Diabetes and Obesity Bias: Are We Intensifying the Pharmacological Treatment in Patients With and Without Obesity With Equity?

The impact of obesity on health is reflected in different spheres and includes not only metabolic consequences, such as type 2 diabetes, but also psychological consequences related to obesity stigma. Studies show that almost 40% of adults with obesity are discriminated against because of their weight (1). Weight-based stereotypes may interfere with health care decision-making in these patients (2). However, for effective management of diabetes, obesity, and associated comorbidities, health professionals must be free from cognitive bias. To better understand the scope of this problem in clinical practice, we evaluated the prevalence of pharmacological diabetes treatment intensification based on weight status.

This is a cross-sectional study of patients with type 2 diabetes who received outpatient care in Southern Brazil from October 2011 to December 2019. The study was approved by the institutional review boards. Participants who had a regular follow-up for ≥1 year, were aged ≥18 years, and had ≥2 measurements of HbA_1c in the period were considered eligible. Participants were randomly selected and then stratified into two groups according to BMI: obesity (BMI ≥30.0 kg/m²) and without obesity (<30.0 kg/m²).

The primary outcome was the adequacy of pharmacological treatment intensification between groups, based on individualized glycemic targets. For participants under 65 years old and without major comorbidities, the HbA_1c target of <7.0–7.5% (<53–58 mmol/mol) was used. For those aged 65 or over and with major comorbidities, the Deyo-Charlson comorbidity index score was used to categorize patients into three subgroups based on the score for each comorbidity and age (3). To assess whether the provision of medical care was similar between the groups, multiple diabetes care quality indicators were evaluated. A multivariable logistic regression model was used to control for possible confounders in the interaction between the primary outcome and interest groups.

Centers involved in this study included Hospital São Lucas da Pontifícia Universidade Católica do Rio Grande do Sul (HSL PUCRS), Hospital de Clínicas de Porto Alegre (HCPA), Basic Health Unit and Family Health Strategy of Institute of Retirements and Pensions for Industrial Workers (IAPI).

The study was approved by the Research Ethics Committee of HSL PUCRS (no. 3.803.681), and the Research Ethics Committee of HCPA (no. 2016-0286), as well as in the Basic Health Unit and Family Health Strategy of IAPI (approved by the National Health Council in accordance with resolution 466/12, and by the Porto Alegre Municipal Health Office).

The data collected for the study, including de-identified participant data, will be available after publication of the article upon justified request and with a signed data access agreement.

According to the sample size calculation, 402 participants were included in this study. Most baseline characteristics were similar among patients without obesity (n = 198) and those with obesity (n = 204) (Table 1). Patients without obesity were older (68.7 ± 9.0 vs. 65.2 ± 8.9 years old, P < 0.001), and fewer used insulin (66.7% vs. 49.5%, P < 0.001) than patients with obesity. Both groups were similar regarding all quality indicators for diabetes care. According to individualized glycemic targets, 43.4% of the participants without obesity and 46.6% with obesity presented with an HbA_1c level above the target (P = 0.53). When assessing the number of patients who received pharmacological treatment intensification when HbA_1c level was above the target, it was found that participants from the group without obesity more frequently received treatment intensification than those from the obesity group (67.4% vs. 53.7%, respectively, P = 0.05). Moreover, in a sensitivity analysis considering the HbA_1c target of ≤7.0% (≤53 mmol/mol) for individuals younger than 65 years and without major comorbidities, 15.2% in the group without obesity and 25.0% in the group with obesity failed to receive intensification of treatment when indicated (P = 0.01). Adjusted analyses, correcting for complexity of care level, age, HbA_1c, hypoglycemia, insulin use and hypertension, also showed that the obesity group more frequently failed in receiving pharmacological treatment intensification when required (odds ratio 1.87, 95% CI 1.02–3.45).

Our results suggest that patients with obesity may be more vulnerable to therapeutic inertia in the treatment of diabetes. Despite presenting an increased risk of diabetes complications and unfavorable outcomes, we found that patients with obesity more frequently fail to receive pharmacological treatment intensification when necessary. Some factors may explain the delay in intensifying treatment in these patients. First, many effective agents that reduce glycemia may result in weight gain (4), and this may lead to a delay in the introduction of other drugs to the pharmacological treatment. Indeed, this may have been one of the limitations of the antihyperglycemic agents used in this study population. Second, the importance of lifestyle changes and weight loss as part of treatment for these patients (4) may delay the pharmacological intensification by physicians while insisting only on lifestyle changes. Also, newer glucose-lowering medications that promote weight loss, such as glucagon-like peptide 1 receptor agonists and sodium–glucose-cotransporter 2 inhibitors, although currently available, have a high cost and are inaccessible to most of the population in developing countries (5). Furthermore, the stigma of obesity has the potential to disrupt the health process and prevent many professionals from providing high-quality care to these patients (2).

The mental processes and cognitive biases that guide medical decision-making when treating patients with obesity are still poorly studied and not fully understood. Despite this, our findings suggest that patients with obesity may have some of their disease aspects neglected and that the limits of glycemic control in patients with type 2 diabetes and obesity are more permissive, which reflect the need to carefully revisit therapeutic decisions in these patients.