Abstract 2475: Excess Cardiovascular Mortality among Lean Hypertensive Nonsmoking Japanese
BACKGROUND: Although several reports demonstrated that underweight was associated with higher cardiovascular (CVD) mortality, smoking was considered to be a major confounding factor. In Japan, prevalence of underweight is higher.
METHODS: We studied 13,089 subjects (mean age 55±13 years, men 18%) who had the annual health examination offered to adult citizens of Moriguchi city, Osaka, Japan in 1997 and were not current smoker at the examination. Underweight was defined as a body mass index (BMI) <18.0 kg/m2. Proportional hazards regression analysis was used to assess the association of BMI categories with CVD mortality.
RESULTS: During a mean follow-up of 9.4±2.4 years, there were 136 CVD deaths. Of those, 78 CVD deaths, including 32 stroke deaths and 22 coronary deaths occurred in the hypertensives (n=3,925). Incidence of CVD deaths according to BMI categories and hypertension status was presented in the figure. Age and sex-adjusted proportional hazards regression analysis in the hypertensives showed CVD mortality was significantly higher in the underweight group (HR=3.2, 95%CI=1.3 to 7.7; p=0.0105), compared with the normal weight group (BMI 18.0 –24.9 kg/m2). After adjustment for age, sex, diabetes mellitus, hypercholesterolemia, and drinking habit in the hypertensives, the result was unchanged (HR=3.1, 95%CI=1.3 to 7.4; p=0.0130). In the analyses restricted to never smokers (n=3,506) of the hypertensives, the result remained unchanged (HR=2.9, 95%CI=1.1 to 7.8; p=0.0296) after adjustment for all clinical variables.
CONCLUSIONS: In the general Japanese hypertensive population, underweight was associated with higher CVD mortality unrelated to smoking.