Post-diagnosis trajectories in treatment, adiposity, glycaemic control, and dietary behaviour among adults with type 2 diabetes in Mexico

Type 2 diabetes mellitus (T2DM) is a major public health challenge, particularly in low- and middle-income countries. Although much is known about its determinants and costs, less is known about how treatment, behaviour, adiposity, and glycaemic control evolve after diagnosis. We examined post-diagnosis trajectories in these domains among adults living with T2DM in Mexico. We used repeated cross-sectional data from ENSANUT 2006, 2012, and 2018 and analysed 9277 adults aged 20 years and older with a prior physician diagnosis of T2DM (mean age 55.7 years, SD 13.1). The main exposure was time since diagnosis. Outcomes included current treatment use, household expenditure on non-recommended foods, body mass index (BMI), overweight, obesity, glycosylated hemoglobin (HbA1c %), and fasting blood glucose in a biomarker subsample. We estimated adjusted post-diagnosis trajectories using pooled models with covariates and fixed effects for age-at-diagnosis-by-sex and municipality, and examined heterogeneity by sex and socioeconomic status (SES). Treatment uptake was higher at longer durations since diagnosis and remained elevated over time, reaching +24.4 percentage points at 12 or more years ( \(p<0.01\) ) relative to the year-of-diagnosis reference. Household expenditure on non-recommended foods showed little evidence of sustained change. BMI declined gradually, remaining at —2.54 kg/m2 lower in the 12 or more years category ( \(p<0.01\) ), while obesity was 16.9 percentage points lower in the same category ( \(p<0.01\) ); changes in overweight were less regular. Glycaemic control did not improve over time: HbA1c remained elevated at longer durations since diagnosis, reaching +1.01 percentage points in the 12 or more years category ( \(p<0.01\) ), and fasting blood glucose showed a similar qualitative pattern. These trajectories exhibited social disparities. At 12 or more years post-diagnosis, the treatment-use increase relative to the year-of-diagnosis reference was 4 percentage points larger among men than women and 5 percentage points larger among higher-SES than lower-SES respondents. In this setting, diagnosis is associated with rapid increases in clinical engagement, but post-diagnosis trajectories show persistent poor glycaemic control despite increased treatment use. Post-diagnosis care that expands treatment without sustained glycaemic control may be insufficient. Improving outcomes after diagnosis may require integrated care models that combine pharmacological management with sustained behavioural support, closer metabolic monitoring, and greater attention to the social and household conditions that shape long-term self-management.