Effects of a combination of dyslipidemia and hypertension on the glycemic control of patients with type 2 diabetes mellitus: a cross-sectional study.

Objectives: Both dyslipidemia and hypertension contribute to poor glycemic control in patients with type 2 diabetes mellitus, but the combined effect of dyslipidemia and hypertension on glycemic control in patients with type 2 diabetes mellitus has not been evaluated. The aim of this study was to analyze the interaction effect between dyslipidemia and hypertension on glycemic control in patients with type 2 diabetes mellitus.

Methods: A total of 2485 patients with type 2 diabetes mellitus were selected from the Xuzhou community of China by multi-stage cluster random sampling for a cross-sectional survey. Their glycated hemoglobin, dyslipidemia, and hypertension were assessed, and the interaction effects between dyslipidemia and hypertension on glycemic control were analyzed using relative excess risk due to the interaction, the synergy index, and the attributable proportion of the additive interaction.

Results: Of the participants, 62.13% (1544/2485) had dyslipidemia and 55.01% (1367/2485) had hypertension. Of the participants, 76.66% (1905/2485) who had both dyslipidemia and hypertension also had poor glycemic control. The prevalence of poor glycemic control was higher in those with both dyslipidemia and hypertension (odds ratio 2.735, 95% confidence interval 2.117-3.532; p < 0.001) compared with those who had normal blood lipids and without hypertension, after adjustment for confounders. The relative excess risk due to the interaction, the attributable proportion, and the synergy index were 1.077 (95% confidence interval 0.558-1.596), 2.637 (95% confidence interval 1.268-4.006), and 0.394 (95% confidence interval 0.230-0.558), respectively, for the interaction between dyslipidemia and hypertension.

Conclusions: Dyslipidemia and hypertension have an additive interaction on poor glycemic control in patients with type 2 diabetes mellitus.