The Association between Parameters of Socioeconomic Status and Hypertension in Korea: the Korean Genome and Epidemiology Study

Abstract

We investigated the association between socioeconomic status and hypertension in Korea, a country that has experienced a dynamic socioeconomic transition. We analyzed participants of a prospective cohort study-the Korean Genome and Epidemiology Study-enrolled between 2001 and 2003. We recruited 7,089 subjects who underwent a 4-year follow up till 2007. Education and income levels, which are important parameters for socioeconomic status, were stratified into 4 groups. Education level was defined as short (≤ 6 years), mid-short (7-9 years), mid-long (10-12 years), and long (≥ 12 years). Monthly income level was stratified as low (< 500,000 KRW), mid-low (500,000-1,499,999 KRW), mid-high (1,500,000-2,999,999 KRW) or high (≥ 3,000,000 KRW). At baseline, 2,805 subjects (39.5%) were diagnosed with hypertension. Education and income levels were inversely associated with the prevalence and incidence of hypertension (P < 0.001). In multivariate analysis, a shorter duration of education was significantly associated with a higher prevalence of hypertension (P < 0.001), but income level was not (P = 0.305). During the follow-up, 605 subjects (14.2%) were newly diagnosed with hypertension. In multivariate adjusted analysis, the hazard ratios (95% confidence interval) for incident hypertension across the longer education groups were 0.749 (0.544-1.032), 0.639 (0.462-0.884), and 0.583 (0.387-0.879), compared with the shortest education group. There was no significant association between incident hypertension and income across higher income groups: 0.988 (0.714-1.366), 0.780 (0.542-1.121), and 0.693 (0.454-1.056), compared with the lowest income group. In conclusion, education and income levels are associated with the prevalence and incidence of hypertension, but only education is an independent prognostic factor in Korea.