Long-Term Risk of Hypertension in Normoglycemia and Prediabetes, and Their Relation to the Change of Glycemic State

Original Article Long-Term Risk of Hypertension in Normoglycemia and Prediabetes, and Their Relation to the Change of Glycemic State Ju Young Jung,1 Chang-Mo Oh,2 Joong-Myung Choi,2 Jae-Hong Ryoo,3 and Sung Keun Park4 METHODS Five thousand four hundred thirteen nondiabetic Koreans were dichotomized into normoglycemia (NG) and prediabetes group and followedup for 10 years. Cox proportional hazard model was used to evaluate hazard ratios (HRs) with 95% confidence interval (CI) [adjusted HRs (95% CI)] for the development of hypertension. Subgroup analysis was conducted in subdivided glycated hemoglobin (HbA1c) with <5.7%, 5.7–5.9%, and 6.0–6.4% and 2 hour post-load glucose (2 hr-PG) with <140, 140–169, and 170–199 mg/dl. The glycemic states are NG, prediabetes, and diabetes mellitus (DM), which are used in evaluating the change of glycemic state during follow-up in baseline NG (NG → NG, NG → prediabetes, and NG → DM) and baseline prediabetes (prediabetes → prediabetes and prediabetes → DM). RESULTS Compared with NG, prediabetes was not significantly associated with the risk of hypertension [1.11 (0.997–1.23)]. HbA1c ≥5.7% [1.13 (1.02–1.26)] and 2 hr-PG ≥140 mg/dl [1.15 (1.004–1.31)] were marginally associated with the risk of hypertension. In subgroup analysis, only 2 hr-PG of 170–199 mg/dl showed the significantly increased risk of hypertension [1.37 (1.09–1.73)]. Compared with the maintaining glycemic state, the progression of glycemic state had the significantly increased risk of hypertension [NG → prediabetes; 1.41 (1.19–1.67), NG→DM; 1.77 (1.36–2.30), and prediabetes → DM; 1.32 (1.13–1.55)]. CONCLUSION The progression of glycemic state was a strong determinant on the development of hypertension. Keywords: 2 hour post-load glucose; blood pressure; glycemic state; HbA1c; hypertension; prediabetes. doi:10.1093/ajh/hpy094 There has been grave concern for the rapidly increasing prevalence of prediabetes as an intermediate metabolic state from normoglycemia (NG) to diabetes mellitus (DM).1 Prediabetes is defined as one of categories comprising impaired fasting glucose (IFG), impaired glucose tolerance (IGT) identified by oral glucose tolerance test and glycated hemoglobin (HbA1c) above specific level, in which each phenotype can overlap.2 The population-based US National Health and Nutrition Examination Survey (NHANES) indicated that 35% of US adults over age of 20 years and 50% of those over age of 65 years had prediabetes in 2005–2008 based on fasting glucose or HbA1c levels.3 When this prevalence was applied to the entire US population in 2010, it was estimated that 79 million adults had prediabetes.3 Moreover, the number of adults with IGT is increasing globally, and expected to reach 472 million by 2030 more predominantly in South-East Asia and the Western Pacific Region.4 Although the prevalence of prediabetes has markedly increased by increasing obesity, nutritional transition to high fat and calorie intake and urbanization, the predicted prevalence may be underestimated due to lack of awareness in developing countries. The recent meta-analysis investigating 53 prospective studies with 1,611,339 individuals suggested that the risk of cardiovascular disease (CVD) significantly increased even at the state of prediabetes.5 Additionally, there has been substantial evidence that links prediabetes to end organ damage on kidney and eye conventionally recognized to be complications of overt DM.6 The pathophysiology of these adverse health outcomes are considerably related to vasculopathy, Correspondence: Sung Keun Park (). 1Total Healthcare Center, Kangbuk Samsung Hospital, Sungkyunkwan University, School of Medicine, Seoul, Republic of Korea; 2Department of Preventive Medicine, School of Medicine, Kyung Hee University, Seoul, Republic of Korea; 3Department of Occupational and Environmental Medicine, College of Medicine, Kyung Hee University, Seoul, Korea; 4Center for Cohort Studies, Total Healthcare Center, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea. Initially submitted May 4, 2018; date of first revision June 1, 2018; accepted for publication June 20, 2018; online publication June 21, 2018. © The Author(s) 2018. Published by Oxford University Press on behalf of American Journal of Hypertension, Ltd. All rights reserved. For permissions, please e-mail: 1042 American Journal of Hypertension 31(9) September 2018 BACKGROUND Although increasing evidence has suggested the significant association between dysglycemia and hypertension, this association is less well described in prediabetes. Additionally, it is unclear how risk of hypertension varies according to the change of glycemic state. Prediabetes and Hypertension and study population of KoGES were described in a previous study.9 The baseline survey of KoGES Ansan and Ansung study was completed in 2001–2002, and follow-up survey was conducted every 2 years for 10 years. Initially, a total of 10,038 participants aged 40–69 participated in the study. Five thousand one hundred eight subjects were recruited by cluster-sampling method stratified by age, sex, and residential district in Ansung community, and 5,012 subjects were selected by random sampling method in Ansan. Out of the 10,038 participants, we initially excluded subjects with baseline hypertension (n = 3,248), subjects without data about blood pressure (BP) (n = 15) and subjects with baseline DM (n = 667). Among remaining 6,108 participants, we further excluded 695 subjects who were lost to follow-up or incomplete in follow-up data during a 10 years’ follow-up period. Finally, 5,413 participants were enrolled in the present study (Figure 1). All subjects voluntarily participated in the study, and informed consent was obtained in all cases. Ethics approvals for the study protocol and analysis of the data were obtained from the institutional review board of Kangbuk Samsung Hospital. METHODS Clinical and biochemical measurements Study design and participants Study data included medical history and sociodemographic information provided by a self-administered questionnaire, anthropometric measurements and laboratory biochemical measurements. All study participants were also asked to respond to a health-related behavior questionnaire, which included the topics of alcohol consumption, smoking, All subjects were participants of the Korean Genome and Epidemiology Study (KoGES) Ansan and Ansung study, which was a population-based, epidemiology study of rural and urban community in South Korea. Detailed methods Figure 1. Flowchart of enrolled study participants. American Journal of Hypertension 31(9) September 2018 1043 and thus, it is expected that the coexistence of hypertension with prediabetes can profoundly increase the risk of adverse health outcome. Nonetheless, there is still limited information about the risk of hypertension in individuals with prediabetes. Given that hypertension is two t (...truncated)