REN and Hypertension: With the findings of the strong impact of behavior factors on BP fluctuation independent of classical predictors of nocturnal hypertension such as renin-aldosterone system, insulin resistance, natriuresis, and apnea or hypopnea, we may need to emphasize more the usefulness of behavioral education including daily exercise and good sleep conditions for the treatment and prevention of nocturnal hypertension in a regular clinical setting.