The Incidence of Metabolic Syndrome and the Valid Blood Pressure Cutoff Value for Predicting Metabolic Syndrome Within the Normal Blood Pressure Range in the Population Over 40 Years Old in Guiyang, China

PURPOSE: The study was conducted to investigate metabolic syndrome (MS) incidence within the normal blood pressure (BP) range in a population over 40 years old in an urban area of Guiyang, Guizhou Province, China, and to identify a valid BP cutoff value for predicting MS. MATERIALS AND METHODS: Data from this study are based on the Risk Evaluation of cAncers in Chinese diabeTic Individuals: a lONgitudinal (REACTION) study. In total, 2935 subjects in the normal BP range and without MS (795 males, 2140 females) aged 40–80 years were included in this study. Follow-up subjects were classified by baseline BP and grouped by age. After the 3-year follow-up, the MS incidence and valid BP cutoff value for predicting MS were calculated for subjects within the normal BP range. RESULTS: After the 3-year follow-up study, the crude and standardized MS incidences in the cohort were 19.83% and 16.89% for follow-up subjects, respectively, with incidences of 10.94% and 10.50% for males and 23.13% and 20.66% for females. The incidence of MS in normotensive subjects (15.53%) was lower than that in subjects with high-normal BP (29.08%). After adjusting for age, sex, BMI, smoking, and drinking, the risk of having MS in the high-normal BP group was 1.823-fold [HR 1.823 95% CI (1.538–2.162)] higher than that in the normotensive group. The ROC curve showed that the BP cutoff values were more than 117/74 mmHg in males and 112/74 mmHg in females. CONCLUSION: When BP was within the normal range, the incidence of MS in participants was very high. The MS incidence was higher among high-normal BP subjects than among normotensive subjects, as was the risk of having MS. The valid BP cutoff value for predicting MS in the population was 117/74 mmHg in males and 112/74 mmHg in females. Currently, epidemiological investigations are needed to determine whether a lower BP cutoff value is needed in diagnosing MS.