BACKGROUND AND AIMS: This study aimed to investigate the association between baseline fasting insulin levels, changes in fasting insulin levels, and future development of hypertension in normotensive, non-diabetic, healthy adults. METHODS: We analyzed data from 11,123 adults, aged 20-65years, who had no history of hypertension or diabetes mellitus at a 2004 medical examination in a health promotion program and had attended a repeat examination in 2008. Subjects were divided into four groups according to baseline quartiles of fasting insulin and dichotomized fasting insulin levels at baseline and after 4years: low-low, low-high, high-low, high-high. We also assessed whether the association differed between the younger (20-40years) and older subjects (41-65years). RESULTS: In four years, 1142 subjects (10.3%) developed hypertension. The odds ratio (OR) for the development for hypertension increased as the quartiles of baseline fasting insulin levels and changes in fasting insulin levels increased from the first to the fourth quartile (OR 1.15, 1.35, and 1.95 vs. 1.07, 1.22, and 1.41, respectively), after adjusting for multiple factors. The OR for hypertension was 2.0-fold higher in the high-high group and 1.34-fold higher in the low-high group than in the low-low group. In comparing the results by age group, we found that these relationships were more prominent in younger subjects. CONCLUSION: High baseline and continuously increasing fasting insulin levels appeared to be independent determinants for the future development of hypertension during this 4-year follow-up study in normotensive, non-diabetic, healthy adults.
BACKGROUND AND AIMS: This study aimed to investigate the association between baseline fasting insulin levels, changes in fasting insulin levels, and future development of hypertension in normotensive, non-diabetic, healthy adults. METHODS: We analyzed data from 11,123 adults, aged 20-65years, who had no history of hypertension or diabetes mellitus at a 2004 medical examination in a health promotion program and had attended a repeat examination in 2008. Subjects were divided into four groups according to baseline quartiles of fasting insulin and dichotomized fasting insulin levels at baseline and after 4years: low-low, low-high, high-low, high-high. We also assessed whether the association differed between the younger (20-40years) and older subjects (41-65years). RESULTS: In four years, 1142 subjects (10.3%) developed hypertension. The odds ratio (OR) for the development for hypertension increased as the quartiles of baseline fasting insulin levels and changes in fasting insulin levels increased from the first to the fourth quartile (OR 1.15, 1.35, and 1.95 vs. 1.07, 1.22, and 1.41, respectively), after adjusting for multiple factors. The OR for hypertension was 2.0-fold higher in the high-high group and 1.34-fold higher in the low-high group than in the low-low group. In comparing the results by age group, we found that these relationships were more prominent in younger subjects. CONCLUSION: High baseline and continuously increasing fasting insulin levels appeared to be independent determinants for the future development of hypertension during this 4-year follow-up study in normotensive, non-diabetic, healthy adults.