Epidemiology of Hypertension and Obesity in Older Mexican Americans

Investigator: Mary N. Haan, DrPH, MPH
Sponsor: NIH National Institute on Aging

Location(s): United States


Aging is often accompanied by weight loss and changes in body composition. Evidence is growing that central obesity increases the risk of cognitive decline and dementia. The pathways by which this occurs are not well understood. Systolic and diastolic blood pressure, which are generally influenced by obesity and overweight, often follow nonlinear trajectories in old age. Little is known about the effects of co-occurring changes in body composition and blood pressures on cognitive/functional decline. This proposal will examine the effects of obesity, central body adiposity, body composition and blood pressure on cognitive and functional decline in the Sacramento Area Latino Study of Aging, a cohort of older Mexican Americans (n=1789) that was followed at six and 12 month intervals from 1998-2008. This application focuses on analysis of existing data and will take advantage of a rich, longitudinal dataset to address the influence of trajectories of modifiable risk factors on cognitive and functional decline and mortality over seven years of follow-up in a high risk elderly cohort. Body composition and blood pressure are interrelated risk factors that exhibit age-related changes over time. Clearly, obesity is associated with higher blood pressure which has been linked to subsequent cognition and functional decline. Declines in physical performance and physical activity also play a role in trajectories of change in blood pressure and body composition. Age-related changes in body composition are characterized by increases in body fat and decreases in lean muscle mass, along with weight loss. Whether these changes in body composition are followed by changes in blood pressure in older people is not well studied. Further, the role in this association of inflammatory and hormonal factors such as C-reactive protein, IL-6 and receptors, TNF-alpha and receptors, leptin, or adiponectin is not delineated. The aims of this analysis project are shown below. AIM 1. Evaluate the effects of change in systolic and diastolic blood pressure, hypertension treatment, and peripheral vascular disease on cognitive and functional decline AIM 2. Evaluate the effects of several measures of weight/body composition and trajectories of change in weight/body composition on cognitive and functional decline. AIM3. Evaluate the effects of age-related changes in weight/body composition on trajectories of change in 5 different blood pressure measures and their association with cognitive and functional decline. AIM 4. Evaluate metabolic, inflammatory and hormonal mediators of the associations between blood pressure and anthropometric factors and cognitive and functional decline.  This study will examine the effects of hypertension and body composition on cognitive and functional decline in older Mexican Americans.