Undiagnosed hypertension and diabetes mellitus in the Tabari cohort: a population-based study

Undiagnosed hypertension (HTN) and diabetes mellitus (DM) are major public health challenges worldwide. We aimed to investigate the prevalence of undiagnosed HTN and DM, and their correlates, in a large-scale population-based cohort study.

In this cross-sectional study, data collected during the enrollment phase of the Tabari Cohort study (TCS) were utilized. Data were collected in the TCS using a standard questionnaire, blood collection, and measurement of anthropometric indices and blood pressure. Data were analyzed using the chi-squared test and univariate and multivariate logistic regression analyses. Undiagnosed HTN included those who were not aware of HTN at the time of enrollment but had systolic and diastolic blood pressures ≥ 140 mm or ≥ 90 mmHg, respectively. Undiagnosed DM included participants who were unaware of their DM at the time of enrollment and had FBS levels ≥ 126 mg/dL.

The total prevalence of undiagnosed HTN and DM were 5% (508) and 4.7% (485), respectively. The findings of multivariable logistic regression analysis showed that young age (OR: 0.40, P < 0.001), residents of urban regions (OR: 0.70, P = 0.03), lower Body Mass Index kg/m2 (BMI) (OR: 0.51, P = 0.002), waist-to-hip ratio (WHR)(OR: 0.70, P = 0.023), total cholesterol (TC) ≥ 200 mg/dL (OR: 0.1.83, P < 0.001), lack of history of DM (OR: 0.38,P < 0.001), cardiovascular diseases (CVD)(OR: 0.12, P < 0.001), and lack of a positive family history of HTN in first-(OR: 0.39, P < 0.001) and second-degree(OR: 0.56, P = 0.009) relatives were the main predictors of undiagnosed HTN. Accordingly, male sex(OR: 0.52, P = 0.004), young age(OR: 0.28, P < 0.001), residence in urban regions(OR: 0.30, P < 0.001), BMI ≥ 30 (OR: 1.51, P = 0.044), low-density lipoprotein (LDL) ≥ 130 mg/dL (OR:1.93, P < 0.001), TC ≥ 200 mg/dL (95% CI, 1.47-2.51, P < 0.001), positive history of chronic kidney disease (OR:1.39, P = 0.010 ), and lack of family history of first-(OR: 0.38, P < 0.001) and second-degree (OR: 0.62, P < 0.015) DM were the main predictors of undiagnosed DM.

Overall, younger participants, those residing in urban areas, those with TC ≥ 200 mg/dL, and those without a positive family history of HTN or DM were at a greater risk of undiagnosed HTN/DM.