1. ¹Division of Epidemiology, Department of Public Health and Forensic Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
2. ²Department of Preventive Cardiology, National Cardiovascular Center, Osaka, Japan
3. ³Department of Health Science, Shiga University of Medical Science, Otsu, Japan
4. ⁴Department of Hygiene and Preventive Medicine, Fukushima Medical University, Fukushima, Japan
5. ⁵The Cardiovascular Epidemiology, Kyoto Women's University, Kyoto, Japan
6. ⁶The First Institute for Health Promotion and Health Care, Japan Anti-Tuberculosis Association, Tokyo, Japan

Correspondence: Dr A Hozawa, Division of Epidemiology, Department of Public Health and Forensic Medicine, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aobaku, Sendai 980-8575, Japan. E-mail: hozawa-thk@umin.ac.jp

⁷Members of the NIPPON DATA80 Research Group are listed in the Appendix.

Received 21 August 2008; Revised 4 November 2008; Accepted 14 November 2008; Published online 18 December 2008.

Abstract

Although several studies have reported on the relation between high blood pressure (BP) and impaired activities of daily living (ADL), only a few studies have reported on the relation of high BP in middle-aged subjects with future impaired ADL. Furthermore, no studies reported an excess impaired ADL due to non-normal BP. Using ADL 1999 data, we compared data from NIPPON DATA80 survivors without impaired ADL (N=1816) with those with impaired ADL (N=75) using baseline BP information collected in 1980. We analysed participants who were aged 47–59 years at baseline. Multiple adjusted logistic regression analyses were used to estimate the risk of impaired ADL, according to baseline BP categories using Joint National Committee 7 guidelines (normal BP, prehypertension, stage 1 hypertension (HT) and stage 2 HT). Subjects who used antihypertensive medications were classified as having stage 2 HT. We calculated excess impaired ADL due to non-normal BP. Compared with normal BP categories, the adjusted odds ratio (OR) and 95% confidence interval (CI) of having impaired ADL was higher in subjects with prehypertension (OR=1.50, 95% CI: 0.55–4.09), stage 1 HT (OR=1.56, 95% CI: 0.56–4.32) and stage 2 HT (OR=2.96, 95% CI: 1.09–8.05). Non-normal BP explained 45% (33.7/75) of impaired ADL. A positive relation of BP categories with the composite end point of mortality and impaired ADL was also observed. In conclusion, controlling BP in middle age may prevent deaths and future ADL decline.