HbA1c <7% (15, 17). Optimal glycemic target has been described in 62.8% of patients in Norway (26), 52.9% in Canada (13), and 46.7% of patients in the United Kingdom (19). Healthcare access and the healthcare provision could explain these differences. By taking into account a global perspective of the disease, health outcomes such as good control of disease may differ by socioeconomic differences. We found that sex and SES were related to the achievement of T2DM targets. The effect of sex on glycemic control has been discussed before without clear findings. Some studies suggested that women were more likely to have suboptimal control (17, 18), but other studies found the opposite (14, 15). Even so, these differences were less than 2% between men and women. In this study, more women reached glycemic targets compared to men (64.2 vs. 62.4%), but sex was not related to optimal glycemic control while the SES index was. The optimal control decreased in both sexes from the 1st quintile to the 5th quintile of SES. Our results are in accordance with Collier et al. (18) and Whyte et al. (19), who showed that greater social deprivation was less likely to reach the glycemic target. These findings caption the importance of addressing social inequalities in people with T2DM to try to improve the glycemic target in those patients most disadvantaged.

Our study found that 10.3% of the patients attained the 3-factor control target with results similar to Wan et al. who registered 9.45%. However, Braga et al. registered that 19% of their patients met the three goals (13), which may be related to differences in participant enrollment. In Spain, Ibáñez et al. published a study in which patients with a lower SES index less frequently reached HbA1c and BP targets, which corresponds with our results (17). In our case, patients who achieved the 3-factor control target more frequently were those in the lowest quintile of SES. This unexpected finding could be explained by patients in the lowest quintile of SES requiring more frequent contact with their primary care centers compared to those in the 1st and 2nd quintiles of SES. Obesity is linked to T2DM (27) and the most deprived quintiles (18). When this risk factor was added, the result was quite poor, only 6.6% of the population achieved the 4-factor control targets.

These findings highlight the need to address whether healthcare outcomes should continue focusing on T2DM management on the HbA1c target as the primary goal or approach it as a 3-factor control target, not only because a few more than half of the patients live with hypertension and obesity but also because guidelines are recommending a 4-factor control target. Improving glycemic control remains a key target to reducing diabetes complications; however, glycemic and especially 3-factor control can be challenging. Moreover, achieving the four targets for a majority of the population is an unrealistic aim. We need more research highlighting the approach to reducing T2DM complications and overall cardiovascular risk factors to understand which targets or combinations of targets are more beneficial for the patients. In contrast, social determinant perspectives, such as the SES index, must be taken into account in developing effective strategies for the management of T2DM. If we address T2DM as an illness where cumulative disadvantage is present (28, 29), we will focus on those groups of patients who are more vulnerable and ensure they receive proper care. Doctors should be trained to address social determinants as they are trained to treat T2DM, but also public policies should take them into account to reduce social inequalities.

This study showed that differences in socioeconomic status are related to poorer glycemic control in patients with T2DM. Optimal 3-factor control targets (HbA1c ≤ 7%, LDL < 100 mg/dl, and BP < 140/90 mmHg) were seldom achieved by the diabetic population, and being women was associated with suboptimal 3-factor control of cardiovascular disease risk factors.

All data generated or analyzed during this study are included in this published article/Supplementary material. All methods were carried out in accordance with relevant guidelines and regulations. Further inquiries can be directed to the corresponding author.

The studies involving human participants were reviewed and approved by the Heart Healthy Hoods study was approved by Madrid Primary Care Research Committee and the Ethics in Research Committee of the Madrid Health Care System (ERC-2013-StG-336893). This work was additionally approved by the Ethics in Research Committee of the Ramón y Cajal Hospital at Madrid city (341/2018). Both Ethics Committees have waived the requirement of the informed consent for this population-based study. Written informed consent for participation was not required for this study in accordance with the national legislation and the institutional requirements.

SAB, EPC, and IDC: conceptualization, funding acquisition, methodology, supervision, and writing – original draft. SAB and FRC: formal analysis. SAB: investigation. IDC and MF: project administration. SAB, EPC, IDC, FRC, PG, and MF: writing – review and editing. All authors contributed to the article and approved the submitted version.