BMI better explains hypertension in Chinese senior adults and the relationship declines with age

Background Researchers have been examining the relationship between obesity and hypertension. However, whether overall or abdominal obesity better explains senior adults' hypertension has not been studied. Methods The purpose of the study was to examine whether body mass index or waist circumference better predicts hypertension in Chinese senior adults and how the magnitude of the relationship is attenuated as they continue to age. The study was based on the 2010 National Physique Monitoring data. There were 7,542 senior adults aged 60-69 years living in urban, suburban, and rural areas of Shanghai City. The participants were categorized into five age groups: 60-61, 62-63, 64-65, 66-67, and 68-69 years. Results The percentage of participants who had hypertension increased as people aged, which was mainly caused by the increase of systolic blood pressure. Logistic regression analysis showed that when body mass index or waist circumference was entered into the model, both were significant predictors for hypertension (p < 0.05). However, when body mass index and waist circumference were mutually entered into the model, body mass index was the only important predictor (p < 0.05). The values of odds ratios were found to decrease from the 60-61 to 68-69 years age groups. More senior adults have hypertension as they age. Conclusion Body mass index, and not waist circumference, better predicts Chinese senior adults' hypertension. However, age attenuates the effects of obesity on hypertension as the senior adults continue to age.