Sex-Specific Associations Between Glycated Hemoglobin and Hypertension in Non-diabetic Chinese Adults

Abstract Background To evaluate the sex-specific associations between glycated hemoglobin (HbA1c) and hypertension in Chinese non-diabetic adults. Methods Based on the data of the China Health and Nutrition Survey (CHNS) from 2009 to 2015, a total of 7,391 non-diabetic adults who had complete basic data and collected blood samples in 2009 were selected, and the data in 2011 and 2015 were used as follow-up data. High HbA1c was defined as HbA1c ≥5.7%. The association between HbA1c and hypertension was assessed by logistic regression and restricted cubic spline analyses. Stratified analysis was performed by sex and age. Results At baseline in 2009, 2,032 of 7,391 residents suffered from hypertension (prevalence 27.5%). In univariable logistic analysis, it was shown that there was a positive association between high HbA1c and risk of hypertension with an OR (95% CI) of 1.871 (1.682–2.08), which was weakened and not statistically significant after adjusting for confounders (such as age, sex, and body mass index) with an OR (95% CI) of 1.114 (0.988–1.257). The linear positive relationship between HbA1c and the risk of hypertension was further confirmed in the restricted cubic spline plot. In the stratified analysis, the association was found only in the women after adjusting for confounders (OR = 1.191, 95% CI 1.003–1.414; P < 0.05). A total of 539 (incidence 12.8%) and 831 (incidence 24.1%) participants developed hypertension after 2 and 6 years among those who were without hypertension at baseline in 2009, respectively. Positive associations between high HbA1c and the incidence of hypertension were also found only in the women after adjusting for confounders (OR = 1.365, 95% CI 1.031–1.807 after 2 years; OR = 1.319, 95% CI 1.037–1.678 after 6 years; all P < 0.05). The association between high HbA1c and hypertension was statistically significant in the women ≥50 years of age [OR 1.238 (95% CI 1.017–1.506), P = 0.033], whereas it was not statistically significant in the women 0.05). Conclusions The association between HbA1c and hypertension in non-diabetic Chinese adults is susceptible to other confounding factors such as sex, age, and body mass index. High HbA1c is associated with an increased risk of hypertension among women.