Type 2 diabetes (T2D) currently represents one of the main public health challenges worldwide [1] - [3] . Its prevalence has increased considerably in recent decades as a consequence of the modern lifestyle, characterized by a high-calorie diet and physical inactivity, factors that have significantly contributed to the increase in obesity and a higher incidence of chronic diseases [1] [2] . From a pathophysiological point of view, T2D is characterised by chronic hyperglycemia derived from inadequate insulin production and peripheral insulin resistance in tissues such as muscle and adipose [1] .

Globally, it is estimated that between 340 and 536 million people live with diabetes, with a projection exceeding 800 million by 2040 [1] [2] . In Mexico, this disease is the second cause of mortality and the main cause of loss of healthy life years, especially in the older adult population [2] [3] . Despite diagnostic and therapeutic advances, adequate glycemic control remains a challenge, particularly in this age group, in which comorbidities, polypharmacy, frailty and functional limitations negatively impact disease management [3] [4] .

Glycemic control, commonly assessed by measuring glycated hemoglobin (HbA1c), is a fundamental pillar in the prevention of micro and macrovascular complications [5] - [7] . However, achieving adequate control requires more than pharmacological intervention; patient-centred strategies, such as health education and self-care promotion, have been shown to be effective in improving clinical outcomes [8] - [10] .

Self-care is the set of behaviours that a person consciously and actively performs in order to manage their disease, including adherence to treatment, glucose monitoring, dietary control, physical activity, and foot care [11] [12] . In older adults, its application may be limited by factors such as low educational level, poor understanding of the disease, unfavourable socioeconomic conditions, and the presence of functional or cognitive impairment [13] - [15] .

Several studies have shown that high levels of self-care are associated with better metabolic control and a reduction in the occurrence of complications in Asian and Middle Eastern populations [16] - [18] . Nevertheless, evidence also shows that many patients fail to apply, or are unaware of these practices adequately, which highlights the importance of their inclusion in the first level of care as an axis of self-care promotion [19] [20] . In the Mexican population, a decrease in T2D related mortality has been documented over time, coinciding with the implementation of the PREVENIMSS program among Mexican Social Security Institute (IMSS) beneficiaries. This program incorporates prevention and health promotion components, including self-care practices as part of a comprehensive approach to the disease. This association suggests a positive impact of institutional preventive strategies on the individual health and clinical outcomes of patients with diabetes. However, it is important to note that PREVENIMSS does not specifically and systematically consider the teaching or formal monitoring of self-care techniques, as this study does [21] - [23] .

In this context, the present study aims to determine the association between the level of self-care and glycemic control in older Mexican adults with T2D.

A cross-sectional, analytical study was conducted in a primary care centre in Mexico between March and December 2024. Men and women aged 60 - 70 years old diagnosed with T2D, with a 10-year history of T2D progression, normal weight (BMI 18.5 - 24.9 kg/m²), overweight (BMI 25 - 29.9 kg/m²), and GI obesity (BMI 30 kg/m²) were included. Those with complications of T2D, autoimmune diseases, geriatric syndromes, neuropsychiatric conditions, and those with master’s or doctoral degrees in education or related fields were excluded.

The sample was calculated with the OpenEpi version 3.01 program, using a formula for the difference in proportions, considering an alpha of 0.05% and power statistics of 80%. Considering the estimated prevalence of those exposed with an effect of 76.9% and of 56.1% with those exposed without an outcome, obtaining an n = 204 [22] [23] . A 1:1 ratio was used, and non-probability sampling was used for consecutive cases. The sample was collected from subjects who attended scheduled and unscheduled appointments at the family medicine outpatient clinic.

To evaluate self-care techniques, the survey questionnaire to assess self-care practices in older adults with T2D [24] , validated in the Hispanic population and with a good internal consistency (Cronbach’s α = 0.799) was applied. The instrument yields scores ranging from 0 to 52 points, categorized as poor (0 - 13 points), average (14 - 26 points), and good (27 - 52 points); for stadistical purposes, the poor and regular categories were combined resulting in a dichotomous scale: Poor (0 - 26 points) and good (27 - 52 points). For the evaluation of glycemic control, Hb1Ac was recorded from the digital clinical record and an Hb1Ac > 7% was considered as glycemic imbalance [25] .

For the descriptive analysis, qualitative variables (gender, education, socioeconomic level, time of evolution, pharmacological treatment, self-care techniques and glycemic control) were expressed in frequencies and percentages. In the case of age, its distribution was evaluated by using the Kolmogorov-Smirnov test (p > 0.05), as well as using the criteria of skewness (values between −0.5 and 0.5) and kurtosis (values between −0.2 and 2) and was reported with median and IQR (25, 75).

Sociodemographic and clinical characteristics were compared with self-care techniques, using the Krussall-Wallis, Pearson’s chi-square, linear trend, and Mann-Whitney U tests, based on mathematical assumptions. A value of p < 0.05 was considered factor dependence. Pearson’s chi-square test was used to determine the association between self-care techniques and glycemic control, yielding OR, 95% CI, and p values.

In addition, a multiple binary logistic regression model was built, which included the variables poor self-care techniques, male gender, evolution time < 10 years and treatment with oral hypoglycemic agents, obtaining values of β, exponential of β, 95% CI, standard error, Nagelkerke’s R², global percentage of the model, Hosmer-Lemeshow test and ROC of model prediction. It was represented with a Forest Plot by using the GraphPad Software. Age, educational level, and socioeconomic level were excluded as they were not statistically significant in bivariate analysis and did not improve model fit.

Among the results found in the present research, a predominance of the female sex was obtained. This is consistent with the data reported by the Encuesta Nacional de Salud y Nutrición (National Health and Nutrition Survey, ENSANUT, for its acronym in Spanish) 2022, which shows a higher percentage of Type 2 diabetes in Mexican women [2] [3] [26] . Likewise, a study whose objective was to determine self-care techniques in subjects with Type 2 diabetes, showed a greater presence of the disease in the female sex [27] . Both studies were conducted in the Mexican population, so the information found is consistent.

The median age was 68 years old. These data coincide with those of the ENSANUT 2022, which shows that the highest presence of disease is found in adults aged 65 to 70 years old [3] . This trend was reported in a clinical research that obtained a predominant age range between 66 and 70 years old [28] [29] , however, self-care techniques or glycemic control were not studied.

The primary education level was present in the majority of the subjects. This is explained based on data from Instituto Nacional de Estadística y Geografía (National Institute of Statistics and Geography, INEGI, for its acronym in Spanish), which indicates that older Mexican adults have basic schooling [3] [30] . This finding coincides with what was reported in a study carried out in a public institution in Brazil, which showed that low schooling was associated with little knowledge of self-care and low efficacy in disease control [28] . It is worth mentioning that the sample size and statistical power were lower in relation to this research.

Likewise, a low socioeconomic level was determined. This can be interpreted based on data from Consejo Nacional de Evaluación de la Política de Desarrollo Social (National Council for the Evaluation of Social Development Policy, CONEVAL, for its acronym in Spanish), where the population over 65 years of age has an income below the poverty line [31] . This is consistent with clinical research that concludes that low economic level significantly influences the effectiveness of self-care [32] .

The predominant treatment was oral hypoglycemic agents. This can be explained based on the Sistema de Información Cultural (Cultural Information System, SIC, for its acronym in Spanish), which determined that treatment regimens include the use of first-line metformin [33] . This is convergent with a study conducted in Ethiopia, which found that patients receiving oral hypoglycemic agents have lower adherence and a lower efficacy of self-care and glycemic control [23] , however, the research design used differs from the present study.

This study showed a predominance of poor self-care techniques. This coincides with what has been reported in some clinical investigations, which conclude that poor self-care techniques are used in subjects with T2D [22] . Nonetheless, these results differ from those obtained in other countries, which conclude that there is a predominance of good self-care techniques associated with demographic and social characteristics [26] [31] [34] .

Most subjects were found to have glycemic imbalance. These data are explained by data presented by ENSANUT, which determined that the majority of the Mexican population with T2D is imbalanced [30] . Likewise, a study determined that the majority of its population has glycemic imbalance, this in relation to age and therapeutic adherence [35] .

The female sex did not show any association with poor self-care techniques or glycemic control. However, it should be considered that women with T2D are susceptible to glycemic imbalance related to hormonal and metabolic changes [36] . Conversely, the findings in this study differ from those shown by clinical research, which conclude that women with T2D had worse glycemic control [37] . Nevertheless, it is consistent with what was presented in a cohort study where no relevance of gender in the performance of self-care techniques was found [37] . Additionally, it is divergent, with respect to studies that conclude the female gender in the knowledge of self-care and adherence to T2D treatment, this is related to the level of awareness of their disease [38] .

The time of evolution was not associated with poor self-care techniques or glycemic imbalance. This is not consistent with what has been described in clinical research, which indicates that one of the most important factors for poor self-care management is a short time of evolution, since it is related to a low knowledge of the disease [38] . This is explained by the fact that, the longer the time of adaptability to the disease, the greater the awareness and habit of self-care develops [39] .

Treatment with oral hypoglycemic agents was not associated with glycemic imbalance or poor self-care techniques. This is explained by the fact that patients with better self-care practices achieve more effective glycemic control, which could allow them to continue their treatment exclusively with oral hypoglycemic agents [35] . Likewise, it agrees with research that concludes that adherence to treatment with oral hypoglycemic agents in people with T2D is influenced by the therapeutic regimen, the frequency of doses and the presence of side effects, therefore, it leads to poor self-care [40] .

No association was found between age and glycemic control. However, advanced age is associated with physiological changes that may affect glycemic control. In addition, factors such as polypharmacy and comorbidities can complicate treatment adherence and glycemic control [39] . The results found are different from clinical studies, which concluded that advanced age is considered a risk factor for diabetes control, although it was not the only determinant [26] .

Primary education level was not associated with glycemic imbalance or poor self-care practices. Nonetheless, a low educational level has been identified as hindering understanding of medical indications, adherence to treatment, and the implementation of lifestyle changes [41] . The results obtained are different from those found in a clinical investigation, which analysed the relationship between the educational level and knowledge about T2D, finding that patients with a higher educational level had a better knowledge of their disease [42] .

Socioeconomic status was not associated with glycemic imbalance or poor self-care techniques. Globally, it has been determined that low income is associated with poor glycemic control [43] . The result obtained in the present research is also different from studies that conclude the risk of complications of T2D is associated with low income [44] .

The time of evolution of T2D greater than 10 years predominated in the group with glycemic imbalance. It has been shown that the prolonged duration of the disease may be associated with a greater burden of complications and comorbidities [43] . A study conducted in Ethiopia found that patients with a diabetes duration greater than 7 years had a greater probability of presenting poor glycemic control, which is in accordance with this research [45] .

Oral hypoglycemic agents were found to be predominant in patients with glycemic imbalance. Although oral hypoglycemic agents are a common therapeutic option in the management of T2D, their effectiveness may decrease over time due to disease progression and other factors [40] . These results are similar to clinical research, which concludes that exclusive treatment with oral hypoglycemic agents does not achieve optimal Hb1Ac levels [46] .

Regarding the primary objective of the study, in the simple and adjusted analysis, it was found that poor self-care practices increase the probability of glycemic imbalance twofold. This is explained by the fact that adequate self-care management by subjects suffering from T2D is essential in order to maintain adequate blood glucose levels. These practices include dietary adherence, regular physical activity, continuous glucose monitoring, and adherence to pharmacological treatment [35] . These results are consistent with a multicentre study in Ethiopia, which aimed to demonstrate the effectiveness of self-care in glycemic control in a general hospital setting. It was shown that poor self-care increases Hb1Ac levels by more than 7%, so they are similar to those presented in this research. In contrast, it is important to note that the sociodemographic characteristics considered in the study are different from those of our population, in addition to considering a quantitative variable in its primary outcome [47] . Moreover, a prospective study, carried out in Africa, found an association between the level of self-care practice and poor glycemic control, data consistent with those found in this research, but in a different ethnic group [48] .

Among the strengths of this research are the implementation of a multivariate model and the consideration of multicausality, with a coefficient of determination that explains 10% of glycemic imbalance, a global percentage of 62.3%, which is not attributed to random error, a test of data fit to the model with p = 0.99 and a moderate discrimination of the model (60%). The instruments validated and adapted to the Hispanic context are also considered strengths, which increases the reliability of the results obtained.

Regarding the study’s limitations, we can mention its cross-sectional design, which prevents a definitive causal association between the variables used. Therefore, prospective and longitudinal studies are needed to better establish the association between self-care and glycemic control. Another limitation is a potential information bias due to the self-care questionnaire’s application, given its autoheterologous nature. In addition, a non-probability consecutive sampling method was used, chosen for its feasibility in accessing the target population within the available timeframe; however, this may have introduced selection bias. The study sample was limited to individuals assigned to a single medical unit, making it difficult to generalise the results to other national or global populations.

The findings suggest that poor self-care techniques increase the likelihood of glycemic imbalance in older Mexican adults with T2D. This highlights the importance of considering psychobehavioural variables in the comprehensive treatment of diabetes, rather than just a biological model of health, by healthcare professionals in primary care centres in Mexico. Similarly, parameters that influence self-care techniques were provided, which can guide prevention and health care strategies for the Mexican population.

The present research underwent an independent evaluation and obtained an institutional registration number R-2024-1406-004 by the Local Health Research Committee 1408 and from the Research Ethics Committee 1406-8 of the Mexican Social Security Institute.

The authors would like to thank the Family Medicine Specialization Program of the Family Medicine Subdivision of the National Autonomous University of Mexico (UNAM) for its commitment to training specialist physicians with a comprehensive approach, as well as for promoting critical thinking, clinical research, and the continuous improvement of medical care. We also acknowledge the Clinical Coordination of Health Education and Research of Family Medicine Unit No. 64 “Tequesquinahuac” of the Decentralized Operational Administrative Body of Mexico East of the Mexican Social Security Institute (IMSS) for the support provided during the academic process and for facilitating the development of this work. This project was part of the requirements for obtaining the degree of specialist in Family Medicine from the TVP and reflects the joint effort of both institutions in the training of professionals committed to public health and primary care.

T. V. P.; F. K. G. N.; F. V. H.: Study design, supervision of data collection, data analysis, manuscript writing.

M. G. S. M.; L. R. G. C.; E. V. A.: Supervision of data collection, data analysis, and manuscript writing.

J. A. T. C.; E. L. G. F.: Data analysis, manuscript review.

O. J. J.; F. V. H.: Supervision of data collection, data analysis, and manuscript review.

T. V. P.; F. K. G. N.: Data analysis, manuscript review.

E. G. C.; I. M. P. R.: Study design, results validation, manuscript review.