GLUCOSE-TOLERANCE AND BLOOD-PRESSURE IN A POPULATION-BASED COHORT STUDY OF MALES AND FEMALES - THE REYKJAVIK STUDY

Objective: To investigate the relationship between fasting and postprandial glucose levels and the risk of hypertension, both cross-sectionally in different age and body mass index (BMI) groups, and prospectively. Design: Long-term prospective health survey in the Reykjavik area, of a targe representative population sample of males and females in various age groups, conducted since 1967. Methods: Values from 8285 males and 9183 females were included in the cross-sectional analysis. The prospective analysis included 2639 males and 2346 females, with two consecutive observations for each individual, with a 3- to 8-year interval. Results: After controlling for year of examination, age, BMI and various other risk factors, we found a strongly significant relationship between the blood glucose level, both fasting and 90 min after an oral glucose load, and risk for hypertension. The strength of the correlation between postprandial glucose value and blood pressure was similar in different age and BMI groups, except for in the males, in whom there was a stronger correlation with diastolic blood pressure with higher BMI. The 90-min glucose level was also predictive for development of hypertension 3-8 years later. The predictive power was somewhat stronger for females. Fasting glucose level was predictive for hypertension only for the females. Concurrent weight gain had a very strong independent explanatory power for development of hypertension. Conclusions: This study confirms the role of metabolic factors in hypertension. The correlation between impaired glucose tolerance and hypertension was found to be remarkably consistent throughout adult life, for both sexes and all values of BMI. Fasting glucose was predictive of hypertension in the females, and blood glucose at 90 min after the glucose-tolerance test was predictive of future development of hypertension in both sexes.