Background: Prediabetes is strongly associated with high blood pressure; however, a little is known about prediabetes and high blood pressure comorbidity in the high-risk individuals. This is the first study in the world to assess the long-term effects of risk factors associated with high blood pressure and prediabetes comorbidity in the first-degree relatives (FDRs) of type 2 diabetes mellitus (T2DM) patients.

Materials and methods: The longitudinal data obtained from 1388 nondiabetic FDRs of T2DM patients with at least two visits between 2003 and 2011. We used univariate and bivariate mixed-effects logistic regressions with a Bayesian approach to identify longitudinal predictors of high blood pressure and prediabetes separately and simultaneously.

Results: The baseline prevalence of high blood pressure, prediabetes, and the coexistence of both was 27.4%, 19.1%, and 29.8%, respectively. The risks of high blood pressure and prediabetes were increased by one-unit raise in the age (odds ratio [OR] of high blood pressure: 1.419 (95% credible intervals [CI], 1.077-1.877), prediabetes: 1.055 (95% CI: 1.040-1.068)) and one-unit raise in remnant-cholesterol (OR of high blood pressure: 1.093 (95%CI, 1.067-1.121), and prediabetes: 1.086 (95% CI, 1.043-1.119)). Obese participants were more likely to have high blood pressure (OR: 2.443 [95% CI, 1.978-3.031]) and prediabetes (OR: 1.399 [95% CI, 1.129-1.730]) than other participants.

Conclusion: We have introduced remnant-cholesterol, along with obesity and age, as a significant predictor of prediabetes, high blood pressure, and the coexistence of both in the FDRs of diabetic patients. Obesity index and remnant-cholesterol showed the stronger effects on high blood pressure and prediabetes comorbidity than on each condition separately.