Changes in the Diagnosis and Management of Diabetes in Mexico City Between 1998–2004 and 2015–2019

<i>Objective: </i>To investigate the trends in diabetes prevalence, diagnosis, and management among Mexican adults who were participants in a long-term prospective study. <p><i> </i></p> <p><i>Research design and methods:</i> In 1998-2004, 159,755 adults from Mexico City were recruited into a prospective study and in 2015-2019 10,144 survivors were resurveyed. Diabetes was defined as self-reported diagnosis, glucose-lowering medication use, or HbA_1c≥6.5%. Controlled diabetes was defined as HbA_1c<7%. Prevalence estimates were uniformly standardised for age, sex and residential district. Cox models explored the relevance of controlled and inadequately controlled diabetes to cause-specific mortality. </p> <p><i> </i></p> <p><i>Results: </i>99,623 participants in 1998-2004 and 8986 participants in 2015-2019 were aged 45-84 years. Diabetes prevalence increased from 26% in 1998-2004 to 35% by 2015-2019. Of those with diabetes, the proportion previously-diagnosed increased from 76% to 89%, and glucose-lowering medication use among them increased from 80% to 94%. Median HbA_1c among all with diabetes decreased from 8.2% to 7.3%, and the proportion of them with controlled diabetes increased from 16% to 37%. Use of blood pressure lowering medication among all with previously-diagnosed diabetes increased from 35% to 51% and their use of lipid-lowering therapy increased from 1% to 14%. The excess mortality risk associated with diabetes accounted for 34% of deaths at ages 35-74 years, of which 5% were attributable to controlled and 29% to inadequately controlled diabetes.</p> <p> </p> <i>Conclusions:</i> Inadequately controlled diabetes is a leading cause of premature adult death in Mexico. Improvements in diabetes management have increased diagnosis and control, but substantial opportunities remain to improve treatment, particularly with lipid-lowering therapy.