Association of alcohol consumption with incident hypertension among middle-aged and older Japanese population: the Ibarakai Prefectural Health Study (IPHS).

The objective of this study was to examine the effect of age on the relationship between alcohol consumption and incident hypertension in a general Japanese population. A cohort of Japanese men (n=37 310) and women (n=78 426) aged 40 to 79 years who underwent community-based health checkups from 1993 to 2004 and were free of hypertension were followed up with annual examinations, including the measurement of blood pressure, until the end of 2010. Incident hypertension was defined as systolic blood pressure of ≥140 mm Hg, diastolic blood pressure of ≥90 mm Hg, or the initiation of treatment for hypertension. Hazard ratios for incident hypertension according to alcohol consumption were estimated using a Cox proportional hazards model adjusted for possible confounding variables. A total of 45 428 participants (39.3%) developed hypertension (16 155 men and 29 273 women) for a mean follow-up time of 3.9 (1-18) years. Significant associations between alcohol consumption and incident hypertension were found in both sexes and age groups (P for trend was <0.001 for men aged 40-59 years and aged 60-79 years; 0.004 for women aged 40-59 years and 0.026 for women aged 60-79 years). No significant interaction with age on the association of alcohol consumption with incident hypertension was found in either sex (P for interaction, >0.05). Our results suggest that alcohol consumption is a similar risk factor for incident hypertension in both the middle-aged and the older populations.