Abstract 62: The Role of Physical Activity in the Hypertension Pathway: A longitudinal pathway-based analysis across 18 years in modernizing China
Background: Urbanization is associated with a decline in physical activity and an increase in CVD, particularly hypertension in lower and middle income countries. We investigate the impact of modernization-related declines in physical activity and pathways through body mass to hypertension in Chinese adults. Methods: Data come from the China Health and Nutrition Survey (CHNS), a household-based study that covers 9 diverse Chinese provinces from 1991 to 2009 across eight waves of data (n=12,018 adults; aged 18-66). We used detailed activity recall across multiple domains (leisure, work, and home), 3 repeated 24-hour-dietary-recalls, measured anthropometry and blood pressure at each exam. We created a multi-level structural equation model in Mplus to estimate direct pathways from specific domains of physical activity to hypertension and indirect paths through BMI. All pathways, including pathways to physical activity domains, were adjusted for gender, age, socioeconomic factors, urbanicity and region. Hypertension-related dietary factors were included in all pathways to BMI and hypertension. Results: The impact of physical activity on hypertension was most notable in the direct pathway to hypertension. Occupational and leisure activity were significantly associated with hypertension (p-value < 0.001), and individuals who were more active were less likely to have hypertension. Estimated from this model, a typical active, highly-educated, high-income middle aged female has a 12% probability of having hypertension, compared to a 43% probability for a similar non-active woman. There was however no direct association between physical activity and BMI. Conclusions: In China, declining physical activity over 18 years of modernization is strongly and directly related to increasing hypertension prevalence, with little evidence for effects along the pathway through BMI. Given continued declines in leisure and occupational activity, it is unlikely that hypertension will decline without additional intervention.