Association between dental visits at primary care and glycated hemoglobin level in patients with type 2 diabetes: a cohort study

Objective: To evaluate the association between dental visits and variation in the glycated hemoglobin index (A1C) of patients with type 2 diabetes (T2DM) with well or not well glycemic control over time. Methods: Patients with T2DM, A1C ≥ 7% (not well-controlled) and < 7% (well-controlled), who attended a primary care service and were followed up from January 2010 to May 2018. The outcome was the variation of A1C obtained from reference laboratories. At the beginning of the study, a questionnaire with behavioral, clinical, and socioeconomic information was carried out. Multiple linear regression analyses tested interaction terms of all variables with the initial glycemic level (not well-controlled or well-controlled). Results: The sample consisted of 507 people, 65% women, and 66% individuals 55 to 74 years old, followed on average for 5.4 years. There was an interaction (p = 0.01) between dental visits and initial A1C. Patients not well-controlled with at least one dental visit had an average reduction in A1C of -0.56 percentage point (95%CI -1.06 – -0.56), whereas the well-controlled group who also had at least one dental visit had an increase of 0.34 percentage point (95%CI -0.18 – 0.87). Conclusion: Dental visits were associated with an improvement in A1C of approximately a half-percentage point in patients who had the initial A1C considered as not well-controlled. RESUMO: Objetivo: Avaliar a associação entre consultas odontológicas e variação no índice de hemoglobina glicada (A1C) em pacientes com diabetes mellitus tipo 2 (DM2) com controle glicêmico bom ou não ao longo do tempo. Métodos: Pacientes com DM2, A1C ≥ 7% (não controlado) e < 7% (bem controlado), que compareceram a um serviço de atenção primária e foram acompanhados de janeiro de 2010 a maio de 2018. O desfecho foi a variação de A1C, obtidos em laboratórios de referência. No início do estudo, foi aplicado um questionário com informações comportamentais, clínicas e socioeconômicas. Foram ajustados modelos de regressão linear múltipla para controle de fatores de confusão, e testou-se a interação de todas as variáveis com o nível glicêmico inicial (não controlado ou controlado). Resultados: A amostra foi composta de 507 pessoas, 65% mulheres e 66% indivíduos de 55 a 74 anos, acompanhados em média por 5,4 anos. Houve interação (p = 0,01) entre as consultas odontológicas e níveis iniciais de A1C. Pacientes não controlados com pelo menos uma consulta odontológica tiveram redução média de A1C de -