Arterial hypertension and glycemia in non-diabetic subjects: is there an association independent of obesity?

BACKGROUND: A possible association of glycemia with arterial hypertension has been suggested by the frequent co-occurrence of impaired glucose tolerance or Type 2 diabetes mellitus with arterial hypertension. The objective was to examine the relationship of glycated hemoglobin (HbA1c) concentration with arterial hypertension status in non-diabetic subjects. METHODS: A cross-sectional analysis of baseline data from the EPIC-Potsdam Cohort Study, Germany, was performed. The study population comprised 1846 non-diabetic subjects, 772 men and 1074 women, age 35-65. Blood pressure was measured three times consecutively. Level of HbA1c was determined by an assay based on monoclonal antibodies. Body height, weight and circumferences were obtained. Arterial hypertension status was either determined through blood pressure measurement (blood pressure > or = 160/95 mmHg) or based on antihypertensive drug use. HbA1c was divided into sex-specific quintiles and logistic regression was used to estimate the odds of being hypertensive and the corresponding confidence intervals. RESULTS: The highest compared to the lowest quintiles of HbA1c were in univariate analysis associated with being hypertensive. Adjustment for age and body mass index completely removed any significant association with arterial hypertension status. The odds ratio in men was 1.1 (95% CI 0.7-1.8), and in women it was 0.9 (95% CI 0.5-1.4). Repeating the analysis with systolic and diastolic blood pressure among untreated hypertensives yielded similar results. CONCLUSION: Unlike previous studies, our data do not support an association of HbA1c with arterial hypertension that is statistically independent of age and body mass index. Whether these established arterial hypertension risk factors are truly confounders of the HbA1c-arterial hypertension association or rather potentially antecedent factors requires further study.